The other day I did a 15k service on my 2018 M8 Road King, and the air cleaner was full of oil. I've been riding since 1978, and back then we had 2 stroke motors. It was allways a debate what amount of oil you should dial in on your oil mixer, and it often was hit and miss. Now adays we have 4 stroke engines in our bikes, and I understand that Harley has to build engines that comply with the epa regulations. But still, our engines are not ment to be burning oil. They never has been, and never will be. Therefore I am going to install a catch can to avoid all that crankcase oil mist being routed into my aircleaner/combustion chamber.
Another benefit of external breathing is to prevent the hot air from the crankcase going to the intake. Harleys run hot as it is so venting that hot oily air into a catch can allows only cooler outside air going into the combustion chamber. Also, oil will build up on your piston heads if not vented and will literally change your compression ratio and messing up your tune.
I have a catch can and the main thing i get when I dump it every 500 miles is coagulated condensation. Usually several ounces. Before I had a catch system there was a carbon build up on the piston top. Last time I pulled the heads (ported heads) the piston crowns were almost clean... Respect the gentleman who made the video, but in my application, I disagree.
Thanks for the polite comment I wish more people were like you. In the vid remember i didn't say don't run one I was letting people know that its not a have to thing, if you have a well tuned engine and healthy breather system then the carbon on the piston should be minimal. take my 2004 carbureted heritage at about 80,000 i pulled the heads to do the same as you and i had maybe a couple inch spot that was so thin i could still read the eched displacement number but as a tech i now how to keep my engine tuned and that helps. the main thing i was wanting to addressee was the thought that the hot air coming in from the breather is hotter than the air that is going into the air cleaner. intake air is taking in air that is absorbing the heat from the fins on the head that is running 250 degrees then going into the combustion charge, so a horsepower gain is very small from a catch can. that was a a early vid and im getting better at explaining my thoughts now so i might need to do a up to date one.
I'm glad you're talking about this all three of my Sportsters are external evented and my 2020 F150 has a high quality catch can and in about four thousand miles you can see the amount of oil it has stopped from going into the system
DK Customs has been putting out a bunch of videos on this subject and they have done a ton of research to confirm that venting the crankcase air helps your bike run cooler and with more power.
Yup, and they have the dyno charts to prove it. I wasted 7:32 of my life to watch this man stick his foot in his mouth 👄 lol! I bypassed mine 5 years ago. I looked at the top of my pistons while changing the plugs this winter. It was shiny in there 😅
In the vid i never said not to use one i said its not needed. the next vid I'm making is me taking the heads off my 99 dyna with 112.000 thousand miles on it. I will show the pistons and you tell me if you think i should have run a catch can. Call bumpus and ask them about the guy that got in the fist fight at the christmas party in 03, thats me and by the way they got a dyno as well and I know D.K. there just trying to sell shit that they make, they got to eat .
My mechanic said the same thing in this video. External breather is just another gadget the after markets push to sell. Sure it can make a difference...but that difference is sooooo negligible and not worth it with adding an unnecessary part.
@@DeathProofProductionsI agree. My 01 tc88 did 180000km in stock form with the breather routed to the a/c backing plate and it was as clean as a whistle inside when it was pulled apart for a rebuild. It was then turned into a 103 via a stroker crank running flat tops and 9.8 comp and only lasted 30000 km due I think to a poor rebuild and excessive blow by issues. I now have a S&S T 111 in the same bike running the same comp and that has taken quite a while to bed in and doesn’t seem to push much oil out through the breather depending on how hard I push it. This motor I have the hose running straight to atmosphere and have changed to Penrite v twin pao/ ester 20/50 full synthetic engine oil away from syn 3 and I think this has made a difference in consumption as well. Enjoy your videos 😊
I put one on my stock twin cam, along with the DK customs O2 sensor Vied's. I just wanted to cool the motor down, which it did. Runs great now, not melting my thighs in the summer. Made my own with flexible fuel line, hose clamps, and a pod filter. Routed it under the motor, pretty cheap.
Been workin as a bike tech on and off for 20 years and honestly don't see many catch cans in this realm but I did once own a twin turbo BMW and the aftermarket catch cans on that engine did a pretty amazing job at keeping the intake runners and valve stems clean over long periods of time. That was a twin turbo engine though.
I made a catch can connected to a vented dipstick and external breather. No pressure at all to the heads, and all the moisture from the cold starts goes to catch can.
I’ve been building engines for over 50 years only about a half dozen Harley’s but to me it’s an engine and I do them all. The reason I go with external breathers is your combustion charge is much better without oil and in some cases moisture which I have seen many times. The only reason Harley doesn’t vent to the atmosphere anymore is because of the EPA plain and simple. They mandated all gasoline motor vehicles to have a pcv in the late 60’s. Before that engines had a breather on the end of a pipe sticking out of the manifold. The EPA is the reason we have so much trouble with vehicles today, diesels, gasoline cars and Harley’s. Too lean and when you tune them they run better. Well that’s my 3 cents, sorry it was so long. Love your videos. Don’t know if you’ll get it since it’s a year old but what the hell I thought I’d try.
I agree the federal government sucks the fun out of everything. Don't get me wrong I'm not against running external breather' s, after close to 30 years as a certified harley tech I just don't think it's absolutely necessary to run them to extend the life of the motor. That being said if the breather system is not working properly then yes it's a option. Take both my twincam's 1 has 110,000 miles on it and the other has 90,000. The carbon on the piston's is no different than my shovels or pans and there vented to the atmosphere. All of them I have are well tuned and that goes a long way. Thanks for the compliment on the vid means alot to know your work is appreciated.
On my TC 103 i modified my SE stage 1 with a blowby bypass with a Filter not a catch can....I was getting a strong smell of burnt oil at operating temp when idling at stop lights....So i did that and put a Jagg oil cooler and it fixed the problem....No burnt oil smell and heating issues in the 100plus Cali heat anymore....
I think one of the differences is that a PCV valve is plumbed into the intake manifold where there is a lot of vacuum most of the time pulling moisture out of the engine , a benefit. That's why I put a ,oil air separator, on the hose that goes to the manifold.
The original EVO engine I had discharged crankcase pressure under the bike, and consequently caked up underneath with grime. Okay, but after a while, I got tired of constantly cleaning the grime up. So I got a catchcan and breather.....The S&S EVO i got discharged into the air cleaner, but eventually, oil would drip out of the bottom of my cleaner cover. So I put the catchcan and breather back on, and this solved the problem, but I (of course) have to drain the can every so often.
Finally found a video explaining why breathers are on a bike been wanting to know everything about Harley cause I do the little maintenance things like fluid changes and air filters but I see weird stuff that aren’t on cars so it throws me off
I put catch cans on everything everything. I’ve seen a new RGS with 3k have carbon covering the tops of both pistons. Just not sure why someone wouldn’t do it?
@@markemery7741 Anything vented back into the intake will benefit from a catch can, better yet an oil separator. With most modern motors being a form of GDI, it should be mandatory.
I would put a catch can if the engine has direct injection as gas is directly sprayed into the cylinder. This can cause carbon build up on the intake ports and valves. Port injection cleans the back of the valves each time the gas is sprayed.
Good explanation to counter the claptrap I watched from DK. High detergent fuel should cancel any problematic carbon build up. As well as good highway runs.
Thanks, you know how it is when you have a company trying to sell a product. There gonna scream dome and gloom unless you buy there stuff. In thirty years of professionally wrenching on bike's I have never seen exesive carbon build-up on a healthy engine even at high mileage.
I just put a catch can on my 14 ultra but only because I got tired of cleaning the oil out of the air filter at every service I hope it makes it easier to maintain.
It should...Honestly..don't market it if you can't prove it. At least somewhat?,, I was looking into the DK Customs set up for both my earlier sportsters I had one of their early tank lift kits and if worked as it was supposed to...
I really like the idea of cleaner , cooler air entering my engine. I first fashioned one myself with my original Harley breather, it worked well. Then when I bought a tuner I went ahead with the DK Customs set up and am very happy w it . Thanks to DeathProof for all your how to’s, 👍👍
True. I found if you vent breathers to atmosphere vent your oil tank as well, even then only if your running a built motor will you notice a difference in the engine (for lack of better terms) fighting itself. It is my understanding that stock set up (venting back into intake) actually helps with ring seal. Great explanation! 👍🏻
Burning hot oily/watery mist is never a good thing, unless the objective is carbon buildup. Plenty of examples of what happens, even with new motor & a vent system working perfectly.
I understand all this, but what about the bikes that are what they refer to as HEAVY SPITTERS with low miles, like less than 20K, that's getting their air filter literally soaked with oil going into the intake? I had one of these, a 2005 Electra Glide. My pistons were getting caked with carbon and oil deposits being burned onto the top of them. Oil was dripping from the filter! The guy I got it from said it has done that since brand new! I put the catch can on it, the bikes idle smoothed out, and it actually ran better. The white gunk removed from the can every 2000 miles was ridiculous. My thing is, all bikes just don't run or operate the same. I'd rather collect that gunk in a can than have it come into my combustion chamber. The tops of my pistons was nasty and coated with burnt oil and carbon deposits. My spark plugs started looking much better after the install also. Man, I really appreciate your videos, keep them coming.
Why do they have videos showing the top of the pistons gathering carbon build up from the blow by back into the manifold intake which is then burned off in the cylinders? External breather system is supposed to care of that situation. No carbon builds up on top of the pistons. Also, they say it was done for Harley Davidson to meet EPA guidelines.
You covered my question. Who puts a catch can on their Hot Rod or Suped up truck? A catch can does not draw air out of the crankcase but it does allow some crankcase venting. PCV = Positive Crankcase Ventilation.
Anything with direct injection should have a catch can to keep your intake valves clean. Older systems had air/fuel mixtures that kept the valves clean, but newer vehicles have only air and the oil residue builds up and burns. I like it for my Harley because I don’t like an oily air filter.
Sucking hot air from the crankcase into the intake is for emissions only,was never meant/designed to help motors run better when they introduced pvc on cars. Re-Burning/combusting the extremely hot oil laden blowby gases from the crankcase builds up excessive carbon deposits on the back of intake valves,on top on pistons & in the combustion chambers in general reducing over engine perf & longjevity/service life. Excessive carbon buildup on pistons can in crease compression a bit over time/miles with the excessive carbon creating excessive hot spots collectively leading to engine damage down the road due to detonation. The external crankcase breather will also keep all that oil out of the intake manifold/throttle body/throttle plates & air filter keeping them much cleaner & making the air filter last a lot longer too. If you install & properly maintain/keep clean an external crankcase breather using small washable k&n type filter mounted under the bike (not in line with rear tire!) where air rushing by at doors creates a Venturi affect small vacuum/suction on the filter therefore venting the crankcase keeping all the hot oil soaked air out of the intake & combustion chambers you & your motor will be much happier! I clean & reoil (sparingly!) the small k&n crankcase breather at every 3k mile oil & filter change on my bike. Iv’e been wrenching restoring classic bikes & American muscle cars & motors for over 5decades & always run external crankcase breather systems in all my 4stroke bikes (esp v-twins!) because the motors like & respond much better to clean cooler air intake charge vs an overheated intake charge full of hot oil mist to gum up the intake,airfilter & combustion chambers eventually making motor detonate due to excessive carbon buildup inc compression a bit also causing hot spots in carbon pos leading to piston/engine damage. Happy motoring!
Thanks for the comment I think it's good to have multiple people's years of experience on this platform to bring as much to the table to help folks as we can. In the vid I'm not saying don't use one I'm pointing out that the benefits are very small in comparison to not running one. Like you I too have years of experience wrenching on old junk iron aka vintage bikes and new ones as well. 32years as of September 3rd of this year, 20 of those years as a factory certified Harley mechanic or tech as they started calling us in the 90s so we sounded fancier. Like I would always say tech's have white lab coats , I'm a freaking mechanic and proud of it. My opinion of the need for a catch can is based on several thing's. I'm sure you know that Harleys prior to the evolution motor were vented to the atmosphere yet I have never tore one down and I've worked on everything from Knuckles to shovels, Norton's ,triumph's and flathead engine's that didn't have carbon on there pistons but they all vented to the atmosphere. I have never tore down a engine that didn't have carbon on there piston's unless it was newish. The carbon on the piston of a healthy motor is from incomplete burn of hydrocarbons or fuel. Keep in mind I am mainly talking about aircooled motors that op temp is close to 270 degree' s at that temp all the moisture in the engine is boiled out unlike liquid cooled engine's that are prone to sludge build-up. The other thing I base my thoughts on is not the low mileage bikes that most mechanics I mean tech's see, because let's face it most bikes spend most of there life in a garage. Its the high mileage bikes that I own and my riding pals own. Two of my twincam's have over 100 thousand miles on them, in the vid you may have seen me hold the white paper against the head to show no oil was coming out. That's my paint and body man's bike, it has right at 240 thousand on it but the paper was clean. His brother's bike is the one I used for the top end disassemble vid an at 114000 his bike did have excessive carbon on the piston's but his bikes breather was leaking internally for about 3 years. Bumpus Harley Davidson in Memphis t.n. has a dyno and when I worked there I put catch cans on bike's and just for curiosity and bordum during the winter, I would test them and couldn't see a change in performance. You mention detonation, you can take a stock Harley head and mill off .060 thats a 1/16th of a inch slap it on and run 87 octane all day long. I've done it to all my twincam's and travel cross country almost every year on one of them. Take my hearetage for instance, decked the heads 70thousand miles ago run the factory breather and run spark advance to the ragged edge of detonation but no spark knock. So based of what some believe I should have enough carbon on it to start detonation since I've lowered the combustion chamber And it's a high mileage bike. Yet I still go off on it for weeks at a time with no fear of being stranded out west. So from my experience if you want to run one run it but it is not going to make or break a engine.
Yes every engine has a PCV system but only Harley's is air gapped, basically drip fed to the opening of the intake and not directly piped back in. I do not like this design and how it makes everything gummy behind the filter, but i can see why it was made that way.
I’m curious to know your thoughts of an EVO motor, 1996 Softail, that’s puking oil from the breathers. The bike has only 12k miles on it. I took a look at the umbrella valves and they’re not terrible. Although I’m replacing them. The EVO motors don’t have the oil pump plate. So what causes the excess oil from the breather ports?
I went the way of a catch can oil breather. After about a year and changing out the catch can filter, I lengthened the hose, got rid of the can and put a 3" copper tube into the end of the hose . The 3' pipe was bent at a 90degree. the end of the tube I beveled but leaving the very end with a 32nd of an inch opening so when I hose clamped it to the front header pipe by my floor board there is still an opening for any buildup to escape. Figured to burn the vapor after combustion. Have about a one inch oil burn mark on the header pipe where clamped. No smoke or oil drips on the ground. Do you see a problem with that?
Thanks for the video. I have a 2002 Road King with 23,000 miles. I don't get to ride much because I have 2 businesses that keep me busy. How many miles do I have before I need to get the cam tensioner s checked out and replaced. I'm no motorcycle tech but don't want to risk waiting and ruining the engine. I've been told by 20,000 and 30,000 miles. Thanks again for your videos.
These M8 engines from new have alot of crankcase pressure that blows alot of oil into even the stock air filter and intake.It seems to me the harder you ride or heavier loaded you travel the more there is.Filtering does not seem to work,either just route to atmosphere or catchcan.
I'm having same issue with my 2023 FXLRST, just started dealing with my dealership, I'm curious, we're the old cylinders bored too big or bad rings, mine is puking oil all over, put on a catch can, fills the catch can up after 500 miles, normal is 5000 to 10,000 miles, appreciate your imput.
I would put a Catch can on the civic lol..you put it to rest for me man. My 2000 and 04 sportiest we're worse than than the 01 fxd for sure. Both of them sporties we're strong AF though...I just lived with it.
got a 2004 flstci 43000 mls was thinking of an ebs not sure now this is my first harley live inlondonderry northern ireland and on my own as far as bike concerned sorted cam chest and do my own service work. i would like to know if i can just add two catch cans to stock breather tubes and hide behind stock cover dont mind the cleaning out regular dont do big miles thanks in advance learning a lot from you
I have a 18 heritage 114 . Do you ever come across failure from the stock oil pump? Harley upgraded the oem pump in 2020 i think, so im wondering if i should bother to up grade ? Thanks for your time ! great video
My 2017 RGS was spitting so much oil that my air filter was wet and Black. Of course I’m told that the blow by is normal. So I put a catch can on, bike runs much better, and I get great gas mileage now.
It's not normal to have that much blow by, at every service you should only have enough around the butterfly to barley get your finger wet. In 26 years as factory certified Harley mechanic when I had a bike with that much blow by I would start checking the breather system to see if rocker box oil was leaking into it or if the pump was scavaging like it should.
@@DeathProofProductions it’s the original pump. (which is actually getting upgraded tomorrow with an oil cooler fan as well). I know the pump is an issue. It doesn’t scavenge properly. The question now is, are my jugs glazed to the point that my rings don’t seal properly? I’ll know that after the pump is replaced. If so, I’ll do a top end this winter.
Yer 100% correct, more oil gets pass the piston rings and valve guides getting burned in the combustion chamber than the few drops from the pcv system,
I’ve been debating on whether or not to add the external breather on my ‘19 RKS 114. One question I have is if you add the external breather, you will take away the vacuum. I’ve heard that if you take away the vacuum especially on an M8 motor with counterbalancer it will promote aeration of the oil and your (already struggling) OEM oil pump will struggle even harder to pick that oil up which can lead to further internal damage. From your experience is this a valid concern?
Kevin Baxter, another really good Harley mech, does state his concerns about this very thing, taking your bike out of a state of vacuum. Man, I'm getting totally lost in all of this and don't know who to believe at this point!
Not true. Your vacuum will not change. Do the breather mod. You do not want oil being pumped into your combustion chamber. The result is heavy carbon buildup over a very short period of time. Once you do the breather mod, run Seafoam in your fuel (1 oz per gallon) to help burn off the carbon and keep your fuel system clean
@@user-ob4nd6or1p - I have not seen any Scientific or specific Mechanical Engineering proof that a PCV bypass or breather system is beneficial in the average lifespan of a car, truck, motorcycle, lawnmower or any other internal combustion engine... If your have a real world test provided by a Society of Automotive Engineering (SAE) association or others, please provide us a source to those documents.
hola deathproof...Lo del aceite y el carbon me queda claro y siempre los hay en los pistones, mi duda es 1-si hay beneficio en sacar la entrada de aire caliente y dejar q solo entre aire frio... 2-si colocas escapes cola de pez, se debe ajustar entrada de aire o solo se coloca y dejas el aire normal..? gracias saludos desde hurlingham bs as Argentina...
If you hold your finger over the breather hole when running you will feel only a small amount of air. That amount is not enough to cause any real effect to the engine's performance. If the bike is injected you shouldn't have to adjust with just the addition of fishtails. What year is the bike.
I am a old Harley rider,,, My 1969 Sportster came with a external side breather,,vented to the ground,,,Engine ran great,,,BUT that system got oil fumes all over my chrome mufflers,,and the oil would burn off and leave burnt on brown sports to clean off with steel wool,,!!!
My twincam's have less carbon at over 100,000 miles then my shovels or pans have at a fraction of the miles and they vented to the atmosphere. I really don't think it matters.
And you sir, are the perfect example for the reason why Harley techs will never lay eyes upon, never mind touch my ride. Harley unlike any vehicle known to myself, is the only vehicle that dumps hot oily PCV gasses in front of idle control units, throttle butterflies and TMAP sensors. But then again, for commercial reasons, little wonder why you pooh pooh the idea of catch cans, your bread and butter, maybe? And BTW you can still remain EPA compliant running a catch can.
I think this just happened to me. Chains in the crank case popped. Primary I believe. I heard a pop. Like a pressure pop. Destroyed alot of stuff. I have the exact air filter. I bet it was a blow buy.and yes I have to rebuild the top end. At the least.
Most of the carbon that gets on pistons comes from unburnt hydrocarbons from fuel. In a healthy engine with a maintained breather system very little is from oil and ther will be minimal carbon on the piston at high mileage .
Do you have them on your bikes?. I have a 2004 rk with 38000 on it, it runs strong. I keep the oil level on the stick down about an 1/8th inch so i dont overfill the case. Is that a good thing to do or should it be to the top level all the time?
@@DeathProofProductions thanks for responding back man. I always appreciate your advice 100%. It seems like with the keeping the oil level down some it has minimum residual oil mist in the air filter does that sound feasible man?. I have the sns stealth on my 04 rk. 95" kit and fueling 525 came, full bassani pipes, dnt mufflers and power curve headers. It runs good for a 95"
Can we assume your not a harley owner, the one difference between your car scenarios and a harley is the harley has its IAT sensor in the manifold. On early bikes say 2000 -2004 the IAT sensor was in the venturi. If oily goop (condensated air and oil residue) got on the sensor which it often did it could cause all sorts of issues. It meant repeated and often filter removal to clean with carb cleaner. Hence by passing the system and using a catch can. Later harley moved the sensor into the fuel tract so it mostly got cleaned with fuel and air, but not always. A fouled sensor can cause lumpy starts, high revs coming down the gears clutch pulled and slow speed cut outs. These are not particularly enjoyable scenarios. Those that dont know its the sensor getting fouled 90% of owners pay harley around $100 to clean the sensor and the path from the head breathers. On the M8 engine one can re-experience these issues again in under 1000 miles. This happens on brand new motorcycles it has absolutely nothing to do with worn engines.
I've been a factory certified Harley mechanic for close to thirty years and I have rarely seen oil cause issues with i.a.t. sensors, unless the breather gasket in the rocker box was leaking above the umbrella valve. Also out of the 20 Harleys I own two of them I've put over 100thousand miles on without a catch can and have had no issues.
@@DeathProofProductionsI live in a damp UK, condensated oil mist makes a creamy goop, seen it on my buells was no different, on twin cams it can take several months to cause issues. my 98 ci never had them, my 103 did, it does not cause issues on all bikes. I've yet to experience issues on my M8 but the oil residue is there at 700 miles from new. I would prefer no issues and no residue. Also these issues are emission controlling issues. i see no benefit to allowing them access my inlet manifold. As for the harley certified mechanic. took my bike to those people who charged me to clean what a catch can eliminated. Given the same old speel they all so that sir, yea whatever!
In the vid i didn't say dont use one i said if you want to use it use it but if you don't it's not the end of the world. I don't run them myself because I think there god awful ugly. Also I have a motorcycle shop so if I start having a issue I can put it on the lift and fix it that day. What I was trying to say in the vid is if you have alot of oil coming out of the breather then there's something that needs to be fixed.
My instincts say this is the truth. That said what if your just wanting to stop Blowby? I get light oil spots on my white saddle bags. 2016 FLH with less than 10k on it. HD said it was from too much oil, even when they did it, still get a small amount. Also seems too new and well maintained to need a rebuild? The catch can thing for horspower and piston seemed overkill...but just for cosmetics, any idea of stopping that mist from getting on your White bike lol?
When i dive more deep into Harleys, I am starting consider to not have a Harley. It is 2024 why Harley engineers goes in that way to not fix that problem ( as stock install air vent breather) ?
They have to follow the e.p.a. guidelines like all manufacturers. That's why all modern engine's on cars and bikes and even lawn mowers have to vent internally. Remember it wasn't that long ago that they were sued by th e.p.a. and lost 12 million dollars for selling race tuners. To stay in business they have to be compliant to what the e.p.a. says.
I feel like that might not be a good comparison, in almost thirty years as a professional Harley mechanic I have never seen a engine die from not having a external breather. The only engine's I've seen with excessive carbon, have a leaking breather gasket in the rocker box or there running to rich. Both twincam's i own have over 100,000 miles on them and both of them might have a 1/3rd of the piston covered with a thin coating of carbon. I didn't say in the vid don't run them I just said it's not gonna make or break an engine. A better comparison would be if taking a daily multivitamin is necessary or a waste of time.
You’re not bringing up the benefit of the catch can though. It’s to not introduce oil vapor into the combustion chamber and fouling the top of the piston. There is def a difference of the piston crowns at 20k with and without a catch can. I even install them on my daily car.
Same. It’s insane the amount of blow by that is reintroduced to the engine without. I installed one on my Infinti after rebuilding engine and finding puddles of oil in the upper plenum. All my vehicles and my Harley now have them 😂
@@DeathProofProductions 192k but I believe all motor vehicles benefit from having an oil catch can or venting somehow to keep the blow by out of the combustion chamber. Just from looking at the throttle body I can tell it is staying much much cleaner. I have one on my Subaru legacy gt that has around 70k and it’s the same thing the catch can collects tons of blow by. Enough evidence for me.
Pre evo days all Harleys vented to the atmosphere, every one I have tore apart had carbon on the piston it's caused by unburnt hydrocarbons. A unhealthy crankcase breather will ad to the carbon but it will be a wet build-up not dry like fuel.
Most of the carbon build up comes from unburnt hydrocarbons in the fuel mainly hexane. If you think about it Harley engine's vented to the atmosphere all the way into the 80's and they still built up carbon.
As a 20 year auto mechanic... one who actually is a lexus master tech... i have seen the result of pcv systems when they converts to sole direct injection... is250 misfire issues which no one could figure out because they need to be epa complaint... you put vacuum on the crank case you will suck up oil,heat, and water which cause carbon on the back of valves and pistons... you have to think not everyone warms up their bike or gets to full operating temperatures... yes i get water in my catch can with a little oil on my bike at even sub 100 miles... upstate new york cold mornings with me idling 2 to 3 mins before even riding... depends where you live... this is why i run catch can on every race motor i build... catch can is essential for performance and you can try to justify epa compliance but you just sound like a clown... 😂😂😂 anyone who is actually a mechanic knows better... it isnt just about hp it is about motor longevity... 😅😅😅
You should go to my playlist to see what kind of mechanic I am. I was certified by Harley Davidson but what do they know. Maybe they should call you and ask what they should do next. On all 17 of my bikes I don't have a issue with carbon on my piston ,that's because I keep my breather healthy and not leaking and the carb tuned. But if you want we can meet up and test my race bike agents yours.
@@Cecil. I think I might have hit a nerve bringing up this issue with some folks.. After market companies are in the business of selling parts Period . Also why does he think I am pro e.p.a. In several of my vids I point out how ridicules they are.
I am not into gadgets... since HD engines run hot and lean from the factory, I am installing parts to combat these concerns so my engine survives : - )
The crankcase temp is no were near the temp of the air that is running over the front head and absorbing the heat from the fins through convection into the air cleaner. In the vid I never said don't run one I said if you have a healthy engine then it doesn't matter if you have one. I have 2 twin cams with 100,000 miles and the have very little carbon. I've rode thousands without catch cans and they run fine. All my pans and shovels vent to the atmosphere and the have the same carbon as my supercharged f150 or other bikes.. sorry for delayed response been covered working on bike's.
WOW....That had to be the poorest explanation of crankcase ventilation and recirculation that I've ever heard! It is clear that you don't really have clear knowledge of how it all works.
I read your Bio.... your a man after my own heart on the things you're into. Like you I've been wrenching for decades and riding for 55 years. Sorry to hear about your 2014 crash... riding without a helmet? Ouch, dumb ass... but you already know that. That may explain why you bounced around and didn't explain crank case ventilation too well.... We all got stuff going on. Way cool that you and your son collaborate on the videos. I'm definitely going to watch your other video and get a feel for your knowledge base... sound pretty deep. two down and be safe brother.
Any harley that revs past 4500 w stock cylinders and pistons and rings will blow by. M8, twin cam, Evo etc. There by blowing oil and water vapor into intake. Sorry I've installed catch cans on over 50 Harleys. Cheaper than fixing the problem. They ain't supposed to blow oil all over the place.
I am a factory trained Harley Davdson mechanic with over 25 years of experience and have worked on thousands of Harley Davidson's. The cheapest way to fix the problem would be to fix the problem. If someone doesn't ride much, the catch can will work as a bandaid solution, but I ride quite a bit. 2 of my 17 bikes have over 100,000 miles. If someone has a blowbye issue, they should watch my top end rebuild video to learn how to fix it themselves on the cheap.
I appreciate your point of view and your experience and thank you for taking the time to tell us this side of things. Can I ask you if you think Doc Harley is not correct saying that the set up on Harley is not good and is agrees with venting and catch cans?
Sorry I hadn't replied missed your comment. The bulk of carbon that builds up on piston's is from incomplete burn of hydrocarbons mainly HEXAN and then gits deposited on the piston and combustion chamber. Fact is with or without a catch can your gonna get carbon in the combustion chamber . Think about it every engine up to the evo vented to the atmosphere and they all got carbon on there piston's.
I put a catch can on my coyote motor F-150 and I'm sure there's a difference, along with my Sportsters. Not to dispute your words but who wants to run oil Mist through their motor not me my friend
Remember in the vid I say if you want to run one to run it. The vid is mainly focused on people who have been told that it's a absolute must to install one or the life of there engine will be affected drastically . Like myself though they can't stand the look of it on there engine. As a professional mechanic for the last 26 years I have tore apart hundreds of engine's and the only ones I have seen that had exesive carbon build-up were the ones run with a leaky breathers for alot of miles. When I put the supercharger on my coyote motor at 180,000 miles, I pulled the heads and it had very little carbon build-up. Thanks for not being rude in the comment though.
The other day I did a 15k service on my 2018 M8 Road King, and the air cleaner was full of oil. I've been riding since 1978, and back then we had 2 stroke motors. It was allways a debate what amount of oil you should dial in on your oil mixer, and it often was hit and miss. Now adays we have 4 stroke engines in our bikes, and I understand that Harley has to build engines that comply with the epa regulations. But still, our engines are not ment to be burning oil. They never has been, and never will be. Therefore I am going to install a catch can to avoid all that crankcase oil mist being routed into my aircleaner/combustion chamber.
Another benefit of external breathing is to prevent the hot air from the crankcase going to the intake. Harleys run hot as it is so venting that hot oily air into a catch can allows only cooler outside air going into the combustion chamber.
Also, oil will build up on your piston heads if not vented and will literally change your compression ratio and messing up your tune.
I have a catch can and the main thing i get when I dump it every 500 miles is coagulated condensation. Usually several ounces. Before I had a catch system there was a carbon build up on the piston top. Last time I pulled the heads (ported heads) the piston crowns were almost clean... Respect the gentleman who made the video, but in my application, I disagree.
Thanks for the polite comment I wish more people were like you. In the vid remember i didn't say don't run one I was letting people know that its not a have to thing, if you have a well tuned engine and healthy breather system then the carbon on the piston should be minimal. take my 2004 carbureted heritage at about 80,000 i pulled the heads to do the same as you and i had maybe a couple inch spot that was so thin i could still read the eched displacement number but as a tech i now how to keep my engine tuned and that helps. the main thing i was wanting to addressee was the thought that the hot air coming in from the breather is hotter than the air that is going into the air cleaner. intake air is taking in air that is absorbing the heat from the fins on the head that is running 250 degrees then going into the combustion charge, so a horsepower gain is very small from a catch can. that was a a early vid and im getting better at explaining my thoughts now so i might need to do a up to date one.
I'm glad you're talking about this all three of my Sportsters are external evented and my 2020 F150 has a high quality catch can and in about four thousand miles you can see the amount of oil it has stopped from going into the system
DK Customs has been putting out a bunch of videos on this subject and they have done a ton of research to confirm that venting the crankcase air helps your bike run cooler and with more power.
Doc Harley, a service tech at at Low Country Harley-Davidson says it’s a good investment to protect your motorcycle.
Yup, and they have the dyno charts to prove it. I wasted 7:32 of my life to watch this man stick his foot in his mouth 👄 lol! I bypassed mine 5 years ago. I looked at the top of my pistons while changing the plugs this winter. It was shiny in there 😅
In the vid i never said not to use one i said its not needed. the next vid I'm making is me taking the heads off my 99 dyna with 112.000 thousand miles on it. I will show the pistons and you tell me if you think i should have run a catch can. Call bumpus and ask them about the guy that got in the fist fight at the christmas party in 03, thats me and by the way they got a dyno as well and I know D.K. there just trying to sell shit that they make, they got to eat .
My mechanic said the same thing in this video. External breather is just another gadget the after markets push to sell. Sure it can make a difference...but that difference is sooooo negligible and not worth it with adding an unnecessary part.
@@DeathProofProductionsI agree. My 01 tc88 did 180000km in stock form with the breather routed to the a/c backing plate and it was as clean as a whistle inside when it was pulled apart for a rebuild. It was then turned into a 103 via a stroker crank running flat tops and 9.8 comp and only lasted 30000 km due I think to a poor rebuild and excessive blow by issues. I now have a S&S T 111 in the same bike running the same comp and that has taken quite a while to bed in and doesn’t seem to push much oil out through the breather depending on how hard I push it. This motor I have the hose running straight to atmosphere and have changed to Penrite v twin pao/ ester 20/50 full synthetic engine oil away from syn 3 and I think this has made a difference in consumption as well. Enjoy your videos 😊
Excellent discussion. One point not touched: the build up of the mist oil inside the throttle body, head and valves.
I put one on my stock twin cam, along with the DK customs O2 sensor Vied's. I just wanted to cool the motor down, which it did. Runs great now, not melting my thighs in the summer. Made my own with flexible fuel line, hose clamps, and a pod filter. Routed it under the motor, pretty cheap.
Been workin as a bike tech on and off for 20 years and honestly don't see many catch cans in this realm but I did once own a twin turbo BMW and the aftermarket catch cans on that engine did a pretty amazing job at keeping the intake runners and valve stems clean over long periods of time. That was a twin turbo engine though.
I agree
And they are direct injected which makes it almost necessary to keep your head and valves from getting jacked up in the long term.
I made a catch can connected to a vented dipstick and external breather. No pressure at all to the heads, and all the moisture from the cold starts goes to catch can.
I’ve been building engines for over 50 years only about a half dozen Harley’s but to me it’s an engine and I do them all. The reason I go with external breathers is your combustion charge is much better without oil and in some cases moisture which I have seen many times. The only reason Harley doesn’t vent to the atmosphere anymore is because of the EPA plain and simple. They mandated all gasoline motor vehicles to have a pcv in the late 60’s. Before that engines had a breather on the end of a pipe sticking out of the manifold. The EPA is the reason we have so much trouble with vehicles today, diesels, gasoline cars and Harley’s. Too lean and when you tune them they run better. Well that’s my 3 cents, sorry it was so long. Love your videos. Don’t know if you’ll get it since it’s a year old but what the hell I thought I’d try.
I agree the federal government sucks the fun out of everything. Don't get me wrong I'm not against running external breather' s, after close to 30 years as a certified harley tech I just don't think it's absolutely necessary to run them to extend the life of the motor. That being said if the breather system is not working properly then yes it's a option. Take both my twincam's 1 has 110,000 miles on it and the other has 90,000. The carbon on the piston's is no different than my shovels or pans and there vented to the atmosphere. All of them I have are well tuned and that goes a long way. Thanks for the compliment on the vid means alot to know your work is appreciated.
That's called a "bottom line" statement.
Thank for the good info man.
thanks for that think i will try and see how it goes see if any difference
On my TC 103 i modified my SE stage 1 with a blowby bypass with a Filter not a catch can....I was getting a strong smell of burnt oil at operating temp when idling at stop lights....So i did that and put a Jagg oil cooler and it fixed the problem....No burnt oil smell and heating issues in the 100plus Cali heat anymore....
Yeah. I want to put an oil cooler on mine, just because of the San Joaquin Valley heat.
@@billcarp3523 It was the best $400 i have spent on my Bike
I think one of the differences is that a PCV valve is plumbed into the intake manifold where there is a lot of vacuum most of the time pulling moisture out of the engine , a benefit.
That's why I put a ,oil air separator, on the hose that goes to the manifold.
The original EVO engine I had discharged crankcase pressure under the bike, and consequently caked up underneath with grime. Okay, but after a while, I got tired of constantly cleaning the grime up. So I got a catchcan and breather.....The S&S EVO i got discharged into the air cleaner, but eventually, oil would drip out of the bottom of my cleaner cover. So I put the catchcan and breather back on, and this solved the problem, but I (of course) have to drain the can every so often.
Hi, What brand catchcan/breather did you use? can you post a link. Best!
I just run a line from my heads down between the engine and transmission and have it stop just below them on my evos. Works just fine.
Holy shit. Thee most informative video ive ever seen on YT. Thank you for this. 🤘
Thanks.
Finally found a video explaining why breathers are on a bike been wanting to know everything about Harley cause I do the little maintenance things like fluid changes and air filters but I see weird stuff that aren’t on cars so it throws me off
Glad to be able to help.
I put catch cans on everything everything. I’ve seen a new RGS with 3k have carbon covering the tops of both pistons. Just not sure why someone wouldn’t do it?
I even put one on my wifes brand new car. Cant hurt
@@markemery7741 Anything vented back into the intake will benefit from a catch can, better yet an oil separator. With most modern motors being a form of GDI, it should be mandatory.
@@freebehindbars8654 I agree completely. Thats why I did it. GDI intakes can be a mess in short order
I would put a catch can if the engine has direct injection as gas is directly sprayed into the cylinder. This can cause carbon build up on the intake ports and valves. Port injection cleans the back of the valves each time the gas is sprayed.
Good explanation to counter the claptrap I watched from DK. High detergent fuel should cancel any problematic carbon build up. As well as good highway runs.
Thanks, you know how it is when you have a company trying to sell a product. There gonna scream dome and gloom unless you buy there stuff. In thirty years of professionally wrenching on bike's I have never seen exesive carbon build-up on a healthy engine even at high mileage.
In your experience, do performance air filters shorten the life of cylinder walls, by letting in micro-fine particles?@@DeathProofProductions
If they do it's miniscule and not enough to worry with.
I just put a catch can on my 14 ultra but only because I got tired of cleaning the oil out of the air filter at every service I hope it makes it easier to maintain.
It should...Honestly..don't market it if you can't prove it. At least somewhat?,, I was looking into the DK Customs set up for both my earlier sportsters I had one of their early tank lift kits and if worked as it was supposed to...
The DK is the one I used and I'm real happy with it
Put a camera down your cylinder. You’ll be surprised at how much carbon is on that piston.
I really like the idea of cleaner , cooler air entering my engine. I first fashioned one myself with my original Harley breather, it worked well. Then when I bought a tuner I went ahead with the DK Customs set up and am very happy w it . Thanks to DeathProof for all your how to’s, 👍👍
True. I found if you vent breathers to atmosphere vent your oil tank as well, even then only if your running a built motor will you notice a difference in the engine (for lack of better terms) fighting itself. It is my understanding that stock set up (venting back into intake) actually helps with ring seal.
Great explanation! 👍🏻
thanks
Burning hot oily/watery mist is never a good thing, unless the objective is carbon buildup. Plenty of examples of what happens, even with new motor & a vent system working perfectly.
Carbon build up is like (almost) a superfine grinding compound. If you want that crap in your combustion chamber, have at it. I think I'll pass.
I understand all this, but what about the bikes that are what they refer to as HEAVY SPITTERS with low miles, like less than 20K, that's getting their air filter literally soaked with oil going into the intake? I had one of these, a 2005 Electra Glide. My pistons were getting caked with carbon and oil deposits being burned onto the top of them. Oil was dripping from the filter! The guy I got it from said it has done that since brand new! I put the catch can on it, the bikes idle smoothed out, and it actually ran better. The white gunk removed from the can every 2000 miles was ridiculous. My thing is, all bikes just don't run or operate the same. I'd rather collect that gunk in a can than have it come into my combustion chamber. The tops of my pistons was nasty and coated with burnt oil and carbon deposits. My spark plugs started looking much better after the install also. Man, I really appreciate your videos, keep them coming.
Why do they have videos showing the top of the pistons gathering carbon build up from the blow by back into the manifold intake which is then burned off in the cylinders? External breather system is supposed to care of that situation. No carbon builds up on top of the pistons. Also, they say it was done for Harley Davidson to meet EPA guidelines.
water. . . and carbon! i love catch cans...
You covered my question.
Who puts a catch can on their Hot Rod or Suped up truck? A catch can does not draw air out of the crankcase but it does allow some crankcase venting.
PCV = Positive Crankcase Ventilation.
Precision engineering from Hardly
I feel on these bikes in particular that a crankcase breather is essential. The oil will return back to the bottom of the engine quicker as well.
True facts u just keep it real ✌️ on 2 's
Anything with direct injection should have a catch can to keep your intake valves clean. Older systems had air/fuel mixtures that kept the valves clean, but newer vehicles have only air and the oil residue builds up and burns. I like it for my Harley because I don’t like an oily air filter.
Good video - Just subscribed!
Thanks
I’m glad my mechanic takes pistons rings serious and gaps😂😂
Sucking hot air from the crankcase into the intake is for emissions only,was never meant/designed to help motors run better when they introduced pvc on cars.
Re-Burning/combusting the extremely hot oil laden blowby gases from the crankcase builds up excessive carbon deposits on the back of intake valves,on top on pistons & in the combustion chambers in general reducing over engine perf & longjevity/service life. Excessive carbon buildup on pistons can in crease compression a bit over time/miles with the excessive carbon creating excessive hot spots collectively leading to engine damage down the road due to detonation.
The external crankcase breather will also keep all that oil out of the intake manifold/throttle body/throttle plates & air filter keeping them much cleaner & making the air filter last a lot longer too.
If you install & properly maintain/keep clean an external crankcase breather using small washable k&n type filter mounted under the bike (not in line with rear tire!) where air rushing by at doors creates a Venturi affect small vacuum/suction on the filter therefore venting the crankcase keeping all the hot oil soaked air out of the intake & combustion chambers you & your motor will be much happier!
I clean & reoil (sparingly!) the small k&n crankcase breather at every 3k mile oil & filter change on my bike.
Iv’e been wrenching restoring classic bikes & American muscle cars & motors for over 5decades & always run external crankcase breather systems in all my 4stroke bikes (esp v-twins!) because the motors like & respond much better to clean cooler air intake charge vs an overheated intake charge full of hot oil mist to gum up the intake,airfilter & combustion chambers eventually making motor detonate due to excessive carbon buildup inc compression a bit also causing hot spots in carbon pos leading to piston/engine damage.
Happy motoring!
Thanks for the comment I think it's good to have multiple people's years of experience on this platform to bring as much to the table to help folks as we can. In the vid I'm not saying don't use one I'm pointing out that the benefits are very small in comparison to not running one. Like you I too have years of experience wrenching on old junk iron aka vintage bikes and new ones as well. 32years as of September 3rd of this year, 20 of those years as a factory certified Harley mechanic or tech as they started calling us in the 90s so we sounded fancier. Like I would always say tech's have white lab coats , I'm a freaking mechanic and proud of it. My opinion of the need for a catch can is based on several thing's. I'm sure you know that Harleys prior to the evolution motor were vented to the atmosphere yet I have never tore one down and I've worked on everything from Knuckles to shovels, Norton's ,triumph's and flathead engine's that didn't have carbon on there pistons but they all vented to the atmosphere. I have never tore down a engine that didn't have carbon on there piston's unless it was newish. The carbon on the piston of a healthy motor is from incomplete burn of hydrocarbons or fuel. Keep in mind I am mainly talking about aircooled motors that op temp is close to 270 degree' s at that temp all the moisture in the engine is boiled out unlike liquid cooled engine's that are prone to sludge build-up. The other thing I base my thoughts on is not the low mileage bikes that most mechanics I mean tech's see, because let's face it most bikes spend most of there life in a garage. Its the high mileage bikes that I own and my riding pals own. Two of my twincam's have over 100 thousand miles on them, in the vid you may have seen me hold the white paper against the head to show no oil was coming out. That's my paint and body man's bike, it has right at 240 thousand on it but the paper was clean. His brother's bike is the one I used for the top end disassemble vid an at 114000 his bike did have excessive carbon on the piston's but his bikes breather was leaking internally for about 3 years. Bumpus Harley Davidson in Memphis t.n. has a dyno and when I worked there I put catch cans on bike's and just for curiosity and bordum during the winter, I would test them and couldn't see a change in performance. You mention detonation, you can take a stock Harley head and mill off .060 thats a 1/16th of a inch slap it on and run 87 octane all day long. I've done it to all my twincam's and travel cross country almost every year on one of them. Take my hearetage for instance, decked the heads 70thousand miles ago run the factory breather and run spark advance to the ragged edge of detonation but no spark knock. So based of what some believe I should have enough carbon on it to start detonation since I've lowered the combustion chamber And it's a high mileage bike. Yet I still go off on it for weeks at a time with no fear of being stranded out west. So from my experience if you want to run one run it but it is not going to make or break a engine.
Yes every engine has a PCV system but only Harley's is air gapped, basically drip fed to the opening of the intake and not directly piped back in. I do not like this design and how it makes everything gummy behind the filter, but i can see why it was made that way.
I’m curious to know your thoughts of an EVO motor, 1996 Softail, that’s puking oil from the breathers.
The bike has only 12k miles on it. I took a look at the umbrella valves and they’re not terrible. Although I’m replacing them. The EVO motors don’t have the oil pump plate. So what causes the excess oil from the breather ports?
Is it doing it after you have rode for awhile or just for a little bit after first riding.
What the lub to the pistonsan vales top will lub Les wear
Catch cans or vented to atmosphere on all my motor vehicles. 2 cars a truck and HD Dyna
I went the way of a catch can oil breather. After about a year and changing out the catch can filter, I lengthened the hose, got rid of the can and put a 3" copper tube into the end of the hose . The 3' pipe was bent at a 90degree. the end of the tube I beveled but leaving the very end with a 32nd of an inch opening so when I hose clamped it to the front header pipe by my floor board there is still an opening for any buildup to escape. Figured to burn the vapor after combustion. Have about a one inch oil burn mark on the header pipe where clamped. No smoke or oil drips on the ground. Do you see a problem with that?
Thats not a bad deal pretty clever.
Thanks for the video. I have a 2002 Road King with 23,000 miles. I don't get to ride much because I have 2 businesses that keep me busy. How many miles do I have before I need to get the cam tensioner s checked out and replaced. I'm no motorcycle tech but don't want to risk waiting and ruining the engine. I've been told by 20,000 and 30,000 miles. Thanks again for your videos.
At that age and miles i would consider doing it now.
Thanks 👍
These M8 engines from new have alot of crankcase pressure that blows alot of oil into even the stock air filter and intake.It seems to me the harder you ride or heavier loaded you travel the more there is.Filtering does not seem to work,either just route to atmosphere or catchcan.
I'm having same issue with my 2023 FXLRST, just started dealing with my dealership, I'm curious, we're the old cylinders bored too big or bad rings, mine is puking oil all over, put on a catch can, fills the catch can up after 500 miles, normal is 5000 to 10,000 miles, appreciate your imput.
I would suspect the oil pump leaking by causing sumping or rocker box oil leaking into the breather system.
I would put a Catch can on the civic lol..you put it to rest for me man. My 2000 and 04 sportiest we're worse than than the 01 fxd for sure. Both of them sporties we're strong AF though...I just lived with it.
Glad to see your still watching . Let me know if there is anything you would like me to film that might help you with a project.
got a 2004 flstci 43000 mls was thinking of an ebs not sure now this is my first harley live inlondonderry northern ireland and on my own as far as bike concerned sorted cam chest and do my own service work. i would like to know if i can just add two catch cans to stock breather tubes and hide behind stock cover dont mind the cleaning out regular dont do big miles thanks in advance learning a lot from you
You could.
I have a 18 heritage 114 . Do you ever come across failure from the stock oil pump? Harley upgraded the oem pump in 2020 i think, so im wondering if i should bother to up grade ? Thanks for your time ! great video
I have never seen one fail. The georotor design is almost foolproof, its the same thats used in almost all cars these day's.
Thanks man @DeathProofProductions
My 2017 RGS was spitting so much oil that my air filter was wet and Black. Of course I’m told that the blow by is normal. So I put a catch can on, bike runs much better, and I get great gas mileage now.
It's not normal to have that much blow by, at every service you should only have enough around the butterfly to barley get your finger wet. In 26 years as factory certified Harley mechanic when I had a bike with that much blow by I would start checking the breather system to see if rocker box oil was leaking into it or if the pump was scavaging like it should.
@@DeathProofProductions it’s the original pump. (which is actually getting upgraded tomorrow with an oil cooler fan as well). I know the pump is an issue. It doesn’t scavenge properly. The question now is, are my jugs glazed to the point that my rings don’t seal properly? I’ll know that after the pump is replaced. If so, I’ll do a top end this winter.
On my old norton commando, the the vent was a chain oiler, simple useful. Messy.
Old Harleys did to but it was messy.
Yer 100% correct, more oil gets pass the piston rings and valve guides getting burned in the combustion chamber than the few drops from the pcv system,
I agree.
What about the oil fumes gumming up the Idle Air Control valve on a harley twin cam?
Since 2001 when I started working on bikes at Bumpus Harley Davidson of Memphis. I personally never ran across a i.a.c. gummed up before.
I’ve been debating on whether or not to add the external breather on my ‘19 RKS 114. One question I have is if you add the external breather, you will take away the vacuum. I’ve heard that if you take away the vacuum especially on an M8 motor with counterbalancer it will promote aeration of the oil and your (already struggling) OEM oil pump will struggle even harder to pick that oil up which can lead to further internal damage. From your experience is this a valid concern?
No thats misinformation, if you want to run one your fine to do it.
Kevin Baxter, another really good Harley mech, does state his concerns about this very thing, taking your bike out of a state of vacuum. Man, I'm getting totally lost in all of this and don't know who to believe at this point!
@@Big88Country - Kevin Baxter knows his stuff.
Not true. Your vacuum will not change. Do the breather mod. You do not want oil being pumped into your combustion chamber. The result is heavy carbon buildup over a very short period of time. Once you do the breather mod, run Seafoam in your fuel (1 oz per gallon) to help burn off the carbon and keep your fuel system clean
@@user-ob4nd6or1p - I have not seen any Scientific or specific Mechanical Engineering proof that a PCV bypass or breather system is beneficial in the average lifespan of a car, truck, motorcycle, lawnmower or any other internal combustion engine...
If your have a real world test provided by a Society of Automotive Engineering (SAE) association or others, please provide us a source to those documents.
hola deathproof...Lo del aceite y el carbon me queda claro y siempre los hay en los pistones, mi duda es 1-si hay beneficio en sacar la entrada de aire caliente y dejar q solo entre aire frio... 2-si colocas escapes cola de pez, se debe ajustar entrada de aire o solo se coloca y dejas el aire normal..? gracias saludos desde hurlingham bs as Argentina...
If you hold your finger over the breather hole when running you will feel only a small amount of air. That amount is not enough to cause any real effect to the engine's performance. If the bike is injected you shouldn't have to adjust with just the addition of fishtails. What year is the bike.
Excelente, la bicicleta es inyectada 2016 103
Yeah your good
Love yours videos, go go go 💪
Very accurately explained thanks for the straight scoop Semper Fi Gunny Lou great videos finally someone who knows their shit
Thanks
I am a old Harley rider,,,
My 1969 Sportster
came with a external
side breather,,vented
to the ground,,,Engine
ran great,,,BUT that
system got oil fumes
all over my chrome
mufflers,,and the oil
would burn off and
leave burnt on brown
sports to clean off
with steel wool,,!!!
But does venting it make your engine any cleaner at all? If yes it seems like its worth it.
My twincam's have less carbon at over 100,000 miles then my shovels or pans have at a fraction of the miles and they vented to the atmosphere. I really don't think it matters.
And you sir, are the perfect example for the reason why Harley techs will never lay eyes upon, never mind touch my ride. Harley unlike any vehicle known to myself, is the only vehicle that dumps hot oily PCV gasses in front of idle control units, throttle butterflies and TMAP sensors. But then again, for commercial reasons, little wonder why you pooh pooh the idea of catch cans, your bread and butter, maybe? And BTW you can still remain EPA compliant running a catch can.
I think this just happened to me. Chains in the crank case popped. Primary I believe. I heard a pop. Like a pressure pop. Destroyed alot of stuff. I have the exact air filter. I bet it was a blow buy.and yes I have to rebuild the top end. At the least.
I hate that happened, what year and model is it.
@@DeathProofProductions 2015 sgs
I have an external breather on my M8 Harley...I just vent it to the ground.
What about the oil sediment that settles on the top of the piston? Isn't that bad?
Most of the carbon that gets on pistons comes from unburnt hydrocarbons from fuel. In a healthy engine with a maintained breather system very little is from oil and ther will be minimal carbon on the piston at high mileage .
@@DeathProofProductions Thank you. I like that answer.
Is that a D104 Microphone on your desk?
It's just a light made to look like one.
Do you have them on your bikes?. I have a 2004 rk with 38000 on it, it runs strong. I keep the oil level on the stick down about an 1/8th inch so i dont overfill the case. Is that a good thing to do or should it be to the top level all the time?
No i dont run them i just keep my top end healthy so i dont need them. Your fine running your oil level like that.
@@DeathProofProductions thanks for responding back man. I always appreciate your advice 100%. It seems like with the keeping the oil level down some it has minimum residual oil mist in the air filter does that sound feasible man?. I have the sns stealth on my 04 rk. 95" kit and fueling 525 came, full bassani pipes, dnt mufflers and power curve headers. It runs good for a 95"
If you over fill the oil tank it will spit more oil into the intake and sometimes drip oil from the air filter
That's true.
Damn, I just need to go back to a jap bike.
Can we assume your not a harley owner, the one difference between your car scenarios and a harley is the harley has its IAT sensor in the manifold. On early bikes say 2000 -2004 the IAT sensor was in the venturi. If oily goop (condensated air and oil residue) got on the sensor which it often did it could cause all sorts of issues. It meant repeated and often filter removal to clean with carb cleaner. Hence by passing the system and using a catch can. Later harley moved the sensor into the fuel tract so it mostly got cleaned with fuel and air, but not always. A fouled sensor can cause lumpy starts, high revs coming down the gears clutch pulled and slow speed cut outs. These are not particularly enjoyable scenarios. Those that dont know its the sensor getting fouled 90% of owners pay harley around $100 to clean the sensor and the path from the head breathers. On the M8 engine one can re-experience these issues again in under 1000 miles. This happens on brand new motorcycles it has absolutely nothing to do with worn engines.
I've been a factory certified Harley mechanic for close to thirty years and I have rarely seen oil cause issues with i.a.t. sensors, unless the breather gasket in the rocker box was leaking above the umbrella valve. Also out of the 20 Harleys I own two of them I've put over 100thousand miles on without a catch can and have had no issues.
@@DeathProofProductionsI live in a damp UK, condensated oil mist makes a creamy goop, seen it on my buells was no different, on twin cams it can take several months to cause issues. my 98 ci never had them, my 103 did, it does not cause issues on all bikes. I've yet to experience issues on my M8 but the oil residue is there at 700 miles from new. I would prefer no issues and no residue. Also these issues are emission controlling issues. i see no benefit to allowing them access my inlet manifold. As for the harley certified mechanic. took my bike to those people who charged me to clean what a catch can eliminated. Given the same old speel they all so that sir, yea whatever!
In the vid i didn't say dont use one i said if you want to use it use it but if you don't it's not the end of the world. I don't run them myself because I think there god awful ugly. Also I have a motorcycle shop so if I start having a issue I can put it on the lift and fix it that day. What I was trying to say in the vid is if you have alot of oil coming out of the breather then there's something that needs to be fixed.
My instincts say this is the truth. That said what if your just wanting to stop Blowby? I get light oil spots on my white saddle bags. 2016 FLH with less than 10k on it. HD said it was from too much oil, even when they did it, still get a small amount. Also seems too new and well maintained to need a rebuild?
The catch can thing for horspower and piston seemed overkill...but just for cosmetics, any idea of stopping that mist from getting on your White bike lol?
Is it a stock Air cleaner.
@@DeathProofProductions Its a "Screaming Eagle Chisel Extreme Billet Air Cleaner Kit", has slip on Vance and Hines. Purchased it that way.
Are the tubes ran into the intake.
@@DeathProofProductions Thanks for the assistance! I think its run back into the intake. Here is a picture.
@@DeathProofProductions drive.google.com/file/d/1lVbyA0DUUC8_vIny966LmpWGyiBu9Ott/view?usp=sharing
When i dive more deep into Harleys, I am starting consider to not have a Harley. It is 2024 why Harley engineers goes in that way to not fix that problem ( as stock install air vent breather) ?
They have to follow the e.p.a. guidelines like all manufacturers. That's why all modern engine's on cars and bikes and even lawn mowers have to vent internally. Remember it wasn't that long ago that they were sued by th e.p.a. and lost 12 million dollars for selling race tuners. To stay in business they have to be compliant to what the e.p.a. says.
So how do you feel about the Covid vaccine? Is it necessary 7:31 or just a waste of time ?
I feel like that might not be a good comparison, in almost thirty years as a professional Harley mechanic I have never seen a engine die from not having a external breather. The only engine's I've seen with excessive carbon, have a leaking breather gasket in the rocker box or there running to rich. Both twincam's i own have over 100,000 miles on them and both of them might have a 1/3rd of the piston covered with a thin coating of carbon. I didn't say in the vid don't run them I just said it's not gonna make or break an engine. A better comparison would be if taking a daily multivitamin is necessary or a waste of time.
You’re not bringing up the benefit of the catch can though. It’s to not introduce oil vapor into the combustion chamber and fouling the top of the piston. There is def a difference of the piston crowns at 20k with and without a catch can. I even install them on my daily car.
Same. It’s insane the amount of blow by that is reintroduced to the engine without. I installed one on my Infinti after rebuilding engine and finding puddles of oil in the upper plenum. All my vehicles and my Harley now have them 😂
How many miles on the Infiniti
@@DeathProofProductions 192k but I believe all motor vehicles benefit from having an oil catch can or venting somehow to keep the blow by out of the combustion chamber. Just from looking at the throttle body I can tell it is staying much much cleaner. I have one on my Subaru legacy gt that has around 70k and it’s the same thing the catch can collects tons of blow by. Enough evidence for me.
Pre evo days all Harleys vented to the atmosphere, every one I have tore apart had carbon on the piston it's caused by unburnt hydrocarbons. A unhealthy crankcase breather will ad to the carbon but it will be a wet build-up not dry like fuel.
Not about horsepower. Its about all the carbon buildup in pistons from the oil.
Most of the carbon build up comes from unburnt hydrocarbons in the fuel mainly hexane. If you think about it Harley engine's vented to the atmosphere all the way into the 80's and they still built up carbon.
1/6th of horse power....shows the mini horse😂
Less than 1 horse. If your spark plugs aren't fouled
What do you mean.
As a 20 year auto mechanic... one who actually is a lexus master tech... i have seen the result of pcv systems when they converts to sole direct injection... is250 misfire issues which no one could figure out because they need to be epa complaint... you put vacuum on the crank case you will suck up oil,heat, and water which cause carbon on the back of valves and pistons... you have to think not everyone warms up their bike or gets to full operating temperatures... yes i get water in my catch can with a little oil on my bike at even sub 100 miles... upstate new york cold mornings with me idling 2 to 3 mins before even riding... depends where you live... this is why i run catch can on every race motor i build... catch can is essential for performance and you can try to justify epa compliance but you just sound like a clown... 😂😂😂 anyone who is actually a mechanic knows better... it isnt just about hp it is about motor longevity... 😅😅😅
You should go to my playlist to see what kind of mechanic I am. I was certified by Harley Davidson but what do they know. Maybe they should call you and ask what they should do next. On all 17 of my bikes I don't have a issue with carbon on my piston ,that's because I keep my breather healthy and not leaking and the carb tuned. But if you want we can meet up and test my race bike agents yours.
Hit a nerve there didn't he? Harley sells bikes, end of story!@@DeathProofProductions
@@Cecil. I think I might have hit a nerve bringing up this issue with some folks.. After market companies are in the business of selling parts Period . Also why does he think I am pro e.p.a. In several of my vids I point out how ridicules they are.
My bike runs much better with an external breather setup...
I am not into gadgets... since HD engines run hot and lean from the factory, I am installing parts to combat these concerns so my engine survives : - )
It is also hot air into motor
The crankcase temp is no were near the temp of the air that is running over the front head and absorbing the heat from the fins through convection into the air cleaner. In the vid I never said don't run one I said if you have a healthy engine then it doesn't matter if you have one. I have 2 twin cams with 100,000 miles and the have very little carbon. I've rode thousands without catch cans and they run fine. All my pans and shovels vent to the atmosphere and the have the same carbon as my supercharged f150 or other bikes.. sorry for delayed response been covered working on bike's.
WOW....That had to be the poorest explanation of crankcase ventilation and recirculation that I've ever heard! It is clear that you don't really have clear knowledge of how it all works.
Let me ask you a question how many bikes you have and how many miles are on them.
@@DeathProofProductions One Bike 2010 Heritage Classic, 32K miles
I read your Bio.... your a man after my own heart on the things you're into. Like you I've been wrenching for decades and riding for 55 years. Sorry to hear about your 2014 crash... riding without a helmet? Ouch, dumb ass... but you already know that. That may explain why you bounced around and didn't explain crank case ventilation too well.... We all got stuff going on. Way cool that you and your son collaborate on the videos. I'm definitely going to watch your other video and get a feel for your knowledge base... sound pretty deep. two down and be safe brother.
Keep drinking beer and stop missinforming people. Check your facts buddy !
What of what I said was misinformation?
Any harley that revs past 4500 w stock cylinders and pistons and rings will blow by. M8, twin cam, Evo etc. There by blowing oil and water vapor into intake. Sorry I've installed catch cans on over 50 Harleys. Cheaper than fixing the problem. They ain't supposed to blow oil all over the place.
I am a factory trained Harley Davdson mechanic with over 25 years of experience and have worked on thousands of Harley Davidson's. The cheapest way to fix the problem would be to fix the problem. If someone doesn't ride much, the catch can will work as a bandaid solution, but I ride quite a bit. 2 of my 17 bikes have over 100,000 miles. If someone has a blowbye issue, they should watch my top end rebuild video to learn how to fix it themselves on the cheap.
I appreciate your point of view and your experience and thank you for taking the time to tell us this side of things. Can I ask you if you think Doc Harley is not correct saying that the set up on Harley is not good and is agrees with venting and catch cans?
Sorry I hadn't replied missed your comment. The bulk of carbon that builds up on piston's is from incomplete burn of hydrocarbons mainly HEXAN and then gits deposited on the piston and combustion chamber. Fact is with or without a catch can your gonna get carbon in the combustion chamber . Think about it every engine up to the evo vented to the atmosphere and they all got carbon on there piston's.
I put a catch can on my coyote motor F-150 and I'm sure there's a difference, along with my Sportsters. Not to dispute your words but who wants to run oil Mist through their motor not me my friend
Remember in the vid I say if you want to run one to run it. The vid is mainly focused on people who have been told that it's a absolute must to install one or the life of there engine will be affected drastically . Like myself though they can't stand the look of it on there engine. As a professional mechanic for the last 26 years I have tore apart hundreds of engine's and the only ones I have seen that had exesive carbon build-up were the ones run with a leaky breathers for alot of miles. When I put the supercharger on my coyote motor at 180,000 miles, I pulled the heads and it had very little carbon build-up. Thanks for not being rude in the comment though.