Hopefully this video made sense. when I started with carbs fuel pressure issues really gave me a run for my money. took me a bit to track the issues down!!!! Reliable 4.5-9 Regulator: amzn.to/2RQ0Scl Reliable NOT liquid filled Fuel Pressure gauge: amzn.to/34OMINI
Quick question I have a 68 cougar I put new plugs in and cleaned the points why does my motor not change sounds when I pull some plugs but 2 or 3 of them change the motor does that mean they are not runing
the advantage of liquid filled gauge is that the needle is dumped, so the gears inside dont move so much under vibration. its last longer this way. cut a little hole in the rubber. if some of the silicone drains no problem, in fact only needs about 70% of liquid cover. bigger industrial gauges have a diaphragm to absorb the pressure
I have learned so much about tuning carbs from you. It is truly a lost art and hard to find anyone anymore that can do it well. Im glad you are teaching others
Yes sir now more than ever the saying " if you want it done right do it yourself" rings true. I have had my car to so many mechanics that could not tune a 2 bbl 302 so I watched some thunderhead vids which helped me out a lot. Hopefully I can pass the knowledge down to my kids someday.
I've been tuning for decades, worked with some of the best, and you are lightyears head of old tech. AMAZING! Folk, you will never find more solid old school tech lessons than here.
thanks. having issues with 350 chevy in my 77 4×4. your channel rocks.thank you. please don't let the trolls get to you. there just seems to be a lot of jerks out there these days. pepole have forgotten about being polite and treating others like they want to be treated. i am sure that I am just one of thousands that appreciate what you are doing.
Luke, it is very kind of you to give all this information for free. Just wish that You Tube and all this knowledge would have been readily available 35-40 years ago. Thank you.
Excellent explanations. I've been tuning for 50+ years and I even learned a bit here. I air/fuel ratio change was much greater than I expected. Great video!!!
Good information! I don't know how many times I've told guys this. The response is almost always "I don't know, always worked from the factory ". My 65 GTO with tripower is very happy with just over 2 psi but without the regulator the rear carb will flood the engine. For anyone who thinks "that pressure wouldn't keep my engine running ". That's not true, the pressure remains a little over 2 psi at idle and at 5500 rpm under full load. Yes your carb may be perfectly happy at higher pressure but as stated in this video, too much pressure can and does cause issues with carburetor cars.
I did a carb swap on my 1994 Chevy C1500, and it worked out great. Your videos were extremely helpful, and you brought to my attention things that I absolutely would have overlooked. Thank you.
Great videos. You are the only guy I have found on youtube who knows wth he is doing for carbs, fuel flow, timing , etc. I really like your "test rig" truck. Great way to display real world performance to many things most are just told about but never knew if they were real or not and the reason behind it.
I agree with others below. My dad was a Caterpillar Mechanic and wouldn't change anything on the weekend so if I was going to learn, it wasn't going to be at home. This caused me to get an education and even with that, small details had to be sought out. Every video I watch of yours, I learn something! I'll recommend everyone to subscribe to your Chanel if they want good accurate advice AND the reason behind your diagnosis. You Rock Brother!👍
I just built an 11:1 aluminum headed SBC 383 with a Holley Brawler 750. I'm getting ready to dive into tuning the carb and I'm glad I came across this video! Great information and I'm going to order a fuel pressure regulator TODAY! Thanks!
WOW,I wish this subject would have been brought to my attention about 40 years ago...I have horrible memories of cars that ran very inconsistantly and not being able to find a cause! I had a drag car with an inline regulator and considering the combination(cam with loads of duration and lift,lobe sep.angle, 2" Hookers,and Holley 850DP) it ran fairly consistantly. Hindsight is 20/20...Very informative video that makes total sense. I'm now a subscriber even though I don't mess with cars much anymore. Keep it up!
I had built a kit car Cobra with a big block. It suffered from vapor lock all the time. I had a regulator with no return. And not one of the engine gurus I presented the problem to suggested that I do a return line or a vapor/ fuel filter the latter being only five bucks. It was yesterday or the day before when I found a channel called Uncle Tony's garage and like you he went through the whole carburetor setup. Hats off to you man you figured it out I never did. I'm in the midst of building another big block and it won't happen this time that's for sure it should run pretty good. By the way until I found your videos I was pretty close to putting 2500 bucks in the fuel injection because I just didn't want the hassle anymore. Thank you
So good! Just had this experience with two new mechanical fuel pumps. I thought I had something on my needle and seat (Weirdo Holley 4180 Motorcraft on an 84 F150 H.O. 4X4) and it turned out I had miraculously not run into this same issue 6 years ago when I got this sucker running after it had been sitting for 10-15 years. I was chasing carb issues, which were legit as it had ~2mm of rust particulate settled into the bowls. Bought one of those leaky dial-style FPR's and at least it got me going with it set at position 2! It cost me $70 in fittings to attach to this darn carb/fuel pump, but at least now I can get a solid baseline. Thanks so much.
I was just researching dry vs liquid-filled gauges and I couldn't find anything that satisfied me. This was the answer I was looking for. Keep up these amazing videos!
you just proved me right about my moms old mustangs problems. it was all un cheap regulator and bad gauge. its in other hands now, and aside from the thing being swapped over to a Holley EFI unit, its exactly as i built the engine in 1998, and its a tire shredder even with a C4 and 3.08 gears!
A vacuum gauge works good with a stock to mild cam, but just a paperweight with a big cam. A big cam will not produce vacuum. Thats why you always see people pull plugs on hopped up engines. Pulling each plug also shows how each cylinder is running.
@@skip7243 Won’t have any breaks because the big cam is sucking all the vacuum it can, if you do happen to stop you’ll have to knock a automatic out of gear and keep on the hossin up the rpm’s.. You have to put in a vacuum pump so it’ll stop when you need it too and run like it supposed too
Man your videos are awesome. I asked yesterday in the Small Block Windsor group on FB who the best guy was to watch. It really surprised me when about 90% of them all said you ( they usually never agree on anything). I only watch a few so for and already feel like I have a better understanding of timing and carbs. Can’t wait to watch the rest. Thanks Man
Thanks Luke. Just got my new Summit 600 carb in place of my Edelbrock. The Summit will flood on idle even after attempting to adjust the fuel level. I'll be adding pressure gauge & regulator and report back. Cheap electric pump currently no regulator or return yet. 1979 Mustang 302 auto and having fun making the car run the way it should. Also buttoning up a 73 Torino before winter, having lots of fun with the ol Fords this summer! Thanks for the info, I'm 50 years old and still learning!
My Carb is completely flooding, to the point that the engine can’t even start. Thanks to this video now I know excessive fuel pressure may be causing fuel to blast through the needle valve and essentially disregard the properly functioning floats and needles. Time to buy a fuel pressure gauge!
great video. very informative.i have had mechanical fuel pumps be all over the place as well.and those liquid filled gauges suck they are all over the place.
I use Qjets, mainly the 170 series. I have a modified fuel inlet that allows me to hook up a remote fuel pressure guage (on the hood). The only problem, is I use that to verify pressure during operation, and not a permanent solution. I suppose I could get some braided line to replace the copper line I used, but as I said, I use it for diagnostic use only. I have always never like the one size fits all fuel line/fuel pressure guages....as too good to be true. Pro safety tip: NEVER mount a fuel pressure guage into your vehicle. Use a guage with an Isolator if you need to do that. Great video, Luke.
Thanks a ton, bro. Your videos, Junkyard Digs, and Uncle Tony's Garage taught me all I needed to know to set up my 5.2L Magnum V8 for carb and HEI ignition, something I have never even attempted before. Cant even tell you how much I appreciate how greatful I am for how good my truck runs and drives. Its a 5 speed and dodge dont make the crank sensor for it no more, could only find chinese ones that would burn out in a week and after 5 of them I said screw this especially when I also found out no one makes the O rings no more for the fuel line to the fuel rail, which failed and caught my engine bay on fire. My good neighbors saw the whoosh of the flames under the hood and ran out with the extinguisher faster than I could get mine and i just popped the hood and let them put it out quick. Gave them my fresh extinguisher which was the same size as a thankyou. My '97 Ram is now Carb'd and the ECU is just used for data logging now. Trimmed down the burnt parts of the harness and oddly, the only stuff the burned was stuff for the EFI I didnt need for the conversion anyway. Bonus! Heck of a learning experience and Im glad where I live dont do smog testing because I would just have to file for an exemption if that were the case.
Now I don't know a carburator from a hole in the wall but I stumbled across you and your brothers channels and think they are great, I do like old cars and listening to people with knowledge talk about things they know about, it seems to me that you should design a carburator, get a drafting book from the library and talk to someone who knows about 3d printing and who knows, you just might reinvent the perfect wheel, although I realize it might be dated technology but you guys still seem to have a use for them so I'm sure a million or so others do too
This is amazing! Carbs are tricky, never actually heard the fuel pressure angle discussed. This makes all kinds of sense! I just rebuilt the carb on my old boat (1976 GM 250 CC inline 6), I actually deleted the mechanical diaphragm pump and installed an inline electric pump. Seems to work well, but I wondered about fuel pressure and flow requirements for this engine. I will address it if I have issues. Cheers!
Great information. I'm about to get into my '53 International commercial truck's carburetor and fuel system so there is a good amount of information for me to look into and components to upgrade to during the repair. Thank you.
Like you, self taught (the hard expensive way) before the internet. This is a great video that shows one of the many small details that can drive you crazy. Thank you for taking the time to show this with all the cool toys installed to show what you mean. And I was not aware of the liquid filled gauge issue. So yes I learned something! I have 8 of these old fords in various condition. They are a great vehicle once you go thru them and repair the many little things from their age, neglect, abuse, and hacking.
Thanks! By soaking-in the knowledge contained in your videos, I hope to avoid some pitfalls when I have time to get into Carb'd cars. (fuel return line, AFR guage, fuel pressure regulator, distributor timing). I also drink Venom once in a while
Old school carb guy here. The #1 reason a carb may lose it's tune is thermal cycling. Other than a carb getting fouled by contaminants or mechanical wear, is it 's mounting and/or assembly hardware that loses torque from thermal cycling. Gaskets get hard and lose elasticity. Check the mounting nuts and carb assembly screws for looseness. Grab the carb and try wiggling it. I have witnessed and corrected this hundreds of times. Used to be the first go to test. Check hard ware torque. Check your intake manifold bolts also. You will be surprised.
you’re saving me with these videos! i’m a few in so i’ll just drop the comment now. I bought a 87 camaro with a carb swap. no fuel regulation and an external fuel pump had been added. so way to much fuel dumping into it. installed regulator and gauge, throttle cable popped off flooded engine. Now spark issue. i’d already replaced the ignition, replaced ignition module, spark plugs(they showed rich fuel mixture), starter, tested alternator and battery, going to test coil tomorrow. cap, rotor, and bad ground left… what else am i missing here.
I just found your page couple days ago, I really enjoy all the input you put on here, I’m having trouble with my two barrel carb for my fe360, ur videos are helping me figure out where I need to start to get it to run better
That’s great Jesus looking guy, I became an ordained minister for a family members wedding and everyone loves or laughs at that pic, I’ll be trying these methods out for tuning timing and carb, but I’ve been struggling to say the least I will report back with progress, I love this 72!350 dump.
What I have learned, watching your carb related videos, is I need to bite the bullet and put together a return style fuel system for my carbs so I can make sure they are running right. Honestly something I never would have thought of so it is much appreciated.
You don’t absolutely need it, but for the purpose of regulating pressure and keeping the fuel supply a consistent temp, it’s extremely worth it. Makes daily driving for easier
Damn it bud you F N nail it! I have a 79 GMC sierra I just drop a 350 N it that my father in law had set up 4 track and she's a mean block 4 sure.But I had to put my oil and fuel pump off my old 350 on there and right off the bat the ( After dropping in the truck ) I had found the the fly wheels don't match and a few other odds and ends.I believe the distance of where the fuel pump arm meets the crank between the 2 motors are not the same.When installing pump it seemed like it required more force tell pump snug up to the block and in doing so making that fuel pump arm have more travel and creating higher fuel presser. So I tested it and sure enough pushing close to 9 psi at idle.So I think its time 4 a new pump or a regulate.Thanks 4 the great info.U now have another sub 2 deal with.
A "trick" I was shown for the liquid filled gauge is to pull the cap and drain just a bit of liquid. Before you put the cap back on use a safety pin and make a small hole (I reamed the out a bit, still a small hole) in the cap so the liquid can expand and contract. It would be cool to see this tested to see if it does help get a true pressure reading.
Non liquid filed gauge shows the fluctuations in the needle much more abruptly, sometimes rendering them impossible to read. So it's always give and take - depending on the scenario. Incidentally i use liquid filed large vac gauge for carb adjustments specifically to counter small pointer movement.
Thanks for the tips Luke, will help me with my scout for sure. Was chasing flooding and other issues but never thought of the fuel pressure. Keep up the good videos
I find myself really liking this Channel. I'm a small block Ford freak at heart, but carburetors and how they work has always eluded me. I have a project I will probably be starting in the next year or so. I have a 1999 Ford Explorer 5.0 that I no longer have the keys for therefore I cannot start it due to the security chip missing from the key. The body is pretty shot but the drivetrain is in real decent condition. My plan is to rip the body off, convert it to distributor and carburetor setup and mount my 1980 fox body Mustang on it . I have the intake, carb, distributor and durospark setup off my old 83 5.0 HO I scrapped years ago. Might be picking your brain for suggestions when the time comes
I learned a couple things actually. Thank you. I found this video trying to figure out a Holley carb. You should come about a video of you running out up for me. 🙃
Good info on the gauge. never thought of the heat affecting the pressure reading.One reason i don't like fluid filled gauges is that the air bubble gets in spot you trying to read and make it hard to see. My truck doesn't have a regulator but runs fine , maybe i will ad one in the near future. Thanks for the info .
Thank you!!! I started working on my 71 F250 with a 352(maybe). This has been a HUGE help to me!!! I installed a performer 390 intake and a edelbrock 1826 carb on it. I also have the pertronix flame thrower dist. I would like to know more about how you setup/routed your return and parts you used.
This should rly help my buddy and I have been working on a 78 f350 6x6 that’s been parked for 30 years and can’t get it to turn over without spitting flames keep it up
Nice video. One comment - I would think the air bubble in the liquid filled gauge is the source of the expansion rather than the liquid. This might be why they become more stable when you allow them to vent. Liquids usually expand very little as temperature changes (except when you go through a phase change, such as freezing water).
The real answer to tuning then is the air fuel meter to establish your baseline. I was thinking of buying one but it's a lot of money just to tune one carb. Having your Vidios 40 years ago would have been priceless.
Thank you for this video. I'm in Edelbrock Hell at the moment , heavy bog with acceleration. Ive been up/down with jets, metering rods and springs squirters and timing currently 18*, but have tryed 15* to 22*. and have my float bowls set at 7/16 & 15/16" as per factory spec. I do have a regulator with liquid filled gage and running 5psi. I do have the purge rubber flap on top and when hot the psi does drop. So I may drop it more to 4psi.
You think way too much like me lol excellent video. I have a stock SBC 350 in one of my trucks. Replaced the factory dead head mechanical fuel pump with the same style unit, having no return line back to the tank and it built too much pressure, flooding the carb. I switched to the fuel pump with the extra line on it allowing the fuel to return to the tank (to prevent vapor lock) and it must internally not build up as much pressure. I'm still going to install a pressure regulator but it makes me wonder how in the heck GM has millions of these mechanical fuel pumps without having carburetor flooding issues on every one!
@@ThunderHead289 yeah I definitely agree. I was a QC inspector for concrete for a few years maybe I should look into the auto parts industry lol they'd hate me
Thanks so much! Exact info i needed. Had to run electric fuel pump on my squarebody as no mechanical pump provision on tbi engine that had been swapped in. Im at 5 to 6 mpg and it runs incredibly rich with the holley 650 at off idle and through the rpm range . Im going to order up the pressure regulator right now!
I just looked at your links, and you can buy the Gauge/Regulator combo for $61.38 (free shipping as of posting this). Before you even think of trying to "tune out" an Edelbrock with the $74.24 Tuning Kit (that will do nothing for you) or worse breaking out the drill bits please take this guys advise. 90% of the time, this will fix your issues, and its cheaper. I've walked away from so many cheap used carburetors that come with the tuning kits because of this. I've been burnt too many times with an "over d.i.y'd" carb that only needed this in the very beginning.
My rebuilt sbc with new Edelbroken 1406 had so much power, 4000 miles later (and sitting all winter a few years) and it's a total dog now! 5 mpg too! (They didn't hook up a return line or regulator but it was just fine till this summer)
I have a Carter Electric pump that said it gave 5-9 psi out of the box. With or without a pressure regulator it's about 4.5 psi. I gave up on mechanical pumps because the last one I had was pumping fuel into the crankcase. I pulled off the right side valve cover, and was hit with the smell of gas. I never cranked it again until I installed the new electrical one on, and the oil changed.
Yes, I learned something. Intresting about the oil-filled gague. I haven't used them in hot spaces, and didn't realize that heat would affect the reading that much, wow!👍🏻👏🏻👏🏻👏🏻👏🏻 Does the regulator cause increased/any back pressure on the fuel pump?
Great info I recently installed a gauge o my 355 in my 56 Chevy and my mechanical pump reads 9 pounds could never get the car to run the way I wanted going out right now to get a regulator thanks for the great video
Great stuff buddy, I'm keen to get a real handle on this. I built my own 1965 Chevy Impala SS 7 years ago. A shop setup my Carb and it's always felt sluggish. I have a 5.7 350 SBC from 1969 came off a Camaro. I know I'm not getting its best right now. So I'm going to setup my total timing, setup up my flaps for minimum vacuum just enough for idle and so on. I will follow your videos and see where I get, I Iook forward to the adventure. Thank you for imparting knowledge.
drain a little glycerin out of the gauge and put a few pin holes in the plug. or use the ones with the pullup vents. We like the filled gauges at work for the vibration damping. Probably if it's 3/4 full would still help some for vibration. Just a guess Love the carb videos
Just my free advice and it’s worth every penny. The regulator you linked to is chrome plated. Unfortunately, there is plating in the internal ports. The plating will flake off and if installed on the inlet side , will foul the carburetor. Holley makes a black anodized regulator and doesn’t have this problem. Since your regulator is on the overflow side , you shouldn’t experience this problem, anyway.
Howdy - the one I linked is polished aluminum with a chrome top cap. - now the crappy dial unit IS chrome, and I wish I would have also mentioned that about it !!!
Carter Muscle car series mechanical pump runs max 5.5 lbs, flows 40% more than stock and is designed for use with an Edelbrock carb. Very cheap too, $23 for a sbc at Summit. I have one on my 350 S10 with after market heads, air gap intake .500 lift cam with a 780 Holley and it runs great.
Awesome video I have 74 Toyota Land Cruiser carburetor is a Asian style carburetor Love's 3 PSI go to high and it will flood out too low lack of power.
Wow while I did know a little bit about fuel pressure and how it could overcome the needle pressure on the seat and flood the engine I had no idea about those oil filled pressure gauges being a bad idea!
Holy crap. I have allot to learn. Kid just bought his first car and its 4 years older than I am....thus the problem. Carb based mechanical tech. Blows out carbon/unburned fuel. SSooo..yeah, I'm going to be watching a tone of video's.
just purchased a 1982 gt 302 with electric pump, no return or regulators on a carter afb 650.. i guess i need to start looking for a full system like yours.. looks complicated lol. ty for vid
I had a near disaster with m 1957 Ford PU and dial fuel pressure regulator and will never use one again. While driving down a long stretch of interstate with no exits for a few miles, and constriction barriers, my truck started to stutter like it was running out of gas. The tank was over half full so I waited for two miles till the next exit to pull into a rest stop. After parking I opened my hood and nearly had a heart attack. My entire engine compartment was soaked with gas. The engine, firewall, inner finder panels, and the under side of the hood, was dripping gasoline. I had left the motor running and gas was running out from under my front bumper as I was parked on a hill. My dial type regulator was squirting a 1/8" diameter stream of gas up under the hood, then raining back down on everything. You will ask "couldn't you smell that", the answer is NO. I lost my sense of smell during a long bout of high fever when I was 13 years old. I quickly shut the engine off ant left the hood open for over an hour till it was dry. Diagnosing the problem, I realized the diaphragm had ruptured and gas squirted out of the hole in the center of the dial. I never knew there was a hole there, because there is normally a sticker covering it. My sticker was gone, the gas had deleted the adhesive. When it started, apparently the motor was starving for gas because the leak was so large. After removing the faulty regulator and re-connecting the fuel line I was able to drive home. Thinking back to that day, I realized that I would have burned to death. Do like I did and throw those cheap dial type fuel pressure regulators in the trash. I
Good info, Luke. You saved a lot of people money and frustration. Fuel pressure in excess will overcome a float; something that isn't talked about very much. Thanks for sharing. Peace.
William Charles oh, much more than that! Fuel pressure will alter your fuel level in your bowl and actually alter your fuel curve and mixture entirely also - even if it doesn’t blow open a needle and seat!
Hopefully this video made sense. when I started with carbs fuel pressure issues really gave me a run for my money. took me a bit to track the issues down!!!!
Reliable 4.5-9 Regulator: amzn.to/2RQ0Scl
Reliable NOT liquid filled Fuel Pressure gauge: amzn.to/34OMINI
Quick question I have a 68 cougar I put new plugs in and cleaned the points why does my motor not change sounds when I pull some plugs but 2 or 3 of them change the motor does that mean they are not runing
It drives but bogs but in park runs Great and reves great
the advantage of liquid filled gauge is that the needle is dumped, so the gears inside dont move so much under vibration. its last longer this way. cut a little hole in the rubber. if some of the silicone drains no problem, in fact only needs about 70% of liquid cover. bigger industrial gauges have a diaphragm to absorb the pressure
I agree with everything you have said - a little hole in the top of the gauge and you are good to go. Absolutely 👍
Im guessing this would work on just abt any carb setup! Even a lil 2.3 ford dirt track car turnin 8-8500 rpms!
I have learned so much about tuning carbs from you. It is truly a lost art and hard to find anyone anymore that can do it well. Im glad you are teaching others
Yes sir now more than ever the saying " if you want it done right do it yourself" rings true. I have had my car to so many mechanics that could not tune a 2 bbl 302 so I watched some thunderhead vids which helped me out a lot. Hopefully I can pass the knowledge down to my kids someday.
Bloody oath, Been having a hard time finding someone whos good with carbs in Australia. Most have retired 🥺
Lol but they talk about cfm all day n disregard lean or rich conditions n don't even know what accelerator pumps do.
I've been tuning for decades, worked with some of the best, and you are lightyears head of old tech. AMAZING! Folk, you will never find more solid old school tech lessons than here.
We appreciate all these videos, even years later. Thanks Luke!
thanks. having issues with 350 chevy in my 77 4×4. your channel rocks.thank you. please don't let the trolls get to you. there just seems to be a lot of jerks out there these days. pepole have forgotten about being polite and treating others like they want to be treated. i am sure that I am just one of thousands that appreciate what you are doing.
Luke, it is very kind of you to give all this information for free. Just wish that You Tube and all this knowledge would have been readily available 35-40 years ago. Thank you.
Excellent explanations. I've been tuning for 50+ years and I even learned a bit here. I air/fuel ratio change was much greater than I expected. Great video!!!
Thanks for the positive feedback 🤝
Good information! I don't know how many times I've told guys this. The response is almost always "I don't know, always worked from the factory ". My 65 GTO with tripower is very happy with just over 2 psi but without the regulator the rear carb will flood the engine.
For anyone who thinks "that pressure wouldn't keep my engine running ". That's not true, the pressure remains a little over 2 psi at idle and at 5500 rpm under full load. Yes your carb may be perfectly happy at higher pressure but as stated in this video, too much pressure can and does cause issues with carburetor cars.
This is really good. Thanks for the good theory and practical examples. And I loved the carb fire going in the background with your calm explanation.
I did a carb swap on my 1994 Chevy C1500, and it worked out great. Your videos were extremely helpful, and you brought to my attention things that I absolutely would have overlooked. Thank you.
Man, I’m so glad I was able to help you out - rework is the worst kind of NO fun. Glad you were able to avoid some it sounds like !!!
A carb swapped '88 -'94 Chevy OBS hell yeah! I bet you noticed tons more power compared to the TBI.
@@trickyricky12147
Yep, sure did!
@@Jerkwad152 😎🤙👍
Great videos. You are the only guy I have found on youtube who knows wth he is doing for carbs, fuel flow, timing , etc. I really like your "test rig" truck. Great way to display real world performance to many things most are just told about but never knew if they were real or not and the reason behind it.
You are like a carbiologist! Keep up the good work and thanks!
I haven’t heard that one before 😂
Thanks!
I agree with others below. My dad was a Caterpillar Mechanic and wouldn't change anything on the weekend so if I was going to learn, it wasn't going to be at home. This caused me to get an education and even with that, small details had to be sought out. Every video I watch of yours, I learn something! I'll recommend everyone to subscribe to your Chanel if they want good accurate advice AND the reason behind your diagnosis. You Rock Brother!👍
Thanks so much, I came from the school of hard knocks, disapointment, and struggle - so I do my best to put out the info I wish I had offered to me 🙂
I just built an 11:1 aluminum headed SBC 383 with a Holley Brawler 750. I'm getting ready to dive into tuning the carb and I'm glad I came across this video! Great information and I'm going to order a fuel pressure regulator TODAY! Thanks!
WOW,I wish this subject would have been brought to my attention about 40 years ago...I have horrible memories of cars that ran very inconsistantly and not being able to find a cause! I had a drag car with an inline regulator and considering the combination(cam with
loads of duration and lift,lobe sep.angle, 2" Hookers,and Holley 850DP) it ran fairly consistantly. Hindsight is 20/20...Very informative
video that makes total sense. I'm now a subscriber even though I don't mess with cars much anymore. Keep it up!
I had built a kit car Cobra with a big block. It suffered from vapor lock all the time. I had a regulator with no return. And not one of the engine gurus I presented the problem to suggested that I do a return line or a vapor/ fuel filter the latter being only five bucks. It was yesterday or the day before when I found a channel called Uncle Tony's garage and like you he went through the whole carburetor setup. Hats off to you man you figured it out I never did. I'm in the midst of building another big block and it won't happen this time that's for sure it should run pretty good. By the way until I found your videos I was pretty close to putting 2500 bucks in the fuel injection because I just didn't want the hassle anymore. Thank you
So good! Just had this experience with two new mechanical fuel pumps. I thought I had something on my needle and seat (Weirdo Holley 4180 Motorcraft on an 84 F150 H.O. 4X4) and it turned out I had miraculously not run into this same issue 6 years ago when I got this sucker running after it had been sitting for 10-15 years. I was chasing carb issues, which were legit as it had ~2mm of rust particulate settled into the bowls. Bought one of those leaky dial-style FPR's and at least it got me going with it set at position 2! It cost me $70 in fittings to attach to this darn carb/fuel pump, but at least now I can get a solid baseline. Thanks so much.
U have helped me unlock the problems and power out of my old car. This saved my day
I was just researching dry vs liquid-filled gauges and I couldn't find anything that satisfied me. This was the answer I was looking for. Keep up these amazing videos!
you just proved me right about my moms old mustangs problems. it was all un cheap regulator and bad gauge. its in other hands now, and aside from the thing being swapped over to a Holley EFI unit, its exactly as i built the engine in 1998, and its a tire shredder even with a C4 and 3.08 gears!
Nice demonstration . I like your setup with the shut off valve, AFR gauge , and manifold vacuum. A vacuum gauge is often ignored as a diagnostic tool.
You can do anything with a vacuum gauge and wideband side by side 👍
A vacuum gauge works good with a stock to mild cam, but just a paperweight with a big cam. A big cam will not produce vacuum. Thats why you always see people pull plugs on hopped up engines.
Pulling each plug also shows how each cylinder is running.
@@ThunderHead289 hey Man, could you recomend me a wide band o2 gaugue please?
@@Guns_N_Gears If there is no vacuum with a big cam, how does the engine run? Gotta suck the air fuel mixture in somehow!
@@skip7243
Won’t have any breaks because the big cam is sucking all the vacuum it can, if you do happen to stop you’ll have to knock a automatic out of gear and keep on the hossin up the rpm’s..
You have to put in a vacuum pump so it’ll stop when you need it too and run like it supposed too
Yes sir. Heat caused the same problem with my liquid filled gauge. They're fine as long as you only rely on them at a cold start. Another great video!
Man your videos are awesome. I asked yesterday in the Small Block Windsor group on FB who the best guy was to watch. It really surprised me when about 90% of them all said you ( they usually never agree on anything). I only watch a few so for and already feel like I have a better understanding of timing and carbs. Can’t wait to watch the rest. Thanks Man
Thank you for your channel just doing a rebuild on a 302 and all your videos have helped a lot! Greetings from Austria
Greetings from Central Northern America 🙂
Thanks Luke. Just got my new Summit 600 carb in place of my Edelbrock. The Summit will flood on idle even after attempting to adjust the fuel level. I'll be adding pressure gauge & regulator and report back. Cheap electric pump currently no regulator or return yet. 1979 Mustang 302 auto and having fun making the car run the way it should. Also buttoning up a 73 Torino before winter, having lots of fun with the ol Fords this summer! Thanks for the info, I'm 50 years old and still learning!
Man I love those trucks. Using your videos to get my 76 f250 back up and running.
That’s great to hear
Thanks Luke, ive been chasin this issue on my 73 F100 302 with an Edelbrock carb, gonna have to get one of these.
thanks for sharing the anomaly with liquid filled gauges...I wasn't aware of that.
It got me bad for a few years back in the day. Had to research how the gauge worked to actually figure it out
Thank you man I'm 26 own jeeps and trucks and cars and love watching and learning with you
My Carb is completely flooding, to the point that the engine can’t even start. Thanks to this video now I know excessive fuel pressure may be causing fuel to blast through the needle valve and essentially disregard the properly functioning floats and needles.
Time to buy a fuel pressure gauge!
great video. very informative.i have had mechanical fuel pumps be all over the place as well.and those liquid filled gauges suck they are all over the place.
Thank you a real mechanic! You can't beat a dialed in carb.
Absolutely!
I use Qjets, mainly the 170 series. I have a modified fuel inlet that allows me to hook up a remote fuel pressure guage (on the hood). The only problem, is I use that to verify pressure during operation, and not a permanent solution. I suppose I could get some braided line to replace the copper line I used, but as I said, I use it for diagnostic use only. I have always never like the one size fits all fuel line/fuel pressure guages....as too good to be true. Pro safety tip: NEVER mount a fuel pressure guage into your vehicle. Use a guage with an Isolator if you need to do that. Great video, Luke.
TH289, I love learning from your videos... even-though I grew up with carbs back in the day :) Your truly an 'Ole School' Mechanic!
I really think you have the right info. I’ve spent a lot of time finding trash advice from people that just don’t know thanks...
When I was learning there was so sooo much bad advice on the internet. Iv made it my goal to put the truth out there, even if no one sees it!
Thanks a ton, bro. Your videos, Junkyard Digs, and Uncle Tony's Garage taught me all I needed to know to set up my 5.2L Magnum V8 for carb and HEI ignition, something I have never even attempted before. Cant even tell you how much I appreciate how greatful I am for how good my truck runs and drives. Its a 5 speed and dodge dont make the crank sensor for it no more, could only find chinese ones that would burn out in a week and after 5 of them I said screw this especially when I also found out no one makes the O rings no more for the fuel line to the fuel rail, which failed and caught my engine bay on fire. My good neighbors saw the whoosh of the flames under the hood and ran out with the extinguisher faster than I could get mine and i just popped the hood and let them put it out quick. Gave them my fresh extinguisher which was the same size as a thankyou. My '97 Ram is now Carb'd and the ECU is just used for data logging now. Trimmed down the burnt parts of the harness and oddly, the only stuff the burned was stuff for the EFI I didnt need for the conversion anyway. Bonus! Heck of a learning experience and Im glad where I live dont do smog testing because I would just have to file for an exemption if that were the case.
Now I don't know a carburator from a hole in the wall but I stumbled across you and your brothers channels and think they are great, I do like old cars and listening to people with knowledge talk about things they know about, it seems to me that you should design a carburator, get a drafting book from the library and talk to someone who knows about 3d printing and who knows, you just might reinvent the perfect wheel, although I realize it might be dated technology but you guys still seem to have a use for them so I'm sure a million or so others do too
Thank You Luke for taking the time to go through a carb and show just how to do the WHY of tuning..
Be safe! Peace and love Luke!
I recently started playing around with carbs for the first time on my 73 Datsun 620 and man you have been so much help! Thank you dude!
This is amazing! Carbs are tricky, never actually heard the fuel pressure angle discussed. This makes all kinds of sense! I just rebuilt the carb on my old boat (1976 GM 250 CC inline 6), I actually deleted the mechanical diaphragm pump and installed an inline electric pump. Seems to work well, but I wondered about fuel pressure and flow requirements for this engine. I will address it if I have issues. Cheers!
Great information. I'm about to get into my '53 International commercial truck's carburetor and fuel system so there is a good amount of information for me to look into and components to upgrade to during the repair. Thank you.
Like you, self taught (the hard expensive way) before the internet. This is a great video that shows one of the many small details that can drive you crazy. Thank you for taking the time to show this with all the cool toys installed to show what you mean.
And I was not aware of the liquid filled gauge issue. So yes I learned something!
I have 8 of these old fords in various condition. They are a great vehicle once you go thru them and repair the many little things from their age, neglect, abuse, and hacking.
Thanks! By soaking-in the knowledge contained in your videos, I hope to avoid some pitfalls when I have time to get into Carb'd cars. (fuel return line, AFR guage, fuel pressure regulator, distributor timing). I also drink Venom once in a while
Really appreciate your work, makes me want to work on old cars again
Old school carb guy here. The #1 reason a carb may lose it's tune is thermal cycling. Other than a carb getting fouled by contaminants or mechanical wear, is it 's mounting and/or assembly hardware that loses torque from thermal cycling. Gaskets get hard and lose elasticity. Check the mounting nuts and carb assembly screws for looseness. Grab the carb and try wiggling it. I have witnessed and corrected this hundreds of times. Used to be the first go to test. Check hard ware torque. Check your intake manifold bolts also. You will be surprised.
you’re saving me with these videos! i’m a few in so i’ll just drop the comment now. I bought a 87 camaro with a carb swap. no fuel regulation and an external fuel pump had been added. so way to much fuel dumping into it. installed regulator and gauge, throttle cable popped off flooded engine. Now spark issue. i’d already replaced the ignition, replaced ignition module, spark plugs(they showed rich fuel mixture), starter, tested alternator and battery, going to test coil tomorrow. cap, rotor, and bad ground left… what else am i missing here.
I just found your page couple days ago, I really enjoy all the input you put on here, I’m having trouble with my two barrel carb for my fe360, ur videos are helping me figure out where I need to start to get it to run better
Thanks Jesus looking guy - glad I was able to help 🙂
That’s great Jesus looking guy, I became an ordained minister for a family members wedding and everyone loves or laughs at that pic, I’ll be trying these methods out for tuning timing and carb, but I’ve been struggling to say the least I will report back with progress, I love this 72!350 dump.
What I have learned, watching your carb related videos, is I need to bite the bullet and put together a return style fuel system for my carbs so I can make sure they are running right. Honestly something I never would have thought of so it is much appreciated.
You don’t absolutely need it, but for the purpose of regulating pressure and keeping the fuel supply a consistent temp, it’s extremely worth it. Makes daily driving for easier
Damn it bud you F N nail it! I have a 79 GMC sierra I just drop a 350 N it that my father in law had set up 4 track and she's a mean block 4 sure.But I had to put my oil and fuel pump off my old 350 on there and right off the bat the ( After dropping in the truck ) I had found the the fly wheels don't match and a few other odds and ends.I believe the distance of where the fuel pump arm meets the crank between the 2 motors are not the same.When installing pump it seemed like it required more force tell pump snug up to the block and in doing so making that fuel pump arm have more travel and creating higher fuel presser. So I tested it and sure enough pushing close to 9 psi at idle.So I think its time 4 a new pump or a regulate.Thanks 4 the great info.U now have another sub 2 deal with.
Thank you..dont ever change..u are extreemly helpful😊😜
A "trick" I was shown for the liquid filled gauge is to pull the cap and drain just a bit of liquid. Before you put the cap back on use a safety pin and make a small hole (I reamed the out a bit, still a small hole) in the cap so the liquid can expand and contract. It would be cool to see this tested to see if it does help get a true pressure reading.
Non liquid filed gauge shows the fluctuations in the needle much more abruptly, sometimes rendering them impossible to read. So it's always give and take - depending on the scenario. Incidentally i use liquid filed large vac gauge for carb adjustments specifically to counter small pointer movement.
Depends - the gauge on my truck is a dry unit
Thanks for the tips Luke, will help me with my scout for sure. Was chasing flooding and other issues but never thought of the fuel pressure. Keep up the good videos
Just started learning about carb tuning after finding your lawnmower carb.
I find myself really liking this Channel. I'm a small block Ford freak at heart, but carburetors and how they work has always eluded me. I have a project I will probably be starting in the next year or so. I have a 1999 Ford Explorer 5.0 that I no longer have the keys for therefore I cannot start it due to the security chip missing from the key. The body is pretty shot but the drivetrain is in real decent condition. My plan is to rip the body off, convert it to distributor and carburetor setup and mount my 1980 fox body Mustang on it . I have the intake, carb, distributor and durospark setup off my old 83 5.0 HO I scrapped years ago. Might be picking your brain for suggestions when the time comes
I learned a couple things actually. Thank you. I found this video trying to figure out a Holley carb. You should come about a video of you running out up for me. 🙃
Very good, I didn't know that about liquid filled non vented gauges, thanks
This finally explains why i fight edelbrocks so much. ive been blaming the carb. ive never had that issue with qjets and thermoquads.
Man I would love to have your truck and your knowledge! I truly do enjoy your channel and Junkyard digs as well. Thanks!
Good info on the gauge. never thought of the heat affecting the pressure reading.One reason i don't like fluid filled gauges is that the air bubble gets in spot you trying to read and make it hard to see. My truck doesn't have a regulator but runs fine , maybe i will ad one in the near future. Thanks for the info .
Thank you!!! I started working on my 71 F250 with a 352(maybe). This has been a HUGE help to me!!! I installed a performer 390 intake and a edelbrock 1826 carb on it. I also have the pertronix flame thrower dist. I would like to know more about how you setup/routed your return and parts you used.
Love that opening scene...pull sounds damn good!!!
This should rly help my buddy and I have been working on a 78 f350 6x6 that’s been parked for 30 years and can’t get it to turn over without spitting flames keep it up
Nice video. One comment - I would think the air bubble in the liquid filled gauge is the source of the expansion rather than the liquid. This might be why they become more stable when you allow them to vent. Liquids usually expand very little as temperature changes (except when you go through a phase change, such as freezing water).
It very well could be - I think the main issue is that they are sealed so well that they read incorrectly as they can’t normalize to atmospheric
The real answer to tuning then is the air fuel meter to establish your baseline. I was thinking of buying one but it's a lot of money just to tune one carb. Having your Vidios 40 years ago would have been priceless.
Greetings from Russia! Nice truck. It’s good that you restore these cars!
Thank you for this video. I'm in Edelbrock Hell at the moment , heavy bog with acceleration. Ive been up/down with jets, metering rods and springs squirters and timing currently 18*, but have tryed 15* to 22*. and have my float bowls set at 7/16 & 15/16" as per factory spec. I do have a regulator with liquid filled gage and running 5psi. I do have the purge rubber flap on top and when hot the psi does drop. So I may drop it more to 4psi.
Oh yeah I like how the carborator was on fire while you where talking funny😉
You think way too much like me lol excellent video. I have a stock SBC 350 in one of my trucks. Replaced the factory dead head mechanical fuel pump with the same style unit, having no return line back to the tank and it built too much pressure, flooding the carb. I switched to the fuel pump with the extra line on it allowing the fuel to return to the tank (to prevent vapor lock) and it must internally not build up as much pressure. I'm still going to install a pressure regulator but it makes me wonder how in the heck GM has millions of these mechanical fuel pumps without having carburetor flooding issues on every one!
Man, it’s hard tellin! All I can figure is that the replacements aren’t manufactured with any level of QC (quality control)
@@ThunderHead289 yeah I definitely agree. I was a QC inspector for concrete for a few years maybe I should look into the auto parts industry lol they'd hate me
Thanks so much! Exact info i needed. Had to run electric fuel pump on my squarebody as no mechanical pump provision on tbi engine that had been swapped in. Im at 5 to 6 mpg and it runs incredibly rich with the holley 650 at off idle and through the rpm range . Im going to order up the pressure regulator right now!
I'd go through my tuning videos - it's not any one thing. Engine tuning is a harmonious blend of ignition timing and carb tuning
I just looked at your links, and you can buy the Gauge/Regulator combo for $61.38 (free shipping as of posting this). Before you even think of trying to "tune out" an Edelbrock with the $74.24 Tuning Kit (that will do nothing for you) or worse breaking out the drill bits please take this guys advise. 90% of the time, this will fix your issues, and its cheaper.
I've walked away from so many cheap used carburetors that come with the tuning kits because of this. I've been burnt too many times with an "over d.i.y'd" carb that only needed this in the very beginning.
My rebuilt sbc with new Edelbroken 1406 had so much power, 4000 miles later (and sitting all winter a few years) and it's a total dog now! 5 mpg too! (They didn't hook up a return line or regulator but it was just fine till this summer)
Man, I wished I saw this video years ago! Very valuable information, good job!
I have a Carter Electric pump that said it gave 5-9 psi out of the box. With or without a pressure regulator it's about 4.5 psi. I gave up on mechanical pumps because the last one I had was pumping fuel into the crankcase. I pulled off the right side valve cover, and was hit with the smell of gas. I never cranked it again until I installed the new electrical one on, and the oil changed.
That fire in the background was an awesome eye catcher!!! Great job and great content!!
Agian what an awesome video thank you Luke for the best information videos out their you turly deserve more viewers
Yes, I learned something. Intresting about the oil-filled gague. I haven't used them in hot spaces, and didn't realize that heat would affect the reading that much, wow!👍🏻👏🏻👏🏻👏🏻👏🏻
Does the regulator cause increased/any back pressure on the fuel pump?
Great info I recently installed a gauge o my 355 in my 56 Chevy and my mechanical pump reads 9 pounds could never get the car to run the way I wanted going out right now to get a regulator thanks for the great video
That truck is screaming for some drag radials ! 👍
Much appreciated! Converting an efi 460 to carb and this really helps me out.
Glad it was helpful! 💪
Great stuff buddy, I'm keen to get a real handle on this. I built my own 1965 Chevy Impala SS 7 years ago. A shop setup my Carb and it's always felt sluggish. I have a 5.7 350 SBC from 1969 came off a Camaro. I know I'm not getting its best right now. So I'm going to setup my total timing, setup up my flaps for minimum vacuum just enough for idle and so on. I will follow your videos and see where I get, I Iook forward to the adventure. Thank you for imparting knowledge.
From Brazil comment. I watch every vid from Thunder, Junkyard and Mccool. Great vids. !
I do it too :)
drain a little glycerin out of the gauge and put a few pin holes in the plug. or use the ones with the pullup vents. We like the filled gauges at work for the vibration damping. Probably if it's 3/4 full would still help some for vibration. Just a guess Love the carb videos
Just my free advice and it’s worth every penny. The regulator you linked to is chrome plated. Unfortunately, there is plating in the internal ports. The plating will flake off and if installed on the inlet side , will foul the carburetor. Holley makes a black anodized regulator and doesn’t have this problem. Since your regulator is on the overflow side , you shouldn’t experience this problem, anyway.
Howdy - the one I linked is polished aluminum with a chrome top cap. - now the crappy dial unit IS chrome, and I wish I would have also mentioned that about it !!!
Ok. It looks like the chrome one I bought from Holley. 🤷🏽♂️.
I’ll have to do some further research then - I have the same one, but I bought mine 8 years ago now. Perhaps manufacturing on them has changed.
You're technical and Master in engine and carburators . Invite Mike to explain clearly .
I love to watch your channel you sure know your engines and carburetors.. thanks again Mr. Luke you are super awesome guy 👍 buddy
I’m glad you enjoy it!
If I can help folks, that’s really all that matters 👍
@@ThunderHead289 you are a good man I can tell. The world needs more like you my friend.
Carter Muscle car series mechanical pump runs max 5.5 lbs, flows 40% more than stock and is designed for use with an Edelbrock carb. Very cheap too, $23 for a sbc at Summit. I have one on my 350 S10 with after market heads, air gap intake .500 lift cam with a 780 Holley and it runs great.
Awesome video I have 74 Toyota Land Cruiser carburetor is a Asian style carburetor Love's 3 PSI go to high and it will flood out too low lack of power.
Wow while I did know a little bit about fuel pressure and how it could overcome the needle pressure on the seat and flood the engine I had no idea about those oil filled pressure gauges being a bad idea!
This video was super helpful!
Too bad all of us toobies don’t live closer together!
Another really informative video. Thank you for taking the time to share your knowledge 👍😁
Holy crap. I have allot to learn. Kid just bought his first car and its 4 years older than I am....thus the problem. Carb based mechanical tech. Blows out carbon/unburned fuel. SSooo..yeah, I'm going to be watching a tone of video's.
just purchased a 1982 gt 302 with electric pump, no return or regulators on a carter afb 650.. i guess i need to start looking for a full system like yours.. looks complicated lol. ty for vid
I had a near disaster with m 1957 Ford PU and dial fuel pressure regulator and will never use one again. While driving down a long stretch of interstate with no exits for a few miles, and constriction barriers, my truck started to stutter like it was running out of gas. The tank was over half full so I waited for two miles till the next exit to pull into a rest stop. After parking I opened my hood and nearly had a heart attack. My entire engine compartment was soaked with gas. The engine, firewall, inner finder panels, and the under side of the hood, was dripping gasoline. I had left the motor running and gas was running out from under my front bumper as I was parked on a hill. My dial type regulator was squirting a 1/8" diameter stream of gas up under the hood, then raining back down on everything. You will ask "couldn't you smell that", the answer is NO. I lost my sense of smell during a long bout of high fever when I was 13 years old. I quickly shut the engine off ant left the hood open for over an hour till it was dry. Diagnosing the problem, I realized the diaphragm had ruptured and gas squirted out of the hole in the center of the dial. I never knew there was a hole there, because there is normally a sticker covering it. My sticker was gone, the gas had deleted the adhesive. When it started, apparently the motor was starving for gas because the leak was so large. After removing the faulty regulator and re-connecting the fuel line I was able to drive home. Thinking back to that day, I realized that I would have burned to death. Do like I did and throw those cheap dial type fuel pressure regulators in the trash.
I
Awesome work mate. Love your tech tips
Thanks so much - I hope they are helpful!
Have always enjoyed and appreciated your videos, thanks.
Great video very informative great for newbies I came to a lot of the same conclusions that you have come to, thanks for your efforts
Good info, Luke. You saved a lot of people money and frustration. Fuel pressure in excess will overcome a float; something that isn't talked about very much. Thanks for sharing. Peace.
William Charles oh, much more than that! Fuel pressure will alter your fuel level in your bowl and actually alter your fuel curve and mixture entirely also - even if it doesn’t blow open a needle and seat!
Haven't had to do much to my edlebrock avs2 and I absolutely love it
Surprising to see a younger guy who knows about carburetors.