Mad props to a company willing to sacrifice profit to make sure the thing is done right all the way instead of just sending it out to be the customers problem
The fact that it makes more boost psi when it looses control of the valve makes sense seeing that boost is a measurement of restriction and when the valves don’t open all the way there is more restriction in the engine so the boost goes up and the power goes down.
Or is it compression from the cylinders being pumped back into the intake manifold under the supercharger when the intake valves are floating and not seating?
I’m not a real engine builder just an assembler, I wouldn’t criticize anything you do…. There are too many experts in the comment section for that. Keep on being you brother
When I hear people talking about engine builders, you guys are the type of people that come to mind. The people that just put stuff together and ship out engines are just assemblers not builders.
I really appreciate you giving away years of experience just to help the next one bring another piece of this puzzle for the future ones to improve (bring another piece)
Boost pressure on the back of the intake valve effectively reduces spring pressure. The area of the intake valve (minus the stem) multiplied by boost pressure is the force acting against the spring, reducing its rating.
@@css0076 That’s not really true, by the time the valve is closing the cylinder is filled so the pressure gradient is not as high. Forced induction does effectively reduce intake spring pressure, but it’s not as much as you suggest.
You can tell the sense of honor that Steve has, truly a good dude to the core and exactly who u want to be building your engine. Customer was dead on about anybody else just shipping it too cause they would not put this much effort into sorting every little detail/issue, being a diag guy i was glued to this video cause its such a great example of how to really diag showing how to hone in on the problem along with the process of elimination. Data is so important and always tells the tale though, problem is knowing how to interpret that data and seeing the differences. Great job and excellent customer support :), I am the same way and wont send a job if its not perfect cause customers don't care about the good reviews since they usually just look at the bad. Its not worth a little money to risk your reputation in this industry and being so transparent about everything really helps assure your customers that your looking out for their best interest, most engine builders only care about the money and would never go maximum effort like this for a random customer. Have seen it many times where people try to save money on a engine build taking it to some dude that their friend knows or whatever, the outcome is either they loose the money invested plus all the parts or they actually get a slapped together engine that's never been run/tested. Most of the builders cant even come close to the level of Steve's stuff cause he has all the data from years and knows what works because of it, the guys slapping parts together bought off ebay/amazon thinking they are a pro engine builder just makes me laugh. Have a guy right now that did a stock "rebuild" on a 98 civic D16y8 and after getting it all back together he has a knocking noise lol, funny thing is that's y he was "rebuilding" the engine and he didn't bother to check tolerances or anything and figured he would just slap some std bearings in along with some fresh rings with dingleball hone action. Tried to bring it to me but i wouldn't take it on cause it was all the cheapest Chinese stuff he could get and didn't wanna spend the money at machine shop, the moment he said that i just put the tailgate back up on his dads truck and told him i just cant do it. That's a whole can of worms problem i don't want and its different when the customer has a clue what it takes to actually rebuild a engine properly, money is always the main factor but to do it right always will cost u more unless u have the tools/skills to do it yourself at that level.
Steve Morris talking to Mike (customer). Mike, I have good news and bad, good news is we got your engine perfect. The bad news is it took 30 runs and its now time for the 30 run refresh, so it will be another week...😂
That engine is fine. Steve didn't over rev it. Didn't make it spark knock or detonate. Didn't Lean it out. It did float the valves a number times but that isn't the biggest deal. Valve float is the poor mans rev limiter.
Fought all these same problems with my bbc, I too put solid roller lifters on my hydraulic roller as well as stronger springs to also solve my problems. Great information and great video.
Talking about solid lifters, even though this is a completely different use case, The Honda J-series still uses them to this day and the service manuals typically only mention adjusting lash once you hear the valvetrain making excessive noise. I have one that likely has never been adjusted over its 360k mile lifetime.
I much prefer to follow builders and tuners as they solve problems and adjust to conditions. Just drop in power and run fast times is less interesting to me. This is like math teachers requiring the student to show the process.
But then there are a selected few who can do complicated math in their head instantly. How do you show the process there? The equivalent would be a guy that makes changes at the track instinctively and improves performance.
At BTR, we always recommend Johnson short travel lifters and our higher rate spring kits with a boosted engine that turns over 7000rpm. We also recommend using stock style rocker arms because they're way lighter.
At least early on, sounds like The intake valve is bouncing on the seat. That way you're getting pressure feedback into the intake manifold from the force of compression in the cylinder. Assuming that all valve springs are identical across the engine, it would contribute significantly to the manifold pressure increase once valve bounce/valve float starts occuring. Either that or maybe (and take this with a large grain of salt) the exhaust header is becoming a partial restriction at or above 6,800 rpm for the exhaust volumetric flow rate that the engine's producing. Or it could be a combination of both to varying degrees.
Valve bounce is what I think. People have commented that the valve isn’t opening all the way, because of leak down of the lifter. I can’t imagine this making a bit of difference.
I've wrenched professionally for over 30 years on everything from chainsaws to tractor trailers, and I'm still learning. Especially when I watch your channel, thank you, sir!
Merry Christmas!!! You guys are on it. Boost goes up when the valve/'s float causing inefficient air flow overall through the engine, creating "back pressure". Stuff like this is exactly why you are respected by many. Hard tedious work is not cheap, but the results are priceless.
Been using solids on hydraulic roller cams for a long time it works extremely well. It’s quiet. You don’t need a ton of spring pressure, Steve is out here telling all of our secrets lol
👍 probably nobody knows what it is here but on our 4G 54B found that solid rocker arms worked fine in the hydraulic roller cams. (25years ago) it's really cool seeing all the Tech and showing how it actually works. I never did very much diary on any of my Motors I always just use the information I got when I went down the Dragway. I've learned so much from watching these videos makes me want to get back into racing, I would not need to do so much trial and error. I think I could come right out of the trailer with a sweet fast car.
On the matter of a solid lifter on a hydraulic camshaft, I have a 383 sbc that we converted around 2 years ago. The engine never really sees more than 6500 rpm and was run for an entire season this past year. The car sees double entry at most events and probably saw around 180-200 runs this season. I had set them during the winter last year, never touched them all year, just checked them a few days ago, and found that they all were still adjusted properly.
To make a long story short, we build quite a few circle track engines that are very rule restrictive. (I know this isn’t a 1300hp deal but same concept) Class rules .450 hyd flat tappet, 9.5 comp, vacuum rule,Holley 500 2brl, stock exhaust manifolds, dual plane manifold. We dynoed 5 different engine from the aftermarket head were allowed to use to the stock production head. It seemed it did not matter the cam profile, head, ci,ect, we couldn’t make these things make any power past 6300rpm. Went down the valve spring/ valve train rabbit hole and finally got these things to make good power all the way to 7200 rpm, then all of a sudden something changed, nothing that we were doing they are pretty much copy and pastes style engines. After about 6 months of changing springs, spring pressures, spring rates, cam profiles, lifter manufactures we noticed that our intake manifold vacuum increased drastically over previous engines in the upper rpm of the pulls,finally determining our issue, We stuck a set of solid lifters in (with breaking them in) and made a pull, seemed to loose tq on the bottom end but picked up power above 6200. Along with intake manifold vacuum reducing in return the power increased on the top end. Unfortunately the rules on the class restricts us from using solids so we’ve gone to the only possible style lifter which is the short/reduced travel haven’t looked back since.
All the guys I knew just all agreed to cheat and run the solid lifters 😁 but they all run the tall mercruiser two barrel intakes which is kind of cheating by the rules too most acid etch the runners to increase the volume without changing the as cast appearance they will find every loophole to to ride the edge of the class rules its the budget street stockers so they are just out there to have fun
work'd with a great guy back..ahhh...say.almost 40 years ago...flop'd hydrolic's to solids on a hydrolic cam...cause same basic issue u had...& corrected it...!..as a 20ish yo kid i dident think u could do that...BUT...learned never to question him again...!..as u do...he knew his s**t...he was a "hard" core drag racer/dealer shop forman...i learnd SO much...!..thanks steve 4 all the videos over the past year...healthy & merry christmas to u & family...!
New to your channel but I can’t already see your attention to detail is superb! If I had an engine to get tested it would be yours to test. I appreciate your demeanor, you have my vote!
5:41 Pretty easy, boost is a measurement of restriction, when you have a valve hanging up and not opening all the way, that is more restriction, which is why your boost is higher.
If a valve was hanging up and "not opening all the way" you'd have broken parts. Rocker, push rod, cam. It's not possible as it's mechanically pushed open by the valvetrain.
I believe the boost went up when the intake valves bounced off the seat letting the cylinder compression pressure return to the intake. BTW You Guys do great videos with great information. Greetings from Brazil 💪🏻🏁
After reading your thoughts on what is happening i was considering it as a possibility but since the intake closes after bdc if the valve bounced it would just effectively increase the duration of the intake closing. It would delay the closing so much it wouldnt gain cylinder fill anymore for compression bc the piston is up too far now thus compressing less air, leading to lower power but i dont believe the intake side would show more boost as like i said the intake already closes after bdc. Im definitely not arguing right or wrong. Im only engaging in discussion bc its interesting and a fun challenge to think about. I hope to always learn and dont care if im right, i do seek to know what is actually happening. Thank you for posting your thoughts on the engine.
Wild guess at 12 minutes, valve float. The intakes are hanging open, and the cylinders are pumping back it´s air into the plenum, making the boost higher.
Hydraulic lifter Hp trend improved with more valvespring pressure. A bad/squishy/leaky hyd lifter would normally be pissed off with more spring pressure. I'll bet the cam lobe/spring pressure combination is allowing some valve bounce on closing, and the hyd lifter took up the slack. Got better with solid lifters because they cant pump up when you have seat bounce on closing. Improved again with solids and more valvespring pressure to combat valve closing bounce. A milder/slower cam lobe might make the hyd setup happier and require less spring and more rpm? Honestly, im just throwing out some ideas, not trying to detract from the video. This was a great problem solving video, paying attention/analyzing the data, and approaching the problem in a scientific method. Thank You Sir!!!
A big TY Steve! Sharing this info is invaluable for the everyday enthusiast that would never have the resources to chase an issue like this down to the root cause. I have to ask now though, in your opinion how many HP would be on the table to replace the hyd roller cam profile for a dedicated solid that had lobes designed to be easy on the valve train? My guess based on nothing is possibly twenty HP. I can't see the cost of changing the cam being worth it though. Being an old school racer from the 1990's, I don't get why it's so common for LS engines at this level (7000+ RPM) to use a hydraulic lifter.... In my days, if it's going to RPM much past 6000, just go solid lifter. Hydraulics just make no sense to me at this level everything taken into consideration.
After watching the rest of the video and thinking about it, valve float/bounce is what I'd say. The intake valve is not completely closing before the compression stroke starts and the piston is pushing air back in the intake manifold. I'd be curious if you could advance the camshaft to get the intake valve open/closed sooner before the compression stroke starts. Assuming there is enough piston to valve clearance between the exhaust valve and piston. I think this is also proof that overkill sometimes hurts you in the case of the push rods being too large and heavy.
I’m only at 7mins or so! Anytime we ever seen boost jump like that, an intake valve, or two was not opening! Like regular travel lifters, bottoming out! LS7 lifters have been garbage lately! Take some apart & see the beautiful machine work, & trash in them! They all quit right around 6800, unless you actually get a good set! Some guys run 8800, season after season with a really good short travel hydraulics! To the lash babies, ask guys that have owned there tractor trailer trucks for decades! It’s called running the overhead! Most of the super experts, get super anal about adjusting the valves! Even at 150000miles, they are all usually within a few thousands! Other than brand new rebuild, or something going away! Merry Christmas 🎄🎄🎄🎄!
Very good lesson this shows what happens when the lifters are collapsing and that the springs can't control the valve even on a Mild lobe profiles cam. Also I ve seeing a hydraulic lifters problem across all the manufacturers. Thanks again Steve .
you are the man Steve...figuring the stuff out and making it right for the customer at your expense!!!!! Marry Christmas and god bless you and your family!!!!!! have been watching you since day one....
Most engine builders probably don't have the conscience that you do plus your dedication to your craft is above and beyond anyone else. You put product over profit... Using solid lifters on a hydraulic cam was done on Engine Masters with really good results, that's the first time I ever heard of that. Could this be the wave of the future? You eliminate hydraulic lifter problems and from the sound of it, valve clearance maintenance isn't an issue.
Loving the search for the root cause of the problem. Thanx for showing us all the extra effort you do. I'll keep buying merchandise to get some coin your way... 😊
If this was a turbo engine, it would have lost boost when the spring/lifter was no longer happy. But since its tied to the crankshaft, the boost is able to bounce the valve a little higher and gain more boost... As far as the lifter deal, if it doesn't say Johnson on it , I dont put it in my customers engine....Just never any drama...Thanks Steve and Kyle for sharing.
Fascinating. Your thirst for more knowledge is inspiring. Hey, Merry Christmas !! Here is to a safe, sane, prosperous New Year for Steve Morris Engines. Thanks for the pro-tips.
Makes sense that boost climbs with valve floating, especially with (heavy) intake valves: combustion gasses escape the floating intake valve and pressurize the intake system, adding to the normal boost charge.
On tuneup stuff we used to drop a cylinder spark or fuel and look for rpm drop and/or look at coil voltage on each spark plug for how much voltage it took to fire it. It’s been around 40 years since I tested engine on for a job so I’m digging a bit into my memory
Hi Steve, great video! I agree with css0076, I too have seen compound turbos on tractor pullers hold valves open: not the case here. The lifters were partially collapsing at high RPM thus not opening the valves all the way as evidenced by the climb in intake pressure not having anywhere to go. Keep up the good work!
Abratable coating great concept. any clearance set up except for valve lash is a static clearance meaning non-running engine. when engines run you have unique heat/pressures etc that are slightly unique to each engine. abratable coating is custom dynamic clearance not static clearance for each particular engine. love the idea and I expect it to show better performance and less wear and be much more widespread in the future
Great video Steve, troubleshooting a valve train really takes a trained eye. Warning I learned something!! Pretty cool watching this from beginning to end.
Supercharged boost of course increases as a function of rpm, but because the valvetrain isnt keeping up, the flow isnt there and boost pressure rises. Furthermore since an engine is an air pump and normally creates suction in the intake. When the vavletrain is not keeping up, the supercharger boost will look like its increasing bc the vacuum of the engine has been reduced and more than likely its exhausting efficiency is lost as well.
boost going up I would think of as a sudden loss of VE so to speak or flow on the part of the engine .. basically losing control of the valve train ... IDK if the valves are bigger/heavier in this case than previous combos you have run with these lifters ?? I am not an engine builder.. Ive assembled them my whole life Im 57, I honestly would have backed the lifters off to 0 lash or + 1/8 turn before changing them as a quick diag check... I am a tuner and fabricator and I dont quote fabrication work I bill hourly, time and materials, I do communicate clearly with customers on a daily basis... I think its admirable that you are willing to eat labor to make sure things are right.. and if its something you built by all means its the thing to do.. if someone brings you a weird combo or like what I do for a living, square peg in round hole .. communicate clearly what the issues are and that it takes time to solve them.. time costs money
Turn smoothing down and valve train issues are easy to see and find. The line gets jagged as you loose valvetrain control. Use individual O2s and valve train issues are easy to see and find.
Props to you guys for always doing the right thing even when it isn't necessarily profitable. Question though, do you guys look at exhaust backpressure on the dyno? Usually you're looking for a restriction, but in this case, I think you may have seen a dip down in EBP that correlated with the boost increase at that 6800rpm mark.
I remember a Hot Rod Magazine article I read a while back, that stated the LS needs the stock rockers to go past 7000. The bulky ones that were installed were so heavy. The engine was twin turbo.
Great video and I enjoy how you go into detail with problems then actually talk about possible causes etc. I’m not a builder either, I’m only just tearing down my 377 sbc street strip engine now after a solid roller lifter cried enough and broke, sending the roller and needles off on a pinball journey through the engine. With that LS and the boost going up like it did, is it because of some valve float creating back pressure behind the inlets causing the boost to rise in the blower and manifold?
Steve love the way your brain works ...boost and valve float are arch enemies...but this video is an exact example of a diagnostic mind at work .. well done ..😊
On our Sand Car Motors, we run a Johnson Lifter setup at .040 preload with a PAC 1209x this gets us around 189lbs on the nose and Johnson wants it 520lbs over the nose on a 660 lift camshaft.
TH-cam makes the most money with ads. During the holiday season, they shift the views to content they believe will sell the most ads and provide the best CTR. As for the engine, it just needs more boost and some nitrous. If that doesn't fix it, being an SMX would solve the problem.
If the light springs were causing float the pressure spike might be the actual boost but rather the effect of reversion across the seats back into the intake.
Great troubleshooting deduction. But in the end he could benefit from getting mecanical roller cam now. But as you said its weird those ls7 lifter did not do the work as they "should". But the customer is happy and the engine runs right. Thats all what matters.
Very interesting Steve on the change in the boost.25 Years a go a friend had a twin turbo bbc that had a weird problem and we put solid roller lifter on hyd. cam and it was fixed. we had spent 3 weeks on his dyno trying to figure it out. did not have the data then that you do now. Thanks Merry Christmas
Defiantly was leaning towards one or more of the lifters collapsing at high rpm. In a blower motor there isn't much else to cause the boost to drastically jump other than lose of valve opening, other than the blower belt finally grabbing.
Great to see the best , still get there thinking cabs out from time to time And not just put together a package that is fantastic don’t get me wrong but want to know how and why It’s why the best get better 😊
I remember one of the Richard Holder videos talking about boost and air flow. When you showed how the boost went up I immediately thought of his video. Interesting troubleshooting session. With the use of the heavy components should something have triggered you to think more about the valvetrain dynamics at the high RPM range?
I had a ls that had a Paxton on it and at high rim the valves would float just a little. It barley burped in the exhaust is the way I caught it. For some reason the boost will build up and back pressure cause it cannot move the air properly. Learned that on huge compressors on the oilfield.
Merry Christmas to Mr Morris, from Brisbane Australia. All the best to you & yours. That is really interesting. Q: A hydraulic roller cam is designed with a specific profile to not mess up the hydraulics. If you're changing over to a solid roller (which is perfectly understandable) when are you going to get rid of that compromised (conservative) hydraulic cam and throw something more aggressive at it? Don't talk to me about valve-lash. You taught me yourself, engines like in Cleetus mac's Mullet and your Wagon, get valve-lash checked and changed twice a day anyway, on the change from petrol / gasolene, to Methanol and back. If you are manually doing a valve adjustment twice a day, then what the hell is the issue with running a solid lifter? The reason you want a hydraulic cam, is so you can drive thirty thousand miles without doing a valve lash adjustment. An engine that's producing one and a half thousand hp ~ that's not the same as what the postman drives or a cab-driver, that's a different animal. You don't need a never-adjust on your valve lash.
Really appreciate when someone cares more about things being done right and being correct before profits and appreciating that every opportunity to learn is one worth taking. Keep up the good work and thank you for all your information sharing
Restriction goes up boost goes up just like a garden hose. Better flow = lower boost required to overcome resistance. Basically the air is stacking up.
friburger did some testing on ls oil pans and how the amount of oil effected the foaming of the oil that allows the lifters to collapse , log oil psi and see if the oil psi drops off where its losing power , he found that if you run it 1-2 qts low the oil psi would not drop and would rev to 7500-8000
I've been running lash (.005) on hydraulic cams since the late 1980's. I had a Ford FE 390 that would not rev. and would pop out the exhaust, put a set of dual springs on it and shorter push rods, no help. Added adjustable rocker arms on it and it turned into a beast. I do it to any hyd. camed eng. I work on.
Yeah exactly, are you saying you add .005” lash on top of hydraulic lifters? 🤨. What would the purpose of that be? I get the solids and some lash but not lash on top of hydros
I've never heard your spiritual journey, but it's easy to see in your actions and decisions. My favorite feature of the SMX is the ring in combination with the copper head gasket with 1/2 inch head bolts (4X per cylinder). These big ideas set your work apart from anything else I've seen. It's a real joy to see just how tough these ideas are. I think 'enlightened' is a fair description of your SMX. BTW: Thank you for this last year's videos. Wish I lived within driving distance. Thank you Stve & Val.
This is how pros like yourself become pros! Because you have been there and done that, you find a problem and work thru it even when maybe you don't really need to. You do it because you just want to know.
Mad props to a company willing to sacrifice profit to make sure the thing is done right all the way instead of just sending it out to be the customers problem
True, Mr Morris is pretty smart. He knows great product and customer service will result in more business and profits in the long run.
What's a "mad prop"?
The fact that it makes more boost psi when it looses control of the valve makes sense seeing that boost is a measurement of restriction and when the valves don’t open all the way there is more restriction in the engine so the boost goes up and the power goes down.
Or is it compression from the cylinders being pumped back into the intake manifold under the supercharger when the intake valves are floating and not seating?
I’m not a real engine builder just an assembler, I wouldn’t criticize anything you do…. There are too many experts in the comment section for that. Keep on being you brother
Props to you for knowing the difference between builder and assembler.
When I hear people talking about engine builders, you guys are the type of people that come to mind. The people that just put stuff together and ship out engines are just assemblers not builders.
Agree 💯
I really appreciate you giving away years of experience just to help the next one bring another piece of this puzzle for the future ones to improve (bring another piece)
Boost pressure on the back of the intake valve effectively reduces spring pressure. The area of the intake valve (minus the stem) multiplied by boost pressure is the force acting against the spring, reducing its rating.
@@css0076 That’s not really true, by the time the valve is closing the cylinder is filled so the pressure gradient is not as high. Forced induction does effectively reduce intake spring pressure, but it’s not as much as you suggest.
You can tell the sense of honor that Steve has, truly a good dude to the core and exactly who u want to be building your engine. Customer was dead on about anybody else just shipping it too cause they would not put this much effort into sorting every little detail/issue, being a diag guy i was glued to this video cause its such a great example of how to really diag showing how to hone in on the problem along with the process of elimination. Data is so important and always tells the tale though, problem is knowing how to interpret that data and seeing the differences. Great job and excellent customer support :), I am the same way and wont send a job if its not perfect cause customers don't care about the good reviews since they usually just look at the bad. Its not worth a little money to risk your reputation in this industry and being so transparent about everything really helps assure your customers that your looking out for their best interest, most engine builders only care about the money and would never go maximum effort like this for a random customer. Have seen it many times where people try to save money on a engine build taking it to some dude that their friend knows or whatever, the outcome is either they loose the money invested plus all the parts or they actually get a slapped together engine that's never been run/tested. Most of the builders cant even come close to the level of Steve's stuff cause he has all the data from years and knows what works because of it, the guys slapping parts together bought off ebay/amazon thinking they are a pro engine builder just makes me laugh. Have a guy right now that did a stock "rebuild" on a 98 civic D16y8 and after getting it all back together he has a knocking noise lol, funny thing is that's y he was "rebuilding" the engine and he didn't bother to check tolerances or anything and figured he would just slap some std bearings in along with some fresh rings with dingleball hone action. Tried to bring it to me but i wouldn't take it on cause it was all the cheapest Chinese stuff he could get and didn't wanna spend the money at machine shop, the moment he said that i just put the tailgate back up on his dads truck and told him i just cant do it. That's a whole can of worms problem i don't want and its different when the customer has a clue what it takes to actually rebuild a engine properly, money is always the main factor but to do it right always will cost u more unless u have the tools/skills to do it yourself at that level.
Steve Morris talking to Mike (customer). Mike, I have good news and bad, good news is we got your engine perfect. The bad news is it took 30 runs and its now time for the 30 run refresh, so it will be another week...😂
That engine is fine. Steve didn't over rev it. Didn't make it spark knock or detonate. Didn't Lean it out. It did float the valves a number times but that isn't the biggest deal. Valve float is the poor mans rev limiter.
@@steveletson6616- Do jokes routinely go right over your head?
@@danmyers9372very well put lol 😂
If it was a aluminum rod hemi it damn near would 😂
Fought all these same problems with my bbc, I too put solid roller lifters on my hydraulic roller as well as stronger springs to also solve my problems. Great information and great video.
Talking about solid lifters, even though this is a completely different use case, The Honda J-series still uses them to this day and the service manuals typically only mention adjusting lash once you hear the valvetrain making excessive noise. I have one that likely has never been adjusted over its 360k mile lifetime.
I much prefer to follow builders and tuners as they solve problems and adjust to conditions. Just drop in power and run fast times is less interesting to me. This is like math teachers requiring the student to show the process.
But then there are a selected few who can do complicated math in their head instantly. How do you show the process there? The equivalent would be a guy that makes changes at the track instinctively and improves performance.
Merry Christmas Mr Morris my teacher , as always teaching this young 60 years young Aussie new information and methods .❤Steve Morris .
At BTR, we always recommend Johnson short travel lifters and our higher rate spring kits with a boosted engine that turns over 7000rpm. We also recommend using stock style rocker arms because they're way lighter.
Boost = volume with nowhere to go!
kudos for doing it right!
At least early on, sounds like The intake valve is bouncing on the seat. That way you're getting pressure feedback into the intake manifold from the force of compression in the cylinder. Assuming that all valve springs are identical across the engine, it would contribute significantly to the manifold pressure increase once valve bounce/valve float starts occuring.
Either that or maybe (and take this with a large grain of salt) the exhaust header is becoming a partial restriction at or above 6,800 rpm for the exhaust volumetric flow rate that the engine's producing.
Or it could be a combination of both to varying degrees.
Valve bounce is what I think. People have commented that the valve isn’t opening all the way, because of leak down of the lifter. I can’t imagine this making a bit of difference.
I've wrenched professionally for over 30 years on everything from chainsaws to tractor trailers, and I'm still learning. Especially when I watch your channel, thank you, sir!
What’s going on with Val’s car? It’s like it fell off the planet when you couldn’t make the test-n-tune in Florida.
I'm thinking it's getting painted!
Merry Christmas!!! You guys are on it. Boost goes up when the valve/'s float causing inefficient air flow overall through the engine, creating "back pressure". Stuff like this is exactly why you are respected by many. Hard tedious work is not cheap, but the results are priceless.
Steve, great demonstration of valve control and how it can affect the engine performance. Hope you and your family have a Merry Christmas.
Been using solids on hydraulic roller cams for a long time it works extremely well. It’s quiet. You don’t need a ton of spring pressure, Steve is out here telling all of our secrets lol
👍 probably nobody knows what it is here but on our 4G 54B found that solid rocker arms worked fine in the hydraulic roller cams. (25years ago) it's really cool seeing all the Tech and showing how it actually works. I never did very much diary on any of my Motors I always just use the information I got when I went down the Dragway.
I've learned so much from watching these videos makes me want to get back into racing, I would not need to do so much trial and error. I think I could come right out of the trailer with a sweet fast car.
@ that’s the great thing about the Internet if you know where to look all the answers are there!
On the matter of a solid lifter on a hydraulic camshaft, I have a 383 sbc that we converted around 2 years ago. The engine never really sees more than 6500 rpm and was run for an entire season this past year. The car sees double entry at most events and probably saw around 180-200 runs this season. I had set them during the winter last year, never touched them all year, just checked them a few days ago, and found that they all were still adjusted properly.
To make a long story short, we build quite a few circle track engines that are very rule restrictive. (I know this isn’t a 1300hp deal but same concept)
Class rules .450 hyd flat tappet, 9.5 comp, vacuum rule,Holley 500 2brl, stock exhaust manifolds, dual plane manifold.
We dynoed 5 different engine from the aftermarket head were allowed to use to the stock production head. It seemed it did not matter the cam profile, head, ci,ect, we couldn’t make these things make any power past 6300rpm.
Went down the valve spring/ valve train rabbit hole and finally got these things to make good power all the way to 7200 rpm, then all of a sudden something changed,
nothing that we were doing they are pretty much copy and pastes style engines.
After about 6 months of changing springs, spring pressures, spring rates, cam profiles, lifter manufactures we noticed that our intake manifold vacuum increased drastically over previous engines in the upper rpm of the pulls,finally determining our issue,
We stuck a set of solid lifters in (with breaking them in) and made a pull, seemed to loose tq on the bottom end but picked up power above 6200.
Along with intake manifold vacuum reducing in return the power increased on the top end.
Unfortunately the rules on the class restricts us from using solids so we’ve gone to the only possible style lifter which is the short/reduced travel haven’t looked back since.
All the guys I knew just all agreed to cheat and run the solid lifters 😁 but they all run the tall mercruiser two barrel intakes which is kind of cheating by the rules too most acid etch the runners to increase the volume without changing the as cast appearance they will find every loophole to to ride the edge of the class rules its the budget street stockers so they are just out there to have fun
work'd with a great guy back..ahhh...say.almost 40 years ago...flop'd hydrolic's to solids on a hydrolic cam...cause same basic issue u had...& corrected it...!..as a 20ish yo kid i dident think u could do that...BUT...learned never to question him again...!..as u do...he knew his s**t...he was a "hard" core drag racer/dealer shop forman...i learnd SO much...!..thanks steve 4 all the videos over the past year...healthy & merry christmas to u & family...!
My guess early on, hydraulic lifter is collapsing at high rpm.
Seen something similar on small GM stuff.
Merry Christmas to the entire SM family and crew!!! God Bless all you folks and thank you for the entertainment as well as the education!!!
New to your channel but I can’t already see your attention to detail is superb! If I had an engine to get tested it would be yours to test. I appreciate your demeanor, you have my vote!
5:41 Pretty easy, boost is a measurement of restriction, when you have a valve hanging up and not opening all the way, that is more restriction, which is why your boost is higher.
If a valve was hanging up and "not opening all the way" you'd have broken parts. Rocker, push rod, cam. It's not possible as it's mechanically pushed open by the valvetrain.
I believe the boost went up when the intake valves bounced off the seat letting the cylinder compression pressure return to the intake. BTW You Guys do great videos with great information. Greetings from Brazil 💪🏻🏁
My guess also. Beat me to it
After reading your thoughts on what is happening i was considering it as a possibility but since the intake closes after bdc if the valve bounced it would just effectively increase the duration of the intake closing. It would delay the closing so much it wouldnt gain cylinder fill anymore for compression bc the piston is up too far now thus compressing less air, leading to lower power but i dont believe the intake side would show more boost as like i said the intake already closes after bdc. Im definitely not arguing right or wrong. Im only engaging in discussion bc its interesting and a fun challenge to think about. I hope to always learn and dont care if im right, i do seek to know what is actually happening. Thank you for posting your thoughts on the engine.
Wild guess at 12 minutes, valve float.
The intakes are hanging open, and the cylinders are pumping back it´s air into the plenum, making the boost higher.
Hydraulic lifter Hp trend improved with more valvespring pressure. A bad/squishy/leaky hyd lifter would normally be pissed off with more spring pressure. I'll bet the cam lobe/spring pressure combination is allowing some valve bounce on closing, and the hyd lifter took up the slack. Got better with solid lifters because they cant pump up when you have seat bounce on closing. Improved again with solids and more valvespring pressure to combat valve closing bounce. A milder/slower cam lobe might make the hyd setup happier and require less spring and more rpm? Honestly, im just throwing out some ideas, not trying to detract from the video. This was a great problem solving video, paying attention/analyzing the data, and approaching the problem in a scientific method. Thank You Sir!!!
Merry Christmas Steve and Family and crew.
Customer:"Cool man that"ll be perfect!"
Steve: "Ok Yeah can t do that."😂
Gotta commend you for always trying to do the right thing.👍
A big TY Steve! Sharing this info is invaluable for the everyday enthusiast that would never have the resources to chase an issue like this down to the root cause.
I have to ask now though, in your opinion how many HP would be on the table to replace the hyd roller cam profile for a dedicated solid that had lobes designed to be easy on the valve train? My guess based on nothing is possibly twenty HP. I can't see the cost of changing the cam being worth it though.
Being an old school racer from the 1990's, I don't get why it's so common for LS engines at this level (7000+ RPM) to use a hydraulic lifter....
In my days, if it's going to RPM much past 6000, just go solid lifter. Hydraulics just make no sense to me at this level everything taken into consideration.
"Best Holiday Present" -- Miles of SME Smiles opening to video
It's lost Control of the valve train somewhere
Learned heaps. The boost going up made sense when you list control of the valve. Merry Christmas to you all the way from NZ in summer.
Logic will say, Boost sensor is in the manifold, so if boost increases then boost is not going in the cylinders = something wrong on the valve train.
Merry Christmas from one long roof lover to another!
I'm 5:37 in and my guess is valve float is allowing some combustion pressure back in the intake manifold.
After watching the rest of the video and thinking about it, valve float/bounce is what I'd say. The intake valve is not completely closing before the compression stroke starts and the piston is pushing air back in the intake manifold. I'd be curious if you could advance the camshaft to get the intake valve open/closed sooner before the compression stroke starts. Assuming there is enough piston to valve clearance between the exhaust valve and piston. I think this is also proof that overkill sometimes hurts you in the case of the push rods being too large and heavy.
I’m only at 7mins or so! Anytime we ever seen boost jump like that, an intake valve, or two was not opening! Like regular travel lifters, bottoming out! LS7 lifters have been garbage lately! Take some apart & see the beautiful machine work, & trash in them! They all quit right around 6800, unless you actually get a good set! Some guys run 8800, season after season with a really good short travel hydraulics! To the lash babies, ask guys that have owned there tractor trailer trucks for decades! It’s called running the overhead! Most of the super experts, get super anal about adjusting the valves! Even at 150000miles, they are all usually within a few thousands! Other than brand new rebuild, or something going away! Merry Christmas 🎄🎄🎄🎄!
Very good lesson this shows what happens when the lifters are collapsing and that the springs can't control the valve even on a
Mild lobe profiles cam.
Also I ve seeing a hydraulic lifters problem across all
the manufacturers.
Thanks again Steve .
you are the man Steve...figuring the stuff out and making it right for the customer at your expense!!!!! Marry Christmas and god bless you and your family!!!!!! have been watching you since day one....
Most engine builders probably don't have the conscience that you do plus your dedication to your craft is above and beyond anyone else. You put product over profit... Using solid lifters on a hydraulic cam was done on Engine Masters with really good results, that's the first time I ever heard of that. Could this be the wave of the future? You eliminate hydraulic lifter problems and from the sound of it, valve clearance maintenance isn't an issue.
Enjoyed the problem solving process! Please enjoy the time off with your family in celebration of Christmas.
Loving the search for the root cause of the problem. Thanx for showing us all the extra effort you do. I'll keep buying merchandise to get some coin your way... 😊
Blessed Christmas men! Learned a lot in today's video. Thanks
If this was a turbo engine, it would have lost boost when the spring/lifter was no longer happy. But since its tied to the crankshaft, the boost is able to bounce the valve a little higher and gain more boost... As far as the lifter deal, if it doesn't say Johnson on it , I dont put it in my customers engine....Just never any drama...Thanks Steve and Kyle for sharing.
What happened to KSR and the Camaro ?
Merry Christmas Steve & Company.
Fascinating. Your thirst for more knowledge is inspiring. Hey, Merry Christmas !!
Here is to a safe, sane, prosperous New Year for Steve Morris Engines. Thanks for the pro-tips.
Another very informative video, heck in fact you even learned something. Merry Christmas to you, your family and crew.
Makes sense that boost climbs with valve floating, especially with (heavy) intake valves: combustion gasses escape the floating intake valve and pressurize the intake system, adding to the normal boost charge.
On tuneup stuff we used to drop a cylinder spark or fuel and look for rpm drop and/or look at coil voltage on each spark plug for how much voltage it took to fire it. It’s been around 40 years since I tested engine on for a job so I’m digging a bit into my memory
Hi Steve, great video! I agree with css0076, I too have seen compound turbos on tractor pullers hold valves open: not the case here. The lifters were partially collapsing at high RPM thus not opening the valves all the way as evidenced by the climb in intake pressure not having anywhere to go. Keep up the good work!
Merry Christmas and God Bless.
Merry Christmas Steve!
Abratable coating great concept. any clearance set up except for valve lash is a static clearance meaning non-running engine. when engines run you have unique heat/pressures etc that are slightly unique to each engine. abratable coating is custom dynamic clearance not static clearance for each particular engine. love the idea and I expect it to show better performance and less wear and be much more widespread in the future
Thanks for the year full of top notch dyno and racing footage Steve and Team. Appreciate it. You guys are the best🔥🔥🔥🔥🔥🔥🔥🔥🔥🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🦅🦅🦅🦅🦅🦅🦅🦅
Great video Steve, troubleshooting a valve train really takes a trained eye. Warning I learned something!! Pretty cool watching this from beginning to end.
Merry Christmas Steve & Kyle ! Love your vids!
Merry Christmas to the Morrison family
Merry Christmas Steve, Val, Kyle and the SME Gang. Top notch tec from Steve and crew. Ohh last cookie "Eats 20 more" LOL
Supercharged boost of course increases as a function of rpm, but because the valvetrain isnt keeping up, the flow isnt there and boost pressure rises. Furthermore since an engine is an air pump and normally creates suction in the intake. When the vavletrain is not keeping up, the supercharger boost will look like its increasing bc the vacuum of the engine has been reduced and more than likely its exhausting efficiency is lost as well.
What fuel? That’s a lot of timing for that setup. Judging off the AFR I’m assuming just pump E85 or something ?
boost going up I would think of as a sudden loss of VE so to speak or flow on the part of the engine .. basically losing control of the valve train ... IDK if the valves are bigger/heavier in this case than previous combos you have run with these lifters ?? I am not an engine builder.. Ive assembled them my whole life Im 57, I honestly would have backed the lifters off to 0 lash or + 1/8 turn before changing them as a quick diag check...
I am a tuner and fabricator and I dont quote fabrication work I bill hourly, time and materials, I do communicate clearly with customers on a daily basis... I think its admirable that you are willing to eat labor to make sure things are right.. and if its something you built by all means its the thing to do.. if someone brings you a weird combo or like what I do for a living, square peg in round hole .. communicate clearly what the issues are and that it takes time to solve them.. time costs money
Turn smoothing down and valve train issues are easy to see and find. The line gets jagged as you loose valvetrain control. Use individual O2s and valve train issues are easy to see and find.
😮 Thank you for sharing that overlay.
Thanks for sharing Steve. Have a Merry Christmas to you and your families
Props to you guys for always doing the right thing even when it isn't necessarily profitable.
Question though, do you guys look at exhaust backpressure on the dyno? Usually you're looking for a restriction, but in this case, I think you may have seen a dip down in EBP that correlated with the boost increase at that 6800rpm mark.
Great video!!! No engine builder on the planet would do all that at no charge other than you!!!!
Merry Christmas
Nah, most know to use Johnston short travel lifters for a higher revving, boosted LS instead of wearing out a motor on dyno.
I remember a Hot Rod Magazine article I read a while back, that stated the LS needs the stock rockers to go past 7000. The bulky ones that were installed were so heavy. The engine was twin turbo.
Way to go above and beyond to make it right at your expense. That’s why you are at the top of the field.
😅Loved the sound of those sequential pulls. Westech has run those solid rollers on hydraulic cams with good results NA
Awesome education Steve, love your work. Cheers from Down Under
Great video and I enjoy how you go into detail with problems then actually talk about possible causes etc. I’m not a builder either, I’m only just tearing down my 377 sbc street strip engine now after a solid roller lifter cried enough and broke, sending the roller and needles off on a pinball journey through the engine.
With that LS and the boost going up like it did, is it because of some valve float creating back pressure behind the inlets causing the boost to rise in the blower and manifold?
Steve love the way your brain works ...boost and valve float are arch enemies...but this video is an exact example of a diagnostic mind at work .. well done ..😊
On our Sand Car Motors, we run a Johnson Lifter setup at .040 preload with a PAC 1209x this gets us around 189lbs on the nose and Johnson wants it 520lbs over the nose on a 660 lift camshaft.
I said "Valve Float" I hope you and your family have a great Christmas! You pinpointed where it was! Thank You!
TH-cam makes the most money with ads. During the holiday season, they shift the views to content they believe will sell the most ads and provide the best CTR. As for the engine, it just needs more boost and some nitrous. If that doesn't fix it, being an SMX would solve the problem.
If the light springs were causing float the pressure spike might be the actual boost but rather the effect of reversion across the seats back into the intake.
Great troubleshooting deduction. But in the end he could benefit from getting mecanical roller cam now. But as you said its weird those ls7 lifter did not do the work as they "should". But the customer is happy and the engine runs right. Thats all what matters.
Rule #1, don’t fix mechanical problems with an electronic solution. Awesome work Steve!
Going the extra mile Steve, love it
Very interesting Steve on the change in the boost.25 Years a go a friend had a twin turbo bbc that had a weird problem and we put solid roller lifter on hyd. cam and it was fixed. we had spent 3 weeks on his dyno trying to figure it out. did not have the data then that you do now. Thanks Merry Christmas
Very interesting , and it looks like you have got it figured out. Thank you for another most informative video.
Hey Steve Merry Christmas to you You, Val, Kyle and the rest of the family and crew!!
Defiantly was leaning towards one or more of the lifters collapsing at high rpm. In a blower motor there isn't much else to cause the boost to drastically jump other than lose of valve opening, other than the blower belt finally grabbing.
Merry Christmas. A guy i worked with always said that boost psi was a reference of restriction.
Great to see the best , still get there thinking cabs out from time to time
And not just put together a package that is fantastic don’t get me wrong but want to know how and why
It’s why the best get better 😊
I remember one of the Richard Holder videos talking about boost and air flow. When you showed how the boost went up I immediately thought of his video. Interesting troubleshooting session. With the use of the heavy components should something have triggered you to think more about the valvetrain dynamics at the high RPM range?
Merry Christmas to you and your family. I see Dewey in the background looking for his present's.
I had a ls that had a Paxton on it and at high rim the valves would float just a little. It barley burped in the exhaust is the way I caught it. For some reason the boost will build up and back pressure cause it cannot move the air properly. Learned that on huge compressors on the oilfield.
Merry Christmas to Mr Morris, from Brisbane Australia. All the best to you & yours.
That is really interesting.
Q: A hydraulic roller cam is designed with a specific profile to not mess up the hydraulics. If you're changing over to a solid roller (which is perfectly understandable) when are you going to get rid of that compromised (conservative) hydraulic cam and throw something more aggressive at it?
Don't talk to me about valve-lash. You taught me yourself, engines like in Cleetus mac's Mullet and your Wagon, get valve-lash checked and changed twice a day anyway, on the change from petrol / gasolene, to Methanol and back. If you are manually doing a valve adjustment twice a day, then what the hell is the issue with running a solid lifter? The reason you want a hydraulic cam, is so you can drive thirty thousand miles without doing a valve lash adjustment.
An engine that's producing one and a half thousand hp ~ that's not the same as what the postman drives or a cab-driver, that's a different animal. You don't need a never-adjust on your valve lash.
Really appreciate when someone cares more about things being done right and being correct before profits and appreciating that every opportunity to learn is one worth taking. Keep up the good work and thank you for all your information sharing
Restriction goes up boost goes up just like a garden hose. Better flow = lower boost required to overcome resistance. Basically the air is stacking up.
friburger did some testing on ls oil pans and how the amount of oil effected the foaming of the oil that allows the lifters to collapse , log oil psi and see if the oil psi drops off where its losing power , he found that if you run it 1-2 qts low the oil psi would not drop and would rev to 7500-8000
If I had the bucks you would be my engine builder.
Merry Christmas. May the Lord richly bless you!
I've been running lash (.005) on hydraulic cams since the late 1980's. I had a Ford FE 390 that would not rev. and would pop out the exhaust, put a set of dual springs on it and shorter push rods, no help. Added adjustable rocker arms on it and it turned into a beast. I do it to any hyd. camed eng. I work on.
Just rockers? or in combination with solid lifters ?
Yeah exactly, are you saying you add .005” lash on top of hydraulic lifters? 🤨. What would the purpose of that be? I get the solids and some lash but not lash on top of hydros
I've never heard your spiritual journey, but it's easy to see in your actions and decisions. My favorite feature of the SMX is the ring in combination with the copper head gasket with 1/2 inch head bolts (4X per cylinder). These big ideas set your work apart from anything else I've seen. It's a real joy to see just how tough these ideas are. I think 'enlightened' is a fair description of your SMX. BTW: Thank you for this last year's videos. Wish I lived within driving distance. Thank you Stve & Val.
This is how pros like yourself become pros! Because you have been there and done that, you find a problem and work thru it even when maybe you don't really need to. You do it because you just want to know.