Lifter differences on the dyno
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
Lifter differences on the dyno I know this wouldn't be a common thing to do, but I'm curious...
Has anyone ever seen a difference on the dyno between ls7 lifters and high quality aftermarket lifters? I know it's probably rare that anyone would only change lifters and not anything else just curious if it's ever been done?
I've been running ls7 lifters for the last 3 years shifting at 7200 rpm and was wondering what if anything I'm giving up above 6000 rpm with these lifters. Cam is 232/248 with .621 and .605 lift. With the nature of my combo procharged with a cathedral port btr equalizer intake I certainly don't lack in power over 6000, but curious if better lifters would actually gain any power.
Has anyone ever seen a difference on the dyno between ls7 lifters and high quality aftermarket lifters? I know it's probably rare that anyone would only change lifters and not anything else just curious if it's ever been done?
I've been running ls7 lifters for the last 3 years shifting at 7200 rpm and was wondering what if anything I'm giving up above 6000 rpm with these lifters. Cam is 232/248 with .621 and .605 lift. With the nature of my combo procharged with a cathedral port btr equalizer intake I certainly don't lack in power over 6000, but curious if better lifters would actually gain any power.
Okay I'll play devils advocate here. Is it the lifters that make more power or is it the camshaft? Now having valvetrain stability which allows for higher RPM's makes more power. More air and more fuel equals more power so just how does a lifter do that? I suppose having lifters capable of turning 8,000-10,000 rpm's is going to make more power but was it the lifter?
Launching!
Joined: Oct 2022
Posts: 206
Likes: 74
From: FL
If lifters are going to cause a loss it's going to be at the low end. There's more time to bleed down when things are happening slower.
Ever think about pushrods? The dyno hero of everyone here did a test on different length pushrods and found that longer makes more power up top. It's because oil in the lifter is more likely to be aeriated at high rpm. Longer pushrod leaves less space for oil.
I had a conversation with Brian Nutter, the engineer for Summit Pro LS cams and he was telling me how dirt track racers figured this out long ago. And since they are under strict rules and engine inspections someone figured out to put spacers in the stock lifters to take up some of the volume, and it did lead to power gains in the high rpm areas.
Ever think about pushrods? The dyno hero of everyone here did a test on different length pushrods and found that longer makes more power up top. It's because oil in the lifter is more likely to be aeriated at high rpm. Longer pushrod leaves less space for oil.
I had a conversation with Brian Nutter, the engineer for Summit Pro LS cams and he was telling me how dirt track racers figured this out long ago. And since they are under strict rules and engine inspections someone figured out to put spacers in the stock lifters to take up some of the volume, and it did lead to power gains in the high rpm areas.
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
This is a street car with a couple track visits a year. Probably not going to spend the money on adjustable rockers. Currently over 900 rwhp estimated with junk heads. I was thinking about upgrading heads and doing lifters at the same time if there was actually a benefit to changing lifters with my combo.
Ls7 lifters with 0.080 preload, summit 11/32 0.120 wall pushrods, btr .660 spring kit, ws6store max effort rockers, and wot shift point approximately 7200 rpm. Ls3 block with forged internals, cathedral port top end, btr equalizer intake, 232/249 621 605 116.5 lsa 112 icl. Twenty psi peak boost.
Ls7 lifters with 0.080 preload, summit 11/32 0.120 wall pushrods, btr .660 spring kit, ws6store max effort rockers, and wot shift point approximately 7200 rpm. Ls3 block with forged internals, cathedral port top end, btr equalizer intake, 232/249 621 605 116.5 lsa 112 icl. Twenty psi peak boost.
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
...but is it necessary at 7200 rpm and would it produce hp gains with this combo? I'd like to stay away from the expense of adjustable rockers if that money could make more power somewhere else like better heads.
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Launching!
Joined: Oct 2022
Posts: 206
Likes: 74
From: FL
Lifter preload doesn't change unless you float the valves. So, how in the hell do you think they're going to make more power?
What I said and what pdxmotorhead said he's actually done is make hydraulic lifters solid or close to it. On a street car you don't typically put solid lifters on a hydraulic cam and that wasn't suggested here.
So if you were to go with solid lifters you'd run a solid cam which would simply be a solid cam conversion. Thats not your question.
The simple answer to your question is NO.
I did mention that Richard Holdener did a test where he ran way more preload than what people typically run, and made more power than the typical preload would make. Thats directly a lifter making more power (by decreasing the amount of oil under the plunger) but if you choose to ignore it, so be it.
What I said and what pdxmotorhead said he's actually done is make hydraulic lifters solid or close to it. On a street car you don't typically put solid lifters on a hydraulic cam and that wasn't suggested here.
So if you were to go with solid lifters you'd run a solid cam which would simply be a solid cam conversion. Thats not your question.
The simple answer to your question is NO.
I did mention that Richard Holdener did a test where he ran way more preload than what people typically run, and made more power than the typical preload would make. Thats directly a lifter making more power (by decreasing the amount of oil under the plunger) but if you choose to ignore it, so be it.
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Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
Lifter preload doesn't change unless you float the valves. So, how in the hell do you think they're going to make more power?
What I said and what pdxmotorhead said he's actually done is make hydraulic lifters solid or close to it. On a street car you don't typically put solid lifters on a hydraulic cam and that wasn't suggested here.
So if you were to go with solid lifters you'd run a solid cam which would simply be a solid cam conversion. Thats not your question.
The simple answer to your question is NO.
I did mention that Richard Holdener did a test where he ran way more preload than what people typically run, and made more power than the typical preload would make. Thats directly a lifter making more power (by decreasing the amount of oil under the plunger) but if you choose to ignore it, so be it.
What I said and what pdxmotorhead said he's actually done is make hydraulic lifters solid or close to it. On a street car you don't typically put solid lifters on a hydraulic cam and that wasn't suggested here.
So if you were to go with solid lifters you'd run a solid cam which would simply be a solid cam conversion. Thats not your question.
The simple answer to your question is NO.
I did mention that Richard Holdener did a test where he ran way more preload than what people typically run, and made more power than the typical preload would make. Thats directly a lifter making more power (by decreasing the amount of oil under the plunger) but if you choose to ignore it, so be it.
It seems your answer to my question is no, just changing to a better lifter would not show a power difference with my combo. That’s all I wanted to know.
You and some others did offer some scenarios and combinations where it would offer a power gain. I said this is a street car and I also said I didn’t want to spend the coin on adjustable rockers because I think that money put towards better heads would give me more bang for my buck. That made you mad, but I’m not sure why.
The answer to whether a better lifter will make more power is not clear cut, a lot depends on the operational parameters of the motor. Like others have said, playing with the preload can help optimize a combo. Thet being said, a better quality lifter like a Johnson, will give more control and more consistency and that equals more power. In your combo, the only way to know is experiment. If definitely won't make less power, that's for sure.
i think comp makes some shimmable pushrods to be used with stock rockers. That is a way around expensive rockers....although my adjustable rockers weren't that expensive. Now how long they'll last I don't know.
Joined: Jul 2007
Posts: 1,503
Likes: 177
From: ELSA, South TEXAS (956) 802-7700
If you've been good with set up for 3 years and happy with top end I wouldn't mess with. Ls7 lifters have worked good up to 7500 rpm since they first came out.
Sure as with all things, technology has made things even lifters better, but worth it to change out in your case, I wouldn't. Now whenever engine dies and you do a total rebuild, then I would consider Johnsons or Caddy.
In the meantime, I would consider any weight reduction or exhaust set up if it can be improved.
Rob D
Sure as with all things, technology has made things even lifters better, but worth it to change out in your case, I wouldn't. Now whenever engine dies and you do a total rebuild, then I would consider Johnsons or Caddy.
In the meantime, I would consider any weight reduction or exhaust set up if it can be improved.
Rob D
My point was that lifters don't make anymore power..Choosing to run them with more preload will make a little more but at the expense of the lifter unless you step up to LLSR and adjustable rockers. Cylinder heads with the right camshaft and the ability to add more air and fuel is where the real gains are.
Joined: Jul 2007
Posts: 1,503
Likes: 177
From: ELSA, South TEXAS (956) 802-7700
My point was that lifters don't make anymore power..Choosing to run them with more preload will make a little more but at the expense of the lifter unless you step up to LLSR and adjustable rockers. Cylinder heads with the right camshaft and the ability to add more air and fuel is where the real gains are.
TECH Fanatic
Joined: Dec 2017
Posts: 1,614
Likes: 1,088
A few years ago my friend did the swap from LS7 lifters to ST2126LSR lifters. There was no power difference between the two. At least not to what he was revving the car to. That was an expensive "test", for sure. As that was his only change, and was purely for a potential power gain.
If you've been good with set up for 3 years and happy with top end I wouldn't mess with. Ls7 lifters have worked good up to 7500 rpm since they first came out.
Sure as with all things, technology has made things even lifters better, but worth it to change out in your case, I wouldn't. Now whenever engine dies and you do a total rebuild, then I would consider Johnsons or Caddy.
In the meantime, I would consider any weight reduction or exhaust set up if it can be improved.
Rob D
Sure as with all things, technology has made things even lifters better, but worth it to change out in your case, I wouldn't. Now whenever engine dies and you do a total rebuild, then I would consider Johnsons or Caddy.
In the meantime, I would consider any weight reduction or exhaust set up if it can be improved.
Rob D
TECH Addict
Joined: Aug 2005
Posts: 2,305
Likes: 126
From: Monroe,NY
On engine masters the dyno guy i for got his name has seen cheap lifters cost close to 30 hp. He did tests back to back. Now this was on a small block. Not sure how the LS7 lifters compare to cheap small block lifters. But he said the cheap lifters were collapsing at high rpm causing the cam to lose duration which caused the power lose.
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
I’ve lost faith in one of the most famous YouTube dyno testers.
Things like do roller tip lifters add power. His answer yes of course. Problem is he compares 1.7 stockers to 1.8 roller tips. Or compares heads X head makes more power than Y head, but uses the large CC combustion chamber Y heads to show X are better even though Y heads flow slightly better. Well yes you proved compression ratio matters. Lol.
Things like do roller tip lifters add power. His answer yes of course. Problem is he compares 1.7 stockers to 1.8 roller tips. Or compares heads X head makes more power than Y head, but uses the large CC combustion chamber Y heads to show X are better even though Y heads flow slightly better. Well yes you proved compression ratio matters. Lol.
TECH Senior Member
Joined: Jun 2016
Posts: 22,298
Likes: 3,619
From: Central Cal.
I’ve lost faith in one of the most famous YouTube dyno testers.
Things like do roller tip lifters add power. His answer yes of course. Problem is he compares 1.7 stockers to 1.8 roller tips. Or compares heads X head makes more power than Y head, but uses the large CC combustion chamber Y heads to show X are better even though Y heads flow slightly better. Well yes you proved compression ratio matters. Lol.
Things like do roller tip lifters add power. His answer yes of course. Problem is he compares 1.7 stockers to 1.8 roller tips. Or compares heads X head makes more power than Y head, but uses the large CC combustion chamber Y heads to show X are better even though Y heads flow slightly better. Well yes you proved compression ratio matters. Lol.
Same for heads. He gets questions like, "what's the better head, X or Y??" He will show WHY head X with the small ports and chambers can be better than larger, better flowing ports and larger lower compression chambers.
You need to look at context.