High lift cams and boost?
Thread Starter
On The Tree
Joined: Oct 2012
Posts: 198
Likes: 33
High lift cams and boost? Since we're on a camshaft kick, what are the downsides of high lift camshafts and boost? I have BTR .660 springs but one cam I'm foolishly eyeballing is .629/.600 lift. (225/229 @ .050", 111lsa and 5 degrees overlap if you are curious). You don't see many "boost" cams with that much intake lift, in fact this one is marketed as an NA drift cam. Is it worse on the springs than NA or gains just not worth it?
My cam is 232/248 621 605 116.5 +4.5 with BTR .660 lift springs. I only spin it to 7200 rpm with a procharger no issues so far. Springs are over 7 years old with 5 years on the current motor. Ls7 lifters and ws6store max effort rockers.
Thread Starter
On The Tree
Joined: Oct 2012
Posts: 198
Likes: 33
Nice, I have the same lifters and rockers. Thanks for the input.
I don't think lift is the ultimate arbiter in determining valve spring life, I think ramp design plays a larger role.
Aggressive ramp profiles seriously tax springs so the question should be, what lobe profile does the cam use.
I'd want the softest lobe profile possible for high rpm and spring longevity.
Baker is one cam grinder who understands this very well, I'm sure there are others as well.
Aggressive ramp profiles seriously tax springs so the question should be, what lobe profile does the cam use.
I'd want the softest lobe profile possible for high rpm and spring longevity.
Baker is one cam grinder who understands this very well, I'm sure there are others as well.
Well mine has .756" lift on the intake and .738" lift on the exhaust but I have a head that flows well into that lift range along with valvetrain components that are made for it. My point is that there are a lot of variables that go into it and generic questions regarding high lift cams and boost will have a ton of different answers. Is higher lift worse on springs? Yes. Is higher lift worth it, that depends on the combo.
Well mine has .756" lift on the intake and .738" lift on the exhaust but I have a head that flows well into that lift range along with valvetrain components that are made for it. My point is that there are a lot of variables that go into it and generic questions regarding high lift cams and boost will have a ton of different answers. Is higher lift worse on springs? Yes. Is higher lift worth it, that depends on the combo.
I knew BBC guys back in the day who would routinely replace the valve springs on their solid roller combos because failure wasn't a question of if but when.
I'd rather not do that again lol.
The way I understood it, you sacrifice valve control for more flow. And if you are on a factory cath casting head there’s not much to be gained flow wise on lifts over .600. If I recall BTR tested this and was really minimal over like .560 on a factory head, esp the exh side. Higher you go lift wise the less stabile the valve train is and the less aggressive ramp rate can be used. Basically, more wear and tear.
Trending Topics
The way I understood it, you sacrifice valve control for more flow. And if you are on a factory cath casting head there’s not much to be gained flow wise on lifts over .600. If I recall BTR tested this and was really minimal over like .560 on a factory head, esp the exh side. Higher you go lift wise the less stabile the valve train is and the less aggressive ramp rate can be used. Basically, more wear and tear.
Found it.
Full tilt porting with larger valves can easily get these numbers into the low to mid 300CFM range.
Last edited by Black_Sunshine_99; Sep 25, 2024 at 12:35 PM.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
