Anyone running Brian Tooley SLR lifters?
03-12-2013, 08:11 AM
#42
Not trying to challenge you all, I agree with you 100%. As far as my cam, Brain is having it ground for me. 242/250 .621/.595 113+4. Running a Fast 102/102 on a 402. Should have no problem pulling to 7000 RPM.
Last edited by 96lt4c4; 03-12-2013 at 08:44 AM.
03-12-2013, 09:07 AM
#46
there's a good chance they would work flawlessly, but there's also a decent chance they would **** themselves (especially when pushed). both cases have been well documented. considering the money involved in a performance engine build, a few extra bucks towards something that is shown to mitigate some of that risk will make me sleep better at night. if the SLR's will do that while saving me $300, then I'd say it's a win.
03-12-2013, 09:14 AM
#47
LOL....just got off the phone with Brian, his response is coming. I thought the same thing until about 5 minutes ago. I am more than likely running my LS7's. There is a lot more to the story as to why the LS7 lifters fail. It’s all about valve train control….
03-12-2013, 09:29 AM
#48
The lifter plunger height is the same as stock, and the plunger travel distance is about the same as stock. Which means in theory they can run the same preload as a stock lifter. However there are pro's and con's to running little preload or a lot of preload. Generally more preload will make less noise, however at high rpm's if the lifter may "pump up" due to valve loft, then it may not bleed down fast enough to seat the valves. At low engine speeds a stock lifter plunger can bleed down too fast and lose lift, which can also cause a tick.
Most guys are using .025"-.075" of preload on these lifters, and so far all have said the lifters eliminated the random tick they had with LS7 lifters. The plunger diameter in these lifters are a good bit larger than stock GM lifters, so I would imagine they gain hydraulic support from the increased plunger area which would also reduce bleed down rates.
In the spintron testing that I was involved in using stock lifters we saw .100"-.150" loss of lift from cycle to cycle at low rpm's, like idle speed. At low speeds the amount of time that the lifter is pushing against spring pressure is at it's greatest, and oil pressure is at it's least. This is what causes the lifters to bleed down.
At high RPM we saw upwards of .100" loft with the old Gold springs on a .600" lift cam. In theory if the lifter pumped up and then didn't bleed down fast enough it would hold the valve open and top end power would be lost.
You can see that having the valve train under control is as important as anything to do with the lifter. If you have too much lift, too much ramp speed, and too little spring pressure, the system will be out of control and damage will occur long term. It's interesting that in this scenario the spring could be at fault for not controlling the valve train, yet the lifter ultimately takes the beating and fails, then the lifter gets the blame. When lofting occurs not only does the lifter take a beating but the cam core does as well. So you have guys running crazy fast lobes like the LSK with springs like the old Gold springs and their cam core and lifters are failing. When the fault really rests on the cam design and spring pressure.
The next problem with lobes that are way too fast is, once you've increased the spring pressure enough to control them, you have too much open pressure to run with stock rockers and now the valve tips are taking a beating.
I've used LS7 lifters up to .670" lift and up to 7500 rpm, so to say a lifter has a RPM limit, really isn't correct. If the valve is light, and the cam ramp speed is low, then the valve train will stay stable. If the valve train stays stable then the lifter is able to do it's job without issues.
The SLR lifter body is made from a proprietary steel forging. The lifter starts as a solid slug and through multiple steps are formed/forged into what roughly looks like a lifter body.
How well these lifters hold up to aggressive lobe profiles is going to depend more on the pushrod stiffness/rocker mass moment/spring pressure/valve weight setup than anything to do with the lifter itself. If any lifter is lofted off the cam and then crashes back down, it's going to lead a short life.
Last edited by Brian Tooley Racing; 03-12-2013 at 09:35 AM.
03-12-2013, 09:48 AM
#51
How well these lifters hold up to aggressive lobe profiles is going to depend more on the pushrod stiffness/rocker mass moment/spring pressure/valve weight setup than anything to do with the lifter itself. If any lifter is lofted off the cam and then crashes back down, it's going to lead a short life.
well my valvetrain should be fairly robust.
My intake valves are 94g while my exhaust valves are 110g(?)
Cam lobes are HUC
springs are TSP's .675 duals
.120 wall pushrods
stock rockers with trunion upgrade
i think your lifters would be a good fit for my build. I plan on turning no more than 7k
and with the prelaod since you recommend .025-.075 im thinking .050 right in the middle would be a safe prelaod.
would you agree with that Brian?? ^^
03-12-2013, 10:31 AM
#53
well my valvetrain should be fairly robust.
My intake valves are 94g while my exhaust valves are 110g(?)
Cam lobes are HUC
springs are TSP's .675 duals
.120 wall pushrods
stock rockers with trunion upgrade
i think your lifters would be a good fit for my build. I plan on turning no more than 7k
and with the prelaod since you recommend .025-.075 im thinking .050 right in the middle would be a safe prelaod.
would you agree with that Brian?? ^^
My intake valves are 94g while my exhaust valves are 110g(?)
Cam lobes are HUC
springs are TSP's .675 duals
.120 wall pushrods
stock rockers with trunion upgrade
i think your lifters would be a good fit for my build. I plan on turning no more than 7k
and with the prelaod since you recommend .025-.075 im thinking .050 right in the middle would be a safe prelaod.
would you agree with that Brian?? ^^
03-12-2013, 11:36 AM
#55
that preload / bleed down comment got me thinking. suppose you could supply the engine with oil at a constant pressure, regardless of engine speed. your net lift loss at low speed as well as your valve float problems at high speed would be greatly reduced, wouldn't they?
03-12-2013, 11:50 AM
#56
that preload / bleed down comment got me thinking. suppose you could supply the engine with oil at a constant pressure, regardless of engine speed. your net lift loss at low speed as well as your valve float problems at high speed would be greatly reduced, wouldn't they?
03-12-2013, 11:58 AM
#58
Hmm, now I'm wondering if I shouldn't do the LS3 valves in my TEA Stage 2 LS6 heads. I am running an EPS cam with LSG/LXL lobes, 11/32nd Manton Pushrods, stock rockers w/ trunion upgrade, and the heavy Ferrea stainless valves. Shaving the weight of the intake valve down from 107g to 83g might be a good way to help lifters stay alive.
03-12-2013, 12:01 PM
#59
Hmm, now I'm wondering if I shouldn't do the LS3 valves in my TEA Stage 2 LS6 heads. I am running an EPS cam with LSG/LXL lobes, 11/32nd Manton Pushrods, stock rockers w/ trunion upgrade, and the heavy Ferrea stainless valves. Shaving the weight of the intake valve down from 107g to 83g might be a good way to help lifters stay alive.
03-12-2013, 12:05 PM
#60
electric pump or design a lifter with a progressive leak rate to maintain lifter cup position through the range of engine speeds. pump would be much easier to do I'd think, and it would also allow you to pre/post flow oil through the engine prior to start up and after shut-down.
just theoretical though, I think the costs associated with doing this would be even more offensive than the prices of some of the link bar lifters.
just theoretical though, I think the costs associated with doing this would be even more offensive than the prices of some of the link bar lifters.
Last edited by ckpitt55; 03-12-2013 at 12:18 PM.