variable duration lifters
TECH Fanatic
Joined: Mar 2003
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From: La Porte, TX
Originally Posted by topfuelman
I've been running them since 2004. One of their earlier customers for an LS application. I believe they are based on stock gm hydraulic lifters that are disassembled and modified (as I understand it from discussing them with the company owner)
My combination is an Eagle 383 stroker with stock rockers, hardened pushrods, custom roadracing grind cam by EDC that makes power through 7K+., Wiseco forged offset wristpin pistons with reliefs, C.R. of ~12:1, PP Stg 2 hand ported 5.3 heads (2.02's) milled 25K, Cometic gaskets, longtubes, dual 3" with Dr. Gas x-pipe, Random Tech cats and Borla XR's, LS6 intake 42 lb injectors, Ported tb, stock maf, fluidamper pulley, aluminum flywheel
-fully balanced and blueprinted rotating assembly
Dynoing this week, will post curves for your opinions.
The car is not fully tuned yet, but will idle dead steady at 850 RPM with these lifters. Full throttle mixture is OK but the mixture is somewhat rich in most other places. Seems to pull hard to 7K+
Been driving with these lifters for sometime and am really happy with how well the engine performs at low rpm. Haven't used other lifters, so I can't make any direct comparisons, so I'll let the graph curves speak for themselves.
T
My combination is an Eagle 383 stroker with stock rockers, hardened pushrods, custom roadracing grind cam by EDC that makes power through 7K+., Wiseco forged offset wristpin pistons with reliefs, C.R. of ~12:1, PP Stg 2 hand ported 5.3 heads (2.02's) milled 25K, Cometic gaskets, longtubes, dual 3" with Dr. Gas x-pipe, Random Tech cats and Borla XR's, LS6 intake 42 lb injectors, Ported tb, stock maf, fluidamper pulley, aluminum flywheel
-fully balanced and blueprinted rotating assembly
Dynoing this week, will post curves for your opinions.
The car is not fully tuned yet, but will idle dead steady at 850 RPM with these lifters. Full throttle mixture is OK but the mixture is somewhat rich in most other places. Seems to pull hard to 7K+
Been driving with these lifters for sometime and am really happy with how well the engine performs at low rpm. Haven't used other lifters, so I can't make any direct comparisons, so I'll let the graph curves speak for themselves.
T
There's an article in last months HotRod about those lifters. They did back to back dyno testing. I was just reading it last night. They picked up low end torque, vacuum and idle quality but lost top end HP compared to the stock lifters.
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Joined: Mar 2003
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From: La Porte, TX
Originally Posted by 1fastWS6
There's an article in last months HotRod about those lifters. They did back to back dyno testing. I was just reading it last night. They picked up low end torque, vacuum and idle quality but lost top end HP compared to the stock lifters.
It's my understanding that they acutally increase your rev range. I wonder if they truly lost power, or if they just didn't rev high enought to accomadate the change in the lifters. The review that I read stated that they caused power to peak 500 rpm later. I'll try to find the article.
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Joined: Mar 2003
Posts: 1,839
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From: La Porte, TX
Originally Posted by WS6snake-eater
It's my understanding that they acutally increase your rev range. I wonder if they truly lost power, or if they just didn't rev high enought to accomadate the change in the lifters. The review that I read stated that they caused power to peak 500 rpm later. I'll try to find the article.
Image attached.
Originally Posted by gollum
There are lots people in this forum that are using too much cam. These lifters will help improve their drivability.
Keith
Dyno Plot
Originally Posted by WS6snake-eater
Cool...Hurry up and get that **** posted, so we can take a look at it. BTW what are the cam specs? Good luck on your dyno.
My cam is a custom grind Comp with (don't have the card handy but from memory) a 242/250 with .610/.613 total lift with a smoother ramp than a toxic lobe spec'd for roadracing style power under the curve not peak hp.
Stock rockers, 2.02 intakes, PP Stage2 5.3 heads, LS6 intake, Long tubes
382 stroker, 12:1 compression
T
TECH Fanatic
Joined: Mar 2003
Posts: 1,839
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From: La Porte, TX
Originally Posted by topfuelman
Well, she's not fully tuned yet, needs timing in the midrange, and some low end work. Not sure about 25% gain on the low end claim. Judge for yourself.
My cam is a custom grind Comp with (don't have the card handy but from memory) a 242/250 with .610/.613 total lift with a smoother ramp than a toxic lobe spec'd for roadracing style power under the curve not peak hp.
Stock rockers, 2.02 intakes, PP Stage2 5.3 heads, LS6 intake, Long tubes
382 stroker, 12:1 compression
T
My cam is a custom grind Comp with (don't have the card handy but from memory) a 242/250 with .610/.613 total lift with a smoother ramp than a toxic lobe spec'd for roadracing style power under the curve not peak hp.
Stock rockers, 2.02 intakes, PP Stage2 5.3 heads, LS6 intake, Long tubes
382 stroker, 12:1 compression
T
How about that idle stability and vacum increase...Was it noticable...Also did you go with the adjustables or the non-adjustables?
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Verdad Gallardo Bleed Down lifters
Originally Posted by WS6snake-eater
How about that idle stability and vacum increase...Was it noticable...Also did you go with the adjustables or the non-adjustables?
http://www.v3auto.com/media/v3gtr_dyno.jpg
Thanks,
T
