TTAWD

I've run H/R cam setups in my turboed SBC with no luck turning rpm's over
5800-6000.
My Q is do you LSX guys have the same rpm limits with H/R cams?

bayer-z28

iTrader: (14)

I'll take a stab at it... Valve springs?

Need specs on sed small block... Stroked? Cam specs? I can rev to 6500, but there's no power there. The stock cam has nothing and my stock valve springs are prolly floating at those speeds (6500).

hammertime

iTrader: (1)

Plenty of HR LS1's out there making power to 6500 and carrying well beyond. What heads and cam are you running on your SBC? Biggest cam in the world won't spin any higher than the airflow will support...

speed_demon24

iTrader: (6)

Stock LS7's rev to 7000...

MeentSS02

iTrader: (11)

People with more aggressive heads/cam setups are turning to 6800 pretty regularly - 7000+ isn't too uncommon either. As long as the valve springs are up to the task, it isn't too difficult.

TTAWD

I’ve been lead to believe that H/R lifters will not
take a lot of spring presser.
Big intake valves are heavy and it takes spring
presser to control them.
Most of my H/R cams have been in the 240@50
range and smaller, with the thinking that there’s
no need for a big cam if you can’t spin the motor
to it’s power band.
Are the LSX lifters different in some way?
Or is my line of thinking all wrong.

hammertime

iTrader: (1)

Small Block Chevy's need more cam to make the same power because of the heads don't flow as well. Box stock LS1 heads flow in the 230's, LS6 in the 250's, and aftermarket heads really start at 300 CFM. Don't forget the 8 degree difference in valve angle between the two.
AFR 205 LS1 = 298 CFM
AFR 195 SBC Street = 280 CFM
AFR 210 SBC Race Ready = 301 CFM
Dart 215 SBC = 268 CFM
Dart 205 LS1 = 296 CFM
TFS R-Series 215 SBC = 287 CFM
TFS 215 LS1 = 320 CFM

While were talking AFR, check out their rev kit
http://www.airflowresearch.com/hydra_rev.php

TTAWD

I hade an AFR rev kit with no luck.
My new heads flow in the 360 rang.

RAACCR

I found that the Gen 1 hydraulic rollers are sensitive to spring pressure. Too little spring pressure can't control the valves, but the oem HR lifters can't handle too much either, especially once they get some miles on them. I ran 135# on the seat and 350# open on my 266" turbo motor (V-6, but same valvetrain as a V-8), and that seemed to be a happy medium. Shift points were 6800-7000.

99blancoSS

iTrader: (115)

gm hi perf lifters and good springs.The lifteres were tested to 8500 rpms I think.

Ryan02SS

iTrader: (3)

I've built both LS1's and Gen 1 SBC's. The LS1's are a much more rev happy motor all day long. This is due to much lighter valvetrain componets. Valves, locks, titanium retainers, rockers and springs. Gen 1 SBC valvetrain componets are normally around 50 grams heavier than the LS1. This is a huge weight difference at the valve. Gen 1 HR's normally float in the 5800-6200 area. You can run a rev kit which you allready have, increase the spring pressure or upgrade to limited pump up lifters, or go solid roller. Aftermarket cammed LS1's normal float range with many variables is about a 1K rpms higher than the Gen 1, 6700-6900rpms. My little 224 cam pulls hard to 6500rpms with no signs of float.

In my 355 boat engine I am using Morel Hyd roller lifters, Isky springs, 130seat, 320open, no rev kit and no float in the 5700-5800 rpm range. The Morel lifters are the best IMO and don't seem to have the float problem.

To address the float problem, AFR has recently introduced LS1 valve technology to their Eliminator Gen 1 23* SBC heads. Meaning you can now have a high rev 6200-6800rpms SBC without a rev kit or other assoicated hassles. Truely a revolutionary step in the Gen 1 SBC game.

hammertime

iTrader: (1)

Thanks for filling in the blanks. It does sound like you have your bases covered.