can Hyd lifters handle sustained high rpm
TECH Senior Member
Joined: Jun 2016
Posts: 22,289
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From: Central Cal.
My first LS build was in 2004 with a '99 LS1 shortblock and AFR205 heads/LS6 intake, LS7 lifters, 233/239 .600" 112LSA cam, T56, street/road race car and I rev'd it up to 7100rpm a zillion times... plus 20-30 minute road race sessions and hundreds of 1/4 mile pulls on the street with a best of 11.30@128mph at the strip in road race form (Mazda RX-7). While not perfectly suited ..... those lifters never gave me any issues. Car made 440rwhp/385rwtq on 91 octane. Commuted/raced it for years.... beat the **** out of it daily.
Now that technology is better I put link bar lifters in the high dollar builds.... and GM Performance (not the Delphi) LS7 lifters in the more budget motors.
Now that technology is better I put link bar lifters in the high dollar builds.... and GM Performance (not the Delphi) LS7 lifters in the more budget motors.
With that much spring pressure you're going to struggle with anything but a short travel lifter. That is a lot of spring for a hyrdraulic cam in general.
With the right lobes and springs you could use stock LS7 lifters. A common misconception...so long as the spring is happy, higher lift lobes are actually smoother than low lift as it uses more of the cam core to grind the profile.
"If the spring is happy at that lift (normal IH and not too close to bind) the design will actually be more stable at higherlift (less loft and crash over the nose at RPM)."
With the right lobes and springs you could use stock LS7 lifters. A common misconception...so long as the spring is happy, higher lift lobes are actually smoother than low lift as it uses more of the cam core to grind the profile.
"If the spring is happy at that lift (normal IH and not too close to bind) the design will actually be more stable at higherlift (less loft and crash over the nose at RPM)."
Thanks for that info, took me a minute to picture it in my head but now I got it. The way I'm picturing it is you'll have a little bit more of a squared off effect with long duration low lift and more of a smooth arc with higher lift at the same duration.
