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Roller Rockers?

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Old 04-17-2010, 02:46 PM
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Originally Posted by chrs1313
i really believe anything over 5/16" pushrods is overkill for our engines...I have swapped between both 5/16 .080 to 11/32 .120 ~50% heavier, the graph was identical to what it was before, no added stability or power to be gained...
Pushrod selection with our LS engines are fairly limited, just get the stiffest ones you can fit. Weight isnt a real factor.

Ive tested a 525fwhp, very small solid roller, ETP 225 heads, 5.7L and made a 15hp gain by switching from 5/16" .080 to 3/8" .080. But ET heads have longer heavier valvles that makes valvetrain control a little harder. On the same engine I also swapped from stock rockers to shaft mounts and lost a few HP, most likely because they were heavier and had a worse MOI.

What we really need is someone with a Spintron to do a pushrod test. If the engine is up and running already, doing the entire test would take a few minutes of added time.
Old 04-17-2010, 02:52 PM
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Originally Posted by SweetS10V8
Pushrod selection with our LS engines are fairly limited, just get the stiffest ones you can fit. Weight isnt a real factor.

Ive tested a 525fwhp, very small solid roller, ETP 225 heads, 5.7L and made a 15hp gain by switching from 5/16" .080 to 3/8" .080. But ET heads have longer heavier valvles that makes valvetrain control a little harder. On the same engine I also swapped from stock rockers to shaft mounts and lost a few HP, most likely because they were heavier and had a worse MOI.

What we really need is someone with a Spintron to do a pushrod test. If the engine is up and running already, doing the entire test would take a few minutes of added time.
Yeah am running the comp hardened 3/8 .080 push rod, I am also running new stock lifters (LS1/LS6) the LS6 valves, stock rockers and Comp 921s. I have a pretty aggressive cam I would say with a .614 lift and pushing a 100 shot through her. I like having a pretty light valve train it has great control especially at higher RPMs I am shifting at 6800 and limiter is set to 7K.
Tomorrow we do the Dyno tune and I'll be posting numbers with the dyno sheet.
Old 04-17-2010, 02:56 PM
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Ive got Comp LSR cam(LSL Lobes), Comp 5/16" .105 wall pushrods, stock rockers(just upgraded trunions), lightweight LS3 valves, 918s all at .060" from coilbind, .607/.621 lift, and I dont have any valvetrain issues.
Old 04-20-2010, 09:55 AM
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So would upping the ratio in a bolt on car make hp? Going to a 1.8 or 1.85 for example.
Old 04-20-2010, 10:11 AM
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Originally Posted by ColossalCamaro
So would upping the ratio in a bolt on car make hp? Going to a 1.8 or 1.85 for example.
Most all lobes on LS cams are too agressive for higher ratio rockers. Stock cams and the ASA and hot cam stuff are the exception.... You will make a lot more HP per dollar by just doing a cam swap and sticking with the 1.7 ratio...
Old 04-20-2010, 12:23 PM
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Originally Posted by SOMbitch
Most all lobes on LS cams are too agressive for higher ratio rockers. Stock cams and the ASA and hot cam stuff are the exception.... You will make a lot more HP per dollar by just doing a cam swap and sticking with the 1.7 ratio...
Old 04-20-2010, 12:33 PM
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What would a car with a stock cam make on 1.85's?
Old 04-20-2010, 12:44 PM
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Originally Posted by ColossalCamaro
What would a car with a stock cam make on 1.85's?
Are numbers more important than having your valve train take a crap because the LS1/LS6 LS2 and LS3 valve trains are not made to run with rockers with such ratios. Save your money and do it right. Get the cam with the specs you want but hey do what you want advise is free not taking advise can get costly after a while.
Old 04-20-2010, 12:51 PM
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Whoa there, they are just questions. Who said it would ever go on my car? How do you know I'm not putting an argument to rest with one of my friends? In any event thank you for the advice. It will, indeed, be heeded. Though I'm still curious of gains. If the valvetrain were upgraded to compensate for the 1.85's.
Old 04-20-2010, 12:54 PM
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Originally Posted by 98purplet/a

lmfao
Old 04-20-2010, 01:03 PM
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if you have a cam spec'd out for 1.85 rockers, yes you will make more power with the 1.85's on that cam than you would with 1.7's. just switching to 1.85 rockers on a stock motor, you will be lucky to see 5hp.



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