Advice on Roller Rockers - Strange Setup
11-04-2003, 12:51 PM
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Advice on Roller Rockers - Strange Setup I'm looking at the new LS1 Comp 1.75 Roller Rockers for my car. I already have a cam, and milled heads, and want to make sure that 1.75 won't give me valve/piston issues.
The cam I have is a LPE GT2+3 207/220 .573/.580 117.5. My heads are milled a little, .030. Pistons are stock.
Can I use these 1.75's without issue or am I asking for trouble? Any help would be welcome!
The cam I have is a LPE GT2+3 207/220 .573/.580 117.5. My heads are milled a little, .030. Pistons are stock.
Can I use these 1.75's without issue or am I asking for trouble? Any help would be welcome!
11-04-2003, 07:33 PM
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That works out to .590/.597 @ 1.75. With .030 milled heads I wouldnt run it until I had it checked (better safe than sorry). You had better make sure your springs are up to the task of .600 lift also.
11-05-2003, 07:47 AM
#4
Duration affects P to V clearance much more then total lift.
For example lets say at TDC you have .100" cam lift, which equates to .170" at the valve, with the 1.75 rocker you are now at .175", so you can see that P to V at TDC is only decreased by about .005"-.010".
With that low of duration you should be good to go. Its only when you get up to 228-230 duration on intake side with your heads milled .030" that you start having problems.
If it were me I would not run that much lift, FWIW, we just had a cam only Z06 on our dyno make 417 RWHP with less then .580 lift.
For example lets say at TDC you have .100" cam lift, which equates to .170" at the valve, with the 1.75 rocker you are now at .175", so you can see that P to V at TDC is only decreased by about .005"-.010".
With that low of duration you should be good to go. Its only when you get up to 228-230 duration on intake side with your heads milled .030" that you start having problems.
If it were me I would not run that much lift, FWIW, we just had a cam only Z06 on our dyno make 417 RWHP with less then .580 lift.
11-05-2003, 11:44 AM
#5
I agree with Brian you should have no trouble. Since you already have the cam put the rockers and go. But....they are not a simple bolt on deal. You will have valve cover clearance issues. I have them and am using 1" spacers to get them to clear. Drop me an e-mail if you want to discuss them.
Chris
Chris