1.6's or 1.7's????

[ninety15.0]

Hey guys im in the middle of a motor buildup and i've arrived at the question of rocker arm ratio. My combo is a fully balanced 306 with SRP high comp. forged pistons, steeda # 18 cam, cobra intake , and ported E7's with 3 angle valve job. I know the heads arent great but for a broke college kid thats the best i can do (for now!). the cam specs out at .480 lift with 1.6's and .512 with 1.7's. Which ratio would be the best for my combo...the car will mostly be street driven with occasional trips to the strip. thanks, Nick.

 

[N8Miller]

go 1.7s.

 

[stangbear427]

Yup... 1.7's.

 

[ninety15.0]

Im a little worried bout loosing too much low end torque just to gain a little high rpm HP. while the HP is great is dont want driveability to suffer much at all....i have 3.73's and full exhaust by the way...thanks again

 

[stangbear427]

With 3.73's, it won't be a problem.

 

[5spd GT]

You obviously want to worry about p-v clearance issues. It isn't soley on lift nor is the torque strickly made by the lift the cam puts out.

Good Luck!

 

[stangbear427]

Ahhh! Good point, P/V clearance should definately be checked. I think there's room for .512 though; I'm not having any trouble with my 1.72's... but I'm not sure about my cam specs anymore.

 

[willys1]

I just posted the same thing.I have ported e-7's(Thumpers) and a stock cam..Thumper told me too use 1.7's with the stock cam to get the extra lift,but if I start changing cams go with the 1.6's.Sorry to add the confusion.

 

[txstang84]

You obviously want to worry about p-v clearance issues. It isn't soley on lift nor is the torque strickly made by the lift the cam puts out.

Good Luck!

good call-you shouldn't have any problems since you're running SRP pistons, most of the manufacturers of their ilk make sure you can run a fairly big cam (up to about .550") without having to worry about P/V interference