88305tpiT/A

iTrader: (2)

I need to know which methodology to use to get my new pushrods

https://www.thirdgen.org/forums/te...lve-train.html (Pushrod Length - valve train geometry problem)

Reply to linked post

Thanks!

1989GTATransAm

iTrader: (3)

The best one is the one that has the least amount of sweep and is centered on the valve. However you are not likely to get that so a compromise is in order.

There is one camp that says to get the least amount of sweep you can and centered on the valve. Others say get the least amount of sweep as long as it is still on the valve. Most say the method on Comp Cams web site is not a good one.

I did a combination of the first two. The least amount of sweep on my combination was 3/4 across the valve towards the exhaust. It was around .031" and the pushrod would have been 7.50" long. This is the Miller Mid Lift Principal.

I backed it off some to get the sweep closer to the center and wound up with a pushrod 7.365" long. The sweep wound up at .042". The center of the sweep still favored the exhaust side.

By the way I went with 3/8" pushrods for the least amount of flex.

88305tpiT/A

iTrader: (2)

Ok -- its good to see that this can be somewhat of a comprimise.

Problem is I cant really use a pushrod long enough to get the least amount of sweep or I dont have enough threads engaged on the stud - I would have to get longer studs or washers.

It would also put the contact patch way to close to the edge of the valve tip for me.

I guess I will just make a guess and go with it...

Thanks for the help.

1989GTATransAm

iTrader: (3)

I forgot to say I had to get longer studs. They are not that expensive in the total scheme of things.

88305tpiT/A

iTrader: (2)

Ok.

The ones I have are 1 7/8 effective length already.

where did you get ones longer than that?

1989GTATransAm

iTrader: (3)

Manley and ARP make good quality rocker studs. Can't remember which ones I bought. I was going back and forth on the length I needed.