Steve Burger

iTrader: (33)

My understanding is that the length of the pushrod has a lot to do with the base circle of the cam. I am not sure if you can make the generic assumtion that a 7.4 is too long and that a 7.35 is too short.

Am I correct?

Nasty N8

iTrader: (33)

You are correct the pushrod length changes the placement of the roller tip on the valve. Too long too far forward, too short too far back, correct dead center. You need to shim the rockers to get the correct preload.

Nate

JF WS6

So have you had to use shims most of the time with these then with 7.4 pushrods?

Nasty N8

iTrader: (33)

No actually most I have installed did not use any shims.

Nate

PK 01somWS6

Can someone just briefly explain what you would need and how you would go about shimming for the stock valve train style set-up.. Is it difficult or is it somthing that'll just take like 10mins and a few bucks to get done?

Country Boy

iTrader: (24)

Guys, trust Spectacle Solutions on this. He REALLY know about Comp stuff. The lifters arent just "pressed" together. There is a clip that holds them together

BOO HOO BRIAN

iTrader: (-10)

Country boy, a true comp R can be identified by the PRESSED in gold cup and the black oxide coating. The regular comp and factory lifters are held in by a c clip . Pictures can be found here : http://compcams.com/Technical/Catalo...ML/282-283.asp

I can take pics of them here at the shop.

Country Boy

iTrader: (24)

Can you snap a pic of the cup area. Mine are at my dads garage and I cant look at them at the moment

1QUIKWS6

iTrader: (61)

Brian-

You are exactly correct - I'm sitting here looking at my Comp 'R's right now. There is a black oxide cup pressed into the end of the lifter body that engages with a slot on the internal diameter of the lifter body. This acts as the retainer for the inner plunger.

This design is similar to a c-clip and must be able to sustain high RPM's since this is what these lifters are made for.

Nate has apparently done installs with this combo and states that in most cases not even shims are required - I would tend to trust his personal experience.

-Jay-

1QUIKWS6

iTrader: (61)

I'd take a pic for ya but my sister borrowed my camera

Unaffliated Racing

iTrader: (15)

well..thats fine and dandy that you would trust nate's expierence..but if you do have .030"-.050" preload on the Comp r's...."IF" they come apart in the motor..please dont ask Comp to buy you a new motor..because of the incorrect preload, just a word to the wise

DanZ28

iTrader: (5)

Wouldn't Cam base circle, milled heads, etc. play a role in PR length? Would you only shim, or would you do a combination. I use 7.350's now and have .010" preload (not comp R's) with .035" off the heads. Should I be using 7.4 and shim the YT rockers?

Dan

1QUIKWS6

iTrader: (61)

Actually Mike @ Rapid will be installing mine along with quite a few other items I'm quite sure he'll do whatever it takes to get the recommended preload of .002-.004 - or shouldn't I trust the guy with the fastest NA TA either?

JF WS6

Yes, all those things do affect the pushrod length. Usually what happens is that you go with milled heads which if that's all you did would require shorter pushrods, but then if you go with a custom cam which frequently has a smaller base circle that puts you back to close to stock pushrod length which is generally around 7.4".

I'm still figuring out some of this stuff myself, but from what I'm getting out of this is that you'd probably want to go with whatever pushrod length you need running a stock valvetrain, then just shim the rockers or use adjustable rockers to get the desired preload on the Comp R's. You have a lot milled off your heads, so the 7.35's are the correct pushrod length most likely. I would just shim your Yella Terra's to get the desired lighter preload.

verbs

Adjustable rockers are too pricey IMO, so I'm shimming mine as we speak w/ my Comp R Lifters. Hoping to get the right preload.

Country Boy

iTrader: (24)

You can trust anyone you want......

DanZ28

iTrader: (5)

Thanks!

Seem's like shimming to me could move the rocker off center from the valve (down on the valve), or am I looking at it wrong. Adjustable rockers would be the same as if you changed the PR length correct? I just don't understand why shimming would be better than using a different PR length like mentioned earlier..

Dan

JF WS6

That's pretty much what I was asking earlier, and from what I gather the only reason why you'd want to shim is just because you can do it in smaller increments to get it just right. Changing the pushrod length *may* be too drastic as Spectacle Solutions said "most rods only come in .050" increments."

If you could somehow get the exact length of pushrod you needed to get the right preload that would be ok I think. Shimming is cheaper than buying a whole new set of pushrods anyway.

eallanboggs

iTrader: (1)

The Jesel shaft mounts aren't that much more expensive than the CC ProMags.

Country Boy

iTrader: (24)

The Jesel SS series shaft mounts are NOT adjustable. Its says they are on Jesels site and SDPC used to seel them as adjustable, but they arent. I bought a set and had to return them. The only rockers adjustable from Jesel are like $1200