ok so i did a search and just got more confused. i want to add a set of roller rockers to my lt1 when i get it assembled, but not sure which ones work best with what i have (bored 30 over, cc305, beehive 918 springs). i see there are many options such as 1.6s, 1.7s, or using combination of both (1 set for intake and other for exhaust). which would work out the best and should i use self adjusting or nonself adjusting? also how does it effect the pushrod length?

 

Would depend in part on the cam you are using, head flow capabilities, etc.

 

im using a cc305 with stock heads, but i may get them ported

 

I would go with 1.6 ratio full rollers, remember if you go with non-self aligning rockers you'll need hardened push rods and guide plates. Whereas with self aligning rockers you can just put em on, set them and go. most guys who tend to spin their motors a bit choose non slef aligning. I've read that 1.7 rockers give you a lot of vave train geometry challenges, I may be wrong, but I believe it throws it off some. Hope I could help.

 

just to be sure it would be a good idea to measure for your pushrod length if u are going with 1.6 rollers. i think u need bigger valve covers for the self aligning roller rockers.

 

He indicated in his first post that its an LT1. He's also posting on the LT1 Based Engine Tech forum, so I don't think he's asking about a 305ci engine from a 3rd Gen . He's saying that the cam he is going to use is the "cc305" = Comp Cams 305 camshaft.

 

ok. i was a bit confused and re read it. all fixed. sorry bout that.

 

you can use stock valve covers but you have to do some clearance work(mostly to the bolt hole supports). you also will more than likely need shorter pushrods, so BE SURE to measure. i'm running a cc306 with 1.6 non self aligning rockers and i had to go down to a 7.1" pushrod.

 

how can i measure for the correct pushrod lenght? i have never put in an aftermarket cam so this is new to me. I only want to do this one time so i want to get it right the first time. Am i right that the sa rockers are fine as long as i dont rev the engine to high? I dont plan on going over the rev limit on the dash gauge.

 

also how do i know which size stud i have?

 

for measuring the pushrod length, you can buy a push rod length checker which is basically an adjustable pushrod that you change the length of to get the best geometry. when the valve is closed you want the roller tip to sit just of center of the valve stem toward the sky, and when the valve is completely depressed you want the roller tip to sit just off center of the valve stem toward the ground.

If you are doing Non self aligning you probably want to go ahead and get new studs while you are at it and go with the 7/16. Stockers I believe are 3/8.

You can spin SA up pretty high fairly often, it's just a matter of taking the risk while doing it that something could mess up. it's not recommended that you consistently spin high rpms with SA.

 

u will need a pushrod length checker. something like this..
http://dagostinoracing.com/index.php...0&currency=USD
and a solid lifter.
this is something i got from lloyd at elliotts portworks for my lt1, hope u can make sence of it.


PR length is something that you need to check to get the EXACT length. Use an adjustable PR checker and start at 7.100" and adjust the length until you get the wear pattern most centered in the valve. Go .050" shorter and watch the wear pattern move. If it gets worse, go .050 longer. It could be anywhere from 7.00 to 7.250 depending on everything done but a 7.100" (Trik Flow 21407100) is what I suggest for people that do not know how (or do not wanna take the time) to do this.

The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):


1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker



2
Install your rocker arm and set it up with zero lash.



3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.




4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.



5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.




6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.

 

Thanks for that guide craby! Thanks to everyboby for your help. One more Question, How high can you rev on sa? i wont be doing much, but they are a couple of imports running around here that i plan on showing them what a real car is

 

Does it have to be a solid lifter to check the push rod length??

 

yes

your welcome jk.