Pushrod length question for Texas Speed LS3 229/236 113 LSA cam with stock L92 heads

[bluegoat06]

I ordered this cam today, and ordered it with 7.40 pushrods?
But reading around, some people say 7.400' should be used if the heads are milled, and 7.425 if the heads are not milled.
My heads would remain stock with no milling/porting,etc, and i also ordered the TSP DOD delete with the LS7 lifters, question is, and i know people would say is better to check the size when installing the items (I'll have a shop do this since i don't have the skills), would be better to have 7.400 or 7.425 to start off? I thought the LS7 lifter were shorter by 0.50 when compared to LS1 lifter or our lifters for example. I've emailed TSP to ask, but it's too late for a response now, what do you guys recommend ? or maybe i'm worrying about it too much ?

Thanks a lot.

[johnbell2]

http://www.compcams.com/Products/CC-...rods%27-0.aspx

[shane]

This is from Shane at Thunder Racing

I used this method and few times now and have had no issues. FYI i had 7.4's on my G8 and worked just fine using this method

The TDC method is NOT always accurate. Try the EO/IC method to check pushrod length. I have posted directions on this forum numerous times... Here it is again:

FWIW, EVERY cam install I have done using the LS7 lifter with a cam with greater than .600" lift (read smaller base circle) AND stock heads w/GM MLS gaskets has taken 7.425" pushrods for ~.050"-.060" preload. We measure lifter preload on each and every cam install we do. I have never had a lifter failure nor do we end up with the dreaded "sewing machine" noise.

Its very simple, If you change ANY of the following:
valve sizes, valve job, head milling, thinner/thicker head gaskets, decked block, cam with an altered base circle, etc... YOU MUST CHECK FOR PROPER PUSHROD LENGTH.

I have helped countless numbers of individuals with this process over the phone, via email, and PM's. I've posted the process on at least 3 occasions.

Here it is again in a nutshell:

1. Using the EO/IC method, get the lifter to the base circle of the cam.
2. Using a known length pushrod (7.400" is a good start with stock rockers) run the rocker arm bolt down to zero lash. This is easily done with your fingers "wiggling" the rocker, the point at which the "slack" is just gone is zero lash.
3. Set your torque wrench to 22 lb./ft. Tighten the rocker to full torque and count the number of turns it takes to get there. 1 full turn wtih a stock 8mm X 1.25 bolt is ~.047" preload as measured at the pushrod/rocker interface.
4. I normally shoot for 1 1/4 to 1 3/4 turns with stock type lifters like Comp 850's, LS1, LS7 etc.

For an example, if you use a 7.400" pushrod and come up with 3/4 of a turn, you will need at least .025" longer pushrod to get into range. If you end up with 2 1/4 turns, you will need one .025" shorter...

I might not know everything but I will tell you that this method has worked for me year after year cam swap after cam swap. We average 3 cam swaps a week here so you can do the math.

If you are not familiar with the EO/IC method for determining valve events in a 4 stroke engine, its very simple:
For a given cylinder as the Exhaust valve is Opening, the intake lifter will be on the base circle of the cam and lash/preload should be checked for that intake valve.
For a given cylinder as the Intake valve is Closing, the exhaust lifter will be on the base circle of the cam and lash/preload should be checked for that exhaust valve.

THIS METHOD ALWAYS WORKS!!!

Check it using the above method and see where you are.

Thanks,
Shane

[todds87ss]

similiar cam here...7.425