SSmikeSS

iTrader: (2)

I posted this on Performance.net but I'd like you all to please look at this for me.
It's the same heads and cam I used on my 6.0. (in my sig) I'm installing on my new 408 from Texas Speed.
I bought the pushrod length checker tool. I checked 4 different spots and made sure I was on the base of the cam. I came up with 8 turns with the length checker all four times.
8x .050= .4 +6.8= 7.2 + preload. That's a pretty short pushrod. Any idea what I'm doing wrong??? Or do I really need that short or a PR.
I've been running 7.4" for years. I never used the length checker before and this is what I'm coming up with.

Today I tried the 7.4" and saw that the valve was opening more than when I used the checker tool opened to 7.275" .
What do you think?

Thanks,
Mike

LS1MCSS

iTrader: (18)

You have the rocker stands on there?

badazz81z28

iTrader: (6)

That seems way short. Are you using solid lifters to check?

hiltsy855

iTrader: (35)

Sounds about right if you are using Morel / Lunati lifters....

SSmikeSS

iTrader: (2)

LOL I did forget the first time around. I only got 4 turns on the length checker. But I did install the stands to come up with these measurements.

I'm using stock rockers and ls7 lifters.

I think I understand your comment about using solid lifters to check though.

If I'm measuring on the base of the cam there should be no question Right??

PARANOIA lol I really want to get this right
Thanks for your help.

Ferocity02

iTrader: (60)

A solid lifter won't help. If the lifter was compressing it would show that you needed a longer pushrod than normal. It's pretty hard to compress a lifter by hand unless it has had spring pressure on it forcing out all of the oil.

Were the heads milled? Block decked? With 0.075" preload yours are only about 0.05" shorter than mine.

Also measure the lenght of the checker to verify. Or just turn it out to 7.4" and see if it matches your other pushrods.

vettenuts

iTrader: (4)

What brand adjustable pushrod do you have? There are different ones that have different starting lengths.

Did you check the wipe on the rockers prior to taking the measurement? If the valve tips are up (or the valves sunk like some of the TSP heads), then the pushrod will appear to be shorter because the rocker geometry is off. You need to verify the rocker geometry prior to taking any measurements.

SSmikeSS

iTrader: (2)

The heads were milled when I got them to achieve the stock compression (10.1:1) I figured that would just make them the same height as the the stock 317's.
I will compare the checker with the 7.4". That's a good Idea.
If everything measures the same when I get to work on it this weekend, I am probably buying 7.275ish PR's. That's the middle of the suggested preload.

It's the comp tool. It is 6.8".
What do you mean by "wipe" on the rockers?

Thanks for your help.

gMAG

iTrader: (1)

When the rocker rolls across the valve tip, the rocker forms a 'wipe' pattern.
Ideally, the wipe pattern should be centered across the valvetip.

vettenuts

iTrader: (4)

This should be checked prior to measuring for pushrods. If the wipe is off, you need to correct the geometry. I am thinking the shorter pushrods might be the result of the valve stem height, and if they are higher than stock the rockers will wipe towards the intake side of the valve stem and need to be raised.

You can't check the wipe with hydraulic lifters and rolling the motor over, you need a set of check springs (they are cheap).