I bought the car with heads/cam already installed. It has the sewing machine sound bigtime, so I pulled the valve covers to check everything out. It has PP Gold springs, stock rockers, and comp hardened 7.350 pushrods. The cam is 224/224 566/566, the heads are milled. No idea how much, cannot verify gasket thickness.

I checked the rockers, all are tightened past 22 ft lbs. I loosened a couple, checked pushrods for straightness, and then reinstalled. It only took 1/4 turn exactly to get to 22 ft lbs. From what I gather, with correct pushrods, I should be turning it more like a full turn. Is this correct? Could I need even shorter pushrods?

AW

 

No, get 7.400". They need to be approx. .050" longer.

 

You should buy a pushrod length checker and measure.

 

What about this makes you say they are too short? Not trying to be argumentative, just trying to learn.

 

Youll need to measure.

 

How much pre load do I add to my pushrod length checker final length for stock lifters?

 

You can add up to .100, but common practice is around .080

 

Picking up the tool today at lunch, will measure tonight. Just want to confirm the steps..

Make sure lifters are on base circle..
insert pushrod
set rocker on pedestal, torque to 22 ft lbs
adjust checker to 0 lash
turn the engine a couple times to verify lash is still at 0
remove pushrod, record length, add .080 to it.

Sound correct?

 

DOn't turn the engine over with a checker pushrod installed or you will ruin it. Just make sure you are on the base circle and get it to 0 lash and record your length. Then add your preload.

 

Got the tool today....measured 7.325 overall length. So I add 0.080 and I get 7.405. So 7.400 rods should take care of it.

Did I add things up correctly for stock lifters?

AW

 

Sounds good to me... You could go for 7.425 pushrods and do a little added preload in th ehopes of quieting things down some, but the 7.400s shoudl do you right. Im happily running my preload 11 over stock and its nice and quiet compared to being .030 under when i was cam only.

 

I thought I read the factory pre load range was 0.050 - 0.100. Id rather go for the 7.400 if that correct, rather than run at the high side of the tolerance

 

7.40 sound good as per your measurements.

 

If you measured OAL, remember the pushrod quoted measurement from the manufacturer is "Gauge Length". There is a difference.

 

What's the difference? The car currently has comp 7.350s in it and they measure 7.350 end to end.

 

I have a question. If you turn the motor over with the PR checker installed along with "normal" valve springs, can you be assured that you got an accurate reading? My concern being that the lifter may no longer be at "full height" after having turned the motor over.

 

Also, my understanding was that the motor should not be turned over with the PR checker installed with regular valve springs. Is that correct?

 

Yeah, you'll jack them up if you do it. Remove it, turn the engine over, then reinstall to check. Don't turn it over with the checker in there...

 

So I swapped pushrods, made little to no difference in sound. Seems to idle a little smoother. Before someone says I need 7.425s, I measured 3 different pistons intake and exhaust side. All the measurements came back at 7.325. 7.425s would put me right at .100 preload which is, as I understand, the max for the stock lifters. I don't feel comfortable running at the max preload, leaves no room for safety.

Guess I just live with it?

 

So you are only running 0.025" preload? Too low for a stock lifter in my opinion, why not get the 7.4's? Also, just for information, I ran 0.120 preload on stock lifters without any problems. They seem to be pretty forgiving, but with only 0.025 they must be noisy.