what do short pushrods sound like

1994Vib.RedGT

Member
Aug 19, 2004
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Denver, CO
just wondering because Ive had this ticking going on for almost a year now, I dont drive the car too much, but everytime I do it annoys me, I plan on checking the length this month, but just curious as to what that would sound like.
 
:lol: Good question



I dont see short pushrods sounding any different. They WILL be contacting the valve on the wrong angle which will cause premature wear and valve failure down the road.

Now if you didnt set the rockers up correctly and theres up + down play on the rockers when the valve isnt being push open then you will have some significant noise..

ANd oh yea i are you stud mount or ped mount?
 
On ped. mount heads I dont think the PR has too much to do with the angle the rocker hits the valve head. The shim/rocker setup is what will setup that angle not the PR.

The PR on ped. heads will either float the valve or you will loose lift/cam timing hosed up if too long or short due to too much lift/no valve fully closed from too long and if too short would make some good noise as there would be up/down movement...I would think the up/down movement would also beat the heck out of the lifters and shock the springs.

I have always heard the valvtrain should sound like a sewing(sp?) mechine with the hood up listening to the motor. So there is going to be some noise.

Also it is not un-common to hear rockers rattle and/or hitting the valve covers depending on what brand. Crane 1.7 (stock cobra rockers) specificly are common to have fitment issues with the valve covers and springs due to the large overhang/face area at the roller tip.
 
I have had the ticking ever since I swapped to aluminum heads.
I first tried a new set of lifters...no help:bang:

I then went with a set of 6.350" PRs and a shim kit.
My reasoning was since the stockers are 6.250" I could get the most adjustability.
The shims are .03" and .06" or .09"(both together).
With the shims you can adjust the length 6.260", 6.290', 6.320" or 6.350"
Turns out 6.290" was too much and 6.260" not quite enough.:mad:
Turns out I needed the 6.272" that FRPP sells but I lived with the 6.260" for awhile.:(

This spring I bought the Crane Cobra 1.7:1 roller rockers and the ticking went away. :D

Go figure:shrug:
 
you really shouldnt use the shims to make a PR work, the shims should be used to get the correct contact and travel patt. on the valve stem head of the rocker ONLY. Just using a shim to get a PR to fit will more than likely set the rocker too far in one direction and putting extra load on the springs/valve...and thats not good.

To really setup the valvetrain you need to use an adj. PR to find out what length you need with the rocker set to its correct contact/travel on the valve. Then measure the adj. PR and get the PR you need.
 
yea, well Im set up using stock rocker arms because I ran out of money on a set of ported e7s and a steeda 19 cam, and there was no tick before I did all of this stuff. I was just thinking that maybe the combination of those made the pushrods not seat all the way in the rockers as someone else on here who had a steeda 19 claimed it did to there's one time. If Im reading this right though with pedestal mount on stock arms theres no way a short pushrod situation could cause a tick? I know lifters can tick too, but I dont think it is the lifters because they are brand new, and dont they usually make more of a slapping sound or something?
 
Have the heads and/or block deck been milled?

The reason I needed shorter PR is that my heads are done 60-65 and the block was also decked so it was shorter as well. All in all I was about a full .1 too long with the stock PR on my production block and gt40 heads. I too run stock rockers for now.
 
rockers hitting the vavle covers, lifters not working right, loose rocker bolts, some kind of weird valve spring/valve hight and rocker setup maybe.

It might be worth a wurl to rotate the motor over and on each comp. stroke make sure your rockers are all trqd. down correctly. Just one or two off/loose could make a racket.

I bent a stock PR one time and it made all kinds of racket, I thought I droped a valve or something. Found out a damn rocker bolt broke an built up preas. and bent the other PR.