Okay. keep in mind I'm not an expert in any way building an engine. Anyway. lol. I started to assemble the top end of my 350 yesterday. Got the pushrods in it and started to tighten everything up. I used a factory length Comp Cams high energy pushrod. The problem i have is that there is way too much play on the rocker arms. its as if the pushrods are too short. Would not tourquing the heads all the way down maybe have anything to do with this? I have only tightened them as tight as I can without a torque wrench. But it just seems like there is way too much movement. 2 out of 8 valves are pretty tight. But the rest of the rockers are extremely loose. I did use a slightly larger than stock cam, but with a factory length pushrod wouldnt they be too tight and need a shorter pushrod? I know they make a length checker, but this is practically a stock mild rebuild. Need help!!!
Pushrod help!!!
- Thread starter cjbritt2013
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First off you should never attempt to tighten heads down without a torque wrench, there is a specific sequence and torque and it is done in stages not all at once.
And there would also be no reason to assemble any of the valvetrain until the heads are torqued properly.
Any time you make changes that can affect the valvetrain it is a good idea to check the pushrod length, things like block decking, head milling, different cams, different kinds of lifters with slightly different pushrod heights etc. all have a possibility of requiring a different length pushrod.
Most of the time on mild builds a stock length pushrod will work properly but it is easy to check and save having issues in the long run.
And there would also be no reason to assemble any of the valvetrain until the heads are torqued properly.
Any time you make changes that can affect the valvetrain it is a good idea to check the pushrod length, things like block decking, head milling, different cams, different kinds of lifters with slightly different pushrod heights etc. all have a possibility of requiring a different length pushrod.
Most of the time on mild builds a stock length pushrod will work properly but it is easy to check and save having issues in the long run.
What kind of "350" are you working on? How does your rocker geometry look....plus like what 565bbchevy said. Torque the heads and use a pushrod length checker
Is this a hydrulic cam, because if your lifters are not pumped full of oil and solid then you could be tighning on the lifter spring and as soon as you start this motor you will have a mess. Tell us more about what you have and how you adjusted the rocker arms.
I am assuming you are working on a 350 Olds. If all parts are stock(same) other than the cam, lifters, and pushrods - I would compare and old lifter and push rod length to a new lifter push rod length (push rod in lifter). If they are the same make sure the base circle for both cams are the same. The only other thing is the rocker arm pedestals - are you re-using ?
Yes it is an Olds 350. The cam is a hydraulic flat tappet. Its not a huge cam. Slighty bigger than stock, although I was told it was junk. Lol. Im using stock rocker arms, 1 piece bridges. The heads have been shaved .010". I didnt really "torque" the heads, I just set them on the block and tightened all the bolts by hand. What I'm confused about the most though is why 2 valves have no play, and on the rest of them the pushrod will move probably 1/4" up and down and the rockers are really loose. Like I said, I am an amateur. Lol. And I couldnt compare the old components because the motor did not have a cam in it when I bought it because the guy I got it from had some big fancy cam in it. No old pushrods. I do have the lifters though, but if they were on an aftermarket cam, I'm going to asssume they aren't "stock" length lifters. Everything looks great, until you play with the rockers. I would check the length, if I knew how to properly to it. Lol.
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