defiant1

Finally, after about 2 months of waiting I got my #6 heads back (I'm still sick to my stomach after paying the bill). But I digress. Need to know how long of push rods I will need or more to the point how do I determine it?

Some of the measurements I have at my disposal.

Factory heads had a .015 head gasket.
The thinnest head gasket I could find was .027 (compressed) and the machinist milled .015 off the combustion chamber deck
So, if I take these measurements at face value it is basically like having a head gasket that is .012 (based on using a stock factory head).

Factory spring height is 1.670.
Springs installed were 1.700

Machinist related he milled valve stems to factory specifications. Unfortunately, I do not know what that is at the moment.

What other measurements do I need to take into consideration? I think I can borrow a push rod measuring tool, but I would like to know the procedure.

I believe the machinist told me you can have a .030 leeway in push rod length. I have nothing in front of me to validate the claim.

I have heard terms such as valve lash, rocker geometry and the like. Any articles or URLs you can send my way to "learn me" on this would be appreciated.

I am close to getting this motor installed and don't want to trip up right before the finish line.

d1

TripDeuces

Rather than guess I would buy an adjustable pushrod and check it that way. That way you can check it with preload and get it right the first time. Can probably pick one up for less than $20 at Summit

defiant1

Got a push rod length checker on order. Hopefully it will do the job. I am using guide plates, anyone have a suggestion on hardened push rods for a 350??

TripDeuces

Smith Brothers makes some nice pushrods. Check them out:

http://www.pushrods.net/index.html

defiant1

Need some help. Got the push rod length checker. But not 100% clear on how to take measurement.

I read different methods so I am not sure if I am getting an accurate reading.

Here is what I did so far.

Motor is at TDC on #1 cylinder. Before I dropped the hydraulic lifter in I noticed the base of the cam lobe.

1. Installed lifter, checker, rocker stud, guide plate, magnum roller tip rocker, etc. on the intake valve side.

2. Adjusted roller tip so it was centered on end of valve stem

3. Adjusted length of checker until I met resistance when turning checker.

4. Measurement at this point is 8.400" with no pre-load. The Erson cam instructions were not very specific other than saying that the pre-load can be between .020 - .080. Sooo, do I add the pre-load to the measurement to get 8.420-8.480 or subtract the pre-load to get 8.320 - 8.380 long push rod???

Not clear if starting the rocker roller tip in the center of the valve stem is correct or how the base of the cam lobe relates to the position of the roller tip on valve stem.

If anyone can fill in the gaps I would be most appreciative.

d1

TripDeuces

You want the longer measurement because you're depressing the plunger in the lifter to get preload

defiant1

This is what I was unclear on. Due to tightening the lock nut I figured that you would need to shorten the push rod to make up the difference. This valve train geometry stuff is confusing...

defiant1

Well, after reading and asking questions, I did not get a "no kidding" method to measure the pushrods, I finally just took all the info and did the best I could to be accurate.

I ultimately wound up with a measurement of 8.350" with no preload. And added an avg preload of .050 and I ordered pushrods at a length of 8.400". Hopefully, it all works out.

d1