Roller Rocker/Push rod question

family xj

Well-Known Member
Joined
Feb 19, 2006
Location
Jacksonville NC
I just got my 89 5.0 put back together and I used some new 1.7 Pedastal roller rockers. For those that don't know the pedastal type rockers are non adjusting. Mine have some slop in them and they are tightened down to spec. Some back ground on the new build. I used the old hydaulic lifters as they were in excellent shape, same valves and springs just cleaned them up and had them reseated. Bored the motor .030 over and used a crank kit, has nothing to do with this and then used the old cam.

My question is How do I figure out what size push rods I need to buy since mine are obvously a little bit short?

I am not sure how to measure to get a longer push rod. This is pretty much the only alternative since I can't adjust them.

I did start the motor and it ran great but it is excessively noisy. Some please educate me.

Thanks
Doug
 
Did you make sure to put the lifters back in the right holes? How long did you run it? The lifters should compensate, but otherwise summit sells a pushrod length checker.
 
When I disassembled I didn't mark the lifters. I didn't know too as I was excited and learning. I ran it for maybe a total of 30 minutes. I will look into the push rod checker. Thanks
 
Your pushrods should be the right length, when you put
roller rockers on pedastal style heads you need rocker shims.
These are available from Crane Cams, they will have three
different thickness and one pack will do both sides.The shims
go under the bolt to give the right aount of preload. If you
need more info let me know.
 
I was looking at shims and didn't understand how they work. It seamed like it lifted the rocker arm up and would cause it to be even more loose fitting meaning reducing preload instead of tightening it. I guess I can't understand how it works well. I have a pic from cranecams website that shows where to install. I have to assume I can get these from jegs as well. What kind of thickness do I order?
 
If you can't find them at Jegs, I have some in stock. One
pack will have three different thickness .015 .030 and .060
that will be enough for both sides. It easier to adjust with the
intake off so that you can see when you hit zero lash and then
preload the lifter (.030-.060) which is usually between 1/2-3/4
of a turn. You can do it with the intake on it just takes a little
longer to see which shim works the best and each rocker may
use a different thickness due to castings, valve depth, etc.
Hope this helps.
 
The roller rocker will actually preload to much, causing the lifter to bottom out and not fill up with oil making them noisy.
I mean't to put this at the top of the last post.
 
I'm not sure oil is the problem. I have oil getting pumped into the valves on the head. When I read how to set the lash it said to tighten down until there was tension on the push rod and then go a quarter turn more. My rocker doesn't even touch the push rod and it is as tight as it will go so I can't even go to zero lash.

I did take the intake off cause you can't even get to the rockers with the intake on.
 
braxton357 said:
Did you make sure to put the lifters back in the right holes? How long did you run it? The lifters should compensate, but otherwise summit sells a pushrod length checker.
Click to expand...


Roller lifters? I wouldn't worry to much about getting them mixed up. If it were a flat tappet cam you would want to keep them in order because of wear b/w the cam and lifters.

The stock rods should be the right length. You don't want them too tight right now. They will snug up when you prime the engine and pump up the lifters. If you go with the longer rods and bottom them in the bores if/when they pump up they will hold the valves open and she won't run very well if at all. And possibly a valve could kiss the top of a piston. Not too good.:shaking: The only time I've had to use the shims under the pedestals were when I shaved the heads for compression. And I'm not talking .005-.010", more like .030-.035".
 
I know it has already primed up and the noise didn't go away. It looks like the rocker is not contacting the push rod by as much as 1/16". It is an obvious amount of play and I know it can't be normal. To set the lash it has to have some contact between the rocker and the rod. It has none until the rod starts coming back up. I am pretty lost on this and that is why I am asking so many questions.
 
OK I went and put the original rockers in and they tighten up the way they should so the rockers I bought obviously require a longer push rod. I called Jegs tech line and the guy I spoke to says it happens pretty often. So I ordered some push rod checkers and they will get here Thursday so I can check and order new rods. I am glad it is something simple. Thanks for the help everyone.
 
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