Haha I see that. We are above such nonsense here. At least the speaker didn't rip up the ..oh nevermind!

 

OP in this case said "My '93 XJ has an '89 Renix head on an '01 HO short block." And I believe a new cam. So, no question he should set preload.
Also, preload is set at the factory and they often used different length pushrods to do it. Sometimes the different ones are clearly marked with a colored band. My guess, sometimes not.
But, with his symptoms, I have my doubts that is all of his problem. Sounds more like head problem..

 

Certainly agree he should check.

However, I'm going to bet a buck it will be normal. I did qualify my question:

so that would exclude weird cams and fat head gaskets (altho it seems to me that a fat gasket wouldn't create his issue).

But TTBOMK the 4.0 has always used the same push rod (3300 2986) so no matter what he mixed up, as long as the parts were within spec they should work.

Another fun thread.

 

Yeah, gotta fix that.

 

Well, no they didn't at all use the same pushrod, as I tried to explain earlier. Which might be one reason the fsm says to keep them in exact order. They mixed them up as needed to adjust the preload because that's the whole point, they may not all be the same. Wherein you might see a particular cylinder with both having a colored band, and none on any others, denoting a different length of rod from the mopar factory..
A fat gasket will certainly throw the preload out to about .100 but yeah might not be his um only issue.

 

x2 that could be it right there if they aren't the same

 

I'd like to inject something here. If the valves were reground and reseated, the whole geometry could have changed. Sinking the valves deeper into the head will cause more preload on the lifter unless the valve stems were dressed to compensate.

There is a lot more to rebuilding an engine than a lot of people realize. Although the Chevy small block could be thrown together with mismatched parts and still run strong.

97Grand4.0, your referenced post about valve preload should be a sticky. It is well done and you used CCKen's picture perfectly! Zero lash and 3/4 turn is the true sweet spot at .042".
I seem to remember that's the same for sbc as well, although the bolt thread is different. 3/8-24 instead of 5/16-24. The thread lead is the same.

 

Thanks, Dave, I thought so too after I re read it! Are you nominating it?
As far as the valve heights, that is something the machine shop should be checking afterwards and grindig the stems so they all are the same installed height, obviously. I was able to lay a straight edge on mine ..very level indeed. But that is a quick check you should do too so right on.
I will add, that getting preload exactly at .040, in the real world probably won't happen with shims. I believe the spec range, to be acceptable anywhere therein, but, you would certainly want to try to aim for the middle at .040.

 

Or just take ccKen's original post (cause his images are bigger for us visually-challenged folks):

https://www.cherokeeforum.com/f2/new...stment-213117/

 

IDK why if you copy ccKen's image it shows up smaller than his original. Oh well...

 

Yeah either way Dave51, when you do yours for the first time you can let us know how it went too.