Slackdaddy

I searched but could not find it.
I am rebuilding a 2001 4.0 with a rebuilt TUPY head.
In my youth, when rebuilding a non adjustable hyd lifter engine, we just torqued to spec and called it a day.
The 4.0 rebuild "books" do not discuss any "adjustments" .
I remember reading a thread here about someone running into problems because after a block and head rebuild the valve train was out of spec?? and I thought someone in the know said something about shimming??

Can someone point me in the right direction?

Ralph77

I am not going to pretend that I understand any of this.
But I think this is what you are asking about. Check out Post# 6.

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

I have come across this info in various threads on this forum.
So guessing a search will give you even more to read.

Dave51

Thanks Ralph! ccKen was the original and best splainer!

The Crane cam link is broken. I wonder if this is the one he was referring to:

https://www.cranecams.com.au/pdfs/pp1110c.pdf

Dave51

Gold mine:

https://www.cherokeeforum.com/g/album/4533483

dave1123

Basically, as long as the head and block haven't been decked (cut) and the valves were reseated by a reputable shop, you can just bolt it together with no problems. A shop will trim the stem ends of the valves to match stock assembled height, but a backyard regrind or using a thinner head gasket can change the lifter preload.

cruiser54

Torque them down.

Slackdaddy

Thanks guys, I will read it all tonight.
This is a full rebuild, machine shot work, home assembly.
Block had a very little taken off to clean it (according to machine shop)
I pulled a TUPY head from the JY and took it to a "well spoken of" guy with a small machine shop at his farm, he said he only took a little to clean it up.

So,, a lot of variables.

97grand4.0

Valve job = preload adjustment, remember, ground valve seats and new valves or faces change the geometry not to mention everybody gets that 'thicker' felpro head gasket, replaces pivots, rockers, pushrods etc
**DISCLAIMER - This post does not and is not intended in any way to contradict or disagree with Cruiser54's "torque them down" post. **

Slackdaddy

Like Reagan: "Trust but verify"

Slackdaddy

OK,,
I set cyl #1 at TDC, hand tightened the rockers evenly till I could feel the slop in the push rod disappear, indexed the bolt head and torqued to 21 Ft/pounds while checking the preload.
Then moved on to the next cyl, #5, set at TDC and repeated the above.

Looks like I have approx .060 - .065 of preload,,, at the end or just beyond the specks of .020 - .060
I had 1 full rotation plus that bit beyound the start line.

Is it worth shimming to get them back in the center of the spec??

Slackdaddy

Hmm,
Thinking I need Pushrods that are .02 shorter,,, where can those be sourced?

Dave51

https://www.pushrods.net/one-piece-pushrods

Since this is a complete rebuild you already got a new cam and lifters?

I would consider getting a caliper, measure your current rods and work from that.

Dave51

http://mantonpushrods.com/

Dave51

http://trendperform.com/

97grand4.0

To answer your question yes, you should. Too much preload runs the risk of poor pumping from the plunger as it doesn't travel enough in the bore, or hammering the plunger causing destructive failure. Not enough will cause poor engine vacuum. For too much preload, you can adjust it out with the shorter pushrods as you say, but an easier way might be to order the adjustment shim washers from Crane. That's what I did. That will raise your rockers and accomplish the same thing.
Within spec is within spec, its the factory way of balancing lifter operation with vacuum.
http://www.summitracing.com/parts/cr...1/applications

Remember the trick is to shim both I and E equally . It says that in the instructions that come with the shims. Therefore you still might need a pushrod down the road if you can't.

Even with the shims I wasn't able to completely get just the exhaust on #6 to completely come in so I need a pushrod. Its operating at the margin like yours, or slightly out. And Darned if when it gets below about 35 outside, that baby ticks for exactly one second, which you can barely hear over the piston slap that has been there for 65000 miles (215,000)..which fades to silence in a minute or two or three. One of these days Ill likely be getting a pushrod.
I still love my 97 zj. The hatch window I can and do stuff so much crud in the thing and it always gets my job done. Its been my main work vehicle for like 10 years and one way or another it's never 100 percent but always, always gets the job done.