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[spazegun2213]

while ordering a set of rocker arms and pivots today I came across a shop that can bore, hone and balance. He said that he had done some of these strokers before and that the biggest problem with them are the valve train. He said that some adjustablity would be needed that the jeep head cant offer. Being a novice i didnt say anything, but is this true? I want the head ported, but other than that what do i need to look out for with it? Im running a new cam and that about it.

I would like to sound semi informed when talking to this guy so i know what is going on.

thanks
-Spaze

 

[Dr. Dyno]

Some adjustability in the valvetrain is always a good thing because you don't know if the lifter preload is going to be in the desired 0.020-0.060" range until you've assembled the engine. There are three ways in which you can correct excessive lifter preload:

1. Shim the rocker arm bridges.
2. Use shorter pushrods.
3. Install adjustable roller rocker arms.

I didn't mill the block nor the head in my stroker yet the possibility that the lifter preload could still be excessive does concern me, especially after I've heard of other strokers going down with bent pushrods, broken lifters, and worn cam lobes.
I'm going to buy a set of Yella Terra RR's after the New Year. Even though the ones I want (YT6627) are non-adjustable, the kit includes a set of shims so if I need to use them, I can install them under the rocker arm pedestals.

 

[spazegun2213]

ok, so how would i go about checking it when the block is fully assembled (sorry as i said i know virtually nothing)?

As for the head, i think I'm going to have it magnafluxed will that change anything?

also are there any shims for the stock RA bridges?

thanks

 

[Dr. Dyno]

magnafluxing is only done to check the block or head for cracks. It doesn't alter valvetrain geometry.
I posted a link to the Crane Tech page on how to check lifter preload on this page of my website:

http://www.jeep4.0performance.4mg.com/valvetrain.html

There's also a link to Crane's page on how to order their 99179-1 rocker arm bridge shim kit.

 

[Bloose]

while ordering a set of rocker arms and pivots today I came across a shop that can bore, hone and balance. He said that he had done some of these strokers before and that the biggest problem with them are the valve train. He said that some adjustablity would be needed that the jeep head cant offer. Being a novice i didnt say anything, but is this true? I want the head ported, but other than that what do i need to look out for with it? Im running a new cam and that about it.

I would like to sound semi informed when talking to this guy so i know what is going on.

thanks
-Spaze

A stroker should have nothing at all to do with the valve train. Crank, rods, pistons, that's all there is to a stroker. If you mill the head, block, and/or run an aftermarket cam (which you will not be able to do with your block) that's another story. The other thing is if you want different cam events than stock, i.e. more lift and/or duration, you must send your cam in for a regrind. I guess in '97 or so they went to a new style cam and no one makes an aftermarket cam yet. If you do send the cam in, and you want more lift they will grind the base circle and then push rod length will become an issue. Not too big a deal as you can order about any length you want. You'll have to get the lower end together, put the head on the block and do some measuring, and check lifter preload. From that you should be able to figure push rod length and shim size needed. If you stay with the stock cam, and do not mill the head or block, though I would still check it, you should be able to use stock push rods and run no shims.

B-loose

 

[spazegun2213]

yes, the head will be magnafluxed for no other purpose then to make sure this engine didnt fail because of a cracked head. As for the valve train, sounds like something i should worry about when i have the lower built. I'll probably just use shims, it seems the easiest and cheapest way to make sure this think will run 200,000 miles with my lead foot, that i I just bought new RA and pivots last week from a dealer.


in any case, is all this measuring something I can do, or should it go to a shop?

thanks
-Spaze

 

[Bloose]

Should be no problem at all to do it yourself. Here are the reasons you should,

1) If they do it, how will you ever know for sure they did it right?

2) You'll learn something

3) You'll save a few $$$

4) You'll have the satisfaction of knowing you did it yourself

It's pretty easy really.

B-loose

 

[92xjr]

Quick question while you guys are on the subject, are the stock rocker arm bridges and/or pivots steel or aluminum?
thank you,
Joe

 

[Menzenski]

Quick question while you guys are on the subject, are the stock rocker arm bridges and/or pivots steel or aluminum?
thank you,
Joe

I very much doubt that they're still on the subject after fifteen months.