Chuck1
Hey all,
I just got my block, heads, rebuild kit back from the machine shop. Had to go .030 over on the pistons because crank walk bored the engine out .015 on its own :shock: . Anyhow, I'm following the TSM for my FSJ and there's two specifications that I'm already NOT meeting.
First is that the ring end gap is .022, range is .010 -.020 so that's no good. Only way to fix this I assume is to get another ring set.
Second, I followed the procedure for checking piston to wall clearance w/ a feeler gauge and it's not binding up on a .004 feeler gauge. The manual states to replace the piston if its that much smaller. So am I gonna be looking at a set of custom pistons or are they going to have to bore it out to .040 over?
Thanks
-Charlie
jeepsr4ever
Charlie...can you or someone you know accurately measure the bores? Will you post the numbers :-|
Chuck1
I don't have access to a dial bore gauge or telescoping gauge. Biggest mike I've got is 3-4 inches so that's no help. I'll try and track down a couple of guys who have more experience with this and see if one of them could measure them for me.
I'll post the numbers as soon as I get them.
Take it the feeler gauge method isn't very reliable?
jeepsr4ever
Well the ring must be placed accurately...meaning around the top it must have the same distance from the top of the block to the top of the ring...all the way around. My guess is that it may have been tilted. These bore rings dont need to be measured if the bores are correct.
fuzz401
take a piston put one of the oil ring rails in it and use it to push the ring down till it hits the oil ring and stops then check the gap
Chuck1
Pushed it in using a piston (but w/o oil ring) to the end of the skirt. I just dropped the block and all eight pistons off at the Napa machine shop. I figure that my machine shop cant really bullshit their way out of this one if I have something in writing from Napa.
I'll post the numbers as soon as I get 'em.
Thanks fellas
JERSEY JOE
This is a common problem when you buy .030 pistons and .030 rings. I always get a ring set that is .010 larger and fit them myself. That way you can hug the tight side of the spec. Sometimes the rings in the smaller set fit ok but in my experience the resulting ring gaps are always on the loose side of the spec. As far as the piston to wall clearance, the feeler guage method is ok and remember even with the proper clearance the feeler guage is not going to " lock up" the piston in the bore. If you end up with .004 clearance I would not worry if the spec was .003. These must be cast pistons I assume?
Chuck1
Hey thanks for the replies. Just got the block back from local speed shop (Napa was being a complete pain in the ass). Machinist spec'd it out as .002 - .0025 clearance for the cylinders. So, I'm going to scrub the block down and get to work. I'll post photos when I'm all done, I'm sure I'll be referring back to these pages for my questions =).
For the rings should I order another set and file fit them or what would y'all recommend?
JERSEY JOE
Chuck: That's what I would do. It takes a lot of time to fit each ring and file it. The job goes faster with a ring file jig. This way you know that the end gaps are going to be spot on. Sure it will run if you just install the rings out of the box, but tight ring gaps go a long way to promote maximum cylinder sealing.
