thetundrawolf

Hello,

I am rebuilding the engine in my motor home, its a 22R engine, 1982 model year.

Well, I had a machine shop bore out the cylinders, he had to go 050 over.

Checking the rings, they are 5 ten thousandths over spec for first ring, and up to .021" which is six thousandths over spec, being too wide. Some of the second rings are within spec.

I need this engine soon for a job out of state. I might have time to putz with a new set of rings.

I'd like some options on this, please...

MudHippy

Ignore the ring gaps. Or rather, don't bother checking them.

Just make sure the cylinders are .050" O/S(or trust that they are). Then install .050" O/S pistons and rings. Plain and simple.

And yes, I have reason for suggesting such. But I don't want to get into to it too deep. Maybe you could e-mail Ted @ engnbldr.com and ask him why he doesn't check ring gaps. He's got 40+ years of experience building engines, so he probably knows better than me anyway.

kawazx636

iTrader: (3)

It is ill advised to ignore your ring gap.

Per the FSM these are the ring gap specs and tolerances:
#1 Ring should be 0.24-0.39mm (0.009-0.015in) - Max: 0.99mm (0.039in)
#2 ring should be 0.18-0.42mm (0.007-0.017in) - Max: 1.02mm (0.040in)
Oil ring should be 0.20-0.82mm (0.008-0.032in) - Max: 1.42mm (0.056in)

The FSM would provide these specs if they were intended to be ignored.

The reason for setting the appropriate ring gap is to ensure that there is enough end gap to account for the metal expanding due to heat and to ensure that the gap isn't too big that it causes a loss of compression. If your ring gap is too small then when your engine heats up the ring ends will connect causing additional friction on the pistons and cylinder walls resulting in premature wear, excessive fuel consumption, blow by and possibly piston failure.

Pistons and their matching rings are made for the "perfect" bore. But when you are talking about fractions of an inch or millimeter, your machine shop (as good as they may be) probably can't match that "perfect" bore but they come pretty close. Thus you fine tune the fit by properly gaping your rings to match your bore.

It's not that difficult, I did all my rings in a couple hours on my current rebuild (see my rebuild link in my signature). I just used a super fine metal file and knocked the gaps down. I gapped mine to 0.32mm on the first ring, 0.30mm on the second ring and 0.51mm on the oil ring (right in the middle of all the specs). Make sure you smooth the edges and don't leave any burrs that could score the cylinder walls.

I don't half ass stuff, and I've rebuilt dozens of engines without failure - including racing engines for motorcycles. I'm currently on my second 22R rebuild for my truck. The first one I rebuild is in my friends truck with over 40,000 miles in 2 years on it with not a single problem.

So listen to the guy who has cracked pistons https://www.yotatech.com/forums/f116...-w-pic-190796/

Or follow the FSM and do it the right way.

thetundrawolf

Well, I got two very different replies here! I might not have time to putz with new ring sets that may be better or worse. But, according to the gaps I have my rings are less than the Max spec! The 83 fsm doesn't list Max! So I am ok, thanks guys!

MudHippy

I'm not sure what he's insinuating with the cracked piston reference(like that was my fault?). In any case, my engine building skills are more than sufficient to say what I've said and stand behind it...with confidence. But, don't believe me then. What do I care?

Quoted from a thread you both should read.

And YES, by stock he means O/S stock too. Meaning, this is still a stock situation we're discussing, so don't be stupid...

BTW...there's no such thing as a "perfect bore". Nor is there any need for one...

thetundrawolf

No sir, you were correct. The stock rings are well within spec. So I will use them

MudHippy

Well, I didn't expect you to be in disagreement with me. Since your experience is obviously a case in point(proof my "assumption" was right).

That was ENTIRELY directed at kawazx636...

kawazx636

iTrader: (3)

A tighter bore will result in higher compression and longer engine life. A tighter bore will also require you to gap your rings when your gap ends up being 0.10 mm. EB may not gap his rings due to his processes and doing his own machining so that it always falls within tolerance. But when a machine shop is boring and honing your block, can you really trust that it was done good enough that you don't check? I use one of the best machine shops on the east coast and I will still double check everything because it's easier to do that then to rebuild it again later on down the road. And like I said, I use a tighter bore so gapping the rings is a must.

thetundrawolf

That's a good point. I *do* want to know for a *fact* it was done right. Nothing to worry about then. That's why I asked... Good to see the info I needed