I've got a 305 with about 130K on it, runs tip top, but has a lot of external oil leaks, and blows some smoke through the exhuast. The engine is out of the car right now, so i figure this is a good oportunity to put new valve seals in, new head gaskets, intake gaskets, and front and rear seals. I'd also like to rering it while it's apart, which leads me to my question:

Should i buy new rod bearings? If so, what do i buy them for, standard sized right? i won't be cutting the crank or anything. New rod bolts nessesary? i know i need new head bolts as the ones in it are tq to yeild.

motor is a 94 LO3 out of a truck if that matters at all

Eric

 

I haven't done it or looked into it for a long time (>30 years), but they used to have .001" undersized bearings.

I'd never heard of LO3's using torque-to-yield head bolts. But, I haven't heard everything yet.

 

how do you know you won't be cutting the crank without checking it first? i think if you aren't prepared to do anything and everything needed it'd be best to leave it alone. replacing the crank and valve seals would be a good idea.

 

I don't have the motor apart yet, so i don't know. But unless i see something wildly wrong, it's not getting cut.

Eric

 

and after you get it back together you'll be here asking what's wrong with it

 

LEAVE IT ALONE.



they've worn into each other too much by now.... either have a machine shop do it right, or leave them alone, and just replace the seals...


ive had several bad experiances in the past along with a few of my friends... ive learned my lesson... unless you plan on doing the proper machine work, leave the bearings alone.

 

I'd be inclined to agree. Either be prepared to get the crank turned, the block bored, and buy new pistons; or just leave it alone. No in between.

At best, you could tear it down, and hone the cyl walls, re-use the stock pistons, and put in new rings; but if you do that, you'll have to clean up the grit, which requires a tear-down and a good wash anyway.

It only makes sense to re-ring a motor without a complete tear-down if it has less miles on it than it takes to break in the rings; i.e., 3k or so. Anything over that, you've got a used cyl wall with no "teeth" to wear new rings to fit it, and they will never really seat right.

In 130k miles, if the oil has been kept changed, the rings aren't worn out. If it was mine, I'd clean any sludge or other funk off of the outside and out of the inside at the car wash with diesel fuel or something but no water, let it dry out for a few days, replace the seals and gaskets, fix up the heads, and run it.