Thread: 1st rebuild

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HI,
I am tearing down my first engine right now which is a 305. I wanted to learn everything so i decided to do the only engine that was laying around, which also smoked so i thought id check out the rings.

I just got the pistons out and two of the top rings were broken when i took them out so im suspecting that that was my problem?
My plan is to do this as cheaply as possible that way i dont spend a whole lot of money on this if it doesnt work. My question is, the ridge at the top of the the block where the piston doesnt quite go up to, how do i tell if its too big to just hone out or if it needs to be bored. The cylinders seem to be in great shape, but thats just a rookies opinion. The ridge to mean doesnt seem that big at all, but i know how a 0.001 inch makes a huge differance.

any help or info would be appreciated.
thanx
david

If this is a first time for you, I suggest you take the block to an automotive machine shop and ask them to mic the bores for you to see if they can hone it and go with the standard pistons or if it has too much taper/out-of-round and will need to be bored to the next oversize. Trust me, whatever this costs will be cheap money spent. Tell them not to ridge ream it, just measure it and report what they find.

There will be no point in removing the ridge (which you can do yourself at home with the proper tool) if you have to bore the block anyway.

Do buy new pistons. The most common cause of top ring failures like that are worn out ring groves.

thanx guys. Im planning on buying a rebuild kit for it but hoping no more than that. DO you guys know a rough estimate on how much theyd charge just to mic it?

thanx
david

Find a good machine shop, and take the bare block and crank to him and ask "is this engine ok for a ring and bearing rebuild?" Tell them you just want an opinion,like Tech said. An honest shop will come back and tell you yes or no, then you can make a decision from there to just hone it, or bore, or whatever.

Even a simple re ring and bearing job should be preceeded by a hot tank, cam bearing, freeze plug, and hone job. This isn't terrible, costwise, and you will be starting with a clean slate. Also have them give you an opinion on if the crank can be used as is or needs polished or turned.


JMO,


Don