My Bores

[V12StealthHunter]

The number of small things started piling up so I decided to pull the engine and clean it up a bit. I'm not too keen on doing any bottom end work but I'd like to get some opinions from the experts on the condition of these bores.

The engine has 80k miles.

The cross hatch pattern can be seen the entire length of the cylinder. I find this a little strange. I'm used to seeing the bores wear out, or at least the top half. Is this a sign of the piston rings not working properly?

Also there are 3 wear stages/lips (although no noticeable lip or step can be felt by hand) at the top of the cylinder. Identifiably by the different colour gradients. The top was the usual carbon build up, but I've not seen a cylinder having another 2 stages of wear like that.

I completely forgot to do a compression test before pulling the heads.

(I've obviously cleaned the piston tops)
http://3.bp.blogspot.com/-8c-CkAx2Sqs/U ... C_0058.JPG

[bradartigue]

Looks like they were honed and re-ringed (but not re-cut) at some point in the past. Those honing scratches look like the stone type and the flex type but its hard to tell from the pictures. Either way it looks like two honings given some look almost flush and some sharp.

At the stage you are with the motor doing bottom end work seems a minor task. At the very least I've have them measured to make sure they are in spec and then figure out what to do next (hone, bore, re-ring, etc.)

[MrJD]

i was under the impression that as long as there is no scoring in the bore, you should just leave it be?

Also, is it a good idea to clean the tops of the pistons?

[fiatfactory]

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[majicwrench]

Looks normal to me. But I agree w above, you have it this far, why not rings and bearing?? Unless this never used a drop of oil, I'd finish what you started. Those vertical scratches are just life in an old engine.

[V12StealthHunter]

Yes I suppose its not a big effort at this point. I'll need to buy some tools to complete the job, including a dial indicator and bore gauge accessories at the very least. I just want a cheap one. Maybe something like this? http://www.ebay.com/itm/2-6-DIAL-INDICA ... 0880385983
There is another one like that called "Fowler" but I think its all the same Chinese stuff. Any recommendations?

If it had been rebuilt, it must have been done like 30 years ago because every gasket I took off on the way down was completely disintegrated.

Here is a picture showing the marking on the piston. Its the same for all the pistons. It reads "80.4 - 66705 / A" . With a little arrow at the end. If thats 80.4mm (3.1654), the Haynes manual says stock 1608cc pistons range from 3.1467 to 3.1486, so that means I have something between 16 to 18.7 thousandths oversized. Some odd numbers here.

http://2.bp.blogspot.com/-Bt-YBNCGYe4/U ... C_0002.JPG

[fiatfactory]

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[majicwrench]

I always have to add something

If it has already been overbored, that would make me think a bit longer before re-ringing it...did this thing use oil?? Smoke?? Knock?? Why did you tear it this far apart??

Before pulling pistons you really should remove ridge. Need a ridge reamer.

Measuring...really, you can still see hone marks, has been overbored, bore is fine, don't really need to measure. Same w crank, if bearings look good, crank is OK, stick new bearings in.
Machine shops have habit of selling you everything possible, they will want to sell you a bore job and a crank grind.

Hve fun with it!

[V12StealthHunter]

Thanks for the advice.

The engine sounded fine, started up cold or hot and ran fine. There was no one single reason why I took the engine apart. It was more of an accumulation of things.

1. Something was wrong with the clutch as it would not engage smoothly (turned out that the flywheel was covered in gunk)
2. It leaked from everywhere and I was tired of the oil stains
3. Unknown timing belt history
4. Had generally low oil pressure (just a smudge over no-reading), yes I tried different gauge, different sender too.
5. Felt very low on power

I thought I would just take it out and clean it up a bit. Hence the hesitation to tear down the bottom end but I think I'm going to at least hone the bores and put new rings and bearings now.

[fiatfactory]

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[fiatfactory]

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[V12StealthHunter]

I had a look at the main bearings and connecting rod bearings today and found that all the mains were pretty worn (can see copper in a few places) but the connecting rod bearings are like new. I have a photo below. Bit alarming to find that one of the connecting rod bearing caps was loose. In fact I removed the nuts by hand. That loose! Also notice the odd one out main bearing bolts. Is that original?

There is a bit of discolouration on the crankshaft webs (i think thats what its called). Looks like something caused by heat, but I could be wrong. Photo below.

I'm going to go buy a 1-1/2" socket to remove the crankshaft nut tomorrow. Hope thats the right size.

Edit: Just noticed the forum doesn't auto scale the photos. Click on the link just above the photo and it should open it in full size.
http://1.bp.blogspot.com/-oQ-LRZwhFfY/U ... C_0010.JPG

http://3.bp.blogspot.com/-GH8KoiO8omQ/U ... C_0011.JPG

[fiatfactory]

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[DanD]

Make sure you clean everything, especially the oil galleries and the crankshaft passages. Swarf eats bearings.