89 951 engine overhaul

[Tom]

Long shot, but have you mic'd that cylinder to confirm it's the same as the other 3...?

[four0four]

PTW clearance is bang on - I measured it after the machine work, was concerned, and had a local shop check over again. Pistons are also very consistent (variance is well into 0.0001s). Chamfer is also present, which is something I suspected at one point in the shower

[Tom]

And all the other ones slid right in?

[four0four]

Yeah - I mean, I still probably had the compressor too tight, so "right in" is relative. But they move smoothly and freely, so.

[four0four]

OK - got it in, but I'm not sold that the cylinder wall is gonna be alright (nothing new, but I can lightly catch a nail). Maybe it would wear in..idfk.

What was causing the issue was the fact that the oil rails weren't perfectly flat after my initial failure(s) - as soon as the gap end was free of the ring land, it would bend out of planarity and refuse to just sit back in. What worked was pushing the compressor down far enough that the oil rails popped out the bottom, and then compressing them by hand and working them gently into place in the compressor.

And yes, I think I was initially overtightening it. Good call @Dave W.

[Tom]

Glad you got it in. My shade-tree opinion is not to worry about the scuffs. My original 2.5 motor has some nasty scoring and it still made over 300hp, and didn't smoke or burn oil excessively, etc. I'd be surprised if that teensy little scratch has any noticeable consequences.

[four0four]

Me too

To be frank, that's probably the advice I'd give someone else. I'm just worried it'll bug the hell out of me.

I suppose it probably won't hurt much that wouldn't be covered by refinishing it right now. In other words...The cost to clean it up now is likely the same as the cost to clean it up after a failure (or within the same OOM). So, maybe I'll send it. I'll complain bitterly if it fails

[stitch2k1]

To be frank, that's probably the advice I'd give someone else. I'm just worried it'll bug the hell out of me.

Schrödinger's cylinder bore

[four0four]

Still slowly plugging away, got the motor in over the last two evenings:

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Pardon the mess.

You'll have to take my word (and that of my sore everything) that it's mated up proper to the TT. It looks like I took this before handling the engine mounts and crossmember too, but that's all squared away.

Suddenly all that nice room I had for running the new oil hoses has vanished, routing this will be interesting:

lolclearance.jpg (2.65 MiB) Viewed 849 times

edit: my attachments fell off, trying again?

[Tom]

Looking great. Fingers crossed on start up!!