Probably doing a first start tomorrow. Hope it works. (Cracked cylinder head) Topic is solved

[dikidera]

I cleaned it to the best of my abilities using brake cleaner, and bought a specialty tool which was machined flat to around 12 micrometers, which is actually 0.012mm.
Not only did the 0.05mm feeler gauge fit underneath the straight edge, I did the light test and saw light underneath where I was measuring on 1st and 2nd cylinders.

In the event that I measured wrong, new head gasket, new bolts and machined flat head, resulting in...a blown head gasket literally hours after installing it would still indicate the block/sleeves.

My head was inspected for not only flatness of the deck, but also warpage of where the camshaft lay, none was found by the machine shop. Also, the head was tested for cracks.

All that is left, is of course the block itself it's the only constant in the whole picture.

And if the blocks are as irreparable as you say, this makes the task of finding a spotless block even more difficult.

[vtl]

0.05 mm is not enough to fail the gasket.

Also 0.05 mm is small enough for thermal expansion to play its role. I.e. when I was doing my engine, I brought micrometer into a cold garage from warm room, started to do measurements and they were drifting while I was moving from left to right. The micrometer was cooling down and that affected the measurements. Had to leave it alone for a couple of hours and remeasure everything in order to get correct results.

I wouldn't swear by 0.05 mm. Nice to not have, but the gasket will crimp it no problem. At least it will not fail in 20 minutes.

Something else is going on.

[dikidera]

We will do a compression test today.

I also have a leakdown tester and as a last resort, I am thinking of pressurizing each cylinder to 100 psi and holding that pressure and noticing which cylinder might produce bubbles in the coolant, although this might not produce bubbles as from my limited reading, actual combustion pressures in a cylinder reach much much higher pressures than static compression.

[abscate]

Volvo spec for cylinder head distortion is

0.5mm lengthwise
0.2 mm lateral

By extension, a block in these specs is also fine

[dikidera]

Here are the results of the compression test. Almost all cylinders are 180 psi, except cylinder 1 surprisingly being 190 psi, which is a 5 percent difference.
Cylinder 1 and 2 were the ones where I had measured warpage of 0.05mm.

I still find the compression a tad bit lower, cause before I did all of this work, the compression was as follows viewtopic.php?p=608107#p608107

Since then obviously the head was machined 0.14mm, which should have increased the compression slightly, new valve seals etc so the head should have sealed better. Or perhaps what I had measured before was with a leaky head and so oil was in the cylinders sealing them better?

In any case, I have no real way to measure just how much pressure is in the coolant system, beyond the normal I mean.

[jonesg]

a leak down test would reveal more.

[abscate]

Wait, did you use RTV between the head and cover? You probably have a massive oil leak between the oil galleries and head into the stem seal area. Maybe that’s the source of the oil?

Remove cam cover and reseal with Permatex

[dikidera]

It's not rtv, no. It's a special non-hardening type of sealant, apparently the stuff which Volvo was almost going to use.

It's victor reinz, reinzoplast but again the type of sealant that does not harden. I simply have not cleaned it, otherwise it's still not hard and I can just wipe it away from the spark plug holes.

The source of the oil from a few pages back was me overfilling the engine for a total of 10l of oil, which is why it smoked and leaked a lot. Thankfully, the crank seals seem to be ok.
As for the initial compression tests, they were done last year when I had just bought the car, since then obviously the head has been serviced(new valve seals, a few new valve guides, machined flat etc).

Anyway, I am curious what you guys think of the current measured compression for this NA motor.

[abscate]

180-190 pounds is fine

[vtl]

When you pull the head, make a real good close pictures of coolant passages between the cylinders and post here.