[Greg Reid]

Originally Posted by smakcruiser

I have the exact same problem underneath. I think its going to be a pain either way

Yeah, but I'd rather deal with a broken off stud at the down pipe flange than a broken off bolt in the head.
They are easier to soak in penetrating oil too. Soak 'em every day for a few days and maybe you'll get them all out in one piece.

[mike nixon]

Break the studs off in the manifold. Deal with the head mounting bolts on the bench. Life will be a lot easier.

Mike

[smakcruiser]

Ok... so I pulled the head today and took some pictures. Do you guys see anything odd?

[mike nixon]

The valves are sitting fairly low in the seats. Pour the chamber full of laquer thinner and see how quickly it leaks out, I'm betting it's gonna run,

[kwt63cat]

Hi,
last picture, the one with the piston down in the bore, at the 6 o'clock position of the cylinder wall, what is all of that discoloration that can be seen? In the picture with that piston up, it looks like there is a nick in the piston at the 3 o'clock position. It not very big but indicate a problem below it. 'hard to scrutinize the condition of things without being there and running a finger over it. Going back to the compressed air test you did, your sure that you heard the air hissing out of the crankcase on #8? If so look closer and verify the head gasket did its job by sealing all the way around the cylinder on both the head and block. Please let us know what you find.

[Deadhead]

It looks like one of the valves in the first Pic has a hole in it? Or is that just something on it?

The RH piston in the 4th Pic also has marks on it as if something got into the chamber and rattled around for a while. You could have a bent pushrod in that one. Roll them on a flat surface to tell. Then, as mentioned, the one looks like there is some scoring on the wall of it but could just be goo running down it. A couple of things to check there.

[smakcruiser]

Originally Posted by kwt63cat

Hi,
last picture, the one with the piston down in the bore, at the 6 o'clock position of the cylinder wall, what is all of that discoloration that can be seen? In the picture with that piston up, it looks like there is a nick in the piston at the 3 o'clock position. It not very big but indicate a problem below it. 'hard to scrutinize the condition of things without being there and running a finger over it. Going back to the compressed air test you did, your sure that you heard the air hissing out of the crankcase on #8? If so look closer and verify the head gasket did its job by sealing all the way around the cylinder on both the head and block. Please let us know what you find.

I am not sure what the discoloration is. I was wondering the same thing myself.

I wouldn't bet my life on it, but I was pretty sure all the hissing I heard was coming from the crank case.

[smakcruiser]

Originally Posted by Deadhead

It looks like one of the valves in the first Pic has a hole in it? Or is that just something on it?

The RH piston in the 4th Pic also has marks on it as if something got into the chamber and rattled around for a while. You could have a bent pushrod in that one. Roll them on a flat surface to tell. Then, as mentioned, the one looks like there is some scoring on the wall of it but could just be goo running down it. A couple of things to check there.

There is just some crap on the valve. I'll roll them around when I get home and see if any of them are bent and let you guys know.

[Deadhead]

Looks like a choke screw got into mine on the wagon. Bent 2 pushrods. Did not check compression or if I did, I don't remember what it was. Ran fine.

[smakcruiser]

Damn that sucks

[smakcruiser]

I checked all the push rods when tonight and all seem to roll perfectly smooth on a table. All pistons do have a notch at 3 o'clock. The discoloration at 6 o'clock is something I am a bit concerned with. I can't wipe it away.

[kwt63cat]

Hi,
That discoloration, if that's all it is, isn't your problem. But if there are deep scratches they could be part of the problem. Remember you said that you had no compression on #8 at all and it would take a very noticable problem to do that. I expected something pretty obvious but from the pictures I see nothing. I'd pull the valves on #8 or do the previously mentioned parts cleaner test for leakage. Again, it takes a BIG "OH OH" for 0 compression.

[smakcruiser]

The discoloration is very smooth and I don't feel any pitting at all when I rub my fingers over it. Maybe the head gasket and the valves aren't sealing properly. I am going to work on those two items, button it back up and test again.

[redhook98]

Did you poor thinner in the chamber as Mike Nixon suggested? That is where I would start. Simple and easy, and can eliminate the head/valves as the issue.

[smakcruiser]

Originally Posted by redhook98

Did you poor thinner in the chamber as Mike Nixon suggested? That is where I would start. Simple and easy, and can eliminate the head/valves as the issue.

I filled the chamber with thinner tonight and it seemed to hold ok... you could hear a drip every 3-4 seconds. Is that enough of a leak to cause my issue?

[63gpman]

If it is only a drip every 3-4 seconds, you have not found the issue yet. Sounds like your rings are sealing.........at least enough to create some compression.

What did the head gasket look like in the area of the staining?

[smakcruiser]

It looked ok. One of the pictures above still has the head gasket on... I dont see anything odd.

[Greg Reid]

I would think with no compression whatsoever, it should have been something pretty obvious...like a valve stuck in the open position, lifter stuck up in the bore, hole in the piston..something like that.
Could you have had a stuck valve or lifter and it came loose while disassembling it?

[smakcruiser]

It is possible. I am tempted to just put it back together and check compression again with a new head gasket.

[Heybuck]

Quite a few years back (about 45 actually), I saw a similar problem to this whereby a friends MG TD had no compression on one cylinder. His father had pulled off the head and found no obvious sign of a problem so he made up a plate and bolted it down on the block. He had an air line fitted to the plate into which he put compressed air.

The end result was as I recall the piston had collapsed around the rings thereby letting all compression blow by. I have no recall at all about what the top of the piston looked like but it must have been reasonably OK if my mates Dad went to that amount of trouble to source the problem

I know that its a hard call comparing a Pontiac engine to a 1952 MG engine but when I look at the stain mark on the cylinder bore, it reminded me of what I had seen all those years ago.

Just my

Ian