ALFAGTV6.COM

[Nikoror]

Hi,
the engine blew the head gasket and I can't get an opinion on why and how it happened from anyone. The engine had about 1500miles on it (more than half of that was break-in and tuning the maps for the injection). We were having blue smoke out of the exhaust (which we think was from running a bit too rich during break-in and not having the rings seat very well), but at some point (after a couple of auto-x) we got white smoke and the water in the overflow reservoir was boiling-over as soon as the engine would warm up. We were running some pretty advanced ignition, but it doesn't look like the engine was detonating. Attached are some pictures of the headgasket after we took them off. Btw this is the 3rd set of gaskets that the engine blows in less than 2000 miles with a full-rebuild the last time. The headgasket is the Guarnit auto one (not very performance oriented), but I don't want to blame it on the headgasket alone (for now ) There was a single case of letting the engine overheat (at idle with the radiator fan off), but i'm not convinced that's it. The heads are straight and are currently being checked for cracks. Liner protrusion was within spec on all except 1 cylinder (#1), but there are no problems with the headgasket on number 1. As you can see from the pictures the headgasket seats really good on the liner side and was leaking from the head side (whatever that means...) Hope you have some idea. Oh, and one of the studs is stretched (bottom 3-4 threads are smaller in diameter than the top ones, not very clear from picture) That was on the right side (cyl 6) of cylinder 5 (headgasket blew between 4 - 5 and 2 - 3)...

[Nikoror]

more pics

[x-rad]

when mine blew...it looked exactly the same...between the cylinders rather than on the side...Guarnit gasket too!! Actually, I had three Guarnits blow out at the same spot (figured it was the block as I switched three heads and liners) you can see the burn through on the middle ring of the middle gasket...

kinda looks like you burned through at two cylinders? and there seems to be excessive corrosion for 1500miles


I switched to Reinz gaskets and another block...very nicely made with all the needed rubber rings BUT $$$

Have yet to run the engine, though

[Nikoror]

Yeah, the gasket is deffinitely low quality, but I'm not sure it's the only thing that's wrong. Will check everything I can think of on the block... don't really want to buy a new one if this one is okay.
Most of that is actually not corosion, but the headgasket-leak-fix-s*it we put in the engine (we were deseprate... ) that is what it looks like after sitting for 3 months

[x-rad]

It's really frustrating...i was dealing with this same problem for months and finally used another block

I hope for you it is just the gasket quality.....and a bad stud

[Barry]

I have used Gaurni Auto gaskets for ages and have never had problems..IMO,Its a good quality gasket..

That stretched stud is a problem..once the yield lets go its like no nut at all...
Must say,Ive torqued up tp 120N/m already and did not stretch a stud like that..

A flat edge(accurate)across all 3 cylinders and again across the block..Your looking for the middle of the block "sagging"

[Barry]

fcukin double posts!
Nothing works here anymore!

[Nikoror]

It is very possible that the stud was stretched while I was checking the torque values before disassembly It makes no sense if it let go as it is on the opposite side of the cylinder (i.e. between 5 and 6 and gasket blew between 4 and 5)

We checked liner protrusion (flat edge across the block) and the deck. There is a low on the exhaust side (above exhaust valves) between 4 and 5. actually, the front and back are low rather than the middle sagging I'm trying to figure out what needs to be done if we want to deck the block...

[x-rad]

just thinking out loud...but to deck the block:

remove studs
check square in relation to crank ..check liner bore depth and liner length

plane upper deck and/or mill liner or mill liner bore as necessary (which comes first I have no idea)

sounds like $$

[Barry]

Remove studs-deck block-machine down liners.-finished.

[x-rad]

Barry, what is the most you can take the deck down assuming standard S-pistons?

[Nikoror]

Remove studs-deck block-machine down liners.-finished.

So the only possible problem could be the piston-valve clearance?

[Barry]

The max is to just clean the block deck...and only where the gaskets are working..If there are pit marks where the gasket is simply not doing any work,leave them..Minimal amount needs to be removed.
The same amount from both side..
You will find the pistons will not need clearencing as the usually have way more clearence than will be removed from the block..

[Nikoror]

We measured the block deck and we got this: On the passanger side (right) the front of the deck is lower compared to the rear. On the driver side the rear is lower compared to the front. The difference is in the <0.1mm range. This is measured by checking the clearance between the deck and a straight edge on top of the liners of each bank.

My question is if this is a possible explanation: On the passanger side the front is lower, so that the head after torqued down sits crooked with the rear rising a little. On this side the leak was between cylinders 2 and 3. On the drivers side the rear is lower, so the head sits crooked with the front rising. On this side the leak was between cylinders 4 and 5. Does this make sense, i.e. should we deck the block or look for other reasons for the headgasket problems? I really don't want to buy a new engine

Nick

[car guy]

Very nice photos of the head gaskets and block.