Cylinder head reconditioning and gasket replacements 1.9 DG

[Mohamster]

Haha ... Petrol vs diesel banter. Love it.

On another note eeeeeeeeek!

[Mohamster]

So an update and some thoughts.

Having taken cylinder barrels out I now have gotten my head around the idea of lapping. But not sure
If lapping will be enough to fix the damage observed. Perhaps it will need machining of the cylinder face and then lapping so I can make a seal.

My thoughts are to machine and lap so Ican make a seal without compression ring. Is that even possible for waterboxer engine? Also wondering whether that could introduce its own problems with the distance between the piston and the cylinder face ... Related to problems in aftermarket Pistons (see article)

http://www.gowesty.com/tech-article-details.php?id=82" onclick="window.open(this.href);return false;

Way I see it the piston top (head?) is gonna be about a millimetre or so closer to cylinder face depending on extent of machining.

Any thoughts from wise folks? Also any recommendations on machine shop nr Manchester that could do the work. Met someone at the northwest van fest but lost his number in phone breakage debacle

Thanks again for all advice so far

[ajsimmo]

My thoughts are to machine and lap so I can make a seal without compression ring. Is that even possible for waterboxer engine?

No. (Well, I very much doubt it, anyway.) It is possible with AMC air-cooled heads because they are cast and machined with a step of extra material in lieu of the seal ring. This step is not there in your old wbx heads.

Why not just fit the rings?

Also wondering whether that could introduce its own problems with the distance between the piston and the cylinder face ...
Way I see it the piston top (head?) is gonna be about a millimetre or so closer to cylinder face depending on extent of machining.

Correct in principal. Great for increased compression, and maybe improved squish, but would you trust it to seal? You'd need to check clearances between piston and valves too.
Another issue this would create is that the head will pull down closer to the case, the water jacket seals would be over-compressed, and may fail because of it. A head stud could even bottom out in a captive head nut (unlikely, but possible).

I wouldn't do it. I'd just fit a better head.

[itchyfeet]

Looks like burning to me.

Agreed, looks like water leak into combustion chamber which has turned to steam and the steam had cut away the aluminium, scrap I'd say.

If barrel seal groove has rusted away you need a good replacement barrell and then it needs honing for the rings to bed in or preferably new rings.
If you fit crap back history will repeat itself.

[itchyfeet]

Another issue this would create is that the head will pull down closer to the case, the water jacket seals would be over-compressed, and may fail because of it.

Correct
I measured the gap and seal thickness when I was concerned about the thickness of dirco and its curing time, there is virtually no gap other than 4mm of rubber.