Ok -- now i need to draw on you all more experienced than I am.

I got the head off, and this is what I found (www.pbase.com/macisaac/volvo).

When the bolt holding on the air filter worked its way loose, the washer went into the cylinder, and as you can see, was banged up against the top of the combustion chamber, was destroyed in the process, and the pieces have welded themselves to the top of the piston. There is a piece about a centemeter long sticking straight up. The sides of the cylinder don't seem to be scored. But the top of the piston has all of this washer on it now, and the bottom of the head around the valve for that back cylinder is a bit scored.

I am guessing I can just snip off the bit of the washer that is sticking up and put her back together. Opinions?

Also, a bit of coolant spilled into the cylinder, but I wiped it out. Anything to worry about?

Finally, I could get a head gasket a little thicker than normal to lower the compression and cut down on the persistent but minor pinging I have when accelerating hard. Good idea or no?

By the by, has anyone had anything large than a washer make its way into a cylinder and attach itself to a piston head, or do I win a prize?

Greg

About the piston/washer bits, I agree with the other, just clear her up.

About the spilled coolant, if you wipped it out, there's no problem. If it was a lot of coolant, some might have passed the piston and ended up in the sump. In that case change your oil.

A B20B has a compression ratio of 9.3 which might be a little bit high for US gasoline, I'm not sure. The B20B has a 1,2mm thick head gasket. The B20A's is 2,0mm thick.
Unlike the others here I would say there's noting wrong with putting on the slightly thicker head gasket. However, if there are other people with B18B/B20B who can run regular gas with no pinging, there will be something wrong with your ignition, or a too lean mixture. In that case, use the original gasket, and fix what's wrong.

cheers, Ben
--
P131, '65, B20B+M47. P131, '69, B20E+AW71L+LSD. (www.tinustechniek.tk)

My Condolences Greg ..... but I do agree with the other guys .... BTW when are you headed back to the Maritimes ??

Brett
--
Brett Sutherland & the 1.5 million mile 122 CANADIAN www.ecvintagevolvo.com

You may be lucky, i have seen top ring lands damaged which jams ring in groove and leads to piston burning out through blowby. Time will tell.

Well, I ran a 5/16" UNF hex nut through a big bore engine in late 1995.
It was pretty bad. Actually the piston and head were still usable but
the nut got between the piston and the flat surface of the head and cocked
the piston in the big-bore cylinder, splitting the cylinder wall from bottom
to top, dumping the coolant into the crankcase and leaving a crack in the
cylinder big enough to stick a spoonhandle through. Pretty traumatic sounds,
also. The only block I could find in Panama at the time was apparently a
74 or 75 8-bolt, so I now have a 6-bolt engine built up in an 8-bolt block.

I think I would try to get those steel pieces out of the top of the piston
or at least cut them off flush (Moto-tool with #409 abrasive cutoff disks).
They will certainly contribute to pinging.

And put your system together so that nothing smaller than a bolt is
exposed to the inside. I know what nuts can do and you've seen what washers
can do.

I agree with the other guys - don't get a fat gasket.
--
George Downs, Bartlesville, Oklahoma, Central US

I am guessing I can just snip off the bit of the washer that is sticking up and put her back together. Opinions?
IMHO if you had decent compression and a tight bottom end I would put it all back and go for it. B18 is tough.

Finally, I could get a head gasket a little thicker than normal to lower the compression and cut down on the persistent but minor pinging I have when accelerating hard. Good idea or no?
That might do it but the real solution is to tune your car so it doesn't ping.
And you win the prize as far as my experiences go.

B18 is tough

I am sure the same thing goes, but its a B20B

Greg

That might do it but the real solution is to tune your car so it doesn't ping.

Yep. No reason for a B18 to ping if it's tuned halfway decently. A B18D will run on 87-octane just fine.

I would NOT go to a thicker head gasket. All that will happen is that you'll lose performance, and the motor will require more timing advance to drive decently, which will bring the pinging back unless you correct what the real problem is.