thought you might get a kick out of this

[chachi]

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[Amskeptic]

i kept getting 0 on #3 so i pulled the head - melted carb or manifold blob holding the valve open:

That is one for the books. Good grief the things these cars have to put up with.
Valve still useable? Will the Blob work out of the port?
Colin

[Hippie]

Dang. Looks like something hit about 1150 degrees F for a little while to melt that aluminum.

[chachi]

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[Hippie]

Borrow one from Autozone?

[tristessa]

That .. is .. AWESOME.

I'd be tempted to leave that head exactly like it is .. and stick it on a shelf. If I had another head laying around anyway...

[chachi]

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[chachi]

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[Hippie]

Me I just alternate left and right heads with one initial snug down pattern, then the final torquing pattern in three steps...still alternating heads. I dunno.

[Amskeptic]

i got the blob out pretty easily, and although i didn't take the valve out all the way, the valve and seat looked pretty good to my untrained eyes. i took the cylinder off and the piston looked very good, like it's recently new. rings looked good. put everything back on and compression tested but only got 30 on #3 (the one with the rock in it) and 90 on #4 (which was 140 before tear down). my head reattachment process needs work obviously, what are you folks' must-dos for cylinder/head reattachment?

Did you fill the combustion chambers with liquid on the bench to see if the valves were sealing?
Did you lap the valves into the seats a bit?
Are you using head sealing rings?
Did you clean and check the mating surfaces of the heads and cylinder barrels for any nicks?

[satchmo]

i got the blob out pretty easily, and although i didn't take the valve out all the way, the valve and seat looked pretty good to my untrained eyes. i took the cylinder off and the piston looked very good, like it's recently new. rings looked good. put everything back on and compression tested but only got 30 on #3 (the one with the rock in it) and 90 on #4 (which was 140 before tear down). my head reattachment process needs work obviously, what are you folks' must-dos for cylinder/head reattachment?

Did you fill the combustion chambers with liquid on the bench to see if the valves were sealing?
Did you lap the valves into the seats a bit?
Are you using head sealing rings?
Did you clean and check the mating surfaces of the heads and cylinder barrels for any nicks?

And how about lapping the cylinders into the heads a bit?

[chachi]

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[Westy78]

Am I missing something? How are you doing a compression test with no rockers and push rods?

[satchmo]

i've never lapped anything before that didn't involve a cat. is this a bentley problem or can you walk me through it a little? i poured gas into the intakes of 3 and 4 and they both held it ok. i can definitely pull it again and check for nicks, etc. i did a search on head sealing rings and got the oval copper heat exchanger to head sealing rings, is this what you're talking about? i don't have the heat exchangers on at this point, no rockers or push rods either.

last night i re-torqued it and tried again this morning (battery was dead, had to wait for the missus' car for a jump) and got 90 on 3 and 30 on 4. i think they'll both be ok if i can get this thing on right. i'm tempted to pull it, give it back to trafton and say make it right! tell me i can do this myself!

You can do this yourself. If you took the cylinder off the piston to check the rings, then the seal at the rings is suspect at this point and you won't know true compression until the rings have a chance to settle in again once you get it running for a while.

Regarding lapping, I like to lap the top of the cylinders to their respective head bores prior to final assembly as way to make sure the surfaces are parallel and the mating surface is smooth as glass. I use valve grinding compound and just rotate the cylinder in the head bore a while, then clean all the valve compound off. I also use some copper spray on gasket stuff from NAPA on the cylinder to head sealing surfaces to give the best chance of good seal on the initial start up (I think this is a can't hurt/might help thing, and the way I use it is by spraying it in a cup, then brushing several coats on each surface prior to assembly. I do it because the last thing I want on first start is a channel where blowby can get an initial foothold before the engine heats up and expands.)

The head sealing rings Colin was referring to are thin crush rings that VW originally had between the cylinder and the head sealing surface. Probably a moot point; if you didn't find any rings in place when you removed the head, then there is no need to put them in.

One other thing to check, since it sounds like all kinds of molten metal was flying around at one time, is the clearance between upper cylinder cooling fins and the head. There needs to be adequate space here so the head bore will seal against the upper cylinder wall rather than the head hanging up on a fin or some other protuberance on the cylinder as you torque it down.

Good luck, Tim

Tim

[chachi]

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