head cracks

[harvey]

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alright guys. maybe i'm crazy, but that doesn't look too good.

she's a '79, with a 1.6L installed in '90. according to the previous owner...

i pulled the head to change the gasket, and when i started cleaning it up, i noticed these little cracks between each intake and exhaust valve. they don't appear to go deeper than the bottom of the valves... the more i think about it, it shouldn't effect performance if the cracks don't actually connect the intake and exhaust ports... correct?

anyway... what would cause these cracks? what should i do? put it back together and forget about it? take it to a machine shop? replace the head?

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more pics
http://www.flickr.com/photos/82383094@N00/sets/

[libbybapa]

Ignore them. They are completely normal and not a problem until they are yawning chasms and penetrate the waterjacket. You will find those same cracks on every head that has more than a few miles on it.

Andrew

[harvey]

thanks andrew. it's the first rabbit engine i've taken apart. last head i pulled off was a '31 model AA. bit of a different setup.

i had a shop replace my injectors a few months ago. is it worth taking them out to clean the swirlchambers?


george

[A1-2-A3]

My head had zero cracks and it had enough miles to wear the valve guides right out. I found it very strange that it had no cracks because everyone says they ALWAYS crack.

[Fatmobile]

I had a used 1.5 head with no cracks, it's the only used head I've seen without them.
The one in the pic doesn't look bad.
Most of the time, if the cracks are too big the head is also warped.

[A1-2-A3]

Mine has the large oil return and its a 1.6L head and no cracks. I think I do have pics of it somewhere after the rebuild with all new gleaming valves.

[harvey]

i wonder if the time and place of production has anything to do with it. maybe slight differences in the aluminum alloy over the years. i think mine was made in brazil around 1990.

[harvey]

another stupid mistake.

i turned the crankshaft a bit when i was under the car, forgetting that i'd locked the camshaft...

it still turns fine. do i risk anything by leaving it?

all i can find for replacements are "g-grind" camshafts; which appear to have a different lift. a post on vwvortex says it'll give more power, but i don't know how that applies to diesels. any opinions?

[surfcam]

I would be tempted to try it but maybe that just me on the edge. If you do I would take the cap off stuff around it with paper towels file it back a bit on the sharp edges so it won't act like tool bit on a lathe. Someone out there probably done this to maybe they will chime in.

[Fatmobile]

Coke???
Any opinion?
I think Coke did this once and kept using the cam with no problems, those sharp edges scare me though.
I think I have a spare used cam if you'd like to buy one.

[coke]

Driver her. I had a car with a camshaft that looked like that. Saga began at 180k miles. Retired with 277k miles.

Just verify the camshaft still moves without binding.

[Op-Ivy]

Wouldn't the camshaft now be off balance because of this?

[coke]

Mine was cracked in the very same spot and I just drove it. Put over 100k miles on it that way and never had one single issue with it at all.

[harvey]

i still have the piece. i could just pull the camshaft and weld it back on... or brazing might be better - lower heat.

[Fatmobile]

Don't worry about it setting it off balance.
I doubt the cam is balanced to begin with.
All the weight is close to the center of the spinning object so it has less of an effect on balance. It spins half as fast as the crank and has a very small diameter compared to it.