prechambers cracked

[rabbitman]

Today I pulled the head off and my faithful old bunny to change the HG to fix the oil and coolant leaks and while inspecting it and found that all of the PC's are cracked. Some are starting a second crack too.

Then while cleaning it I blew air into the PC from the HG side with the injectors in and 3 of 'em popped right out!!! One looks like it's been dancing around for a little while too it's kinda scuffed on the sides.

BTW this is a topline head with about 80,000 miles on it. All of the valves have small cracks between them that are not too big.

So should I just peen around the PC's and call it good? I have another head with good PC's but last I tried all but one was stuck. I'm heating the head now so if I get 'em out I'll use 'em I guess.

If they're stuck what's my options?

[rabbitman]

Just check and the PC's from the topline head are NOT magnetic while the ones from my mexican "F" head are. FWIW the F head also has "ME" cast into it. This is all mech stuff.


I got the PC's out of the vw head and they're also cracked but not as bad.

[rallydiesel]

I would just peen them back in. I've seen lots of pre-cups with fine cracks but never actual pieces missing from them. The few pre-cup horror stories I've ever read about dealt with the whole pre-cup falling out for whatever reason.

[R.O.R-2.0]

Just check and the PC's from the topline head are NOT magnetic while the ones from my mexican "F" head are. FWIW the F head also has "ME" cast into it. This is all mech stuff.


I got the PC's out of the vw head and they're also cracked but not as bad.

any head that has ME, or ME3 cast into it, means its made in mexico.

[rabbitman]

I peened 'em in and put it back together. They weren't super tight like I wish but it'll have to do. If I'd never removed the head I wouldn't have known they were loose anyways if that makes any sense, so now I'll just try not to think about it.......

While I had it in the shop I changed out the IP bushings which had tons of slop. Put it back together and it still runs perfect accept for the slightly too retarded timing that will be fixed today.