pre chamber cups ? !?!

[K10ANDY]

i was checking my head last night with about 90 psi of compd air and one of the cups popped out! The others leaked a bit so i took those 2 all the way out and cleaned everything and used loctite sleeve retainer stuff on them . is it bad that they leak into the cylinder ?
i didnt find a crack from the one cyl that had coolant in it which is good . my truck is also an 84 but it has the kidney coolant hole but stamped rocker arms ... ?

[john8662]

With the pre-cups, there isn't much conern with them being loose. If you blasted one out with 90 PSI of air pressure Id' say it was still pretty well seated in the head. The cups are just pressed in, the are snugly fit, but not pressed in by much more than being driven in. There is no need for any sealant on the cups when re-installing them, just align and drive them back in place, making sure they make a flush mounting with the surface of the head. The head gaskets have a sealing ring that cover the part of the pre-cup that's not in the firing ring, so if they leak, the gasket is there to seal them.

[K10ANDY]

thanks John .

[FWBennett]

Can I interject a question here - I purchased a rebuilt long-block - after installing it was VERY hard to start the first time, remained a lousy start - when I put my foot into it - I would get lots of black smoke and the blow-by seemed excessive for a new motor. I took it to the mechanic to have the timing set and have it looked over. Eventually it stopped running alltogether and he couldn't get it started. He did a compression test on 2 cylinders and got 180 and 220 lbs so we wrote it off as bad - I had to pull it and ship it back! The rebuild shop said there were 2 inserts that were very loose - he described them as inserts in the head that the injector and glowplug go into - I'm assuming that it's these pre-injector cups that he was describing and you're talking about. John makes it sound like them getting loose is no big deal - could it affect the compression? WOuld it keep the motor from running - you've got me concerned - After my motor being gone for a MONTH! and my Suburban being basically down since Mid November - I'm wondering if this fix is REALLY gonna fix my motor - I went with a long-bloc instead of tearing it all down myself because I didn't want my Suburban down very long - wellll so much for THAT theory!!
- thanks!