pre-com. chambers

[Spore]

Hi all-

I recently removed the head frorm a 3b. The pre-combustion chanbers all seemed very loose; you can move them back and forth in the head with your fingers. When the head is set face down on a table, the chambers all fall out (not just one). I am more familiar with newer diesels where they snuggly fit in the head and tools are needed for removal. Anyway, this doesn't seem right - how tight should they be seated in the head?

Help?

 

[brownbear]

that sounds odd, I thought they would be a pressed fit..... But I have never had the head off mine.... I look tonight at the FSM to see how they remove them in the manual.

 

[cruiser_guy]

They can be quite loose. Chances are the pre-cups and the head are both cracked anyways. Have you magnafluxed the head yet or examined the pre-cups closely?

 

[Spore]

Yes, the head and pre-cups have been checked. Everything checks out fine except for this "looseness" thing. The manual I have simply calls for a screwdriver to remove them and soft hammer to tap them back in, but that suggests to me that they shouldn't be as loose as they are.

 

[Deny]

When I was changing the head gasket on my 3B, the cups were all cracked, but still had to give them a few wacks to get them out. The new ones had to be smacked quite a few times. I don't think they should be loose at all.
Cheers,
Deny

 

[brownbear]

Call OZ where they sell the replacement heads and ask the question.

Hopefully an expert head guy will know. Then post it here, so we can all be experts

 

[cruiser_guy]

When I had a damaged head repaired the guy used a center punch around the edge of the pre-cup to keep it in so te looseness thing is likely not a big concern. They are sandwiched between the block and the head when it is all together and they have an indexing lobe as well to keep them from rotating.

 

[UpsideDown]

The pre cups should be a slight interference fit. I would recommend installing new cups if you have had the old ones out for any reason.

Rob Lassman may have some available. (Radd Cruisers)

 

[crushers]

the precups can not fall into the combustion chamber since a good portion sits pinched between the block and the head outside the chamber.
if the cups are in good shape then red locktight them into place and set the head back on, you will be fine.
if they have ANY cracking then replace them with new.

cheers