Hello folks, I'm wondering about machining D315 cylinder head to convert to glow plug combustion chambers. How to I get machining specifications. Would caterpillar supply the required information?

Just bore to receive the new chambers, 0-rings still does the sealing.
 

Ok thanks om.

My local caterpillar dealer called it indexing. Said you are locating glow plug out of the way of fuel line. By trial and error using different thicknesses of glow sealing seats until you find a location so fuel line and glow plug dosen't interfere with each other.

That's different thicknesses of precombustion chamber seats.

Caterpillar said can't get all the different thicknesses of seat seals anymore. I would think there are more options for seat availability with aftermarket. But,I was also told by very knowledgeable mechanics this is a situation we're only caterpillar seals should be used if possible.

I will try to clarify a bit better. If there are four different thicknesses of seat seals available, you would purchase a set of four for each cylinder. Install precombustion chambers one at a time using trial and error until your indexing is good enough. Most likely you will only get good enough, unless you get lucky. You only get what the shim thickness will allow.

I over heated a D6 9u with the Cat 318 engine and the same pre combustion chambers as the 315. A faulty temperature gauge from good USA company. Well 20 years ago so, I never thought to look if it was made in the land of almost good enough. Thinking the worst pulled the head. Mr super finicky that was always wanting perfection that lived down the road said the head is good. With a new gasket put it back together. It still had gases in the radiator. So we cleaned the pre chambers looking for pin wholes, none. So a new set washer seals under chambers. Still pushing water. Friend down the road says he had no tooling to clean the seats, and he felt they should be good enough. So we started checking all the seals. Cat as well as some after market ones I had where steel with copper paint. So he ordered copper washers from McMaster-Carr, that fit nicely. They sealed end of problems with that head.

So I would advocate you try different washers from other sources if Cat only sells one thickness. My after market washers maybe a bit softer than the old Cat ones. But the new Cat ones are to hard if the seats are not perfect. And if worst happens, I would think you could use a belt sander and thin down one until you get the fit you need. Because as I understand the old Cat system was trial and error fit until you got it where it would clear the fuel lines. As Mr. SWB has pasted I have no idea of who to get help for my one off things now. He could be a grouchy O'l cuss but always got my old crap put back together. I found if you could present it as a challenge to his ability, why of course he could find a fix. Rest in peace Zorn.