I'm doing various transplants from my 220D donor motor to 240D that is actually being rebuilt. I've noticed that the injectors for the 220 ('69) had the special machined steel heat shields originally installed. My new gasket set came with those also. However, the injectors from the 240 ('74) had no machined heat shields in place, but rather a small soft-looking washer with a flange that extends into the hole in the prechamber. The hole through the washer is consequently much smaller than the hole into the prechamber (as opposed to the hole throught the machined seals, which is quite large). They look like they would be very difficult to remove without damaging something as one would have to somehow punch them out through the glow plug hole. I think that they will still seal, but my question is were there two kinds of seals in use? Should I try to get the little washer thingies out so that I can put in the heat shields? The 220 had been rebuilt at some point in time and new pistons with the star-shaped recess put in along with the newer rounded tip prechambers (yes they bored it out to 91 mm!) So I wonder if the older flat-ended prechambers came with a smaller hole and I'm supposed to put the heat shields in on top of the washers?
Does anyone out there know?
Thanks and have a great day

The larger heat sheilds (seals) are a replacement for the early ones that went into the hole. Remove the old ones and just install the new ones. It makes removal of the early ones easier if you use a tapered punch to "rock" them back and forth. Try to find something close to the right diameter so it doesn't go through too far and knock the diffuser ball loose in the pre-chamber.
Regards,
Randy D.