Installing prechamber D318
Been messing with this engine for a week. Didn't know I had a later model head on it. Ordering parts and nothing fits. Finally find I have a head that has a larger size prechamber. That story is in the ( for sale/ wanted) topics.Thanks Old Magnet for getting me to the right parts. I install the prechambers without the adapters. Then go to install the Adapter and the valve cover base is in the way. CRAP. Didn't even need the retainer installation tool. Pull the chambers back out. Good thing I did. The proper cat crush washer(5B3265) was to big and even though I tried to center the washer on the head, one only had 1/16 inch of crushed area on 2 of them. The washer is 1.130 id X 1.5 od. The prechamber has a relieved area at the contact area that is .98 dia. The ring can get off to one side as much as .150 and nearly miss the sealing surface. The ring widths only .185. Someone said they liked the Mc Master Carr crush rings better (94397-A001) 1 in x 1.5 X .064. I am going to relieve the ID just enough to get the ring over the threads (1.100). That will get me .030 more contact. Them I am going to center the crush ring on the chamber and use 3 little spots of 2 part epoxy to center up the sloppy fit during installation. All this sloppy fit may be why prechambers leak, and maybe all this works if everything is brand new but we are not working with new.
Last edited by oldbeek; 07-10-2019 at 11:59 AM.
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