Sutiable metal front cover o ring? Pics inside
 

I work at a powersports dealership, and have been reading up about possibly using a metal washer in place of the front cover O-ring. I found that the drain plug crush washer for an Arctic Cat 1100 Turbo snowmobile is the same size as the o-ring, and it is a hollow crush style washer, it is taller, but will collapse. Do you think this will work? I will try it on my spare motor, to see how it collapses, the metal washer is hollow, not solid, and is designed to crush about 1/2 its height.

Metal washer on left, new Mazda o-ring on the right:
https://www.rx7club.com/attachment.p...1&d=1425743430

https://www.rx7club.com/attachment.p...1&d=1425743430

New Mazda o-ring on top of metal washer:
https://www.rx7club.com/attachment.p...1&d=1425743430

https://www.rx7club.com/attachment.p...1&d=1425743430

The Arctic Cat part number is 3402-011 and retails for about $2.

The only issue is that the metal crush washer is very slightly smaller inside, but I will install it on my spare motor, tighten the front cover down with the old gasket, and take it apart to see how it looks first. I don't think it will be an issue.

why not just run the later FD, or Rx8 front cover gasket? it eliminates the o ring.

N390-10-502 or N3H1-10-502B

I have a S4 with the small front cover, I think the metal gaskets only work with the S5 and later.

for the 1996 and later FD's Mazda removed the o ring, and just used the metal gasket instead. the 89-95 engines have a paper gasket with the nylon retainer.

I have used them on S4 and pre-'85 engines. No problems unless "not leaking" and "maintaining oil pressure" are problems.

The original o ring works, I would be very hesitant putting in a crush washer as there is no compliance for expansion and contraction

I found the original o-ring did NOT work in my application and every time I took my motor apart I was fishing the o-ring out of the oil relief regulator galley where it had gone on vacation.

I finally press fit a dowel in the front side housing that interfaces with the front cover. Now there is no where for the o-ring to escape to when the front cover gets pushed away from the front side housing.

https://www.rx7club.com/attachments/...icture-050.jpg

I found the O-ring in the oil filter pedestal once! I have no idea how it made it past the oil cooler.

That was the Incident where I stopped being so cheap and paid the 18 bucks for the RX-8 gasket.