Hey I'm rebuilding a S5 TII engine and i have everything but the Water jacket coolant seals. I could just go with the stock mazda seals but the reason I'm rebuilding the engine is because of the water seals. I heard there are allternatives to Mazda seals and I'd rather try something else or a different type of seal (ie. not cheap mazda rubber). What are there and where can I get these other seals people sell for my rotary rocket?

 

Try Atkins or Rotoryaviation

 

Atkins sells oem coolant seals repackaged. Rotaryaviation, and I think Hayes, sells teflon encapsulated inner cooler seals with basically stock outers.

These inner rings are apparently off the shelf from Mcmaster carr, not developed for the rotary specifically. As such they are simply a close fit as far as diameter of the o-ring and cross sectional thickness. They are actually too small in diameter and must be stretched during assembly slightly, and they are actually too fat when compressed in the groove in the iron. The FC irons already have thin, weak castings that hold the water seals in place, and sometimes these castings break on their own due to age/heat/stress. Well, these thick seals add a lot more stress and can actually cause the jackets to break more rapidly, CAUSING the very coolant leak that they are meant to prevent. The reason that they seem to seal better (in some people's opinion) than stock is that they are oversize and get crushed when installed. Also, by it's very nature, I feel that the teflon coating is too slick to actually do the job of a seal, which is to grip the surface adjacent to it. The only real good thing about these is that they are reuseable several times, but the outer rubber seals are still usually going to stretch during disassembly so you'll still have to buy more next time.

Pineapple has recently started selling their "heavy duty" seals which are said to be different from stock or these teflon encapsulated ones. I have not had a chance to see or use their product, but I can say that in the past I have had issues with PR's service and product backing so I do not plan to explore them.

With some examples making it to 200+k miles, I do not see that stock coolant seals are a problem or are inferior as is...the failures happen for other reasons most of the time IMO.

 

I was thinking along the same lines. I don't understand the point of these "upgraded seals". 99% of the coolant channel failures that I have seen or heard of are due to the groove wall breaking away and allowing the ring to slip out. No seal is going to help that.

I believe that it's the same reason that 1st gens are running around with the original seals. The grooves are cut into the aluminum rotor housings on those engines, which tend not to corrode as deeply or as readily as the iron side housings.