I know this idea won't sit well with everyone but...we're not all made of $$$





I've rebuilt about 6 engines and was wondering about re-using my old but inner and outer water jacket seals instead of paying for the mazda o-ring kit each time...just use a good amount of hi-temp silicone gasket maker ( Orange type ) And I'm not talking about factory o-rings...I mean like ones I replaces the last rebuild



Will this hold up? I hate wasting the $150 each rebuild for the o-ring kit when I just blow the motor about 10k miles later from running the **** out of it.





-Ryan

 

I've heard of people reusing the teflon encapsulated inner rings, and then you could just buy the outer. I personlly wouldnt try it but if you tear the motor down so much it might be worth it to you to test it out.

 

It sits fine with me.



Way back when money was tight in the 80s and we ran in the RS series I reused the "O" rings for everything.

The oil scraper rings are fine if you have never overheat the oil.



The black (outer) water "O" ring is fine if you cut it through at a steep angle and load it into the groove and notice that it is too long. Just cut out a piece to get the length right and add a dab of 100% GE silicone to the junction. Add a small bead of silicone to the groove. Put the junction at the top of the engine so you could see any leak. I never had one.



The compression "O" ring also can be reused. I lay in a small bead of silicone into the groove as I lay in the ring. No worries about excess silicone in the engine. I have also used aircraft teflon coated electrical wire, instead of the factory "O" ring along with the silicone. It worked just fine. So long as the compressed wire does not fill the groove when compressed. Otherwise you will hydraulic the groove and the stack will not pull up when torqued. A friend of mine (Bill Koch) uses regular 18 gage wire as the "O" ring and has had no problems. Put the joint on the intake side so there is no compression load at all. Put a dab of silicone on the joint.



In a bridge ported engine you cut through the compression "O" ring where the port is located. It still works, right?



After the engine sits a few hours after assembly, turn it over in the running direction to remove the excess silicone through the exhaust ports.



Lynn E. Hanover

 

Thanks Lynn for your helpful and detailed response.

 

Another option is:



http://fc3spro.com/TECH/MODS/ENGINE/INTERN...SING/tefsil.htm

 

is it required to use silicone sealant, or can you just install with the normal seals and set them with vasoline like in the manual?

 

If you are still talking about used seals, I would say use the silicone. New seals need only the lubricant to hold them in place during assembly.



Lynn E. Hanover

 

do you think its possible that the 18 gauge wire solution might even be stronger then the stock o rings? i would think so... the plastic is harder and there is less of it.

 

Just be careful that they aren't oversize. If you "hydraulic lock" a seal in an FC/FD engine, you can and will crack the O-ring seal land area out. Nothing good has even been written about that happening.



If I had more spare time, I'd assemble an engine with just Right Stuff sealant, no O-rings at all, and put it in my daily driver to see how long it lasted. I went overboard on one engine and the sealant pushed an oil pedestal O-ring into the passage. Even with no O-ring, it never leaked a drop. That was the same engine where I actually broke the front cover while trying to remove it. No gasket, just Right Stuff. Very tough *hit.

 

First of all think about the junction you are trying to protect. If the factory "O" ring were to be exposed to the combustion pressure (400 PSI?) would it hold up?



No it would not. Nor would just about anything short of a metal seal of some sort. So how does it work?



It just keeps the water in the water jacket. and the combustion gasses in the combustion chamber.



Well we know that. What the hell are you saying?



There is virtually no heat involved. With thousands of pounds holding the mechanical seal of the housing pressing onto the iron. There is no clearance at all. Zero with an addiditional 1,000 PSI holding back the 400 or 500 PSI gasses. Some pressure might work its way into the "O" ring groove over time. And then on shut down leak back out into the chamber.



So my friend who used just the wire and silicone was as close to the right seal as I was with my cool Teflon coated wire. It all works, just because there is little stress on that junction. Look at the stock seal. A chaep *** built up chunk of crap.



Remember the "V" shaped metal "O" ring protectors? Where are they today? Gone! Not needed then. Now gone. No need for them.



How about a Republic gas filled stainless "O" ring that expands with heat?



Much better but not at all needed.



Lynn E. Hanover