Just wondering if anyone has tried using viton o-rings for coolant seals?
I have used the FEP encapsulated silicone ones before, but they are a pain in the ***, and sometimes don't seal as well. Mcmaster sells viton o-rings in the same size for $2.70 each.

Seems to me viton would be a better choice, it is softer so would seal better, but has similar chemical and temperature resistance to the teflon encapsulated ones....

I am getting ready to rebuild the 20B again so I can add some reinforcement to the irons, so I am thinking about using these viton critters for both inner and outer coolant seals, just wondered if anyone had and feedback on them...

 

Yes, we used a Viton material in our Heavy Duty Water Seal Kit. It only took 7 years of testing to get the right specs and be assured the product would last 100K+ miles before selling them to customers, so they have only been on the market 3+ years at this point. Not one complaint so far, and it's the same material we use in our 5 year warrantee motors. Just be aware that you cannot buy them from McMaster Carr...we had to try many variations to get something that worked for extended periods and it required using a supplier to work with us to source a specific non-standard durometer, and play with diameter, length, etc.

 

Blake that is pretty cool, I did not know you guys had that available.

Unfortunately, it is way out of my price range. You guys got a sponsorship program? lol

I don't need it to last 100k miles, I will almost certainly blow it up way before then. What I do need is it to seal well and take a lot of abuse for 20 or 30k miles. If you don't mind, can you tell me what problems you had with just the standard viton like I am considering?

 

I can't be specific because I wasn't around back then and I'm sure Rob wouldn't want me to save our competitors the R&D to figure out a way to make them last, but you can imagine a variety of seepage and other failures. We also wanted them to be re-usable, since at the time we were building a lot of race engines that needed frequent refreshing. However, they are great for the street as well. We have had customers overheat their engines so bad that the plates turned blue and the cooling system was still holding pressure!

 

well i guess if noone else has any input i'll just order a set from mcmaster and see what happens... the nice thing is a whole set for the 20B inner and outer is only 30 bucks

 

i guess this is one of those things where i shouldn't "worry about what the playaz are doing," but i just can't wrap my head around that. what if you don't blow it up?

 

well if it lasts 50k miles and the coolant seals fail, i'll be happy as ****. coolant seals are cheap and not that hard to replace.

still tho...i dont see any reason why they shouldnt last at least as long as the teflon encapsulated ones. What I dont want is to get the car hot and have them start leaking after 5k miles. I'm willing to trade longevity for short term performance

 

which is why, i'd say just use the stock replacements. they are the same as the 12A and 13B ones, right? (i don't have a 20B). i know you can buy them separately from Mazdatrix. i bought some late last year and the prices were okay, even on my tight-*** budget. not trying to tell you your business, but that's just how i see it.

 

i think you missed my point. i dont expect my seals to last 100k miles, but I do want them to survive 15-20k miles of heavy abuse. stock mazda seals won't do that. teflon encapsulated silicone ones will, but they are a pain to install and tend to leak a little sometimes.

and as far as money goes- stock seals x 3 rotors=$180
mcmaster viton o-rings x 3 rotors= $30

150 bucks will feed me for almost 2 months (not counting beer), and my semi-educated guess is the viton rings will work just as well as stock, and be more robust

 

When you like rebuilding yourself, re-opening an engine is second nature. Hell I actually look forward to it.

 

Which version of the tephlon seal are you having problems with? I know there is a difference between the ones that Rotary aviation sell and the ones you get from McMaster-Carr. I have used the McMaster-Carr inners on 2 Fd engines and my own 91 NA and they were a perfect fit. No problems so far.

 

i love disassembling and rebuilding, myself. i embrace it. i guess i'm just not there yet on you guys' level. sure sounds like a fun place to be though .

 

 

Patman, which part numbers are you planning to use? I have used the Viton oil rings from McMaster with good results.

 

i will be using 9464K537 for inner seals, and 94245K52 bonded with high temp silicone for outers. Unfortunately, mcmaster has a long lead time, so I am going to stop in at the local grainger in the morning and see what they can do for me.

I have decided to put my motor back together without studding it for about 2 months, then when it gets cold here I will park it for the winter and stud it and put a cage in the car, so that should be a perfect opportunity to test these seals. Anyone who knows me knows that I am pretty good at providing a durability test lol. If it can survive a couple thousand miles of 750-800bhp on the street, its probably a pretty good solution.

Also for all you "always use stock" types, see link below for pics of the stock outer seals that disintegrated on my engine, probably due to an air bubble in the system

http://s149.photobucket.com/albums/s44/patmanxc/20B/

sorry for the poor quality, I cant find the cord for my camera so im taking all pics with my cell phone lately.

 

hey pat. couple questions. a search of the second part # yeilds this page

http://www.mcmaster.com/ctlg/DisplCt...88007245327955

it appears to be o-ring cord stock you are going to use. is this true? mcmaster recommends the cord to be vulcanized after joining. are you going to do this or simply join it with adhesive and rely on the expansion pressure to ensure a good durable joint?

there is another company similar to mcmaster that offers viton o-rings and teflon/silcone in whatever o-ring diameter you want. i was thinking of buying my o-rings from them but have not priced anything yet. i cant remeber the name but when i get home i will post the site for anyone who is interested.

ol an by the way.. hows my tII hood treating you?

 

i have not been able to find an o-ring in the right dimensions for the outer seals. the necessary size would be 11.5" ID x 3/32 diameter. (11.6x 2mm square is the exact size)

if you can find that that would be sweet, but it is not a standard aerospace size so it may be hard to get hold of, especially at a reasonable price.

as far as joining, i am certainly not gonna spend a g on a vulcanizing kit. I have heard many people say they have had good results with cutting at an angle and sealing the splice with high temp silicone, so I am planning to try that.

I am planning to tear my motor back down this winter to stud it, so I will hopefully be able to check and see how well the seals are holding up.

your hood is treating me fine, is your beast running yet?


also mcmaster has the inner seals on backorder right now, but i was able to get some from grainger, they will be here Friday. The grainger PN is 1BYU2

 

creavey.com was the place i was thinking of, but their site is down today or something. come to think about it i dont think their seals were very cheap either.

ok i might not know what im talking about here but i would be carful with your selection. both part numbers you supplied are Fractional Size 3/32". but they have an actual O.D. of 0.103" + or - 0.012" error where 3/32" is 0.09375". some parts could be as wide as 0.115"

i believe the outer coolant seal slot is only 0.120" wide and .061 deep. ( i might be wrong about that cant find my caliper) by the time you compress this 3/32" seal down to match the depth of the slot it will already be wider than 0.103" add some error to it and some thermal expansion and you know what happens.

i thought the seal diameter should be .093" or 3/32" not the 3/32" "Fractional Size"

i would probably buy the metric 2.4 mm cord stock from mcmaster. its O.D. is 0.094" and it has a better tolerance (+or- 0.008")

what do you think?

my beast?? no not yet i need some s5 NA rotors.. and i need to figure out if i want a street port or a half bridge.. so many choices..

 

yep, already figured all that out. the part number i listed should be 2.4mm cord stock....

 

Thx for posting that link! I'm really interested in that square cross section instead of the round tephlon I've been using (more sealing surface). I my may give silicone stuff a try on my 20b. Temp ranges are well with-in range.


Edit: Damn never mind! The square section is only available in Buna and not silicone.

 

i am not using silicone, i am using viton....

 

Update:

I broke another iron, so I had to pull the motor today. Just wanted to let everyone know that the viton seals look GREAT. They are still perfectly pliable and fit in the grooves just fine. I will be reassembling this motor with the same seals, and will most likely use them on every motor I build from now on.

Pat

 

Source:
http://www.rotaryeng.net/O-ring-size2.html


-Ted

 

what does the center of the rotor have to do with coolant seals?

also, in case you didnt notice, I just posted that these have been in a motor running 17-21 psi for the last month or so, and they came out in perfect condition...

these cost less than half as much as the TEC ones, but the price isnt really the issue. The TEC ones are too stiff. they don't seal well because the teflon outer part doesnt compress enough. They are also a pain to install, where these go in perfectly.

 

Why dont you take some pics of them. What do you use for oil seals, i heard viton isnt good.

viton isnt rated to 500f, you dont think it will be a problem? Anyway what is oem made of? I got lots of questions.