i use 2.0 mm off the roll nitrile cord outside
and 2.4 mm off the roll viton cord inside join with superglue,, pin in the housings/ plates with a dab of silicon will take severe 250 F overheat and live ,, will work with less than perfectly true housings - and cost peanuts compared to the OEM rubbish which is often faulty out of the packet |
I just built an engine for a customer, and the teflon o-rings were horrible. After the most careful assembly I find out that one has popped out ever so much has no been squished and is useless. I replaced them all with some Pineapple HD seals I keep in stock. Generally I'm pleased with RA parts, but this last engine really tested my patience. Maybe I'm more forgiving than others, but I'll be sticking with Rob's parts from now on.
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Ain't that somethin', Bumpstart! Could you go into a bit more detail? I may give this a whirl on my next teardown-build.
B |
Originally Posted by bumpstart
(Post 10383044)
i use 2.0 mm off the roll nitrile cord outside
and 2.4 mm off the roll viton cord inside join with superglue,, pin in the housings/ plates with a dab of silicon will take severe 250 F overheat and live ,, will work with less than perfectly true housings - and cost peanuts compared to the OEM rubbish which is often faulty out of the packet I experiment a lot myself and saw this on the McMaster Carr page. Isn't what your using the same thing as the Buna but only rated at 212 degrees? I know it's cheap as shit but why didn't you go with the higher temp rated Viton (392 degrees) instead? http://www.mcmaster.com/#catalog/116/3465/=acotin |
Originally Posted by t-von
(Post 10387990)
I experiment a lot myself and saw this on the McMaster Carr page. Isn't what your using the same thing as the Buna but only rated at 212 degrees? I know it's cheap as shit but why didn't you go with the higher temp rated Viton (392 degrees) instead?
http://www.mcmaster.com/#catalog/116/3465/=acotin while the nitrile 70 is somewhere around 110C -120 C ( 230 F ) http://www.transeals.com.au/seals/o-rings.php originally i trialled 2.5 mm nitrile ( $3 per metre compared to $20 for viton ) until i had a plate fail in the water groove ( to be honest the plate wasn't the best there before the build ) and the nitrile was in fact 100 % intact,, and if anything ,, a little too wide for groove in plate type grooves now i use viton,,,( inner ) and nitrile ( outer ) have done the last few years , no fail ( since 10 / 2008 ) for exactly the reason you posted above,, heat range and chemical resistance ( not that after 12 months i had any evidence the nitrile had suffered adversely , just a rusty plate groove ) there is a "jipped on O rings" thread in ausrotary and you can see for yourself the evolutions from nitrile to viton inner -- i surmise that as one of the US suppliers is supplying 2.55 mm,, and the other 2.4 mm then they have conducted there research on seperately rx4/GSL-SE/12a type plates for the large diameter and 13b s4/5 rx7 for the lesser one -- this would explain the differences in the diameter,, and the spread of good V bad results -- no one is picking the diameter difference needed for the different grooves here is my quoted reply to the similar question asked in PM- NBR 70 is exactly what i use for outer O rings the NBR usually comes also in 2.4 and 2.5 ,, though i dont recommend it for inside O ring duty as there isnt the same buffer for temp that viton has nitrile is rated to 120 C,, viton is rated to 205 C - i have however trialled nitrile there myself and the car went for 12 months before failing the groove in one of the plates ( suspect 2.5 was just a little too large for groove in plate style ) just to make it all stunningly easy - inner 740 mm , 2.4 mm CS per plate surface ( its fractionally long and fills outer edge of groove perfectly ) = 3m for engine - outer 930 mm , 2.0 mm CS = 3.8 m for engine you also need 4 x ( 15.8 mm x 2.4 mm ) NBR O rings for the engine oil passage dowels and 1 x ( 11.8 mm x 2.4 mm ) NBR O ring for the S5 type timing cover passage ( and nylon insert ) you will find with the length measurements this makes the seal slightly too long - on purpose,, as you will have to move all of the ring to the outside edge of each groove before it all beds down -- this will amount to the but joined ends being forced together under compression - a small amount of silicon in the bottom of each groove before you place the seal will hold it all in place while you stack ( a small amount will squeeze into the engine if you use too much,, but will not hurt anything if you turn the engine over and fetch the cut off out of the exhaust port ) once you get experience up you can get sparing with the silicon and only use a dab here and there to hold the seal in place - glue ends of the roll with superglue - you can use superglue on just one end,, and join them alternate method is to dab both ends in glue, hold together and dust with a little bit of baking soda ( i use the first method now ,, but originally used the second method ) the glue bond is secondary to the compression of the stack forcing the but ends together |
:suitdance
https://img296.imageshack.us/img296/...1009630fe7.jpg https://img296.imageshack.us/img296/...jpg/1/w640.png 0cm2v7 ( 2.0, viton 75 ) 0cm2-4v7 ( 2.4, viton 75 ) 0cm2n7 ( 2.0, NBR 70 ) 0cm2-5n7 ( 2.5 NBR 70 ) 0k2setn7 --kits, o ring NBR 70 , set of 5 ( thats the massive O ring kits ! ) ( $60 looked after ) transeals 08 94516011 ( WA ) inner and outer oil seals , not mazda VITON 75 O'ring 4.737 x 0.103'' PART No 158v7 at $4.99each VITON 75 O'ring 110.0 x 3.0mm part No 110X3v7 at $8.21each NBR is nitrile butyl rubber, or buna-n for WW2 buffs viton 75 is a newer , better alternative, as discussed above ( has 67% flouro silicon which makes it a newer closer cousin to mazdas special O rings ) here is the sting nitrile is around $3.70 a metre - well worth the effort but due to its -40 to 120 centigrade design temps you may want to use the RTV silicon to heat buffer it ! ( not that i think that the heat range is incorrect, just not any buffer ! ) the viton 75 is MUCH more expensive at $20 a metre but handles -30 to 205 centigrade but , doesn't work out cheaper for the outer ring ( maybe select NBR there for 2.0 ) and works out only around 50% of a saving over mazda inners - but will be physically more compression resistant ( and by reports reusable ) more chemically resistant equivalent in heat resistant more tear resistant and prouder for less true housings the number code used signifies hardness [ shore test A ] and you can get NBR and VITON in 90 !! http://www.transeals.com.au/seals/datas ... -rings.pdf order by quoting the dash number ( imperial ) or the metric size, then material specify ID, then CS ( inside diameter of ring, cross section of rubber ) https://img160.imageshack.us/img160/...1015652kp5.jpg https://img160.imageshack.us/img160/...jpg/1/w640.png using a little silicon as holding helper is not as messy as it sounds ! https://img510.imageshack.us/img510/...1015651xv9.jpg https://img510.imageshack.us/img510/...jpg/1/w640.png this is a viton glue join and it joined easily and strongly ( stronger than a laminated OEM inner seal join ) its cut straight and glued with black and gold super glue ! just to make it all stunningly easy - inner 740 mm , 2.4 mm CS per plate surface ( its fractionally long and fills outer edge of groove perfectly ) = 3m for engine - outer 930 mm , 2.0 mm CS = 3.8 m for engine you also need 4 x ( 15.8 mm x 2.4 mm ) NBR O rings for the engine oil passage dowels and 1 x ( 11.8 mm x 2.4 mm ) NBR O ring for the S5 type timing cover passage ( and nylon insert ) using charts i have supplied above, it wont be hard to suss the rear stat O ring and oil pedestal O rings which brings rebuilds down to bare minimum OEM front and rear seals and timing and inlet and exhaust gaskets ( and pickup gasket ) edit ,, o ring length reviewed 4/10/2009 to be fractionally longer - push o ring to outside of the track to make the longer lengths fit |
quote myself again --
buna-N ( butadene natrium ) = brand name for NBR = Nitrile butadiene rubber :wink: rated for -40 to 120C commonly sold as NBR-70 ( shore hardness test A = 70 ) ,, but can be got in NBR-90 buna also comes as buna-S = styrene butadine rubber which is rated to from -40 c to 100C with a shore A test hardeness between 50 - 90 viton is a flouroproylene and is rated -30 to 205C and comes as viton 75 ( shore hardness test A = 75 ) or viton 90 ( shore test A = 90 ) |
I have REALLY got to try this.
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Originally Posted by BDC
(Post 10388820)
I have REALLY got to try this.
I love re-usable seals. I've reused the same seals three times already. ;) I also have a solution for the tension bolt seals. |
Originally Posted by bumpstart
(Post 10388400)
there is a "jipped on O rings" thread in ausrotary and you can see for yourself the evolutions from nitrile to viton inner
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I also have a solution for the tension bolt seals. this is where i am now,, working out something for the through bolts - for me the OEM ones are $3 something each ,, so 17 or 19 in one go is a sting and something i wish to get around ( have reused them with RTV and not had a fail , but wish for a new solution around the mazda ones ) in WA, OZ,, the mazda parts dealer never stocks the rotary rebuild parts ,, and charges arms and legs well beyond the local costs that some of you US guys are getting OZ dollar is good ATM,,( but traditionally can be 60-75 % of of the US $ ) but shipping delays is the other biggy and so we are forced to innovate and try alternatives |
Mcmaster-carr (mcmaster.com) carries Shore A 75 Viton cord stock 2.4mm at $1.36/ft (cheap!). Part # is 94245K52.
Found another place to order it online cheaper than mcmaster carr: http://acehose.com/75duro-viton-rubber-cord-stock.htm And they carry 2.4mm metric! Searching around on Google right now for a 2mm Viton as I don't feel comfortable with the Buna's temp ranges. I'd rather do an overkill o-ring and not have to worry about it. I'll post up some more of what I find. Thanks for the killer idea, Bumpstart. This might turn out to be a great community-wide jump for us in having a superior and substantially cheaper than OEM o-ring! B |
One thing Bump - 2.4mm for the tubular dowel pin o-rings? That seems awful thick at first blush.
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Originally Posted by bumpstart
(Post 10389370)
moar info !
this is where i am now,, working out something for the through bolts - for me the OEM ones are $3 something each ,, so 17 or 19 in one go is a sting and something i wish to get around ( have reused them with RTV and not had a fail , but wish for a new solution around the mazda ones ) I just pulled my 20b apart so tomorrow I'll take pics of what I'm using for my modified tensions. It's so cheap, it's no even funny. Quick tip, don't throw away your old tension bolt seals. I'll show you how to make then usable again. ;) Also on the outer coolant seals, the factory ones get stretched. I just simply cut them back down to size and silicon them together. Lastly in that link I posted above, I'm gonna try the viton square cord this time around (2542T21) for the inners. They are the same size as the 2.4mm rounds but cost a little bit more. That should give me more sealing area. |
Originally Posted by BDC
(Post 10389738)
One thing Bump - 2.4mm for the tubular dowel pin o-rings? That seems awful thick at first blush.
the replacement one is 2.4 mm CS, 15.8 ID ( same as the O ring suit the oil filter pedestal ) if you have a 2.4 mm CS inner coolant O ring,, then 2.4mm along the oil dowels is a prudent upgrade -- no fails here-- and in view i have had to pull down totally factory engines in past to fix dowel O rings that are passing - i am 100% behind the 2.4mm CS upgrade i also do similar for the timing cover O ring = [JIS] 11.8 ( ID ) x 2.4mm ( C/S ) O ring to prevent timing cover passage blow out here is the JIS universal O ring kit and pictured is a 2.4mm CS, 15.8 ID O ring from the kit above a stock mazda oil filter pedestal O ring from the open soft seal kit below ( i know my camera and lighting sucks ) http://img24.imageshack.us/img24/6044/pic1230628.jpg |
Also on the outer coolant seals, the factory ones get stretched. I just simply cut them back down to size and silicon them together. Lastly in that link I posted above, I'm gonna try the viton square cord this time around (2542T21) for the inners. They are the same size as the 2.4mm rounds but cost a little bit more. That should give me more sealing area. ( im still cheap ! ) the square section chord is something i wish to trial myself,, just make sure it isnt twisted before you join ( BTW i use a splice kit and razor blade to cut off dead square ) |
Got some juicy stuff:
McMaster-Carr carries this stuff in both Buna and Viton. Here's the 11.8mmID x 2.4mm Thick ones: 93125K35 70 Hardness $11/100 -35*F to 250*F Buna-N 9263K677 75 Hardness $11/10 -40* to 400*F Viton ... and the 15.8mmID x 2.4mm Thick rings: 93125K43 70 Hardness $11.80/100 Buna-N 9263K685 75 Hardness $11.91/20 Viton I'd rather do overkill and do the Viton even though you can get a zillion of those Buna-N ones for almost nothing. B |
This is what I'm currently been running for my inners.
9464K537 Viton 2 per pack. Don't get any cheaper than that. :) THX to IronMdx for that one. ;) |
Plug in 9319K239 - That's the teflon encapsulated silicone o-ring I used to use on my old builds bout 10 years ago.
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Originally Posted by t-von
(Post 10390346)
This is what I'm currently been running for my inners.
9464K537 Viton 2 per pack. Don't get any cheaper than that. :) THX to IronMdx for that one. ;) Ignore that. I should've paid attention to the whole message instead of the mcmaster-carr part # I immediately locked my eyes on. |
Originally Posted by BDC
(Post 10390412)
These you're using for the outers?
Ignore that. I should've paid attention to the whole message instead of the mcmaster-carr part # I immediately locked my eyes on. So far these are working pretty damn good for the inners. They fit perfectly however, my 20b is one of the few that has the bad castings on some side plates. I now have a total of 6 broken lips around my inner coolant seal valleys. Don't worry it's not from me using these seals. I read that Mazda had a bad series of 20b engines that had casting problems in the coolant seal areas. There are sections that don't have enough support metal around the coolant passages that break over time causing the coolant seal to fall into the coolant ports. Even though I have a "D" series engine, unfortunately I still got some of the bad castings on my intermediate and thick center housing. Up untll this point, I had been fighting hard hot starting problems and a slow loss of coolant. I'm glad I finally found the problem. I'm currently fixing them right now and will start a new thread showing everyone what's going on. It's a good thing I have the tools necessary to do the repairs (which aren't hard at all). |
Could someone write up a comprehensive list of o-rings, part numbers and manufacturers and descriptions please.
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Originally Posted by t-von
(Post 10390612)
So far these are working pretty damn good for the inners. They fit perfectly however, my 20b is one of the few that has the bad castings on some side plates. I now have a total of 6 broken lips around my inner coolant seal valleys. Don't worry it's not from me using these seals. I read that Mazda had a bad series of 20b engines that had casting problems in the coolant seal areas. There are sections that don't have enough support metal around the coolant passages that break over time causing the coolant seal to fall into the coolant ports. Even though I have a "D" series engine, unfortunately I still got some of the bad castings on my intermediate and thick center housing. Up untll this point, I had been fighting hard hot starting problems and a slow loss of coolant. I'm glad I finally found the problem. I'm currently fixing them right now and will start a new thread showing everyone what's going on. It's a good thing I have the tools necessary to do the repairs (which aren't hard at all).
Bumpstart, run into any problems with using a 2.55mm wide o-ring for the inners? B |
Originally Posted by Slevin_FD
(Post 10395282)
Could someone write up a comprehensive list of o-rings, part numbers and manufacturers and descriptions please.
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