What could cause coolant seals to go bad on a rebuilt w/ less than 40k on it?

 

Overheating.
Shitty seals were used.

 

Constant abuse and not allowing the car to warm up before hard driving.

 

Id say improper break in period, maybe you pushed it a little too hard too soon.

 

straight water will corrode it the thin side of the groove wall pretty fast, especially used plates/housings that are allready prolly a lil coroded.,.. other than that what everyone else said, overheating and not warming the car up.

 

To my knowledge, only 2 kinds of seals are commonly available for the rotary engine.

1) OEM type

2) mcmaster-carr teflon encapsulated

Both have been well proven and are being run in hundreds of thousands of rotary engines worldwide. Care to elaborate on this comment?

 

Drago hit on a point- if used housing were put in for the rebuild (very likely), it may be more the housings' fault than the coolant jacket rings...

 

Dont forget Banzi racings godly silver plated C section spring metalic ones,... technology taken directly frm nuclear reacters,..

 

Well, if anything I don't drive this car hard enough. I was real careful during the break-in. It was a mazda-rebuilt so I'd assume they use quality stuff, butt it did overheat once when the alt belt went--but that was a year or 2 back.
It still runs good, it's just tough to start. I installed an egi switch to deal with the flooding problem common in these cars to help with starting, but now it seems that it takes 3 x's as long to get this started if it's only been sitting for 15 min's. 1st thing in the morn it usually starts right up, but twice in the past month it wouldn't start at all, then tried the next day and it started right up. Not to mention I have to top off the coolant daily. So it's still gettin me around with some minor annoyances.
How tough is it to rebuild these engines? I've heard alot about Rotary Resurrection, but I wouldn't mind taking it off the road for a month this winter and giving it a shot. But if it's like stinkin rocket science once you open these engine's up, I'm not gonna waste my time.

 

Please don't guess - your not doing the guy asking the quesitns any favors.

As Kevin said - two proven types (jury is out on the Bonzai seals just with price alone)

As wayne said bad housings - or

frankly either they were pinched and the seal finally let go or the rotor housing was not cleaned perfectly - it matters, or the seal was rolled. think about it, its an installation issue - the material is proven.

 

Is it eating up coolant or pushing it out? If not, i would not be talking about coolant seals at all, from description it looks more like flooding problems (leaking injectors?)

 

I think the RA teflon-encapsulated ones are different than Atkins/Mcmaster-Carr. A few of us have been discussing this; They don't fit as well, they are a slightly different size when checked with a micrometer, and the seam is slightly different.

Regardless, use of the RA teflon encapsulated seals has bit me in the ***. I did a bunch of rebuilds using them, and they would drive fine for 5000-1000 miles, using 50/50 mixtures of denatured water and prestone ethylene gylcol, and then all of a sudden start leaking. No overheating, no not letting the car warm up.
Upon taking the engines apart, none of the seals were pinched. They were all simply compressed flat on the compression side and letting combustion chamber gases into the coolant system.
Most of these rebuilds were done with new rotor housings, which have been checked and passed for being warped, and all of the engine irons were checked and passed for sizing and pitting of the seal groove. Hylomar was used as the soul engine assembly sealant.

 

Well there are both your reasons. I have heard about 3 Mazda Reman premature coolant seal failures now and an overheat defnately does not make things easier on the engine.

I have heard a lot of good things about Kevin's engines and think he would be the person for the job. Sounds like he has some pretty high standards for his engines and doesn't sacrifice reliability for performance like other shops do.

 

That's interesting- what kind of power are you getting out of these engines, though, on average? I'm going on 8,000 miles on mine now, 3 of the 4 seals are RA, and the very front one is Mazda OEM (SOB popped out of the groove on me during the stacking, and didn't realize it until she was all torqued down, and little bits of orange rubber came passing by the exhaust ports while turning the engine. I can laugh about it now, but you can imagine how pissed I was at the time).

Did you go back to the OEM seals, then, Sean?

 

I'm sure Kevin's engines are built with more attention to detail compared to the Mazda remans...Gotta figure, the companies that supply the remans are in it to make a buck, profit margins are everything to these guys, therefore they're going to use parts that may be good by the book, but us engine builders would consider borderline, at best. Kevin's got a well-deserved reputation to uphold, and he's not going to build with borderline components...

Free advertising for ya, Kev, lol

 

I've heard rebuilding these engines is not "like rocket science". I've never done it, but have heard it's not too difficult if you have the proper tools (pretty basic), a FSM and/or a walk-through video, and patience. Lowfreq, if you're ok with having it down for a month this winter, you might want to consider taking the motor apart yourself and rebuilding it. If you do some searching I'm sure you could find out some more about the 'rebuild process'.

 

Yes, though the Atkins seals haven't given me any real problems, just the RA ones.

I prefer the fitment of the Mazda seals. If you don't overheat them, they work fantastic.

 

Only problem I had with the OEM one was that they had packaged the thing up in a little bag and twisted it all to hell, lol...Lots of halomar went into that groove

So you never answered the question about the power levels you're running with the RA seals in the rebuilds...

 

Taking it off the road for a month or so would be no problem. I've never done a rebuild, but I'm pretty proficient mechanically--even tho I'm not a mechanic by trade. Maybe I should do the rebuild myself. Hmmm, I'll have to do some research.

 

Only 2 of them were less than 300hp.
they were also the two N/A's.

 

Eh...?

RA seals ARE the teflon mcmaster carr seals.

Atkins, and everyone else to my knowledge, uses the stock mazda seals.

I think you should consider using a sealant that dries solid on the rotorhousing side...keep in mind that hylomar is an assembly aid only and gets washed away pretty soon after water is poured in to the engine and heats up.

Don't you think pooled water could flood an engine just like excess gas?

 

Side by side comparisons of the inner coolant seals from McMaster-Carr and from RA showed differences in dimension, fitment, and seam, as noted by myself, and other engine rebuilders.
If the RA seals ARE indeed McMAster-CArr seals, then some very serious discrepencies between seals exist, which makes me even more hesitant to use them.

I won't use a drying sealant for o-rings such as RTV; I feel that the o-ring should be able to move in its groove in order to seat itself, and to be able to move with the heat expansion. If I need to use a sealant on the rotor housing to fill pits, then I should have just used new housing in the first place. I've all but stopped rebuilding with used rotor housings.
Re-assembling the engines in question with hylomar only, no RTV, and stock Mazda coolant seals has kept these same engines running perfect.

I am only stating my observations here. I know these seals worked great for some people, but I also know I am not the only person to experience these problems.

 

See Kevin- someone else besides me advocates the use of new rotor housings for rebuilds, lol...

Just messin' with ya, man