Not to badmouth any other builder including mazda, but man, wtf are they thinking?

I have personally taken apart many remans, to include one FD reman with a 9.7:1 89-91 NA rotor mixed with a stock 9.0:1 FD rotor (guess which half blew the seals).

This one is just about as bad.

Supposed 25k miles. Failed coolant seal in rear.

Rear rotorhousing shows signs of previous apex seal breakage and mazda BUILT the new engine with it this way. It couldn't have happened while in this engine. All of the seals in this engine are intact with no chips or breaks in them. IT also could not have been a foreign object entering into this engine while running. Because those marks are from something driving a piece of something into the housing...that "something" would have to be the rotor, and it'd also show some signs of contact such as dents or scratches. The rotor is perfect and shows no such signs of contact with anything.

These are "high" spots and though this is not the area of the engine that builds compression, a high spot anywhere in the housing will cause a gap to form in the seal edge, causing compression loss on the other side from a poor seal.





Direct coolant injection anyone?



I hope they get better, since the price just went up. If not, I guess I'll be the first to know.

 

ouch...good looking out
ive always knew theres a downside of buying mazda remans
not saying theyre all like that...but taking a risk of getting one thats bad

 

Keep in mind, a reman (at least US ones) are not built by Mazda. Mazda contracts that out something like every 2-3 years to a US company.

 

Very very interesting.

 

I thought mazda puts in brand new housings on all their remans?? If this is false, why would anyone buy a reman??

 

wow... shittay

 

They replace the parts that don't spec out (i.e. if the housing is still good, they reuse it like most other rebuilders).

It can be cheaper if someone shreds more than just a single rotor housing than to buy everything brand new.

 

Wow, damn man thats some carbon. MY FD had done 70k and it didnt look anywhere near as carboned up as that!

 

Remans have been hard to judge sometimes. It really depends on who is currently building the motors. I would say from reading experiences and personal experience that the majority are good motors. But, **** happens unfortunately.

My reman that came with my car has been going for about 30,000 miles now - pulls great vacuum, makes great power, runs cool, starts just fine, you name it.

Dale

 

Thanks for the info Kyle. I'm glad that I never decided to go with reman.

I thought they all had new housings and seals..

 

I have "heard" the remans no longer have new housings but they have good quality used rotor housings. Not in that baby.

 

Kevin, what's your opinion on the teflon-encapsulated coolant seals sold by Rotary Aviation? I've been doing a little research, and the specs look good on paper.

-s-

 

^off topic?

anyways, this is exactly why i like to get **** done myself. thanks for posting your ugly finds. looks like you uncovered some re-man outfit's dirty secret.

 

They're not to my personal liking, but they do work, and may be advantageous for a purpose built race engine.

They are not a proper fit for the engine, and must be stretched.

The surface is a bit too hard, and too slick, and doesn't have a good 'grip" effect, to form a seal on a housing. I mean, it is after all, teflon. When was the last time you heard of teflon being used to SEAL anything? Why do you think mazda did not elect to wrap the entire seal in teflon, versus just laying a strip on the side? I have known a couple of people who built using these seals and had sealing problems...it could have been due to an install error, but I just dont like their harness and lack of grip.

To partially make up for the above, these are made over stock thickness, so that they are a pressure fit and squeeze in place, helping them form a seal. This is more stressful on coolant jacket walls, which are thin and weak already.

The only really good things about them are that they are cheap (not much cheaper than stockers, though) and very durable (you can even reuse them, they are so hard).

 

Ive got the RA seals in my car im rebuilding, hopefully itll be ok.

If you wanna know, i should know how they fare in a week or two. Drop me a PM and i can give you links to pictures of the whole build and let you know my results.

I do agree though, they are very hard, do need stretching and are a bit of a pain in the *** to get to stay in the grooves. Some hylomar well painted inside the grooves works well to retain them, but if you so much as touch the seal with an oily finger, that part of the seal loses its grip on the hylomar,pops out and you have to clean it thoroughly or itll NEVER stay in its groove.

 

I "heard" that people where finding some what seemed to be new parts in rebuilds. They reported that the housing seemed to be new. Some what of a gamble but doesnt seem to be too bad of an gamble.

 

In a reman, everything is measured up and if it doesn't meet manufacturers specs, its replaced. If it does, it's re-used. They are just doing what any builder would do.

Doesnt mean they dont make mistakes though.

 

See this is weird! I used Teflon coolant seals in my last rebuild. Based on the info from these forums, as I walked over to my shop I started slightly stretching one of them. When I placed it on the engine, it was actually to big to fit in the groove. I was like "****". Then I grabbed the other un-stretched seals and they fit perfectly in the groove. I don't know maybe there's some inconsistencies with them as far as sizes go. I didn't have any issues with putting my un-stretched ones on the engine with a little vaseline covering the top of them however, I did get mine directly from McMaster-Carr.

 

They have always used new and used parts throught the engine but they use to use new rotor housings all the time. Not the case anymore.

 

T-von - they dont need literal "stretching" to get them to fit, they maybe need to stretch 3-4mm max, but this makes them a bit of a PIA to fit.

 

I did have a reman with 0 miles and did look like it had new housings. This engine was built 2 years ago. Hence I thought all reman's had new housings (and read this before).

Regarding teflon coolant seals.. Well, I asked this question to my engine builder (w/25 years of experience building rotary engines, built his own lap table, cranks every engine he builds on a custom engine stand) and he told me that he tried everything thats available on the market and always went back to OEM. If you are worried about coolant seals, get your plates and housings lapped.

Anyone who wants to meet him and Kevin, they both will be attending DGRR2006.

 

Thanks and sorry for the thread hijack. My coolant seals are on the way out, and I'd like to replace them with the best possible solution.

-s-

 

Well like I said earlier, I didn't stretch the other ones and they fit perfect. So I don't know what the deal is then.

 

That is prbably a foreign piece of material causing the housing wear. What else could have done that w/out a seal letting go?

 

A seal in a previous motor.