Tim, are you using the old three piece or the newer two piece oem seals in your 1st gen drag car?

I have seen LOTS and I mean lots of back yard manufactured ferrous alternatives to Mazda seals and they are all junk ! They (if they survive) will root rotor housings just like they have done to yours, they are not tested to be compatible with the rotor housing surfaces Mazda manufacture PERIOD, they are prodominantly made to cater for drag racing people who detonate engines every other day and if made (as some are) out of cold drawn mild steel bar !!! YES MILD STEEL BAR !!!! you can bend those fuckers in a vice and they will not break.............. but they are pure shit in so far as durability and wear properties on rotor housings ans rotor slots.

Mazda OEM seals are the only (steel type) seals I have seen that are long term durable on rotor housings, so if cost is an issue I recommend those. If long term costs are what you are looking at then you cannot beat quality ceramic apex seals, they last many times longer and are much kinder on mating parts than even OEM seals. You can get them in multy piece style and match the OEM compression figures, but I prodominantly run one piece style for much increased strength and mechanical design reasons (greater clearances) so the seals are far more tolerant to running 40+psi boost and up to a 400+shot of spray !!! The 2% to 5% loss in compression (due to racing spec end clearances) is not a factor when the seal is 100% reliable.

PLEASE STEER AWAY FROM THESE SHITTY NON MAZDA STEEL SEALS, THEY ARE NOTHING BUT HEAD ACHES AND A PURE WASTE OF MONEY !

very interesting rice!!

what ceramic seals do you like the best?

nrs? never heard of them....
12a seals available?

I only use NRS Ceramic Power Seals, I/and my assosiates have used all other alternatives (from various vendors). I like them that much that I am a sole distributor for them in my part of the world, we sell to lots of shops & race teams with great sucsess ;)

e-mail me

riceracing@ozemail.com.au

I am using the old two piece,it is still a 12A.
The one piece ceramics only gave 5 bar compression,like having a worn out engine.I get 8 bar with the mazda steel ones.I have had the rotor housings 'cermet A' coated,and intend to use the Mazda seals,so will I have a compatibility problem? I shouldn't have,because ceramic seals don't score the housing,but how ceramic is 'cermet A'?

ups

Those rotor housings are gone.

owner said it was sanded down and polished and came out pretty good

you shoudl post the pic of the second housing

We have one piece ceramic producing from 7.9 kg/cm^2 to 8.10kg/cm^2 on a corrected high accuracy gauge. You have some other issues to be only reading 5 bar, faulty set of seals probably ???

Yes you will have a comatability problem, the people who do the Cermet coating infact recommend our NRS seals as a compatable seal, or to use their own manufactured seal.... you better check with them before you buy Mazda OEM seals.

What about contamination? Was the owner running without a air filter down a dirt road pretending to be Bo and Luke Duke?

how did the bearings look in that engine?
any marks on the rotors towards the trailing end near the apex seal groove?

i've seen motors that ate the bearings for one reason or another and the rotor housings came out looking similar to that.

so, other than the score marks and flattened springs, how did the rest of the parts look?

yes , bad bearings can contribute to the premature wear of the housings. the eccentric shaft becomes unlevel and has more room move (vibrate), which also moves the rotors and apex seals.

Bearings were brand new in the engine when I assembled it. When I removed them they looked just as good as when I put them in.

Rest of the parts looked good, just the flattend springs and a couple cracked corner seals.

With the Iannetti one piece seals,problem is I had 0.15mm end clearance as they came,I couldn't make them longer.There was a brown streak on each side plate,where gas had escaped around the end of the seal.Are you saying the NRS seals are better than the Iannetti ones? What end clearance do you have to get 8 bar compression? Maybe I should buy some NRS seals.

The NRS seals come with a 0.14mm (0.0055") end clearance.
3.1455" total length on 13B seals.

Can you actually sand down the surface of the rotor housing? I was told that the housings were specially coated and could not/should not be sanded. :)

You can, just not much. I didnt sand that much to go through the coating, its still on there.

How do you get 8bar readings from a comp test with ceramics? Every car with ceramics that i have seen comp test results has been below 6.5bar. At a rough guess that is 5 cars. Not a lot I agree but wow what great compression. When you put mazda OEM seals in you get 8 bar Nooo prob.
In my FC with second hand 2 peice Mazda tips( and everything else is second hand) i am getting 7.5 bar. This engine has been seriously abused. And I mean seriously abused

so you detonated on a set of seals that had been recalled by the manufacturer with a clear explanation that the seals were flawed and not treated properly for wear purposes

and you're complaining publically as if the seals are ALL bad?

No smart one. Those seals were never recalled. The ones that were recalled had a different problem and were made AFTER mine were. I actually asked them about it, and they said the ones with reported problems were sold a while after I bought mine. Get the facts straight before you start bitching.

My understanding is that they did not have a "window" of bad seals, anything before Dec 19th 2003 was suspected bad. They provided full recall of them and upgraded to a CNC cold method of finishing the seals.

Perhaps you should get your facts straight? I mean, after all....when notified, I pulled my seals and replaced, you did not...now you have no motor. You claim you ran lean, detonated, etc...what do you think that does to springs? It certainly doesn't increase their life.

You come on here like you want some type of support or a shoulder to cry on, trying to warn others of your misfortune, but you are really not an ideal candidate for evaluating the integrity of a seal. And what qualifies "like new" versus "new" on rotor housings? You used 320grit sandpaper on your rotor housings? Are you kidding me?

1). he's not talking about the springs buddy... look at the housings - they're scored. springs have a whole lot of nothing to do with that (especially if they're too weak)

2). Read the first post again... does that sound like 'crying'? What's your problem? Do you have a personal interest in RA or something? What's wrong with somebody posting some data on the forum?

Those housings as-is look pretty trashed, and while I wouldn't personally have used sandpaper on them, there's nothing to lose here.

The RA seals do not appear to be made out of a material suitable for direct contact with the housing surface. There's a reason mazda spent so much money testing, and even then it took a few tries to get it right. If this was the only case with scored housings, I'd be suspicious that something else caused the problem, however a few people have posted similar findings...