I would like to rebuild my engine. It's got about 175K miles on it and I wanna port it.

If I don't have to spend the money for someone else to rebuild it, then I'd rather not. I'll just rebuild it in my yard and have the side and rotor housings brought away to be lapped and ported.

The thing is, I do not have a micrometer, nor can I use one accurately. (When ever I mic brake rotors at work I always end up with fluctuating results. We have a digital mic there. It has screw on caliper extensions, so that may have something to do with it.) Nor do I have any good optical devices with which to examine the rotor housings for flaking.

I intend to replace the following:

Apex Seals + Springs
Corner Seals + Rubber parts
Side Seals + springs
Oil control rings + springs
All soft gaskets and O-Rings

I'm debating on replacing:
Front/Rear main bearings
Rotor Bearings
Stationary gears

If I get all the seals replaced and the housings lapped, what do I need to mic?

If there is no visible flaking on the rotor housings, should they be good, or will a closer examination be necessary to determine it?

Which apex seals should I go for?

My known choices thus far are:
Atkins Rotary Apex Seals
Hurley Engineering Apex Seals
Stock Apex seals from Mazdatrix

I'm also considering going for Hurley engineering's modified rotors so that the apex seals get better lubrication. Is this a good investment or not? This is for a road driven car, some road racing/auto X...

 

Check everything to make sure that it's not out of tolerance. I've got a book with all that stuff in it. With 175K on it, check out the price of a rebuilt engine. I had 163k, and I determined that it was not worth rebuilding since Mazda rocks you for parts. Atkins Rotary is really good and Kathy is really nice to work with. Their prices are really reasonable for most parts.

 

So you're saying that at 175k Miles, the housings might not be reusable?

I was never thinking of going to Mazda for parts. Mazdatrix, Victoria British, and the scrap yard are the only places I'd go for genuine Mazda parts.

C'mon guys, I dont wanna let this go with one reply.

 

I'd go with the atkins seals. They are slightly longer and are more forgiving in the long run. A friend of mine rebuilt his with them, and they have done very well. He is even burning less oil now that he did before he rebuilt it. BTW. His spinner had 212,000 on it when he rebuilt it , and his housings were just fine. It depends on how well taken care of the engine was to begin with. If there is any rust or pitting on the inside of the housing, it WILL get worse with a rebuild, just to keep that in mind.

 

The engine ran fine about 6-8 months ago before the trailing ignitor blew. Since I had no cash then, I just dumped some MMO down the carb, cranked it a few times with teh throttle open, and dumped the rest of the quart in the gas tank. Then I covereid it with a tarp and waited for cash to accumulate.

 

For Mazda parts, talk with Ralph Hatley @ ralphh@dgdg.com
Genuine Mazda parts much cheaper than anyone else.

The big problem is the rotor housings. If you have to buy new, you are better off buying a rebuilt from Atkins or Mazda or whomever.
Check the water coolant passages. Even a tiny almost unnoticeable crack will doom your engine.
hanman