Just wondering what they are for knowledge sake!

 

no compression.

 

Other than the obvoius!
Any sounds or smells? And feeling that the car may have, ie shuddering, running funny, stalling?

 

runs like ****, poor idle if any, very poor MPG, fuel smell.

When mine blew, it took about 20 sec of constant cranking to get it started, I drove 22 miles to a garage to have the comp checked and burned almost a half tank of fuel, it took about 5 miles of straight road to get up to 70 MPH.

But I replaced it with a SP, so it all worked out.

 

when mine went the car seemed like it just freakin blew up!

engine started shakin like hell. the shifter was shaking like crazy

it would start, but it wouldnt like it at all and would not idle.

then i took the pre cat out and sure enough.... apex seal chunks in it

 

Had same happen to me while trying to show up Porsches at the local PCA chapter autocross. Damn 2nd gear syncho was gone, so I kept bouncing off the rev limiter to keep from shifting. Not a good idea with 190k miles on motor. I thought I broke a motor mount at first, it shaked so bad.

Ren

 

Apex seals are the rotary equivalent of a piston ring. Their purpose is to seal the apex or corner of the rotary triangle against the rotor housing.

The stock Mazda apex seal consists of three pieces plus a spring. The spring is used to keep the seals against the rotor housing sruface. The apex seal itself is two straight pieces of metal with a triangle shaped corner piece on one side. I can't tell you why they are built this way, but the early developers of the Wankel engine spent untold hours of engineering research trying to resolve the poor sealing problems before Mazda came along. The shape of the sealing surface of the seal is a very complex area and presents difficult machining problems. Not until the advent of computer controlled machine tools did the manufacture on a mass scale of these seals become viable. Human hands are not capable of machining these complex shapes.

The very few attempts at marketing a rotary anything before Mazda did were for the most part miserable and costly failures. The most promising attempts were the Suzuki and Hercules (NSU in Germany) motorcycles back in the '70s. Both of these attempts performed poorly in the sales department.

John Deere and Lycoming (aircraft engine manufacturer) spent tens of millions on research before giving up on the idea. GM spent a bunch as well.

 

It felt like someone swapped out my 13b for a lawnmower motor. Kinda sounded like it too.

 

well, my 1975 REPU has apex nubs (no longer seal).

Takes ~25 seconds of crank to start.

No compression - around 25psi!!

Must slip clutch like hell just to get moving in 1st.

Top speed of 25 mph

 

It all depnds if the rotor is stuck on the seal or if the seal is blown. yoyu can get rid of a stuck seal by using a trick ive heard about but cant remember. someone on this site should know what im talking about

 

AGREED!!!
When my 10th AE went out lost compression, had bad gas smell,
idle loped, took about 10 mins to start but..... KICKIN" THAT PORSCHE's @SS FELT GOOD!!!!!!!!

There is only so much time for a rotary in the middle of the desert.... God I hate PHOENIX!

 

All of what everyone's saying is how my car is right now.


I can't wait till April. That's when I'm doing a rebuild and streetport and much more...

 

Are you still driving it????

 

Hah, of course not. She's been sitting since September 22nd.

After a hard day at the track, I turned the car off. I went to turn it back on about 20 minutes later and the engine was seized. I towed her to my mom's house which was close by and I did the ATF trick the next day. I was able to unseize the engine, but the engine was running like **** with all the symptoms everyone is describing. I'm sure a seal is stuck because I could hear it scraping around the engine when I turned it on. Can't wait till April...

 

bought my '90 GXL with a blown rear seal, as a project car (undergoing motor rebuild right now). What I thought was going to be a "get this car running agan as cheaply as possible" thing is basicall turning out to be a full-blown restoration..

anyway:

the car started right up, and idled normally/smoothly when warming up. after getting fully warmed up, the engine began shaking the entire car, the shifter was waggling around something fierce, wanting to leave and find a better home. :p

the engine would not rev freely up to redline, it would simply not go past about 5.5k - 6k. One the road, the car would not want to start out without revving to it's "new" redline, and slipping the clutch. At a stop, I had to keep blipping the throtle, otherwise the motor wanted to die.

Interestingly enough, most of the 50 mile journey to my home was interstate travel. I was able to get the car going about 80, but that had a lot to do with the nice, flat road I was traveling on.

go home, did a compression test: 0-0-0 on the rear rotor.

after the motor was disassembled, the prognosis was that a small chip of one apex seal crashed into the next, completely taking it out along the way. What was left is not pretty. Bits of metal embedded in the rotor and huge gouges in the rotor housing. two of the three rotor apex grooves are colapsed to the point that I can't get the bottom 1/3 of the seal and spring out.

so, yeah: no power, runs rough after warm-up, sucks down an inordinate amount of gas, are all signs of a blown apex seal.

one thing to try, even if getting 0 compression, is the ATF trick. If a motor has been sitting for awhile, the apex seals can get stuck, and the the ATF trick can break down the carbon deposits, possibly releasing the apex seal again.


Regards,
SHAWN

 

Good stuff! I guess my baby is good then! Idles ok (sometimes) She starts right up, and the engine does rattle a bit, but I think it is only time for a tune up! Great info!!!