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Discussion Starter · #1 ·
Hey everyone. I'm from florida, so the motor is definitly not in a snowmobile, but here is an awesome source it looks like for info. I've got 2 of these motors, one that i tore down & put back together again (reason was, was that the tube that compression pulses go through to operate the fuel pump in the tilliotson carb, well it was clogged, and had to be opened up to unclog it). Any way i've got a gokart using this engine, its a blast! lets just say i've done 60mph at around 4500rpm... so i've got some speed left to go, lol. Anyway I've got 3 questions:
1) does anybody have any apex seals, used & still good, or NOS, along with apex seal springs for this motor? my second one, upon opening it up, the seals were about 20,000 of an inch below the maximum still useable wear, so ya they've been around that housing many times.
2) my second question, has anyone made their own seals? All you need is a mill & to have some patience, and you could make mirror copies of these apex seals without a problem
3) I was thinking- A mazda 12A rotary engine's rotors are the same width as a sachs 303 rotor. (im pretty sure 70mm?) Well, turns out the apex seal groove's are the same as well, 3mm. however the depth of the seal slots, i believe is alot deeper on the mazdas, there for i think i could get away using seals which are no longer giving good compression in a mazda, yet would be still about a thousandth of an inch too tall to be "new" size of a sachs apex seal. I'm trying to get some 12a seaLS from some people on rx7club.com, and will keep you up to speed on what happens. If this is the case, i think alot of these 303 motors can be saved! anyway, let me know if anyone has actually tried this? i am very certain it will work. Thanks for all the help!
 

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Discussion Starter · #2 ·
update: i got mazda 12A seals, and they fit right in, just need to be trimmed down. They are .270'' tall, and need to be .236'' to get into sachs specs. So i'm thinking of making a jig, chucking them in a lathe & cutting them down that way. Then, I'll be left with a even, straight surface, that is also rounded to seal up against the rotor housing properly. While the motor is apart, i dremeled the intake port, basiclly rounding it off, and opening it up a bit. Doessent increase the overlap, just allows more air in, and ups the duration just a tad. ill post some pics. I'm into mazda rx-7s, so tricks like this come natural to me... I'll keep everyone updated on these seals. By the way, i got 6 seals and springs, for FREE. so if this works, it is definitly an excellent alternative to sachs seals. One more advantage- The seals are from the early to mid 1980s, so the technology behind devolping them exists alot more than the sachs seals of the late 60s very early 70s.
 

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Has this become a success story? Just curious how this ended as I have a shelf full of 303's. I too have one in a go kart, a shopping kart go kart. Thanks.

Adam
 
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