Hey everyone. My '93 Touring just turned to 89,262 miles and is still running strong. I just got it in November and haven't driven it much due to the cold weather here in Pittsburgh . I heard around the 80K mile mark is the ideal time for a rebuild. I'm training to be a mechanic but i haven't done too much with rotary engines, so my rotary mechanic says i should get a full rebuild even tho the compression test came out almost perfect. Is my mechanic trying to jack me or does my 13B need this rebuild? Because i got it used (of course), there is no telling how hard the previous owner drove it. it still has the stock twins. Thanx for your help.
Dave

 

IMO, if the compression test came out fine, I see no reason to rebuild it.

 

that's what i was thinking. thanx 4 ur help

 

I have to agree. Why rebuild? Just wait until you have problems to rebuild. Maybe he thinks you should rebuild just to play it safe. If an old apex seal breaks that always puts the housings in jeopardy.

 

seems like on the mostly stock cars with stock motors the coolant seals go before one of the apex seals do.

If the apex seal is just old is it more likely to come out just because it is old or do you still have to run lean for that to happen?
I'm sure you don't have to run as lean on an older seal as a new seal but what about the first part?

 

A friend of mine had a seal chip. You could look through the exhaust port and see a chunk missing from the seal. He wasn't running much boost and had plenty of fuel. I just figured the metal became old and brittle. Maybe there was some other contributing factor, I just don't know. It certainly does seem like something detonation would cause.

 

May I ask what your vacuum is at idle? my car just hit 78k miles. and I get 16-17 sometimes high 15's

 

These engines can run quite a while if you take care of them so if you got good compression and vacume, don't do it until you have problems. Rebuild isn't cheap. The engine is one cost but since these engines run so hot, once you start taking things apart to swap out to the new motor, you break a lot of the parts that get rigid. Small problems will also plague you for the first few thousand miles after. So save your pesos, plan it out, especially if you want to port something or get some performance upgrades done that are easier when the motor is out.

Things like a better radiator, maby a different turbo setup, wiring harness for a Haltech, silicone hose change-out, lots of things are possible.

When I bought mine, it needed the engine changed out since it had low vacume and wouldn't idle. If I had it to do over agin, would have done the porting and some other things that would have saved me some time down the road.

 

thanx 4 ur help guys. my RX-7 is running 16-19 vacuum at idle. I dunno if that's good?
my mechanic says all rotaries tend to break after 90K, and mine is at 89K+. he says i will have to buy a whole new engine (Housing, rotors, the works) if the thing blows all together but if i play it safe and rebuild it now i could save it. I don't know if he is being honest or just trying to pocket an extra 2,500.

 

u get 16-19 at 750 rpms?

 

I agree with shred re the rigid parts and upgrades. I would not rebuild if in your situation. The price is right cause a reman from mazda costs more than that and most rotor shops charge at least 4K. Wait and save.

 

Well, he's not completely blowing smoke up your tail.

It is true that when a seal goes, it can cause a lot of damage. You can do preventive maintanence on everything if you have the money, however I don't think doing a rebuild when you already have good compression exactly "preventive maintanence".

If a seal does break and tear up the engine, it's not necessarily more expensive. You can get a remanufactured engine from Malloy Mazda for around $2000. Most (quality) rebuilds will be more than that.

Turbos also can get torn up when losing a seal, so that would be extra money should that happen. However, as the other guys in this thread stated, there are other ways of losing a seal even on a new engine.

IMO, wait until you have to cross that bridge before worrying about it. If the engine is currently fine, just do your best to keep it that way and enjoy the car.

 

No need to opt for the rebuild now. Poke around with the search button and you'll find that some guys get as much as 110K+ miles out of their original setup. Mine has 90XXX on the clock with the original engine and turbos and still pulls strong.

As long as you plan on keeping the car stock I can't imagine NEEDING a rebuild. Now, if you're going to upgrade your turbos, or go single, if it were my engine I'd think about getting a rebuild and a streetport. You'd hate to spit a seal and have it f%ck up your brand new turbo. Most people opt for a streetport (or wish they had) during the rebuild.

 

i made a type-o, i get 17-19 vacuum at 850rpm, my RX-7 idles a little high

 

good compression
good vacuum
------- mechanic.