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-   -   lifespan of 3rd gen rotary engine (https://www.rx7club.com/3rd-gen-archives-73/lifespan-3rd-gen-rotary-engine-12426/)

jeff8932612 07-29-01 05:08 PM

lifespan of 3rd gen rotary engine
 
i am thinking about buying a 93-95 rx-7, but i dont know too much about rotary engines. are they reliable? can they handle alot of miles? has anyone had alot of problems, or no problems? And last, i heard someone say you can expect an engine re-build approx every 50,000 miles, is this true? thanks for your help.


jeff

rxrotary2_7 07-29-01 08:38 PM

i am at 49k and working on my 5th motor in my fd. on the other side of the coin, i had a 86 w/ 260k on the odometer when i sold it (speedo was disconected for 9 months prior to selling). i know it was the original motor b/c it was in my family since it rolled off the showroom floor.
my 5 motors in this fd have been stictly my fault. i like to see how far i can go w/out blowing it up....and usualy fail....but i do find my "limit".
my current daily driver has 162k on it. and the one i just gave to my girl has 189k. both original motors.

kevinmfaust 07-29-01 10:12 PM

Not all rotary engines enjoy the same living enviroment. My engine went 70k miles before it took the big shitter. I think you can expect about that on average. There are some things I think you can do to help with the gracefull aging of the engine. I think heat is the killer of the 3rd grn engine. First it has a very poorly designed air box that actually breaths it hot air from the radiator so it needs to have a true cold air induction installed. It also has 2 cataletic converters. One of them sits in the back of the engine bay just under the rear turbo and it cooks every thing in its range........like the back rotor housing, rear turbo, oil pan, anti-lock break box........you get the drift.....it has to go. The car will still pass emissions. Expect to pay $ 8k on engine and turbo rebuild without doing big mods. Some people will get more miles some less.

Kevin Faust

jeff8932612 07-30-01 07:10 PM

who makes better turbo timers, boost controllers, etc, h.k.s. or greddy?

GoodfellaFD3S 07-31-01 09:58 AM


Originally posted by jeff8932612
who makes better turbo timers, boost controllers, etc, h.k.s. or greddy?
The Greddy Profec B is the best boost controller b/c it doesn't have fuzzy logic, which is incompatible w/the stock sequential twin turbos. Jason sells them through the rx7 store for ~$350. I have one and love it; works extremely well. No spikes or creep with my current setup (see below). I also have a greddy turbo timer and have no complaints. I would think the HKS one is good too.

The motor in my R1 lasted 9 years and 63k miles. It was pulling strong right until the end, as evidenced by my 1/4 run in my sig. I think the previous owner (who thought the car had a V8) overheated the car and didn't think it was important enough to tell me. That will kill a rotary, and it eventually caught up w/my motor. If you search the net for information and become knowledgeable on rotaries, your 3rd gen will last you a long time. Warm it up, cool it down, change the oil every 1500 miles, don't overheat, don't overboost, use 93 octane.


jeff8932612 08-01-01 07:37 AM

buy a frame and build the motor myself? how much do you think a motor would cost, and it would probably have to be done professionally cause i dont know enough about rotaries yet

Nathan Kwok 08-01-01 11:42 PM

Jeff,
One good idea is to buy a car with a blown motor for cheap (9k-11k) and get a new motor put in. Recently on the big list BRAND NEW short blocks were going for ~$3000 through John Duff and Malloy Mazda, and through another dealer. This is brand new, from Japan, 0 miles, not a rebuild mind you. Also understand that rotaries in general are long lasting motors. Maybe not as long lasting as pistons, but if not, very close. Its just 13BREWs, and to a lesser extent, 13BTs that have shorter lives. One, because 3rd gens have cooling problems and can overboost, and people like to mod them like crazy until they explode, so that drags down the average (how many 100k mile civics do you see running 14lbs of boost? See my point?). Another thing is that turbo cars simply don't last as long as NA cars, period. Even "bulletproof" Turbo Supras don't have a ton of 100k+ cars, although, granted, they are much more durable. When you look at the NA rotaries, there are quite a few 200k mile+ original engines on the forum. I think if you take good care of a 13BREW and don't mod it to death, just do everything conservatively, it will last.

jeff8932612 08-02-01 12:29 PM

will the rebuild of the turbos be included with a rebuild of the engine or is that seperate?

Nathan Kwok 08-03-01 01:11 AM

Jeff,
The shortblock doesn't include the turbos, and you need your own core (no problem there). However you can still pick up a blown engine (lets say coolant O-rings) with good turbos for cheap, or just get them rebuilt for ~$500.

RX7145 08-03-01 12:07 PM

200K
 
My 84' Rx just turned 200,000 mi. today. Just keep the oil changed and the other general mant. Which is't much on a 1st Gen. Later,

Paul


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