jwx

how long do this engines last? like how many miles can one get out of one. I am looking at buying an FC thats why I ask and why I posted in this forum (attn MODS I wasn't sure where to post this so move it if you like)

1987RX7guy

iTrader: (3)

that depends on man things but N/a's last around 150-200k normally but some have gotten around 300k
Turbos are around 100-150k normally and you might see 200k if you get lucky.

Mykl

It depends on a lot of different factors.

If you're content to keeping the car stock, the numbers posted by 1987 are what you can reasonably expect to get out of an engine before a rebuild is required.

If you want to turn up the boost on a turbocharged car, you need to deduct miles from those numbers depending upon how extreme those modifications are.

One thing to note, the rotary engine by itself is a very reliable machine. A carbed 12A will typically run beyond the point in which the rest of the car falls apart. But when you get to the EFI and turbocharged engines typically the engine gets ruined becomes prematurely damaged/ruined/disabled by the electronics controlling the engine.

Had Mazda equipped the FC and later model engines with more simple, reliable hardware you'd find that the engines would last longer and wouldn't require nearly as much attention as they seem to.

But I could be wrong and it may not even be a matter of inadequate engine control hardware on the part of Mazda. It could just be a matter of new engines being controlled by old parts that are eventually prone to failure just as the engines are.

Aaron Cake

iTrader: (1)

Umm, not to be rude, but what?!?

The turbo engines are usually killed by detonation caused by too much boost.

The NA engines just plain wear out, or blow through abuse.

EFI has nothing to do with it.

Mykl

By EFI I mean electronic controls in general, not only the method in which fuel is fed to the engine. I used the carbed 12A's as an example because almost every aspect regarding the operation of the engine was mechanical.

In the '86-'88 cars you have pulsation damper failure to worry about for a premature death, on the '89-'91 cars you have the electronic OMP's that have been known to fail causing excess wear and premature engine failure. On the FD's, Mazda's half-assed ECU is what causes premature engine failures. I'm talking about stuff like that.

My last FC, the convertible, had the engine replaced at 100k miles for unknown reasons. That was before I purchased the car. At 170k I was starting to see so many electronic gremlins popping up here and there that hindered the engine that I decided to ditch the car while I still could.

Basically what I'm saying is that when Mazda moved over to controlling the engine electronically they introduced a lot of new ways for the engine to fail aside from simply wearing out or through being abused.

Aaron Cake

iTrader: (1)

I see. So you were referring to electronic failure, not actual engine failure.

1987RX7guy

iTrader: (3)

I think he means electronic weak points that are IMPORTANT to proper engine health.

Mykl

Aye.

...and that in many cases these electronic failures can easily promote actual engine failure.