These days, those engines are far better but still tend to need a rebuild at around 80-100k miles, but there are now plenty of specialists who do the job regularly and compared to a regular engine they're very mechanically simple with few moving parts. So fitting an guaranteed exchange engine from a Wankel specialist will typically cost less than trying to convert to a totally different engine design. Conversion has other problems as well: the car is worth less afterwards, may have some significant compromises such as inefficient/absent heating, awkward throttle pedal rates, and the weight difference tends to result in ruined handling with a nose-heavy car. That also means additional expense in altering the front suspension and brakes and the insurance quotations are always far higher for non-standard modified cars. Repairs are also more difficult as it's more difficult to identify the correct parts and some exhaust parts and mountings may well be custom-fabricated.
In summary, the best option is to get your engine replaced with a rebuilt exchange unit. It will be more reliable and cheaper. But note that there's no such thing as a cheap rebuild, a good one is simply cheaper than a new engine. If you cannot afford a rebuilt engine then look for a good low mileage used engine from a scrapped car, and sometimes they do come with a service history.
Are you just trying to make power? The main feature of the rx8 is its handling. It has won several awards. Though the rx8 is slow it handles like no other. You lose that with a swap. Having said that if I had an rx8 again and unlimited resources and time. It would be fun to drop in a disi MZR from a mazdaspeed. You're looking at a lot of supporting parts and fabrication though. I know a lot of FD guys like to shoehorn in a ls engine. Again lots of fabrication but they do make kits for this.
Sounds like a nightmare in the making. The ECU is not going to work with a piston engine, and neither will the engine harness or ECU harness. Funny thing about harness swaps - they tend to spread as you find the next harness does not mate, and the next, and the next.... The odds of ever getting it back on the road are not good.
Sell it and buy something else?
The whole coolness of a RX 8 is the rotary engine. If you don't want that, sell it and buy a MX 5
Hi like jack i would agree any way no other engine is as low profile that will ft in where it is except a possibly a porsche engine. and gearbox then it would go better in reverse than forwards.
Why would you replace a Rotary by a Piston engine ???
More than the car is worth, as said sell it and get a decent car.
