Comment by elihu
5 years ago
I'm hoping LiquidPiston's rotary engine design pans out: https://news.ycombinator.com/item?id=25450477
In theory, it should fix some of the maintenance issues (apex seals are attached to a stationary part of the engine where they can be more easily lubricated) and fuel efficiency / emissions issues (combustion chamber is closer to spherical).
I like the idea of the Mazda rotary engine, but I'm not really surprised they stopped making them, due to fuel economy and emissions. And at them moment, the hundred-thousand mile engine rebuild interval basically means you can get an RX-8 with a bad engine for almost nothing, which opens up a nice opportunity for EV conversion. It's hard to imagine a nicer platform to start from.
Wow, that LiquidPiston rotary looks very interesting! I hadn't seen that before - I too hope it pans out.
> I'm not really surprised they stopped making them, due to fuel economy...
Eh, nobody bought that car for the fuel economy!
The car sold itself... just one test drive and you had to have it. I've owned and driven muscle and other sports cars, and still nothing compares to the RX-8 - it's just such a unique experience.
Not sure how you're doing the conversion, but if you're keeping the carbon fiber driveshaft (vs. a motor on each wheel I suppose), there will be nothing keeping it from screaming off the line with an electric motor under the hood (traditionally the wankel wasn't good off the line with low RPM's, power band kicking in around 6500 if I recall - could make for a great "sleeper"). Although I'm unsure if the driveshaft would stand up to the torque a motor would output, since the wankel wasn't particularly torquey.
If you're not already, keep a blog and pictures of the conversion - that would make for an interesting read!
> Eh, nobody bought that car for the fuel economy!
True enough, but I'm sure there are other factors in play, such as public policy. Fuel economy standards have been going up.
The motor I'm putting in my conversion is a Netgain Hyper9 (high-voltage, double-ended shaft version). It's about 120 horsepower and less than 200 foot pounds of torque, so in theory the clutch/transmission/driveshaft should be fine. (I'm keeping the 6-speed transmission.) It probably won't be particularly fast, but we'll see. More powerful AC motors exist, but they tend to be expensive.
I haven't posted any pictures yet; I've been meaning to, just haven't gotten around to it. There's another guy in the UK I think with a youtube channel that's doing close to the same thing, but with a Leaf motor.