I've been reading about motorcycle engines being used in cars, in some cases with two I-4s mated together to form a small, lightweight V8 with 300+ hp. The numbers are very impressive... so what's the catch? Why aren't we seeing these things in more sports cars? Emissions? Life span? Durability?

Caterham RST V8
Powertec V8:

 

I don't know but I think it would be cool to use. I always though of building a small V8 that rev'd to 10k+ and put it in something like a Noble or Elise.

Off-Topic- This also reminds me of the motorcylce that used rotary engines in bike races. I can't remember the manufacturers name.

 

I would also add costs, possibly low end power (driveability) and efficiency.

It's a fair question though. I also wonder why aren't there hardly any sports cars weighing less than 2000 lbs.?

A car be it a 4 or even a 3 wheeler is in many ways more fun to drive than a motorcycle. Yet, there aren't really any small sports cars based on motorcycles. Or in other words why aren't there any street ATVs? Of course it would be less safe than a car. But isn't a motorcycle less safe than a car anyway?

 

Complexity of design is an issue. Lots of moving parts on such a small engine. Most companies seem to prefer a similar displacment with less cylinders.

Iteresing no one's done this though...i'd love to see the results.

 

The rotary engine is the future...stop trying to add yet another engine type (sort of) to the mix, our 8 needs to have it's foot in the door.

lol

 

some years back there was a "kit" car which ran a GSXR1300 (hayabusa) engine and transmission. Reverse was provided by an electric motor. Of course it was very light-weight and very quick.

I think that something like this should and could be done. Look at the Lotus Elise. 180hp Toyota engine in that light weight body. Imagine dropping that engine in favor of a 180hp 1.0L Yamaha R1 engine.

Motorcycles get great gas mileage... probably due to the power/weight ratio. But they also do extract some amazing power from these engines while always working to make them more compact and lighter.

Ever seen the Honda Beat, Daihatsu Capuccino or Copen? Hot 660cc 2 seat convertible light class sports cars. Imagine a 2 seater convertible powered by the CBR1000RR engine... nice for weekends or with the gas mileage it'll get... what a commuter!

 

That Busa engine in an Elise would have some serious driveability issues though. I wouldn't want to drive it on the street. I have seen turbo Busa engines used in kit cars though. Solves a bit of the low end problem, but still peaky.

 

I saw tiff drive a car powered by two ZX12R engines, I believe. One to drive the front wheels, one to drive the rear. You could shift them independently, which I thought was pretty cool. It would be an interesting car, to say the least.

 

V5 GP race bike engine... like the RC211V. Wonder what its low-end is like.

As has been mentioned... you can always bolt up two I-4 for a V8. Suzuki should do that... a small light-weight 2 seater sport coupe powered by a 2.0 or 2.6L V8. Keep the bike transmission for sequential shifting. It can even be clutch optional like on the I-6 bike they showed at the Tokyo Motorshow.

 

If only people would put this much research in to the rotary!

 

It was made by Norton and was called the F1. As soon as I had read about these I wanted one, but they are extremely rare and amost 99% found in Europe and still cost like $23,000 and are like 10 years old. But it's an idea for the future.
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GorgeousLily