Motorbike engines in cars - Why do it?

R1 engine about 150BHP or more depending which version,6 speed sequential box,compact, light weight, reliable and capable of being thrashed without going bang on a regular basis and ultimately cheap per bhp

That looks the business!!

Because you can do this;


What's better than an old car with a motorcycle engine?
An old car with 2 motorcycle engines!

BTW, that looks like its a Davrian.

Bike engines are great, but very uncompromising.

A performance bike is a lot closer to a race bike than a performance car is to a race car. And so bike engines are also much more like a race engine.

The power to weight/size of a bike engine is amazing, and as has already been mentioned the engines are everyday reliable at this power, and expected to be thrashed.

Bikes also come with 6 speed sequential gearboxes, and with modern bikes there’s technology that allows for clutchless full throttle up shifts and auto-blipping for smooth rev matched downshifts.

And on top of this, they’re cheap. Bikes get crashed, and often the engines are unharmed, so there’s plenty available at breakers.

On the down side, but they are uncompromising engines. They make the impressive power numbers by revving high, which sounds amazing and feels great, but it has downsides for every day driving.

The peak torque is often way up the Rev range, meaning lots of clutch work to get rolling. Finding the right gearing can also be an issue. Lots of sports bikes will do +60mph by the time you hit that 13-15,000rpm redline in 1st gear. If you want to be able to use your 150hp at under 60mph, then you need to shorten the gearing quite a bit. But then that means you’ll end up cruising at 8,000rpm! Now the bike engine won’t care, it will happily sit on the motorway for a few hours at 8,000rpm. As a driver it wouldn’t be much fun though!

The service intervals are also much shorter than a car engine, 2000mile service isn’t uncommon. Some of the servicing can be a pain, like shim under bucket valve clearances that will need doing every 10,000 miles and alike.

In a small lightweight car, that you want to feel like a little race car, that will really only be used to go out and have fun in, they can be fantastic. For most other situations a car based engine is probably a better choice.

I think a small electric motor is used in most cases nowadays as they're relatively cheap and easy to install.

I borrowed a Suzuki 1000 cc engine for a project, it was a standard motor but with a better ECU and injection put out 175bhp at the wheel.... i could pick that engine up and carry it through a factory for about 30 Meters no problem at all,,, and when you think that's the engine, box, starter, alternator etc that's very impressive.. especially in a car like the Davrian that weigh a bit more than a crisp packet !! lol
As its been said a bit on the loud side at 14,000 rpm but imagine the smiles per mile and damn hard to keep up with on country lanes.

Thats awesome. If I hadnt read this post id be wondering what the heck it was, I might have thought it was a kitcar, but id never think it was anything over 15-20 years old.

Fair point, 10k is probably exaggerating a bit! Modern bikes in my head are 90s and newer...

I should add that bike engines are awesome in both bikes and cars, just kinda time and a place for them in cars. I’d happily rock a small light car with a bike engine.