Extremely thirsty supermodel - eco attempt!

[serialk11r]

I actually really want to have a motorcycle engined Lotus Elise (register it in Montana or something so no one has to "inspect" the emissions equipment), but the motorcycle riders I know are trying hard to persuade me that a motorcycle is the way to go...Maybe someday I'll have a motorcycle. I definitely believe it's much more fun than a car.

It's weird because I was always kind of an automotive masochist and found most "daily drivable sports cars" too quiet and comfortable but I actually really enjoy driving this car when I get the occasional chance to. It's only a little slower than a modern base 911, you get a great dose of beautiful engine sound but subdued wind and tire noise, and it has an incredible amount of grip thanks to the dry sump, low ride, and wide track.

Definitely not friendly to the Earth but...I drive under 2000 miles a year so it's not that bad.

[cRiPpLe_rOoStEr]

Originally Posted by serialk11r

I actually really want to have a motorcycle engined Lotus Elise (register it in Montana or something so no one has to "inspect" the emissions equipment), but the motorcycle riders I know are trying hard to persuade me that a motorcycle is the way to go...Maybe someday I'll have a motorcycle. I definitely believe it's much more fun than a car.

Motorcycles are cool, but my knees are not something to write home about, and a car will most likely be easier to take the dog along for a ride

I also used to daydream about fitting a motorcycle engine into some lightweight car when I was a teen and didn't care about torque curves, yet I would take a much more austere approach.

[serialk11r]

The attractive thing about motorcycle engine is that you can get beautiful race car noises for a relatively low price. A 911 GT3 is going for...230k? I'm sure it's a great car, but considering how they're appreciating assets these days, it would be scary to actually drive such a car.

A motorcycle engine car is a lot of expensive custom work...but it's much cheaper than any supercar, and it's WAY more fuel efficient.

[cRiPpLe_rOoStEr]

Originally Posted by serialk11r

A motorcycle engine car is a lot of expensive custom work...but it's much cheaper than any supercar, and it's WAY more fuel efficient.

Not so sure about the greater fuel efficiency, since usually a smaller engine at a much higher RPM may end up consuming the same amount of fuel. But it's cool to hear a Honda CBX 1050 with its straight-6 sounding like a Formula One car...

[serialk11r]

Originally Posted by cRiPpLe_rOoStEr

Not so sure about the greater fuel efficiency, since usually a smaller engine at a much higher RPM may end up consuming the same amount of fuel. But it's cool to hear a Honda CBX 1050 with its straight-6 sounding like a Formula One car...

I was thinking a BMW K1600 either with some custom transmission gears, or some kind of custom attachment to a car gearbox. It's a relatively relaxed bike engine that should be efficient at low rpm, but you can probably still unlock 30hp from the top end. That bike has a GVWR of 1189lbs so maybe putting it a Lotus that comes in at 1700 with the driver isn't too much of a stretch, it's got dry sump lubrication and has a respectable amount of power even by car engine standards.

The 6th gear on that bike is geared like a car, but the 1st gear is going to be a bit too tall to launch even a 1500lb car with, but I can add some "hybrid drive" to fix that (e.g. starter motor on a normal RWD diff) and handle reverse at the same time. Alternatively, I could have a shorter 1st gear made, or a taller 6th gear with a shorter final drive (probably the taller 6th, I feel like it's not a good idea to increase the torque going through a motorcycle trans).

I feel like it has to be possible to connect the transmission input shaft (which is attached to the wet clutch) to a car transmission. The bell housing would be tossed out, use a spline adapter to connect the two shafts maybe with some cutting, and then an adapter plate can be used to connect the transmission to the engine block casting. An oil seal would have to be added to the shaft so the engine oil doesn't pour out from the clutch area.

The whole shaft drive mechanism is another headache. Campagna T-Rexes use the same engine with some custom chain drive conversion, which theoretically could be borrowed and converted to a driveshaft. The engine is so tiny it will fit in any orientation in any car more or less.

[cRiPpLe_rOoStEr]

Originally Posted by serialk11r

I was thinking a BMW K1600 either with some custom transmission gears, or some kind of custom attachment to a car gearbox.

IIRC the transmission and engine share the same housing, and it already has some provision for reverse, so most likely I would be favorable to custom transmission gears. Companies such as Quaife, or Rito from Portugal, may provide it.

[serialk11r]

Originally Posted by cRiPpLe_rOoStEr

IIRC the transmission and engine share the same housing, and it already has some provision for reverse, so most likely I would be favorable to custom transmission gears. Companies such as Quaife, or Rito from Portugal, may provide it.

It's a very feeble motorcycle engine starter powered reverse, which won't do IMO. A car starter reverse would weigh a few lbs more but can be used in both polarities to provide assistance.

I think it should be possible to either remove the shaft drive housing or cut into it and remove the bevel gears to remove a few % drivetrain loss. I'm sure the Campagna T-Rex chain drive solution couldn't have been that hard to build (at least without their reverse feature), but chain drive is a bit more difficult to set up than just using a short driveshaft and car rear differential.

[cRiPpLe_rOoStEr]

If your pockets are deep enough, and you're willing to take this dive, go for it. But I wouldn't be willing to resort to a chain drive. And even though the transverse engine with a shaft drive wouldn't make as much sense as a longitudinal engine, I'd actually be more concerned about torque steer.

[serialk11r]

Yea transverse shaft drive doesn't really make much sense, it just reduces the amount of modification needed.

S1 Elises have to be imported and the S2s are way too valuable to modify, and it would need to be titled and registered in a state with no emissions regulations. I *could* use something besides a Lotus Elise but as far as I can see, the Elise is absolutely perfect: it has very well sorted suspension/brakes/steering, zero creature comforts and zero excess weight, and a lot of aftermarket support.

I'm already "borrowing" my parents' extra parking space and going to get yet another car, so there isn't really space for yet another car that just sits around, so I'm not motivated to go import a car. If people start importing more of them from the UK, I'll probably grab one. The Rover engine would probably be very valuable to someone else with an S1 in that case, and I imagine the lack of emissions certification means the prices will stay at a significant discount to S2s.

I believe it costs something like 15k to get a motorcycle engine fitted to a car with a chain drive, which these days is a huge bargain compared to trying to buy a used Lotus or a spicier Porsche. I kind of want to do the electric assist part myself because it seems very simple. I think I want to disassemble the transmission myself just for fun and to make sure it's feasible before committing, but I need some spare space which I won't have for another 2 years most likely.

The other project I want to do at some point is an electric 2 speed ultra-lightweight because I anticipate that future electric cars will prioritize speed and gizmos over fun, but I'm waiting on future battery chemistries for that.

[alexshock]

Originally Posted by serialk11r

I actually really want to have a motorcycle engined Lotus Elise (register it in Montana or something so no one has to "inspect" the emissions equipment), but the motorcycle riders I know are trying hard to persuade me that a motorcycle is the way to go...Maybe someday I'll have a motorcycle. I definitely believe it's much more fun than a car.

BTW, Lotus Elise has same engine as Toyota Prius III (different head / pistons / turbo, but block is the same).
May be it is reasonable to review a hybrid upgrade