why has noone made a car engined bike

[UFO]

If you want efficiency at higher speeds, aerodynamics is where you focus first.

[freebeard]

Another thread where I though it was one page, but by the time I post it's three pages, and now it's four pages already.

Vman455 -- Is that still a motorcycle. Fred Luther, two runs at Bonneville Salt Flats in 1935:



The (1950) text is wrong about streamlining in the 30s.

I did take the time to read Ed Roth's story about the Rubber Ducky

It wasn't as fast as other bikes on road trips, but he didn't have to stop for gas as often. It had a 600cc Honda engine/transmission and the whole Kevlar body is a 26 gallon fuel tank.

[niky]

The question is what your 90% needs are. A good 250CC will be able to hit the ton plus change. It'll be revving its lungs out... but how often will you do that?

A bigger bike will do it easily, but that other 90% of the time, you're coasting along at just 60, using more fuel simply because you have more engine and more weight to lug around.

-

People always want more power. The funny thing is, most people don't use it at all. I see V6s and V8s on the highway accelerating at a glacial pace, or maintaining just 60-70. Something I did with a 1,000 cc car last week (for a test drive) while still getting nearly 50 mpg.

*Disclaimer: I typically only drive at 50 mph, where I got 70 mpg with that one. I've got to post about it in the appropriate thread some time.

[UFO]

Originally Posted by niky

-

People always want more power. The funny thing is, most people don't use it at all. I see V6s and V8s on the highway accelerating at a glacial pace, or maintaining just 60-70. Something I did with a 1,000 cc car last week (for a test drive) while still getting nearly 50 mpg.
...

Isn't that the truth? And the other ridiculous thing, all that extra power gets used to accelerate past me to get into the gap I leave in front, then braking it off when they realize I'm moving the same speed as the rest of traffic. I just have to laugh as it's so pathetic.

[HiFlite]

Originally Posted by Grant-53

According to the website these bikes are sold only to the military.

The website also says that they are willing to sell to the civilian market with sufficient external investment funding. Since this has not been forthcoming in the several years since these diesel bikes were developed, one can assume ppl with money think it wouldn't be a commercial success.

A 28 hp 550 cc diesel would be a tough sell, especially at a significant price premium. The military's interest had nothing to do with fuel economy, btw, it was part of the transition to an all-diesel/kerosene/jet fuel supply chain. It's dangerous and expensive to transport gasoline to combat zones as a boutique fuel.

The other relevant point is that these bikes represent what can be achieved for a few million $. Off-the-shelf diesel engines will be lucky to be only twice as heavy while producing half the horsepower.

[fearlessjoe]

i dont think it was even danger...... the bikes were i think the only thing left that ran on petrol.... meaning the entire supply chain just for them.... getting rid of all that for an extra few percent diesel that they already use is a massive logistical saving......

and diesel tends not to explode

see if i could find one of those bikes surplus and use the running gear i would... but if and when they ever do come up.... there silly money

and from above.... a good 250 will hit a ton plus change..... really... the cbr claims 88... the ninja 300 probably does to be fair..... but i who wants a screeeeeaaming engine.... this is why i like my diesel idea

i would like to...... bare with me cos this is a bit in cloud cookoo land...... take a 1.6 diesel.... and remove 2 cylinders..... i dont mean chop the engine in half... i mean take out 2 of the pistons and rods whatnot.... as long as they were opisit each other in the firing sequence it should remain ballenced... (wild speculation).... disconect the fuel and weld the exhaust up..... weld shut or somehow block the unused pistons... put a turbo on thats half the capacity..... boom 800cc diesel... essentually what the xl1 has......

i could so all that reasonably easily.... but it would only work if.... and i stress IF... you could fool the ecu etc into still working..... that... no idea if its plausible

[Grant-53]

A 3 cyl. Kubota or Hatz turbo in the 700cc to 900cc range might fit the bill with the right gearing and aerodynamics.

[freebeard]

Originally Posted by fearlessjoe

i would like to...... bare with me cos this is a bit in cloud cookoo land...... take a 1.6 diesel.... and remove 2 cylinders..... i dont mean chop the engine in half...

If cylinder deactivation works, then the same firing scheme should translate.

OTOH cutting a boxer six down to a four or a four down to a twin is settled art. And there exists at least one flat-four diesel, from Subaru.

[jakobnev]

.

[UFO]