I need your help for a Hayabusa V8 building

[machin]

I stole this off the locost builders forum....



Not sure why they bother having the short chain drive on the LH engine... they could just as well have connected the output direct on that one...???

[Tim.Wright]

I'd be very tempted to design a weak point in the shaft between the 2 chain attachments which will serve to protect the gearboxes in the inevitable case when the one gearbox upshifts and the other one doesn't...

[machin]

I'd be very tempted to design a weak point in the shaft between the 2 chain attachments which will serve to protect the gearboxes in the inevitable case when the one gearbox upshifts and the other one doesn't...

Ha ha, yes... weirdly that Z-cars Westfield had two gear levers (mounted back-to-back so you could use both with one hand)... and I remember reading somewhere about driving in two different gears.... does sound like a recipe for disaster, but it appears people do get away with it....

Another alternative I came up with.... turn one engine around and then connect one of the engines by chain drive and the other by gear drive onto a central shaft (to get the rotation directions correct)... that way it might look on first glance like a V8... especially if that central shaft where encased in a box which connected to the two engines... Not the most efficient arrangement in the world, but you do have the power of two Hayabusa engines....

[LVDH]

Would it not be better to connect the two engines with a differential and connect that to the main transmission?
Operating two gear levers with one hand simultaneously sounds very crazy to me.

[George75]

There's lots of grass track companies that do dial bike engine transfer boxes. Like you say, it's not a V8. Making one crankcase will be more expensive than buying one engine...

I'm sorry, I don't understand what you mean....

[machin]

Yeah, that would be another way (I'm not sure I'd say better, but I'm not saying worse either)... you'd still need to have one gear pair to swap the rotation direction of one of the engines (in this case, the left hand rear-most engine)...:-

[machin]

...Or just drive each rear wheel with one engine and not have them linked... kind of like having two motorbike swing arms at the rear....

A couple of options....

[machin]

There's lots of grass track companies that do dial bike engine transfer boxes. Like you say, it's not a V8. Making one crankcase will be more expensive than buying one engine...

I'm sorry, I don't understand what you mean....

Grass-Track is a branch of motorsport and there are cars that compete there that use two engines much like the arrangements I've posted above... do a google for "Twin-engine Grass Track Car"....

[machin]

Mental twin R1-engined Mini (from the company Z-cars that I linked before....)

[youtube]http://www.youtube.com/watch?v=X2Tyi3XFt5g[/youtube]

[RicME85]

Back in the 90's there was a twin engined VW Golf, had one in the front and one in the back, just mental.

[andylaurence]

The Furore F1 kit car used two bike engines, with one driving each rear wheel. Both transversely mounted with chain drive. I've seen dusk engine cars with a split gear lever like the throttles on a boat. Usually it works like one, but when one mid-shifts, you can pull half the lever. A flat shift or pneumatics would add reliability.

[George75]

There's lots of grass track companies that do dial bike engine transfer boxes. Like you say, it's not a V8. Making one crankcase will be more expensive than buying one engine...

I'm sorry, I don't understand what you mean....

Grass-Track is a branch of motorsport and there are cars that compete there that use two engines much like the arrangements I've posted above... do a google for "Twin-engine Grass Track Car"....

I saw the Grass track cars Class 10 that have twin bike engines,and it's a very intresting concept ,
but it's something I can not understand...
They have two separated bike engines istalled on the car
or they match together the two engines in order to have a V8?

[Tommy Cookers]

this looks like a good read
(18 articles on a Hayabusa-powered Miata - including the adaptor to couple the Hayabusa engine to the Miata transmission)
http://www.motoiq.com/MagazineArticles/ ... abusa.aspx
http://www.miatabusa.com/
similarly couple 2 Haya engines in V-ish/U-ish disposition via the (original clutch) gear on to a car transmission or transaxle ?
engine 2 lower case being replaced by a large adaptor plate attaching to the top of engine 1 lower case in the transmission region
precision positioned by design (for gear mesh) via the new shaft's bearing outer races
the adaptor plate may have its faces that mate to the engines at an angular offset to optimise engine positioning
if the V angle is small the engine counterbalancer shafts might be removed and the engines coupled about 90 deg out of phase

also this (magazine's) adaption could simply allow engine coupling (incorporating both engine's gear casings) as a straight 8 emulator
this could be transverse (with central takeoff to a transverse transaxle) or longitudinal


btw
this adaption is roughly what I had in mind decades ago ....
for aircooled (twin cyl) motorcycle engine/reduction gear for homebuilt aircraft - the reduction ratio is naturally suitable
(yes, it'd need a high end thrust capacity bearing - but it's totally doable)
car units were and are less than suitable for this

[machin]

I saw the Grass track cars Class 10 that have twin bike engines,and it's a very intresting concept ,
but it's something I can not understand...
They have two separated bike engines istalled on the car
or they match together the two engines in order to have a V8?

The output is joined like in all those arrangements I posted above... I presume you can see the linked images?

[mzivtins]

Isn't the NET output of two individual engines always less than the double expected?

Would transmission shocks cause problems in each engine? under/over fueling.

I think i should look at this subjectively; it looks fking cool and would probably be so much fun and a load of power... with an ultimate awesome failure of one of the drive-line components