Can someone explain twin engines?

[BenzBoy]

No, this isn't yet another thing to do on my Merc!
I'm just trying to figure out how twin engined cars work, or more precisely, how they are faster.
You see, in my head I'm thinking that if a car was to have two identical engines: one driving the front wheels, one driving the back, the car could only go as fast as the fastest engine... if you get my drift....
If the front engine is at 6000rpm @ 130mph and the back one is the same, surely you could just have one engine doing the same job

Obviously I'm missing something here, as twin engined cars are extremely fast! Is it more about the acceleration and not top-end speed? Or have I got it all round my neck?!

[nickb]

I have been thinking the same.
How would you stop the "slower engine" from effectively braking the faster one?

[jamieandthemagictorch]

it is more about acceleration.

BHP to weight = fast 0-60, therefore the car will have potentially double the BHP to go that much faster.

top speed is limited by a number of factors, power, gears, aerodynamics etc...

Ideally you would want 2 identical engines, with equal power, so that as you say one doesnt brake the other.


on topic but off a bit. There was a twin engined Westfield with 2x Hiyabusa engines. the gearstick (obviously sequential for the M/bike gearbox), was T shaped & split in 2, so that you could grab the whole thing & change both engines up or down. but you could also grab the left or right side of the T bar gearshift to change one axle to a different gear................eg. go into a roundabout & change the rear wheels down into 2nd gear, with the front in 3rd, pulling yourself round but powering opposite lock......................how cool !

[DerbyDan]

Yes you would need two engines of equal power and characteristics - but basically each engine is sharing the task of propelling the car of a given weight, therefore when the two engines are at full power it has the effect of doubling the power to weight ratio (abeit not quite, due the weight of the second engine and extra transmission losses)

[jamieandthemagictorch]

the hassle being your gear & throttle linkages.

[jamieandthemagictorch]

just had a thought, recently on "ScrapHeap Challenge - Scrappy Races", they have been saying that the competators couldnt not build a twin engined car, as it was "illegal for road use"!!!!!!! I thought that strange when they said it, as I'd seen many Maxy P twin engine conversions in the past (curse word, did I just admit to the fact that I used to read Maxy P ?.................I'll go get my coat)

[BenzBoy]

Ah, of course! I knew I was missing something obvious. Yeah cornering must be tricky as you don't have a central differential.
I'm not about to do a twin V8 conversion on the Merc - installing one V8 is quite enough work for me at the moment!! ;D

[Revolution 9]

It's definately not illegal, I've seen twin engined cars, it's been done a few times on VWs.

The other issue is that you would have to be careful that both the engines were putting out the same power as a few of you've said, and if one of the engines isn't running that well then things could get a bit complicated couldn't they?