Is their anything to say that two engines can't be used? Both would be connected to the rear, not one driving front and one rear.

Just thinking while bored at work with the friday feeling.

look up Z Cars

is it deja vu day? I asked similar question about bike engine exactly one week ago.

yes it can be done, inf fact a lot of thinkgs can be done given evnough time and money.

I was thinking that the SVA would have some silly rule saying you can't but i had an idea about using 2 Suzuki TL1000 engines. These are V twins so much slimmer than your average bike engine and i recon they could be put side by side. They're about 125bhp each with wicked torque. hmmm. They can also be picked up much cheaper than the usual choices.

Mr Rob what an interesting idea, could you make an adapter to join one crank to another making a v4?

just an idea.

Ditch

Its been done - the furore (or how ever its spelt) did it.

Look him up on here, Russ is his name. He's also got a web site selling a rather taste F1 look a like car.

I was thinking if running the two straight down the car, having a chain drive fom each motor down onto one shaft and taking it from there. And yes it would be a 2L V4.....

I think you are allowed to do it provided that they are both driving the same axle. I am sure I read somewhere that you can't have one driving the front and one driving the back.

Thats what i thought, i seem to remember it on scrap heap challenges wacky with the cut and shut black cab.

I've got it all planned out in my head but i'll have some other supid idea tomorrow. I need to find out the width of the TL engines and then an appropriate transfere box.

Did someone mention my name, thought my ears were burning! My engines drive one rear wheel each - there is no connection between the 2 engines other than linked clutches & gearshift & obviously throttle. There is no form of "clever" engine management to control them & it works brilliantlly, was a nightmare to engineer tho' & SVA did give me a hard time, but had to back down in the end.
It's a great way of geting cheap power (where else can you get 274BHP for less than a grand?!!), but don't forget 2 x bike engines/gearboxes weigh nearly as much as 1 Pinto!

No sva rules about which wheel can be driven.
Russ's car has two rear engines, one driving each rear wheel seperately.

Cool i've just found this... it's the sort of thing i'd need to get power from the two gears to the prop.

http://www.bareco.com.au/files/pto2002/pto92.htm

Only thing is it needs to be rated for another 100hp.

Looks like my 5 year apprenticeship has its benefits. The next thing is to put my ideas down on CAD.

If you want to link the engines up, then it will cost you a lot more than you think to make it reliable. A mate of mine built one of the few twin ZX9 Westfields around (the orange one with full cage), and it ended up costing the best part of £10k to do the conversion with the Z Cars transfer box, two sets of custom manifolds, lots of mods to aid cooling etc, and in all honesty you end up with a car that's not a huge amount quicker than a single busa powered car.

Will all due respect to Russbost, although its a cheap way of doing it and Im sure its a fun car to drive, running two completely seperate engines each driving a seperate wheel is not a good engineering solution if you're looking for the best car dynamics (handling) because no matter how hard you try you'll never get both engines to produce exactly the same amount of power at all times at all revs, and without the engines being linked in any way you can't mimic the effects of a diff to allow the car to corner properly or control the inside wheel from spinning up when unloaded.

Great in a straight line though I imagine.

Chris

[Edited on 31/8/07 by ChrisGamlin]

Twin engines = money pit and totally pointless. IMHO.

Here's my twin bike engined fiat 126, where the engines ARE mechanically interlinked (via chain drive)



shell on rear corner

As was mentioned in the thread though, getting it "road reliable", rather than a racing car, would be another thing, as the chains are very short and as such will be short lived. Doubt they would do more than 500 miles before a drastic tensioning was required if not replacement.

I also know that some years ago a chap used to race a vauxhall nova in autograss with a pair of vauxhall XE 16v engines in the back, arranged side by side longitudinally driving via a chain transfer box to the diff with no gearbox. ( again, easy in autograss where with plenty of torque direct drives are common, but not much use on the road)

hope this is of some help

Nat

Probably not viable on a bike engine, but Ive seen car engines inline with the front crank just bolted to the rear crank. Would have to be the right engine, or a custom crank to handle the load on the snout w/o breaking. Ive seen top speed cars, and the odd vintage drag racer like that.
Gets rid of any "power combiners" which tend to be expensive, heavy, and have low torque ratings.

It was the low torque ratings that have plagued my transmission bits choice, and that is where most of the 10k that Zcars (as chrisgamlin mentioned) spent went.

GB Engineering built the bits for them and I spoke at some length to Geoff about the stuff they do on the grassers, and it was that that formed most of the basis for what I have done.

630 3/4" pitch chains are not light or cheap though, and there is a lot of machining involved in making the bits as they just aren't available off the shelf.

Not being a biker, this may seem daft but what about the various versions of shaft drive - one on each engine driving a common shaft where the rear wheel would be?

Steve

Thats essentially what the Z Cars transfer box does but with props bolted to the two ZX9 engines (which were originally chain drive). Its this "common shaft" joining it all together and making it reliable that costs the money

Chris

I see what you mean. Amongst other things, close tolerances and strength mean that it's not an item that can be home built reliably.
It's obviously a completely different application and one where weight isn't an issue but I wonder how the tractor pullers combine 5 high power/torque engines from all directions?

On mine, the "common shaft" is made of TI6V alloy steel, (hollow bar) of 55mm OD and 35mm bore (approx) machined to take a pair of these:



drive cup

which take some machining, these were made from 155mm OD EN8 solid bar, and are designed to take a 108mm CV joint bolted into the end, with a 630 chain 38 tooth sprocket bolted to the outer 8 bolt circle.

The cups are pressed and welded on.

The drive is taken from each engine using a slip fit cup which slips over the std output sprocket, made from EN24T billet, TIG welded with 312 rods to a 30mm EN24T shaft, running in a pair of sealed bearings in an alloy mounting block bolted to the chassis.

All home machined except the slip fit cups which my mate cut from a 4:1 scaled print of a cad drawing that I did, on his manual pantograph engraver. Each took 100 passes (around 5 hours) to cut.

Tractors use massive industrial "combining gearboxes". Each one probably weighs about what a locost does. There are lighter ones, mostly for the aircraft industry, but they arent rated to handle any torque. There are lots of ways to do it, but the cost gets high enough you would do better to just add some boost/parts to a decent engine

Here's my mate's twin ZX9 website

There's some good pics in there of the transfer box (which cost ~£3k from ZCars IIRC) and the mods he had to do to it to make it more reliable.

when i first started looking at building a kit, i was looking at engine options. crazy idea no.1 join 2 st1300 engine together to make a V8, joining cranks but it looks like the clutch would be in the way crazy idea 2 joing together 2 rsv engines, at the crank

Crazy ideas rarely end up being locost..

The real problem is torsional vibration