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second engine how to link up
kit Car KIDDA - 15/12/05 at 11:10 PM

can anyone tell me how i either link up the second engine? or how it drives my wheels


froggy - 16/12/05 at 01:48 AM

practical performance car has an article about twin bike engines out on dec 29 or have a search on this topic, a recent thread went into this in detail and will give you a rough cost of a finished twin engined installation


zzrpowerd-locost - 16/12/05 at 08:32 AM

Here we go again pmsl


zxrlocost - 16/12/05 at 09:02 AM

I hope your a qualified aerospace engineer

why not just put 1 engine in for now


britishtrident - 16/12/05 at 09:27 AM

well put


ChrisGamlin - 16/12/05 at 10:25 AM

Agreed.
It will be much more complicated and expensive than you probably think, you're going to need to budget at least £4-5k plus engines, over and above the normal cost of a single engine build.
As mentioned above, have a look at this thread for starters to decide if you really want to go that route.

[Edited on 16/12/05 by ChrisGamlin]


ChrisGamlin - 16/12/05 at 10:45 AM

Also, in another thread I notice that you said you've nearly finished the chassis? If this is the case then be prepared to be chopping half of it all up again because you wont fit two ZX9s into a standard book chassis, at the very least you'll need to significantly shorten the passenger footwell to make space, plus strengthen up various other parts to take the power.

[Edited on 16/12/05 by ChrisGamlin]


gingerprince - 16/12/05 at 12:13 PM

Whilst we're all having a laugh, I'll share an idea I had a while ago. I'm not an engineer so it's probably heavily flawed, and someone's probably thought and dismissed it before, but: -

How about a tandem bicycle approach whereby each engine is one of the pedallers. Each engine is hooked to the propshaft with a ratchety-sprockety freewheel type thing (like bike pedals) to transmit the power.

In this case there's no real need for the engines to be perfectly synchronised. If one engine starts to pull quicker, the other one is under less load and can therefore catch up, and vice versa.

Daft twin-engine thing
Daft twin-engine thing


First obvious flaw is the lack of engine braking but I'm sure you guys can pick plenty more holes in this daft idea

Open season...


ChrisGamlin - 16/12/05 at 12:22 PM

Thats basically how the transfer boxes work, but without the freewheeling capability. Syncronising the power isnt the issue because if one engine produces more power, has more throttle open, or in a different gear, it will just drive the other engine a bit as well, dont forget they are joined together after the gearbox so each engine doesnt have to be at the same rpm etc.


zxrlocost - 16/12/05 at 12:45 PM

its a shame you cant do one simply ie like my go kart was twin engined

so basically get the most powerful carb engines available but try and find the smallest hence keeping space and wiring loom simplicity

then two cogs on a back drive train use the original bike gearing etc twin up a gear shift mechanism that activates both

that would be fun


joolsmi16 - 16/12/05 at 01:55 PM

I'd personally opt for turbocharging a large capacity bike engine, I think for about £3300 you get 300bhp from a blackbird not to mention what a busa can cope with.


carnut - 16/12/05 at 02:04 PM

Main problem I see with having 2 engines is when you change gear. If one engine misses a gear as they sometimes do, something will break.


zxrlocost - 16/12/05 at 03:27 PM

do they turbo the r1 carb engine? if they do "show me the way and Ill buy one today"

I know they do the injection

anyone got any figures for r1 (maintaining some kind of reliability)


colibriman - 16/12/05 at 04:45 PM

Holeshot turbo'd a carb'd R1 for a customer of mine, It made 225bhp.

If someone shows you how, I'll sell you an engine today......


ChrisGamlin - 16/12/05 at 05:34 PM

quote:
Originally posted by carnut
Main problem I see with having 2 engines is when you change gear. If one engine misses a gear as they sometimes do, something will break.

Yep, but only because of over-revving, ie each engine can be in different gears and nothing will break, its only when the engine in the lower gear hits its limiter and the other engine then pushes it over the limiter that you have problems. I guess with a bit of electronics you could alleviate that problem by making something that if the revs of one engine exceed a certain threshold, the sparks to both engines are cut. You might even be able to use an off the shelf rev limiter to do that if you could somehow splice in the feeds?


ChrisGamlin - 16/12/05 at 05:42 PM

Last I heard Jack at Holeshot was actually more keen on turbo-ing the carb R1 engine than the injected one. A mate of mine was looking into it and wanted to go EFI, and Jack wasnt really that keen - I think possibly because of the slightly odd design of the R1 throttle bodies where they have a vacuum slide a bit like a carb.

[Edited on 16/12/05 by ChrisGamlin]


kit Car KIDDA - 16/12/05 at 07:19 PM

quote:
Originally posted by zxrlocost
I hope your a qualified aerospace engineer

why not just put 1 engine in for now


why settle for 1
formula 1 performance


kit Car KIDDA - 16/12/05 at 07:30 PM

quote:
Originally posted by ChrisGamlin
Agreed.
It will be much more complicated and expensive than you probably think, you're going to need to budget at least £4-5k plus engines, over and above the normal cost of a single engine build.
As mentioned above, have a look at this thread for starters to decide if you really want to go that route.

[Edited on 16/12/05 by ChrisGamlin]

why 5k extra only got 9500 in total


ChrisGamlin - 16/12/05 at 07:33 PM

Im smelling a wind up here but anyway

In reality they aren't a lot quicker than a standard busa, maybe half a second quicker to 60, a second quicker to 100, you add 150bhp to the car but also add 100+kgs in weight so the gains arent as high as you first think, certainly not "F1 performance"

A 250bhp turbocharged BEC would be just as quick in a straight line and quicker round a track (much less weight), it would also be much more driveable and probably much more reliable too, but pays your money and takes your choice, just dont be suprised if you spend more time with it off the road in bits than actually driving it .


ChrisGamlin - 16/12/05 at 07:35 PM

quote:
Originally posted by kit Car KIDDA
why 5k extra only got 9500 in total


Read the thread I linked to and you'll get the idea, £3k for the transfer box alone assuming you dont want to risk being a pioneer and make your own, plus twice as many exhausts, twice as many rev counters and loads of other extra stuff like oil pumps and coolers for the transfer box.


kit Car KIDDA - 16/12/05 at 08:51 PM

quote:
Originally posted by ChrisGamlin
quote:
Originally posted by kit Car KIDDA
why 5k extra only got 9500 in total


Read the thread I linked to and you'll get the idea, £3k for the transfer box alone assuming you dont want to risk being a pioneer and make your own, plus twice as many exhausts, twice as many rev counters and loads of other extra stuff like oil pumps and coolers for the transfer box.



cheers mate



..............two turds and a brain go into the pub,ask landlord for three pints and three packs of crisps ................

lanlord replies i'm not serving you lot,

you two are steaming and your out ya head!!!!!!!!


zxrlocost - 16/12/05 at 09:15 PM

anyone got any links to an r1 turbo kit car


Winston Todge - 17/12/05 at 12:29 AM

There is this lot... http://www.mc-xpress.com/

But also this lot do a supercharger for a later injected version... http://www.dynomite.co.uk/Dynosite/HTMLfiles/home_fin.html

I am personally going the NOS route for a little more power on demand for the R1... Detailed on... http://www.r1-forum.com/ Tends to be a little slow with all the sponsors banners... and http://www.turbobits.co.uk/acatalog/sitemap.html

30 to 50 bhp under the button with very little reduction in reliability, if set up correctly.

Chris.


gazza285 - 17/12/05 at 01:17 AM

quote:
Originally posted by zxrlocost
Its a shame you cant do one simply i.e. like my go kart was twin engine




You can do it simply. There's no room for the engines side by side, so they go one behind the other but offset. A prop runs from the front output shaft using the standard prop adapter to a centre bearing.
Fixed to either the front or rear of this centre bearing is a sprocket of the same size as the output of the second engine to which it is fastened to by a chain drive. The output of this centre bearing is fastened to either a sliding prop joint for use with a live axle, or to a fixed length prop for use with a diff. If that costs £4-5k then I'm in the wrong business.


kb58 - 17/12/05 at 04:28 AM

quote:
Originally posted by Winston Todge
But also this lot do a supercharger for a later injected version... http://www.dynomite.co.uk/Dynosite/HTMLfiles/home_fin.html
Chris.


This is an example of the goal being lost in the drive to get there... 200hp for nearly $8000 + the cost of the R1 engine???

Ugg, no thanks. In fact this makes a good argument *for* using two R1 engines...

[Edited on 12/17/05 by kb58]


ChrisGamlin - 17/12/05 at 11:53 AM

In theory it is quite simple, but having seen someone go through the process, there do appear to be lots of small issues to overcome to make them reliable which all take time and money to develop, only to end up with a car thats not much quicker than a decent single engine'd Busa.

The Z Cars transfer box is expensive, but when you consider theyve probably only ever sold half a dozen of them, you can see that there's such a small market for it that it is always going to be expensive due to the time spent developing it as well as making it. It could be made simpler if you didnt need reverse, but its still going to cost quite a bit to get manufactured as a one-off.

The chain drive Gazza mentions sounds interesting but I dont know if its been tried much before, so putting you in the same R&D boat again? I can imagine the difficulty may be in getting the chain drive from the second engine reliable, for example you couldnt use a normal centre bearing because that has too much play in it and wouldnt like the side loading from the chain. Also I might be off target here but when running a small length chain isnt there some limitations on how small the sprockets it runs around can be, ie would the chain wear a lot quicker if shorter and running round two small output sprockets rather than round a large back sprocket a on the bike?

Don't get me wrong I do like the idea of a twin BEC, Im just trying to put forward as many of the pitfalls as possible before anyone decides to do it on a limited budget because if you go into it thinking that its just the cost of the additional engine plus a few other bits and bobs, you're going to run out of money pretty quickly!

Chris