mstieff
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| posted on 5/9/03 at 03:15 AM |
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Chain drive Locost
I am currently considering installing an R1 engine in the front of a Locost and driving the differential by chain in a manner similar to that used in
some mid-engined applications Does anyone on the list have experience or advice with this? I am planning on using a differential from a VW Golf and
building an independent rear suspension.
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Rorty
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| posted on 5/9/03 at 03:41 AM |
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To chain drive the rearwheels with the engine located in the front would require a hell of a length of chain. The amount of slack that would develope
in a chain that length would be huge. The diff would have to be adjustable, fore and aft, by about 75-100mm.
How do you propose to support the chain on such a long run?
Why not just mid-mount the engine and be done with it?
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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Noodle
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| posted on 5/9/03 at 08:56 AM |
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Rorty's quite right, transversely mounting the engine in the front of a Locost makes no sense from a drive point of view.
How do you propose to mount the Golf diff? Is it the rear from a 4WD version?
Front engined/rear drive with chain sounds a bit pre-WWI Napier to me. I can't imagine the front-drive diff could be particularly useful with a
different housing casting.
The Wolverhampton-built 1000hp Sunbeam Golden Arrow was front-engined/chain drive and that did 200mph or so. There was a bit more bodywork (and a
constant team of technicians) to hide the chain though.
Mstieff, what's your take on this? Have you some more details on this project?
Cheers
Neil.
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mstieff
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| posted on 5/9/03 at 01:26 PM |
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My plan was to actually use two lengths of chain with back to back sprockets mounted in the middle of the long run. My motivation for this is weight
distribution and limiting the power losses associated with the crown gear and pinion that would be involved if a traditional rear end were used with a
driveshaft and longitudinally mounted engine. With an R1 engine in a LHD Locost the shift mechanism also becomes incredibly simple and direct. I
want to keep the traditional "7" appearance.
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ChrisGamlin
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| posted on 5/9/03 at 02:16 PM |
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Seems a lot of work for very little gain (and probably a lot of pain). If you run the engine transversely, I cant see how its going to fit to one side
of the chassis sufficiently so that the sprocket can drive a chain directly down the tunnel, so you are going to also need to build some kind of
transfer box to take the power from the gearbox output to the centre line of the car.
Chris
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suparuss
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| posted on 5/9/03 at 03:40 PM |
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i think involute gears are about 97-98% efficient, losing power through the way the teeth contact each other, with chain you also have the effect of
stretching and flex, as well as the way the teeth contact the chain, so the amount of power you will lose will probably be much higher with a chain,
x2 if you use 2 chains. also, gear change mechanisms should be listed way lower in the priority list than being at a point where it would effect how
you mount the engine. i would definately say aither use drive shafts or mid mount it. (engines go in the rear in real cars anyway!  )
Russ.
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Viper
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| posted on 5/9/03 at 04:07 PM |
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quote:
Originally posted by suparuss(engines go in the rear in real cars anyway! )
Russ.
Stupid statement of the day?
i think so.
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Stu16v
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| posted on 5/9/03 at 05:06 PM |
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I reckon the disadvantages will more than likey outweigh any benefits gained. As Chris mentions, you will more than likely require a dummy shaft
behind the engine to get the chain lined up with the tunnel because I dont think that you will get the engine far enough across to the right (although
I obviously havent done any measuring). This will need to be adustable for tension (you could use an idler gear for this ). Then to run it to another
shaft, with back to back sprockets (again, some form of tensioning system required on these two chains).
In summary, you may end up with three chains, two idler shafts, and way fo tensioning the three chains. I doubt there will be any gain in trying to
recover mechanical losses. A beefy M/C chain is a fair weight, with this setup there is likely to be a significant increase. A good quality chain
costs a fortune too, and is always going to be the weakest link....(sorry )
Dont just build it.....make it!
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Liam
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| posted on 5/9/03 at 05:26 PM |
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Hello...
My first reaction, like most other's, was along the lines of "What the hell?", but the more I think about it the more I like it!!
Just perusing the R1 engine lying outside...and believe it or not doubters, the engine could be mounted almost centrally transversely right in front
of the footwells. The sprocket would then drive a chain down the n/s of the tranny tunnel - perfect for driving a centrally positioned rear diff.
Engine position would be awesome for weight distribution!
Dunno about golf diffs - I'd go for an Audi Quattro centre diff (as used in formula student cars) every time. You'd need to make a
sleeve/housing for it to keep the oil in and bob's your uncle - 5kg torsen lsd.
Only headache i can see in an otherwise beautifully elegant installation is the chain itself. You'd need to keep it under plenty of tension
somehow and I can imagine quite significant backlash in the transmission. And the chain will be a heavy thing too - probably cancel out your ultra
light diff arrangement - but then that weight is better distributed in the car.
Gear linkage for any side drive would be a p.o.p. Where are you based? Will you be making a LHD then?
Sounds very interesting indeed. If you can solve the chain problems it would be awesome. They must run long in all sorts of industry applications,
and I've seen very-steep-hill-climbing-trials type motorbikes with massive (about 2m) swing arms. So i'm sure it can be done - justs
needs plenty of support and tensioning. Good luck.
Liam
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mstieff
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| posted on 5/9/03 at 06:06 PM |
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I am located near St. Louis, Missouri in the U.S. The reason I chose the Golf Diff is because that is a popular choice in DSR class SCCA racing over
here. Allegedly a sprocket bolts up easily to the diff and it is simply suspended between two 30mm bearings mounted to the frame. It also looks to
me like a ring gear could be easily mounted along side of it which could be driven by a starter motor for electric reverse gear. For anyone who is
interested, the DSR web site offers a wealth of information on what the racers are doing. http://pub6.ezboard.com/bdsrforum
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Alan B
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| posted on 5/9/03 at 08:31 PM |
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quote:
Originally posted by Viper
quote:
Originally posted by suparuss(engines go in the rear in real cars anyway! )
Russ.
Stupid statement of the day?
i think so.
Ermmm?....no.....makes sense to me..
But then I would say that....
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suparuss
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| posted on 5/9/03 at 10:07 PM |
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uh oh, i think i might have started something here, knew it was mistake to say that on here. fact is tho, engine in rear + rear wheel drive = tonnes
of grip/better weight distribution + make yer car a real one!  *ducks for cover.*
Russ.
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Rorty
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| posted on 9/9/03 at 07:33 AM |
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I decided to refrain from becoming entangled in this thread, but before I do, I'd just like to add that I approve of mounting engines in places
other than the glove box.
Rear-engined? 
Mid-engined? 
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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