akumabito
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posted on 20/4/07 at 02:04 PM |
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Really silly engine idea..
I just had a brain-spasm, and I'm sorry for bothering you guys with it..
I was thinking, what if you use two engines, mounted transversely, side by side, connected together by a differential which in turn is connected to a
short gearbox, which drives another diff which drives the wheels.
Sortof like this:
code:
ENGINE 1 ENGINE 2
ENGINE 1-(DIFF)-ENGINE 2
ENGINE 1 [T] ENGINE 2
[R]
[A]
[N]
WHEEL [S] WHEEL
WHEEL----(DIFF)----WHEEL
WHEEL WHEEL
As it was just a brainfart, I haven't actually though about whether or not it is possible to combine the power of two engines through a diff.. I
guess it would speed up the input a lot... hmm, the second diff steps it down again, but I guess not enough. Unless you could somehow factor in an
additional final ratio...
Oh well.. I guess my 'birlliant' idea failed right away.
Sorry to have wasted your time!
(I bet my ascii art is getting all messed up, too!)
EDIT: Yup, as expected, the ASCII art got screwed up.. oh well.. I hope you can still make out my stupid idea..
[Edited on 20/4/07 by akumabito]
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DIY Si
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posted on 20/4/07 at 02:13 PM |
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Only problem is you'd need two 1-1 diffs, which no one makes. I looked into something similar for a 205 T16 (4 x 4, mid engined) type car. The
option is chains.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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rav
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posted on 20/4/07 at 02:15 PM |
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Is that not similar to what Z-cars (and probably lots of other before them) did with thier twin bike engined tiger?
That had engines in line though, which is probably better cos you wouldn't need to turn the drive through 90 degrees before it goes to the
gearbox. Oh and they didn't need a gearbox cos the engines had one each, er so not very similar at all then.
Maybe I should stop putting it off and go and build something....
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akumabito
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posted on 20/4/07 at 02:30 PM |
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quote: Originally posted by DIY Si
Only problem is you'd need two 1-1 diffs, which no one makes. I looked into something similar for a 205 T16 (4 x 4, mid engined) type car. The
option is chains.
Why would you need 1:1 diffs? The first diff (unfortunately) speeds up the engine output, the last diff steps it back down again. In essence,
wouldn't this be the same as fitting 1:1 ratio diffs? (Well, besides the point that you'd probably destroy most transmissions with such
high speeds, lol..)
I guess the biggest problem I see is the final ratio, as with this design, there really isn't one. Don't most cars have a 1:1.2 to
1:1.4-ish final drive ratio?
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02GF74
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posted on 20/4/07 at 02:40 PM |
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hhmmmm, I can't seem to get my brain round this but my reaction is will the prop turn the right way?
i.e. if engine 1 is running and engine 2 is not, prop truns one way but other way if engine 2 is running but engine 1 is stopped.
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DavidM
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posted on 20/4/07 at 02:48 PM |
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If the engines are transverse with the flywheels facing each other, they will effectively be rotating in opposite directions. This effectively means
no drive from the first diff.
David
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akumabito
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posted on 20/4/07 at 03:01 PM |
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D'oh! Can't believe I hadn't thought of that, lol! Hmmm... any (easy) way around that?
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Agriv8
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posted on 20/4/07 at 03:46 PM |
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Asci art that takes me back to my computer room days.
we had a few 164 char impact printers.
We had the naked lady that used to get printed out for special ocasions.
.
Simple days before Viruses and Microshaft ( funny how they turned up just about togeteher !!!! ) Anyway back to payroll running on good ols AIX
!!!.
regards
Agriv8
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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speedyxjs
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posted on 20/4/07 at 06:32 PM |
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quote: Originally posted by akumabito
D'oh! Can't believe I hadn't thought of that, lol! Hmmm... any (easy) way around that?
Doesn't the honda s2000 spin the opposite direction to most engines? The down side is if it does, you would have to have two different engines.
Great idea though
How long can i resist the temptation to drop a V8 in?
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nick205
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posted on 20/4/07 at 07:35 PM |
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I've been thinking about this too (in a similar vein to DIY Si with the 205 4x4).
My thoughts recently have been on whether you could realistically run without a centre diff (?)
What I'm thinking is to use a front and rear diff (e.g. Sierra XR 4x4 or similar) with a propshaft running the length of the car connecting the
inputs of the diffs together (not sure if the rotation direction works out rigtht).
Next up, mount your engine and gearbox (CEC or BEC) North/South in the middle of the car parallel to the propshaft. Then use a chain drive between
the gearbox output shaft and the propshaft.
Could this work?
Would the lack of centre diff make it undriveable?
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greggors84
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posted on 20/4/07 at 07:52 PM |
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Im sure the Honda S2000 engine spins the right way, whereas some other Hondas B16, B20 etc spin the wrong way.
I think...
Chris
The Magnificent 7!
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akumabito
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posted on 21/4/07 at 05:36 AM |
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I don't think having two different engines is an option, unless they hav the same RPM range, the same output-per-RPM, etc., etc. if not, the
whole thing is kindof pointless as it would just be run by the faster-turning engine...
I'm thinking about a home-made transfer case.. this could also solve the problem of the final ratio.
In essence, it would just be a small, rectangular box. Inside, there would be two gears (salvaged from old transmission?) which give a 1:1.3 overall
reduction. This transfer case reverses output direction and give a reduction.
The other engine would get a similar transfer case, only here it would consist of two cogs connected by a chain that would also give an exact 1:1.3
reduction, but not reverse the drive.
One goes on the left engine, the other on the right engine, the engines are connected through the TC's to the diffs, then to the transmission,
the other diff and finally the wheels.
I guess that would solve the problems, right? Final ratio and reverse drive on one engine..
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CaptainJosh
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posted on 21/4/07 at 12:20 PM |
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http://www.aerotwinmotors.com/
Someone posted this in another thread^ thought it might be of use for an engine idea, you can swap the starter and cams around so you can run the
engine in the other direction.
Looks pretty good.
Although it is a plane engine... But as you said, its a silly idea anyway so pretty much all ideas are probably welcome.
[Edited on 21/4/07 by CaptainJosh]
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akumabito
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posted on 21/4/07 at 12:39 PM |
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Twin 65Hp engines, now THAT is just plain silly..
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kb58
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posted on 21/4/07 at 12:57 PM |
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quote: Originally posted by CaptainJosh
http://www.aerotwinmotors.com/
Someone posted this in another thread^ thought it might be of use for an engine idea, you can swap the starter and cams around so you can run the
engine in the other direction.
[Edited on 21/4/07 by CaptainJosh]
And oil pump!
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kb58
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posted on 21/4/07 at 01:01 PM |
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quote: Originally posted by akumabito
I don't think having two different engines is an option, unless they hav the same RPM range, the same output-per-RPM, etc., etc. if not, the
whole thing is kindof pointless as it would just be run by the faster-turning engine...
No, it really would work. Both engines add their share. Think of them both being in neutral, running at, oh, 3000rpm. Let the clutch out on the first
engine, and the car will go some speed, with the first engine slowing down to perhaps 2000rpm. Now let the clutch out on the second. It does in fact
add its share of "effort" to the mix.
As counter-intuitive as it sounds, you can have a 200hp engine and a 5hp engine to a common shaft, and it really does put out 205hp.
One other way to think of it is by fuel consumption (energy in). The work of both has to go somewhere.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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akumabito
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posted on 21/4/07 at 01:17 PM |
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There's no way an engine could run in reverse direction, right?
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Doug68
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posted on 21/4/07 at 01:58 PM |
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How about this?
Have your 2 chosen engines face for aft in the normal fashion. Then fabricate a primary drive case like those on old motorcycles or (cough) Harley
(cough) Davidson's (vomit). The two engines are joined by a wide continuous belt or duplex chain that drives the output shaft in the middle
which has the clutch mounted on it.
Go this way and there's only one diff and relatively normal gearbox required. But there is a bespoke primary drive to make.
It would make a fairly wide car though. I'm sure that this has been done before for some movies at least.
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akumabito
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posted on 21/4/07 at 02:11 PM |
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Well, as the thread title suggested, it was a silly idea to bein with, so don't worry about it not being entirely realistic.
Hmm... they should do some more Mad Max type movies.. I'm sure we could all chip in some bizarre ideas...
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kb58
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posted on 21/4/07 at 03:15 PM |
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quote: Originally posted by akumabito
There's no way an engine could run in reverse direction, right?
Sure it can, and it has been done, but it's a bit of a pain, plus the expense of getting it done.
[Edited on 4/21/07 by kb58]
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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Simon
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posted on 23/4/07 at 11:46 PM |
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Wolfrace did the twin engine thing nearly 30 years ago with the Sonic
(http://www.supercarworld.com/cgi-bin/prototypes.cgi?startfrom=61&sortby=atoz) - 2nd one down.
Engine will run any way you like (you have two choices) so long as cam(s) opens/closes valves in right order, the mix goes bang at the right time and
your oil is pumped.
Is this the kind of thing you have in mind:
ATB
Simon
[Edited on 23/4/07 by Simon]
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