cymtriks
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| posted on 4/2/05 at 09:00 PM |
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IDEA! lowering a transverse engine
I had an idea a while back. I was thinking about how to lower a FWD transverse gearbox and engine so as to get a low body without silly drive shaft
angles.
The idea is to fit an adaptor plate between the engine and gearbox which has the bolt holes advanced round on one side by about 15 to 20 degrees.
When fitted the engine remains at the same angle as in its original setting but the gearbox is at an angle relative to its original setting.
The result is to tuck the drive shafts up closer and higher behind the block thus effectively lowering the engine 2 to 3 inches.
The reduced road clearance will probably be OK as production cars run much higher clearance than our kind of cars.
The only downside is that the expense of a clutch and flwheel cobination that reaches the extra width of the adaptor plat would be needed and
you'd have to check that the new drive shaft positions didn't foul something.
Any thoughts on this concept?
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kb58
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| posted on 4/2/05 at 09:19 PM |
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Well, the adaptor will have some thickness, maybe 1/4-1/2" or so? That may or may not be an issue for transmission pilot shaft engagment.
Also it means the oil pan will be 2-3" closer to the ground. In my mid-engine Mini, with 4.5" ground clearance under the oil pan, it gave
a straight shot for the axles. Lowering the engine any amount will cause problems with ground clearance unless a dry-sump is added.
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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Alan B
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| posted on 4/2/05 at 09:41 PM |
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Sounds like a good idea to me.
I think it would be better either without an adapter (maybe not practical with welding extra metal on) or a very thin adapter....I think extensive
flywheel/clutch mods would kill the practicality of it.
Also, you'd have be aware of oil fill level, adjusting as or if needed.
But, yes I like it...got me thinking..
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sgraber
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| posted on 5/2/05 at 03:52 AM |
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I have seen FWD cars that have the entire engine tilted back over top of the half-shaft area with the idea of moving the weight towards the rear of
the car. The Toyota Camry 4cyl comes to mind.
But in a mid engine position: why don't you take the entire engine/transaxle and rotate it around the axis of the crankshaft (by 15 degrees or
so) so that the head is angled more forwards and the half-shafts would be more up in the rear. A simple oil pan/sump pickup modification and
you'd have the same effect as the adapter plate but without the expense/complications of the machine work. As long as the oil drainback from the
head is not affected...
One might argue that the front edge of the cam covers would be too far forward, but since the header is now pointing more downwards, this would negate
that effect.
What do you think?
Steve
Steve Graber
http://www.grabercars.com/
"Quickness through lightness"
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cymtriks
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| posted on 5/2/05 at 08:56 AM |
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quote:
Originally posted by kb58
Well, the adaptor will have some thickness, maybe 1/4-1/2" or so? That may or may not be an issue for transmission pilot shaft engagment.
Also it means the oil pan will be 2-3" closer to the ground. In my mid-engine Mini, with 4.5" ground clearance under the oil pan, it gave
a straight shot for the axles. Lowering the engine any amount will cause problems with ground clearance unless a dry-sump is added.
I assumed that a new clutch/flywheel combination would be needed as I didn't think a standard one would permit that amount of slop. Perhaps only
a spacer washer would be needed.
Only 4.5 inches ground clearance for a Honda engine? Does it really run this low in a production car?
I've taken a quick look under my Focus and there is certainly scope for lowering Fords Zetec by a few inches.
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nick205
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| posted on 5/2/05 at 09:46 AM |
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As Steve says, a lot of manufacturers tilt their engines anyway. The Peugeot 205s engine lays back at ~15-20 deg over the driveshafts. The sump is
shaped accordingly to give good oil collection for the pick-up. Although north/south, BMW engines also sit over at quite an angle.
If you start with an engine that's designed that way you won't have too much work to do.
Nick
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Liam
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| posted on 5/2/05 at 04:52 PM |
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As long as it's accurately machined with registers for both the crank and flywheel, there's no reason you couldn't space the
flywheel out the thickness of the adaptor plate.
Liam
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Liam
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| posted on 5/2/05 at 04:54 PM |
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Trouble is - you usually have an intermediate bearing for the driveshaft on the other end of the block.
Liam
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kb58
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| posted on 5/2/05 at 05:36 PM |
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quote:
Originally posted by cymtriks
Only 4.5 inches ground clearance for a Honda engine? Does it really run this low in a production car?
Yes, when used with 13" wheels.
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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cymtriks
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| posted on 5/2/05 at 06:26 PM |
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quote:
Originally posted by Liam
Trouble is - you usually have an intermediate bearing for the driveshaft on the other end of the block.
Liam
Err.. Yes.
This would need to be repositioned. I only just spotted this issue myself as the last time I looked at fwd drivetrain axles this feature wasn't
used. It is used on more modern fwd drivetrains however so it will need to be considered.
Is the intermediate bearing cast into the block or is it bolted on? Very hard to get under my Focus to look at this part! If it can be moved then this
idea is still possible.
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Liam
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| posted on 5/2/05 at 07:43 PM |
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Bolted on bracket in any applications i've seen. Occasionally holding other stuff (e.g. engine steadying mount on my 205) but could be
substituted.
Liam
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