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mid engine bike motor build questions

bennjamin - 5/7/16 at 11:59 PM

hey team

Just sussing out more ideas on a bike engine build in a old Honda S600.
I am using a cbr1000 motor - and yet to decide the layout - so here I am with some pretty exact questions.
I was considering front engine RWD but am worried on the angle of prop shaft vs diff , balance etc

1. Can a bike engine be slightly offset to chain diff then to driveshafts - to maintain equal length shafts ?
2 What is the general weight saving from a front engine RWD setup to a direct chain drive to mid engine setup ?
3. Due to the lighter weight (<1200pounds all up) would there be much issue with balance and handling compared to the standard front engine RWD layout ?
4. Finally , what is the absolute distances from front sprocket to diff sprocket ? I am likely to have an extremely tight clearance - there is also the consideration for running the engine even slightly rear engine.

Many thanks Ben

daniel mason - 6/7/16 at 06:27 AM

You don't need equal length drive shafts.although the nearside shaft will run at a steeper angle due to it being shorter!
The distance between the sprockets can be tight as well.
My Jedi has a decent distance between them but some are very tight.take a look at all the bike engined single seaters.almost all use chain drive

ReMan - 6/7/16 at 07:43 AM

ISTR seeing one of these with a bike engine at stoneleigh about 3 years ago.
That was front engined and lovely.
That's the way to go if the engine fits

Sam_68 - 6/7/16 at 08:55 AM

quote:
Originally posted by ReMan
ISTR seeing one of these with a bike engine at stoneleigh about 3 years ago.

Are you sure it was a bike engine? The standard engine looks (and is) very bike like.

I assume the equal length driveshafts is because you don't want to mess with the existing rear end arrangement (which ISTR is basically a live axle fixed to the chassis that then chain drives IRS via sealed roller chains)?

It'd be a great shame to bastardise a genuine S600 in this way - they're becoming rare and valuable in original condition - but wouldn't the easier way be to consider a more modern triple car engine, like the Suzuki Cappuccinio, Toyota Aygo or Smart ForTwo?

twybrow - 6/7/16 at 05:46 PM

quote:
Originally posted by Sam_68

quote:
Originally posted by ReMan
ISTR seeing one of these with a bike engine at stoneleigh about 3 years ago.

Are you sure it was a bike engine? The standard engine looks (and is) very bike like.

I assume the equal length driveshafts is because you don't want to mess with the existing rear end arrangement (which ISTR is basically a live axle fixed to the chassis that then chain drives IRS via sealed roller chains)?

It'd be a great shame to bastardise a genuine S600 in this way - they're becoming rare and valuable in original condition - but wouldn't the easier way be to consider a more modern triple car engine, like the Suzuki Cappuccinio, Toyota Aygo or Smart ForTwo?

Or a Triumph bike engine? They sound awesome, are very torquey for the cc and are very compact being 3 cylinders.

Sam_68 - 6/7/16 at 06:40 PM

quote:
Originally posted by twybrow
Or a Triumph bike engine? They sound awesome, are very torquey for the cc and are very compact being 3 cylinders.

If I'm understanding the OP correctly, though, the problem is that any chain-drive bike engine, with its integral gearbox, offsets the engine to the left of the transmission tunnel on the S600?

Advantage of any car engine is that the crank remains on the centreline of the car, in line with the propshaft.

For anyone unfamiliar with the S600, this s what the chassis and drivetrain looks like:

Engine bay:

That oddball rear axle arrangement:

And the finished article:

Gotta say, I'm struggling to imagine how you'd make one mid-engined, unless you put the motor where the passenger seat was: they're tiny, so engine behind the seats would need to be really tightly packaged.

ReMan - 6/7/16 at 09:28 PM

quote:
Originally posted by Sam_68

quote:
Originally posted by ReMan
ISTR seeing one of these with a bike engine at stoneleigh about 3 years ago.

Are you sure it was a bike engine? The standard engine looks (and is) very bike like.

I assume the equal length driveshafts is because you don't want to mess with the existing rear end arrangement (which ISTR is basically a live axle fixed to the chassis that then chain drives IRS via sealed roller chains)?

It'd be a great shame to bastardise a genuine S600 in this way - they're becoming rare and valuable in original condition - but wouldn't the easier way be to consider a more modern triple car engine, like the Suzuki Cappuccinio, Toyota Aygo or Smart ForTwo?

It was actually 2011!
I'm not sure of anything
But pictures don't lie! See below
You are correct!! I possibly had a chat with the owner re another one he has too though perhaps going this way?
And I agree re-chopping one, unless, as it can be done reversibly, e.g. cradled to existing mount points perhaps

hond1

hond2

hond3

bennjamin - 6/7/16 at 10:05 PM

Many thanks on the replies...and opinions on the car itself !

Yes as pointed out above , there is bizarre chain drive setup in the rear which I intend to replace with a solid axle arrangement (front engine rwd) or as discussed mid engine. The entire bit weighs a ton and wouldnt respond well (handling wise) with double the power going through.

A major point is to keep as much of the original body as possible - doing a simple front engine build will leave the body untouched.

Im yet to get some proper measurements as the chassis is sitting in my garage while the body is getting touched up - but more so to this thread I have had some input from Doug from West garage and he too is pushing away from a mid engine setup in this particular body. The motor likely wont have a decent distance front to rear sprocket and likely wont keep inline to make it work.