reb
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| posted on 26/10/16 at 10:55 AM |
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Bike engine installation - propshaft, reverse mechanism, engine mounts
Hi,
I am in the progress of installing a 2nd gen hayabusa engine into my Seven.
What kind of propshaft design is the best for a bike engine? A single piece propshaft or a two piece propshaft?
What kind of propshafts are you using? Old Sierra ones or custom made units?
Are the Sierra ones long enough or do they need to be extended?
I would also like to add a reverse mechanism with a starter and ring gear.
I always see those installed in the back between the propshaft and the diff.
Would it also be possible to install the starter for the reverse in the front, between the engine and the propshaft?
I have much more space in the engine bay for such an installation compared to the tight spot in the back of the transmission/propshaft tunnel.
I am also wondering if I can install the reverse mechanism between the axle/output shaft and the differential?
However I heard that this solution is not working properly? I also have an LSD!
Furthermore I am interested to know why these reverse mechanisms kits which are based on a starter and a ring gear cost 300 bucks and more?
What makes these kit so expensive? Is some kind of special and expensive starter necessary?
Can I maybe source these parts on my own and get away for a more reasonable price?
Do I require a larger battery for the reverse mechanism to work properly? What AH size would be ideal but not too big?
What is the best way to install the bike engine? Does it have to be installed in a specific angle or is it enough if the sump sits parallel to the
ground?
Do the engine mounts require rubber or polyurethane bushings or can I fab up some engine mounts without bushings?
If I need bushings can I use polyurethane ones or are these too hard?
I hope you guys can help me out with all your experience and expertise regarding this subject!
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Andy B
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| posted on 26/10/16 at 11:13 AM |
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Hi
lots of questions there so will try and work through them
1 In general the propshaft will be too long for single piece design (too much whip) the accepted general practice is to use a two piece with centre
bearing and incorporate a tube in tube resilient rear section which allows some twist and compliance - if you use a simple steel rear section you will
knock out gearboxes quickly.
2 easiest way is to measure the twl and then spec a prop and have it manufactured for the job
3 see 2
4 when installing reverse sprockets it is usual to fit them at the diff end. It is not space around the engine that prohibits front installation -
more the physical size of sprocket and the position of generator covers etc - they clash
5 Normally sandwich gear between prop flange and diff flange and put a protective steel strap around it - otherwise you are sitting next to a very
effective high speed saw!
6 Works fine
7 The motors employed incorporate a 5-1 reduction gear and are slightly more expensive than those without by the time you spend £60 on a gear and add
the motor you will be up around £300 - the current draw is quite large and can stall the motor when used but we have them on our Arion racecars
running off stock 14AH bike battery
8 As you are using the busa you need to dry sump if you are going to give it some real stick, simple baffling and swing sumps are, in our experience,
the road to big expensive failures - remember oil surge is subjective - the harder you corner, brake and accelerate the worse it will get. Usual
practice is to keep the sump flat to the floor
9 Open to debate - we solid mount but some prefer to try and isolate with bushes - either works and to be honest there is so much noise and vibration
in a BEC you probably wont notice the difference
Thats my opinions - all we do is bike engined cars and the lessons have been learnt over 20 plus years
Hope that helps
Andy
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reb
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| posted on 26/10/16 at 01:01 PM |
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quote:
Originally posted by Andy B
Hi
lots of questions there so will try and work through them
1 In general the propshaft will be too long for single piece design (too much whip) the accepted general practice is to use a two piece with centre
bearing and incorporate a tube in tube resilient rear section which allows some twist and compliance - if you use a simple steel rear section you will
knock out gearboxes quickly.
2 easiest way is to measure the twl and then spec a prop and have it manufactured for the job
3 see 2
4 when installing reverse sprockets it is usual to fit them at the diff end. It is not space around the engine that prohibits front installation -
more the physical size of sprocket and the position of generator covers etc - they clash
5 Normally sandwich gear between prop flange and diff flange and put a protective steel strap around it - otherwise you are sitting next to a very
effective high speed saw!
6 Works fine
7 The motors employed incorporate a 5-1 reduction gear and are slightly more expensive than those without by the time you spend £60 on a gear and add
the motor you will be up around £300 - the current draw is quite large and can stall the motor when used but we have them on our Arion racecars
running off stock 14AH bike battery
8 As you are using the busa you need to dry sump if you are going to give it some real stick, simple baffling and swing sumps are, in our experience,
the road to big expensive failures - remember oil surge is subjective - the harder you corner, brake and accelerate the worse it will get. Usual
practice is to keep the sump flat to the floor
9 Open to debate - we solid mount but some prefer to try and isolate with bushes - either works and to be honest there is so much noise and vibration
in a BEC you probably wont notice the difference
Thats my opinions - all we do is bike engined cars and the lessons have been learnt over 20 plus years
Hope that helps
Andy
Hi Andy, thanks for all the detailed infos and your very swift response!
How does a "tube in tube resilient rear section" look like? Do you have a picture?
I have never heard of such a rear section, nor seen one.
Do you maybe have a picture of such a rear section or can link to one?
Can you explain how such a rear section exactly works?
Can I order such a propshaft from you and if so how much does it cost?
Is this propshaft made from scratch or do you use donor propshaft?
What do you mean by twl?
I am aware that the busa engine needs a dry sump system and I already plan to install one.
If the engine gets solid mounted I am afraid that it will vibrate loose all sorts of nuts and bolts. What is your experience regarding this
subject?
For me it is not about driving comfort but I also dont want to spend much time retightening all kinds of bolts and nuts on a regular basis.
How do I angle the engine in the front - rear position (you already explained the left-right position)? Does the sump has to be flat again? I know
that car engines have to lean backwards by 15° or so.
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Andy B
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| posted on 26/10/16 at 01:57 PM |
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Hi
in a bike the chain drives a hub which in turn drives the wheel through a number of v shaped cush drive rubbers to take the slap out of the drive on
gear changes protecting both gearbox and diff. We need to replicate this in a propshaft. Imagine two tubes - one 4ich diameter, one 3inch diameter
with the 3 inch sitting inside the 4 inch diameter bonded together with rubber. the inner is connected to the centre bearing driven by the engine and
the outer to the diff so as power is put through it the prop has the ability to twist to absorb shock loads
TWL is total working length measured from engine flange to diff flange. So say the TWL was 1400mm like a westfield, it would be usual to have a short
front section say 500mm from engine to centre bearing then the remainder from centre bearing to diff
We can have props made to spec once we know TWL, distance from engine flange to centre bearing and the flanges being used at front and rear - if it is
a busa we do a dedicated prop adaptor which we know the dimensions of - you would need to fit this to the engine and measure from its face to the diff
to get TWL
Engine should sit flat on its sump in all plains ideally
Hope that helps
Andy
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reb
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| posted on 26/10/16 at 05:23 PM |
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quote:
Originally posted by Andy B
Hi
in a bike the chain drives a hub which in turn drives the wheel through a number of v shaped cush drive rubbers to take the slap out of the drive on
gear changes protecting both gearbox and diff. We need to replicate this in a propshaft. Imagine two tubes - one 4ich diameter, one 3inch diameter
with the 3 inch sitting inside the 4 inch diameter bonded together with rubber. the inner is connected to the centre bearing driven by the engine and
the outer to the diff so as power is put through it the prop has the ability to twist to absorb shock loads
TWL is total working length measured from engine flange to diff flange. So say the TWL was 1400mm like a westfield, it would be usual to have a short
front section say 500mm from engine to centre bearing then the remainder from centre bearing to diff
We can have props made to spec once we know TWL, distance from engine flange to centre bearing and the flanges being used at front and rear - if it is
a busa we do a dedicated prop adaptor which we know the dimensions of - you would need to fit this to the engine and measure from its face to the diff
to get TWL
Engine should sit flat on its sump in all plains ideally
Hope that helps
Andy
Thanks for the explanation Andy.
I took a bike apart recently and noticed that it has these cush drive rubbers in the wheel and on the sprocket you are speaking about.
However this rubber mechanism was similar in size to a hardy disc from a car propshaft.
I assume you tried using such a hardy disc from a car propshaft already and it was not sufficient for a bike engine installation in a kit car?
Or is it impossible to fit a hardy disc from a car due to space restrictions (same as with the ring gear for the reverse mechanism)?
So this resilient propshaft design is really the best?
[Edited on 26/10/16 by reb]
[Edited on 26/10/16 by reb]
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hkp57
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| posted on 27/10/16 at 02:49 AM |
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As Andy previously stated most people end up with a custom made resilient tube Prop.
Much has been tried over the years to dampen the gear change in a bike engine install and the proven best way is a TRT
Dont be under the illusion it will all be smooth as silk from there, the very nature of the bike box will always result in a clunky, noisy full of
vibration experience. Once you get used to driving it and don't use the clutch on up shifts you will love it.
They are not really that expensive for the peace of mind that the mass of metal spinning next to your leg has been professionally made and won't
kneecap you.
http://www.baileymorris.co.uk/en/kit-cars-self-builds
Fleet
SKC Raptor R - Hayabusa
Toyota C-HR Hybrid Limited Edition
Honda VFR1200 CrossTourer
DCT
Marlin Roadster 1800
Mercedes Vito 116 Sport
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