smart51
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| posted on 22/1/05 at 08:46 PM |
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which engine and donor
Which engine gives the lightest weight / most power / easiest build combination at V low cost (ie without having to buy carbs / ECUs etc)?
I was thinking about 1.8/2.0/2.0i pinto (not powerful, heavy but CHEAP) versus 1.6/1.8/2.0 zetec (lighter, more powerful, more expensive, more
complicated)
also, which donor vehicle is best to get a zetec from without having to worry about immobilisor / other problems?
budet cost = £0.00 (oh go on then £200-300)
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Hellfire
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| posted on 22/1/05 at 08:52 PM |
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In answer to this question:
- Lightest weight - Bike Engine
- Most power - Bike Engine
- Easiest build combination - Bike Engine
- Cost - maybe not bike engine.
- 3 out of 4 is good
With a car engine you only get 1 out of 4! Go on, you know you want to... 
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JoelP
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| posted on 22/1/05 at 08:53 PM |
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you can get a good bike engine for 3 or 4 hundred quid too!
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britishtrident
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| posted on 22/1/05 at 08:56 PM |
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1600 CVH loads of cheap go faster stuff around.
see http://www.sylva.co.uk/cvh.html
http://www.pumaracing.co.uk/cvh.htm
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stevebubs
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| posted on 22/1/05 at 08:58 PM |
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quote:
Originally posted by JoelP
you can get a good bike engine for 3 or 4 hundred quid too!
Then add-up the bike-specific bits....
mounts & exhaust (depends on engine for price)
sprocket adapter
props with centre support bearing.
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smart51
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| posted on 22/1/05 at 09:00 PM |
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yeah. quite like the idea of a bike engine but cost / no reverse / clutch wear mean that a car engine is probably my favorite choice at the moment.
Just which one?
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Hellfire
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| posted on 22/1/05 at 09:09 PM |
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Clutch replacement takes 20 minutes... kind of offsets the balance in payment for a hoist!!!
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Mark Allanson
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| posted on 22/1/05 at 10:19 PM |
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I know that bike engines work well in cars, but I have always had a nagging doubt in my mind. The engine is designed to push 200kg's along and
the japanesse will never make things heavier than they have to, so when you are pushing 600kgs, there has to be abnormal stress on the components. I
know the clutch can be easily changed, what about all the other components - the crank comes to mind initially - there must be a hell of a strain on
the main bearings
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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gazza285
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| posted on 22/1/05 at 10:28 PM |
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I wouldn't worry myself, it has been designed to push 200kg along at close to 200mph, not a car at 120/130mph and will run at peak power without
cause for concern.
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zetec
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| posted on 22/1/05 at 10:34 PM |
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The slight concern I have with bike power is not so much the engine but the gearbox. I've heard from a couple of people that they are on their
second/third gearbox. I suspect too much engine braking is a real killer.
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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Mark Allanson
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| posted on 22/1/05 at 10:35 PM |
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Its not the power that I was worried about its the stress on the components 400Kg difference is the same whatever speed you are going.
An analagy is trying to use a 1/4 drive ratchet to undo a sierra hub nut - a 6 foot extension bar is no advantage
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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tri
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| posted on 22/1/05 at 10:53 PM |
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all i can say is tthe idea of a "bike" engine in a car don't seam right to me each in the thing they are designed for are exelant
but not together
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gazza285
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| posted on 22/1/05 at 11:09 PM |
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quote:
Originally posted by Mark Allanson
An analagy is trying to use a 1/4 drive ratchet to undo a sierra hub nut - a 6 foot extension bar is no advantage
But that is like saying you can never run a bike engine to its full potential whatever vehicle its in, bike or car. At wide open throttle the
components are under as much strain in the bike as in the car, its just that to get the same effect on the bike you would have to be going a lot
faster. I can't see how the crank would be worse off in a car that's all.
[Edited on 22/1/05 by gazza285]
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JoelP
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| posted on 22/1/05 at 11:43 PM |
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the proof is in the eating...
yup, some engines have shady gearboxes, but ive never heard of stuff like cranks going west etc. Main cause of BEC failure is oil starvation IMHO,
occational fuel pump trouble etc. Or gearbox as said.
as an aside, if you compare exploded diagrams of zx9c and zx9e gearboxes, you can see why the e ones are reputedly stronger. more bearings, better
spec etc.
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Mark Allanson
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| posted on 23/1/05 at 12:09 AM |
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Imaging 2 mates have identical bikes, they go for a european tour and drive at the same speeds over the same route (as they would). Except, one of
them has drawn the short straw and has to tow all the camping gear on a 400kg trailer.
A peanut goes to the first person who can figure which bike is under the most stress and liable to mechanical failure. You could argue that one bike
would need less throttle to maintain the same speeds/ accelleration which my point exactly
quote:
Originally posted by gazza285
quote:
Originally posted by Mark Allanson
An analagy is trying to use a 1/4 drive ratchet to undo a sierra hub nut - a 6 foot extension bar is no advantage
But that is like saying you can never run a bike engine to its full potential whatever vehicle its in, bike or car. At wide open throttle the
components are under as much strain in the bike as in the car, its just that to get the same effect on the bike you would have to be going a lot
faster. I can't see how the crank would be worse off in a car that's all.
[Edited on 22/1/05 by gazza285]
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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gazza285
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| posted on 23/1/05 at 12:22 AM |
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Or you could say one bike goes at 200mph as designed and the other goes at 120. The difference in speed is due to the rear axle ratio which also
changes the stresses on the engine. If a car was geared the same as a bike then your analogy would be true.
If it were a daily driver car then I could understand it, but these cars are a bit of fun. Answer me this then, would crossflow big end bearings be
good enough for an F1 engine?
[Edited on 23/1/05 by gazza285]
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Mark Allanson
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| posted on 23/1/05 at 12:36 AM |
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I really do not understand what all this 200mph 120mph stuff is all about.
The torque (twisting force) required to push a car is far greater than a bike therefore the stress on the mechanical components is bound to be
greater
In a BEC, you are going to use more throttle to get the desired effect (remember the extra 400kg's) so there is even more stress.
Yes the car is a fun thing not a daily drive, so you are going to do it more often.............
penny dropped?
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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gazza285
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| posted on 23/1/05 at 12:41 AM |
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The 200/120 comes into play because the final drive ratios are different. Back to your 1/4" socket drive analogy. If you put a torque multiplier
in between the 1/4" drive and the nut would you be able to loosen it then? If you changed the ratio of the final drive would the stresses be as
high?
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Mark Allanson
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| posted on 23/1/05 at 12:49 AM |
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Geez this is getting difficult.
At a constant speed, all the engine has to do is overcome the mechanical/aerodynamic drag to maintian the same speed - very little stress.
Going back to the ratchet analagy - Imagine you are winding down a pinto head gasket, you use a 1/4 drive with which ever multiplier you want and I
will use a 1/2 drive. Your 1/4 extension bar is going to snap, but my 1/2 bar is going to be fine
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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gazza285
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| posted on 23/1/05 at 01:06 AM |
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Your original point was that you were worried about mechanical failure of a bike engine due to it not being designed for a car. A bike engine is
designed to accelerate a bike to 200mph. You then put this in a car. If you want the car to do 200 mph then the engine is no good as it does not have
the torque (twisting force) to manage this and the stresses are to high.
However there is an easy way of increasing the torque (twisting force) and reducing the stresses on the engine. This is called gearing. By reducing
the final drive, the top speed is reduced and the torque (twisting force) increased and engine stresses reduced.
Which penny?
Torque multipliers are available in 70:1 so my 6" 1/4 drive ratchet multiplied 70 times should see off your 1/2" bar without much effort.
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DEAN C.
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| posted on 23/1/05 at 02:20 AM |
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Who's winding who up here?
It started as a simple question ,bike or car engine.
I had the same dilemma 3 years ago,I went for a 8000rpm screaming tiny jap lump,Toyota 4 age,not quite a bike engine but the nearest I could get in a
car type engine.
DEAN.........
Once I've finished a project why do I start another?
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stevebubs
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| posted on 23/1/05 at 02:59 AM |
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With careful choice, a BEC will be just as reliable as a CEC. I know of several BECs out there that have been around for a good few years now with a
few 10s of thousands of miles on them without incident.
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britishtrident
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| posted on 23/1/05 at 09:38 AM |
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quote:
Originally posted by gazza285
snip
Answer me this then, would crossflow big end bearings be good enough for an F1 engine?
[Edited on 23/1/05 by gazza285]
In the 1960s and 1970s --- yes.
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Jon Ison
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| posted on 23/1/05 at 12:47 PM |
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go to a track day.......
look at the CEC's come in after a session, bonnet up, steam all over, oil drippin all over, "cant go out yet letting things cool a
bit"
look at a BEC come in, engine sits there ticking over n burbling away shouting "take me out for more"
Did 8hrs solid at donnington in isonblade 2 up all day as several on here will testify with zero probs.
Did 8hrs solid in the GT1 same track, 2 up all day, never missed a beat, of the four MK's on track it was the only one running flat out all day,
yup the others where CEC's, 2 blown engines and overheating probs killed em.
Ok the car as to be light but in a 7 clone a bike engine will take it all day every day.
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britishtrident
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| posted on 23/1/05 at 12:56 PM |
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quote:
Originally posted by Jon Ison
go to a track day.......
look at the CEC's come in after a session, bonnet up, steam all over, oil drippin all over, "cant go out yet letting things cool a
bit"
look at a BEC come in, engine sits there ticking over n burbling away shouting "take me out for more"
snip
Bike engines will stand high rpm for long periods much more so than a car engine -- but the trouble bike engines weren't designed to be fitted
to cars.
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