Bike engined cars
Bike engined cars
Author
Discussion

big h h

Original Poster:

44 posts

174 months

Monday 24th June 2013
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I have just sold a TVR and i am considering buying a bike engined caterham, but i have been put of by people saying they are only for the track. The car would be used for fine weather blats, and now an again for track days.

Could anyone tell me if there is any problem with bike gearboxes, i have been told you can change into a lower gear and over rev the engine by mistake. All these points i have raised are probable old wives tales, but i thought i would ask anyway.

Many thanks for any advice.

JeffC

1,833 posts

241 months

Monday 24th June 2013
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I run bike engined cars for 5 years and as you have been advised they are more suited to track work , in saying that I did use mine occasionally on the road but was always a quick blat , I never went so far, problem is they use a lot of revs which is great for acceleration but at cruising speed they make a lot of noise,more so if running the mechanical reverse gearbox!! I found earplugs made a journey bearable, Ive never had a gearbox failure and my first hayabusa powered car did 8,000 miles and pretty much all of them were on track driven flat out, they do occasionally hit a false neutral but just grit your teeth close your eyes and quickly upshift the noise is very mechanical and awful!!, you get used to the shift pretty quickly pull back for up forward for down or you can convert to paddles quite easily if preferred, my advice though if for a car mainly used on road I would go CEC every time .

Edited by JeffC on Monday 24th June 20:09

pikeyboy

2,349 posts

243 months

Monday 24th June 2013
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Well as a caterham fireblade owner i feel quite well qualified to answer. They can be a bit clunky in terms of gear change at slow speed. No need for the clutch going up the box, however i do tend to use mine if going slowly. They come alive on track and get better the faster you go they are also great fun on the road although i dont think i'd take mine touring, 80mph is 8k rpm which gets a bit boring.

People say bec have no torque this isnt true, they do, its just further up the rev range. You need to try one and see if you like or think you could live with one.

Gear boxes are considered the weak link and usually its cheaper to swap the engine for a used one from a bike breakers than repair it.

Pm your number if you'd like more info or a chat.

grazo

23 posts

256 months

Tuesday 25th June 2013
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The missed shifts /false neutral and clunky gear change problem when using bike engines in cars / bikes can be virtually eliminated by fitting a new redesigned gear shift star, not expensive Google Slik-shift kit from Flatshifter uk.

Yazza54

20,319 posts

210 months

Tuesday 25th June 2013
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They can be a little tiring to drive on the road just due to the nature of the engine and box, if I was to get another lightweight kitcar/caterham it'd be type r/duratec powered or something of that nature. The bit about over revving etc is all down to the driver, yes if you hit a false neutral you can over rev it but to be honest bike engines are made to rev and you'd be unlucky to pop one from the occasional missed gear, but really the answer there would be to get used to the gearchange and make more precise gearchanges. Or as above, fit a flashifter.

Gearboxes are pretty strong but you must remember you're pushing along twice the weight through double the rubber, so a bit of mechanical sympathy with the clutch and box from a standing start is always good. The gearing is much lower than it would be on a bike generally, my old R1 fisher fury was geared for 130 so had no trouble getting moving as opposed to the bike being geared for nearer 190.

I sold the R1 fisher fury and bought.... an R1.


Yazza54

20,319 posts

210 months

Tuesday 25th June 2013
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DDg said:
and having passengers (the car's meant to be under 400kgs, passengers really affect the power to weight ratio).
yes very noticeably

renmure

4,919 posts

253 months

Sunday 30th June 2013
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I had a fireblade engined Westfield which ostensibly was for sunny day blats. Must confess I found it a bit of a chore on the road fairly quickly. To get the full benefit you need to go the whole "lightweight" route so for me it was pretty uncompromising (and uncomfortable) seating, stripped out interior, aeroscreen and helmet, lots of noise etc. There was also the feeling that you were thrashing the car in order to make rapid progress which was great fun ... until it began to also get a bit wearing. All these compromises make for a great track car but less so on the road.

Later, I had a Caterham R300 which obviously is no comfortable barge, but offered at least as much thrill but without ever feeling like too much bother to have a blat in.

maxgas

176 posts

196 months

Sunday 30th June 2013
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I ran a Westfield fire blade for 9 years, covering 9000 miles and 9 track days.

Advantages:-

The engine is bulletproof, not a single drop of oil used, the noise is guaranteed to put a smile on your face, sequential box, which I think is very difficult to select the wrong gear on and over rev even when on track. Cheap to run, cheap to replace the engine if it did go wrong, lightweight equals brake pads that still seem like new after 9 track days , and tyres that just about need changing after 9000 miles.

Did I mention the noise and addiction to tunnels!


Disadvantages:-

Lack of torque, bike engines do not have as much torque as car engine equivalents, I think the fire blade was about 130 bhp and about 65 ft/lb torque. So you do need to rev the things hard, 70 mph is about 7500 rpm. This gets very tiring and noisy,
you can wear a helmet but then you may look like a muppet on the road.
No windscreen means tat after a longish drive it feels like you have been to a heavy metal rock concert on Ben Nevis!
Your face is smashed , your ears are battered, and you are knackered.
No heater , you need to dress much warmer then is normal.
No roof, better plan your trips very carefully.

So would I buy another?

Yes! It is noisy, uncomfortable , impractical but I loved it.

Feeling down, had a bad day, wife nagging . One quick blast and you will be smiling guaranteed. It should be available on the HHS .

Try it!

radical78

398 posts

173 months

Sunday 30th June 2013
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country lane on a sunny sunday afternoon = great fun. drive to work every day in heavy traffic it would be crap

andrewmorpeth

24 posts

212 months

Monday 1st July 2013
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I've got a hayabusa powered ex grad.Just come back from 500 mile round trip to Scotland.mine has had rear diff changed to BMW 320d 2.35 ratio so it cruises at lower revs.it started out with std sierra 3.9 and that was frantic!It will now do 70mph in 1st.The car has been nothing but reliable and great on track and road.1.5k gets you a 74kg engine and sequential gearbox with an ultra reliable 180bhp which revs to a leisurely 10k.rover k series is 90kg on its own.I also drove this with the k in it and comfort wise not much difference bearing in mind the hayabusa is solid mounted to chassis.ive not over revved mine.hope this helps.

sam919

1,078 posts

225 months

Tuesday 2nd July 2013
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Out of interest Andrew, what sort of gearing/ mph was the 3.9 FD giving you?

JeffC

1,833 posts

241 months

Tuesday 2nd July 2013
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Sam from memory with standard limiter on Busa on 13" wheels 205 rears I could get 124 with a 3.24 freelander diff and close to 130 with a 3.13 this was indicated speed on speedo . I did run with a 3.3 briefly but found it too short at places like Croft, I would imagine with a 3.9 you would be snatching gears very quickly!! interesting about fitting a beemer diesel diff never heard of anyone doing that



Edited by JeffC on Tuesday 2nd July 08:33

Yazza54

20,319 posts

210 months

Tuesday 2nd July 2013
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Freelander diff topped out about 130mph on a 2003 5PW R1

sam919

1,078 posts

225 months

Tuesday 2nd July 2013
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OK Jeff cheers for that, i have a 3.62 but still might be too high ratio for the likes of croft.

andrewmorpeth

24 posts

212 months

Tuesday 2nd July 2013
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Can't remember but i soon changed it for a 3.14 and the biggest diameter 13" tyres I could use.the trouble with bec is the bikes use 17" wheels.caterhams have 13" wheels so you have to either change wheel size or gearbox or diff.i tried 15" wheels on the car.i only did nine miles before realising that wouldn't work .a 3.14 is the minimum you need in my opinion on a bec.in reality mine is never going to reach the rev limiter in sixth but I can pull away no problems and I'm not frantically changing gear all the time.bmw diffs are also plentiful and cheap.

DaveK-S1

304 posts

230 months

Wednesday 3rd July 2013
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I've got a Caterham busa with a 1585cc busa so i'm restricted to 10k max rev due to the longer stroke, using the longer ratio 5th and 6 th gears with the 215/55-13 Avon ZZr tyres it will still pull close on 140mph.
Gear speeds are shown below
3.14 47.9 64.7 82.1 97.5 125.3 137.0