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Background / FAQ

This website is aimed at people wishing to put a bike-engine into a kitcar.   Whether the car is already built and is having a transplant, or whether it is a new car does not matter.  There is information for all. 

Note that we are not professional mechanics etc, just people who enjoy tinkering with cars and the challenges/rewards that bike engines bring with them.

But why a Bike Engine?

Putting a Bike engine into a lightweight kitcar is all the rage at the moment.  

Formula27 were arguably the first to bring this to the masses with their Sevenesque kitcar powered by a Honda Fireblade engine.  Fisher folowed suit with their Fury Fireblade and now the mainstream players such as Caterham and Westfield are in on the action too.

Of course bike engines have been fitted into competition cars for far longer.   They have been popular in hillclimb single seaters, have several circuit race formuale dedicated to them (Formula 600, BK Lights, Radical sportscars), and also have several classes in autograss too.

The sound of a superbike engine at full-chat is intoxicating and is arguably the nearest thing you will hear on the road to a Formula 1 car.  Of course there will always be people who prefer the sound of an 8Valve engine with a pair of gargling slurping Webers!  There is no accounting for taste!

So what prompted us to do bike engine transplants and builds?

Marc: Well basically I wanted a more modern engine than my previous XFlow.  I also wanted a box-standard engine to give improved road civility and reliability.  I also wanted more speeds than 4 in the gearbox and I had a target power-tp-weight ratio of around 400bhp/tonne in a Sylva Striker. 

A bike engine fulfills all of these goals and offers several other advantages too!!



Q Are there any Bike scrapyards around?

Q Yes - lots.  Due to the fact that bikers seem to crash a lot there are many around.
A good place to start looking is in the back of MCN (Motorcycle News).  This is a weekly paper. 
One particularly good service is provided by PARTFINDER.  Here you call them and specifiy the parts/engines you are looking for and they then farm this out to 200 scrapyards!  Within an hour or two your phone will not stop ringing!

Q How much do the engines cost?

QApproximate costs for a low-mileage SH engine kit with most parts needed are:

as of Jan 2000

QWhat do I need for Engine Mounts?

QMake them yourself.   One MIG welder and some steel is all that's required ;-) 
For some bikes/cars you can buy these from the manufacturers.

QHow about the Bike Instrument Pod/Tacho/Speedo?

QThe speedo is unlikely to be useable due to the non-recalibratable nature of them.  Car electronic speedos are 100+  Pushbike speedos  are around 15 and will do the job just fine.   Get the Tacho as there aren't many cars that rev to 14,000RPM ;-)

QWhat about the Props/UJ's/Drive Flanges?

QCan all be bought from Fisher et al.  Most flanges start life as front sprockets.  They are welded to a steel drive plate and the whole assembly turned down on a lathe to look pretty(er).   Make sure you check the flange for run-out in both planes.  You DO NOT want vibration with a prop spinning at 10,000RPM!


QEither buy a purpose built reverser box for 500 or so, build an electric one or do-without!! 


QEither use the bikes or some small car radiator.  Hose joining/extending will be required for both methods.

QOil Cooler

QSome bikes have these as standard.  If so - keep it.  If not then this is a competition only thing.

QDo I need to Dry Sump?

QOnly if you are going racing or fitting a large 1000cc+ engine.  See Marc's diary for more info.

QCan I retain the original Ignition System?

QYes - completely.

QDo I need to get the Carbs Re-jetted?

QProbably.  Even if you use the bike silencer and airbox the loads on the engine will be different and the fuelling may need changing.

QHow can I set the gearchange up?

QEither pushrod or electronic.  This is easily achieved.  Fisher can supply kits etc.

QWhat will be the correct Engine Position/Orientation/Angle/Clearance?

QThe one that is the same as the bike.  Generally the sump willl be horizontal or thereabouts.

QDo I need to keep Air Boxes and Ram-Air?

QMaybe, maybe not.  See Marc's diary and Nick's diary for more (conflicting) info ;-)