Car engine or Bike engine?

[VladD]

Just a hypothetical question here. Obviously the driveability of the two engines is different, but if you wnated to go the bike engine route, at what weight of car would you consider that it is just not suitable? Is it also BHP dependant or is it not that simple at all?

[MK INDY]

I would say from building and driving many different BEC's,that for the big bike engines,busa/zx12/zzr1400 etc you could go up to around 600kgs before the performance of the engine would be seriously effected,the smaller modern 1000cc engines this would be around 550kgs,if your car weighs more than this I think you need to be looking at a car engine,as by the time you have added a tank of fuel,a driver and passenger,you could then be asking the engine to be pulling around 800kgs and 750kgs respectively,its alot to ask of the engine,especially on the clutch and transmission.

[VladD]

Cool, thanks.

[Sam_68]

I'd say MK Indy's figures are about spot-on, but I'd add that you ought to be aiming for at least 100 kilos less in either case, to make the best advantage of bike power.

[BadgerBill]

Yeah, drove my Striker 'Blade and 100kgs (a large passenger) made a bit of difference to the performance. Car was 428kgs road going with 1/2 tank of fuel, engine was around 120bhp (carbs with no air box). For what it is worth, it was significantly quicker than my last 128bhp Caterham which was 100kgs heavier to start with. Still did 18k miles in less than 2 years with only oil & filter every 3k and a set of plugs at 10k.

BB