Technical Super Bike Carbs

[faster4_tec]

having just read this months retro cars i read an article on a pair of bros that have started a business.
basically they are soucing super bike carbs from a scrapyard and then fabricating inlet manifolds to suport these carbs then setting them up and the results are well take a looksy :-
on an old micra 1.0l twin cam (i think doesn;t say but they are popular) which was kicking out around 56bhp and 70lbft (or thereabouts)and limited to 6200rpm.
after some 800cc honda carbs and some rolling road time it now kicks out 93bhp and 95lbft and they had it revving well over 10krpm (wouldn;t let it rev higher as belt and pump etc wouldn;t take it)
and it costs:-
carbs from heap = £30
custom fabricated inlet manifold = £150-200
enough rolling road time to tune it properly = £300-350
so for around £600 you can have a whole lot more power than any injection system could kick out and thats without using hotter cams and flowed heads and fancy exhausts.
scope for a 1.2 8v would prob be around same as micra but with a hotter cam, performance manifold and rest of system, lighter weight springs and followers and then porting and flowinng head might give 110bhp
obviously the life span of the engine would be greatly reduced but not as much as forcing the induction

 

[rpaterson]

Retro cars were probably showing the price difference between bike carbs and a set of Weber twin 40/45's (perhaps about £350+ nowadays!). You end up with one carb for each cylinder (kinda like multipoint injection, but cruder). You will get more power, but driveability won't be as good as a fuel injected engine.

 

[HP]

The Micra engine will probably last all of 5 minutes if used up to 10k revs.

A 1242cc FIRE engine's bottom end is allegedly ok up to 8k revs max, any more and you'll need to spend a massive amount on balanced billet cranks, uprated rods etc.

I'd have to disagree with the forced induction killing the engine quicker though, properly set up a turbo 1242 should last ages. Novitec and others run them up to 118bhp and you don't need to use superbike RPM to get it.