car carbs on a bike engine

[Skates]

had an interesting chat with a trike builder today. he said about changing my carbs on the z'd over to car carbs. said they are soooooo much cheaper to fix and balance up plus will give better performance and MPG
anyone ever heard of this being done b4

[Ianb]

seen it done with a Norton running a single SU, but a Z might be a different story.

better MPG and cheaper maybe, but better performance...probably not

[devon-tony]

SU on a big jap engine isnt a problem, seen it done several times on CB750's etc

if your on britchopper forum then theres a guy on there Robbie, hes great guy and very clever, hes done it I know for a fact, several times.

might be worth asking on there, its a bit more build orientated than this forum

[harry]

All other things equal. The power output of an engine is directly proportional to the air you can get through it.
Every bend in the inlet tract reduces the flow of air. One carb cannot feed more than one cylinder without bends, this is why multi carb set ups are used.

Manufacturers are a mean bunch they wouldn't fit 4 carbs if one would do.

Car carbs will be cheaper, but by the time you've made manifolds to fit ......

As for economy maybe if you can get the set up spot on. At least as good as the original. If you are one jet size too rich you will use more fuel than before.
Too small and it will run like a pig and may melt pistons, plugs and valves.

Why not stick a blower on it, not much harder and much more power.
They work well with a single SU carb. :thumbsu:

[happybiker]

Neval's used to sometimes replace bike carbs with a single SU on the soviet boxer engines but icing was a problem due to the longer inlet tract they used. I had a GS850 running an early Ford fiesta carb and that suffered similar problems.

[BARNY the bearded leg emd]

I ran a mini SU on a XV 750 chop no probs,had to tinker making upthe ' v ' metal tube to fit between barrels and rubbers but otherwise sweet

[johnr]

plenty of folk in the goldwing world running twin choke webbers, set up so you can potter round on one choke, but when you nail it, it opens both chokes and goes like stink. seen a fair few bikes with su carbs on em.