anyone put motorbike carbs on a car engine?

[Billzilla]

<off-topic>
Bill - I couldn't help noticing that your adjustable cam gears are not anodised in bright blue/pink. I was under the impression that the lurid colour was required for them to work properly ?
At least the inlet plumbing is a bright enough colour.
</off-topic>
I assume the engine is longitudinal mounted in a clubman or similar ?
Nice point about fuel pressure - I'd forgotten that bike carbs are gravity fed. Also most bike setups have the carbies rubber-mounted like yours - I assume for vibration isolation.

They aren't cam gears, they're cam pulleys. (grrrrrrrr)
Yes it's a Suzuki Swift GTi engine in a Sports 1300 racer. Check out my web site for pics & stuff.

OP you know it wont suddenly just make more power by just putting motorbike carbys on right?

They can often do that, as with the flat-slides there's no crap in the way of the inlet so the airflow can be better.

7thanks for that billzilla that was exactly the information i needed and the pictures were perfect, thats EXACTLY what i wanna do... how does it go? rev? and torque wise?.. compared to if you would of say bolted two big webbers on there?

It drives really nicely, much better than when it had the Webers on it. The problem with the Webers was that with most twin-cam engines they have a quirk of the airflow where you have to lean off the mixture in the mid-range. We fiddled with the Webers for ages trying to get them right but gave up and fitted the Mikuni's. Previously, the Webers would run way too rich from about 5,000 rpm to about 6,000rpm and I'd lose a lot of speed out of the corners. The Mikuni's don't have that bad flat-spot at all and I can get down to just over 4,000rpm and the engine pulls really well all the way to the rev-limiter. (8,000rpm)
Here's a vid of the car with the Webers on it, you can hear the engine coughing (and nearly me swearing) as I exit some corners and not accelerate and get passed again.
http://www.youtube.com/watch?v=0lOGxCpuynQ There's another vid like there as well.

[Billzilla]

Oh and here's a crappy photo of it with when we ran Webers.

[pandaah]

yeh wow it does look gay with webbers.. and yeh motorbike carbies i thort at least would smooth the power delivery due to the smaller size and more progessive fuel delivery and air speed thru a smaller diameter venturi for EACH intake port.....

well big thanks mate youve answered every doubt that i have had in mind, just finally what CC motorbike did the mikunis come from or designed for? .. i was thinking of doing up a set of CBR 1000cc carbies to make them suit the 1.5ltr motor

[Billzilla]

yeh wow it does look gay with webbers.. and yeh motorbike carbies i thort at least would smooth the power delivery due to the smaller size and more progessive fuel delivery and air speed thru a smaller diameter venturi for EACH intake port.....

well big thanks mate youve answered every doubt that i have had in mind, just finally what CC motorbike did the mikunis come from or designed for? .. i was thinking of doing up a set of CBR 1000cc carbies to make them suit the 1.5ltr motor

Mine are from a Suzuki GSXR1100 - Also there's a few different types of bike carby so do some more research before getting any.

[pandaah]

awesome will do for sure.. was also thinkin i might have to add a vacuum pump and an accumlator to run shit like the brake booster and the vacuums for the charcoal cannister cos its a road going car

[AdrianS]

.. was also thinkin i might have to add a vacuum pump and an accumlator to run shit like the brake booster and the vacuums for the charcoal cannister cos its a road going car

Diesels are your friend here - a lot of them run a belt-driven vacuum pump for the brake booster. I had one from an Isuzu 2.4 (Rodeo) in a non-automotive project.
The charcoal canister is a different issue, because it's supposed to go to the inlet so fumes are burnt by the engine - you could probably just run the vent line to one carby.
Bill - sorry about mis-naming your cam PULLEYS.

[Sunchaser]

There is a thread on Sigma-Galant where quad 38mm carbs were put on an Astron.

http://www.sigma-galant.com/viewtopic.php?f=30&t=4016

[pandaah]

awesome info guys.. and yeh adrian i was thinking of stealing it off a a 3L engine maybe just use the alternator from that engine instead of the alternator in the civic cos it incorperates the vaccuum pump, just get an accumulator and bobs your uncle i can run all my vaccuums..

[pandaah]

well he also said he had 36mm carbs running on a 2ltr.. so ill check into the size of the cbr 1000 carbs and make sure there relative to the 1.5 engine, but alas, once the manifold is made up (which is really quite easy) then i can switch the carbies im using no problems..

[oldcorollas]

can't you get FCR manifold for your engine?

[pandaah]

FCR ?
10char

[Z2TT]

http://www.keihin-us.com/fcr.htm

[amichie]

The Honda S600 & S800 had four motor cycle type carbs in its 2-seat sports cars. Many racing cars of the 1950s used a motor cycle carb for each cylinder.

I had one of these years ago. A s600 with twin chain drive rear end.

[ReQuieM]

How would you go sizing bike carbs to suit? I'd assume this wouldn't work, but you can hope, would a set of 4 carbs off a 650 suit a very old 218ci (3.4lt?) engine? Redlined about 4500 ish I guess. What if I ran a set of 6?

[ReQuieM]

Sorry for the dig btw.