Bike carbs.

[John]

Hi all, I'm after some good info on fitting bike carbs, Anyone got the link to toms thread? any other good threads? I need to know exactly whats needed, the pros and cons, gains, costs etc. (small block 8v) :)

[mk1nova_rich]

The actual physical fitting is very easy if you can get a manifold made up, its getting the carbs set up right thats the hardest bit - this is where I gave up with mine.

Parts needed:
Carbs
Manifold
Silicone hose joiners and clamps
Fuel regulator or bike pump
Bit of fuel hose
Choke cable
Throttle cable

I made my manifold for free, bit of an ungainly mild steel jobbie but did the trick and was just an exercise more than anything. I spent approx £100 fitting mine, then if I'd got them set up properly then whatever that would have cost.

Gains can be similar to twin 40s if the manifold flows well enough, but can be done much cheaper. The main con is that a lot of people seem reluctant to try them and as such there isnt a huge amount of info out there regarding fitting them to a car, and same applies with carb tuners - very few have actually had experience with setting them up

All in all I reckon its worth doing if you take your time with it :thumb:

This is a very useful link (http://www.totalvauxhall.co.uk/files/legacy/TOV64.tech60697.pdf) for info John :)

[John]

Thanks Rich! Rep left :)

[Lewis.]

i'm in the process of fitting them to mine now, and they are a nightmare. making the manifold is the easy bit, making the fookers run right is enough to drive you insane. mine have been on and off so many times now, that i've worn the jubilee clips out lol i'm on the verge of giving up on them too

[Edd]

I'm interested in a bike carb set up for something I have planned after the Sport is done

Is there a certain make of bike carbs that is better/easier for the conversion on a 1300/1400/1600 ?

Most of the conversions I've read people doing always seem to have problems overfueling as well ?

[Paul]

Twin 40s IMO.

They are cheaper too.

[John]

I'm interested in a bike carb set up for something I have planned after the Sport is done

Is there a certain make of bike carbs that is better/easier for the conversion on a 1300/1400/1600 ?

Most of the conversions I've read people doing always seem to have problems overfueling as well ?

agreed edd, the tv article says r1 carbs. is there a reason why? I will be using a 1.2 ignition set up, i take it this will be ok?

[John]

Twin 40s IMO.

They are cheaper too.

I would have to disagree paul, Decent sets of 40's on the bay make good money. You'd then need an inlet manifold, trumpet socks or filters, throttle linakge and a good setting up. Looking at it the bike crabs can be done for less. :)

[mk1nova_rich]

The small block coil and dizzy are fine, makes the conversion much cheaper than on say a baby XE, where aftermarket ignition would be needed. The overfuelling is mainly down to improper setting up and wrong jets.

R1 carbs seem a popular choice due to them being easy to get hold of so its become the 'basis' for conversions. Other carbs are fine to use...you just tend to struggle when looking for important info for jet sizes and so on. Far cheaper than twin carbs, anyone who says otherwise is talking rubbish

[Edd]

His there any body who sells the correct jets for each size of smallblock engine?

Are the jets sizes worked out by anyone ? Or just trial and error ?

[mk1nova_rich]

Jets tend to be a bit of trial and error depending on the mods done to the engine. IIRC 1.35mm is a starting point for an SR, don't quote me on that though! R1 jets are same as Weber jets but not sure about other carbs.

Wish I'd kept at mine til I'd finished then would have some solid figures to go from. Fireblade carbs tend to be cheaper than R1s

[phunkynova]

I'm running R1 bike carbs on my 1.4SR. I'v had no problems they are on a Bogg Bro's inlet using a bike fuel pump mounted near the tank I have a fuel pressure regulator but not needed with the bike pump . Different accelerator cable (longer) lowering bracket for alt with longer arm but same belt. using the coil and dizzy from the 1.4 NV (SR) works well.
Carbs were set up by a guy who used to race motor bikes. :thumb:

[Southie]

On my old SR I had the full setup done by Bogg Bros 7 years ago when they were just starting the bike carb conversions, I payed the £750 to have the conversion and it was correctly setup and rejetted to suit my 1.4. Tbh all they did was a trial and error on the rollers and kept redrilling the jets until the right amount of fuel was getting through... to them that was, 3 months down the line and the car ran crap, luckly I knew a guy locally who owned a bike shop that had a set of rollers and he drilled into the manifold to get the correct air flow and had a pressure tester on each carb to get each one setup correctly.

My advice is don't try to do it on the cheap or you'll feck your engine, eventually borewashing it ;)

Tom Reid knows his stuff tbh so would be best on giving advice.

[mk1nova_rich]

I borewashed mine lol so I would back Southie up in advising the setting up being left to the pros, but no harm in making a cheap manifold and so on

[Paul]

I would have to disagree paul, Decent sets of 40's on the bay make good money. You'd then need an inlet manifold, trumpet socks or filters, throttle linakge and a good setting up. Looking at it the bike crabs can be done for less. :)

You will also need filters for the r1 carbs.

The t40 inlet is cheaper than the motorbike carb manifold.

The carbs are similarly priced, as are the rebuild kits.

Cheaper to have webers set up than bike carbs. Will only need webers setting up once as people know what theyre doing with them.

Throttle linkage is cheaper for webers than bike carbs.

Bike carbs seem to be a false economy IME.

Paul

[Edd]

Mmmm that's the problem really, I would want to know how to do it all myself, as down in the south west you ain't got a hope in hell in finding someone to help out setting up bike carbs on a nova lol

[phunkynova]

I would not make my own inlet manifold as it is the most important part in the fuel delivery after the carbs get it wrong the car will run crap, they are far more than just a set of round tubes between the carbs and the head.

[Southie]

My advice tbh if I had the cash would be get a set of Webers... end of, sorry to all you bike carb fans but bike carbs are great if you do small amounts of miles or competitions but for daily there terrible, I know I ran them for 5 years.

[tom reid]

My advice tbh if I had the cash would be get a set of Webers... end of, sorry to all you bike carb fans but bike carbs are great if you do small amounts of miles or competitions but for daily there terrible, I know I ran them for 5 years.

Have to disagree with you mate.
I ran a 1400 SR daily for 18 months, never had an issue with the carbs during that time, they were checked a few times and found to be fine, I had 3 different cams and MegaJolt fitted during that time and other than rejetting the carbs and mapping I had no reliability issues.

I'm not looking to upset anyone with the following, but in the bike carb'd cars Iv'e looked at or asisted with, most have had faults built in by the owners who try to do it on the cheap, or have badly installed/built parts.
There's nothing wrong with trying this conversion at home, christ I did it and I'm no rocket scientist, BUT, you do need some mechanical knowledge and a few tools, welding/fabrication ability and general spares and equipment, spare cash and new parts help too.
It also helps that you don't NEED to have the car running the next day for work, rushing a job never works.
I must have spent around 3k getting mine done, that included buying
Innovate wideband xd16 gauge kit
Innovate LM2
Designing and having 5 manifolds made
Megajolt kit, edis, coil packs, wiring looms
Porting a few heads to differing levels of tune
New cams, springs, valves, guides, pistons, gaskets etc, a new engine in essence
3 different sets of spark plugs
New fuel pump, pressure reg, fuel hose, hose clips
2 sets of R1 carbs, one of which I left with the fabricator, and he still has!
40 jets, thats not a typo, loads of solderless nipples and throttle cables.
Lots of folk seem to think I'm some kind of expert on bike carbs, I'm not, I'm a hairy arsed jock basket truck driver, that has taken the time, despite a few funk ups and spent the money to see a project to a successful conclusion, I don't like being beaten, and also maybe don't know when to give inlol

[Edd]

So after all the problems you encountered in your opinion could you say what carbs and what size jets you would need for say a 1300 ?

[matt_vaughan]

IME a 1300 should be running approx 135-140 jets, but that's just drawn from snippets of information from various people.

[blue_peg_16v]

john bogg brothers only charge about £60 to set up and well worth it imo thats all it way with my 48s anyway and they changed all the jets etc

[Edd]

Maybe but it would could me £200 plus to transport a car up there lol

[tom reid]

I have only used R1's, so thats my preference.
Standard engine?, about 155-160, start small and use an AFR guage, drill the jets as you need to, but also optomise the timing and needle heights for mid range/under load afr before drilling the jets too big, assuming you only have one set of jets.

[John]

I will be running a standard 1.3, with possibly a cam of some sort. It's just the manifold that's putting me off. Tom if i do go down that route you will have many pm's lol

[tom reid]

No problem mate.
I might have a spare s/h manifold for a 1400 head.

[swedge]

So for setting up the fuelling do you need an afr gauge? Who would you take it to for setting up? A bike place or car? Lol

[jonn]

are all r1 carbs the same?

[tom reid]

Some car tuners won't touch bike carbs, others will, don't know about bike tuners though.
Buying the afr stuff is the easy bit, knowing how to use it is a different matter.

[swedge]

Yeah tom I wasn't thinking about doing it myself was just wondering about the afr if it's needed or not

[tom reid]

Yeah tom I wasn't thinking about doing it myself was just wondering about the afr if it's needed or not

An afr is needed.

[calibra-keith]

im trying to get as much info as possible as i am wanting to do a c14se or c16se with R1 carbs and manifold from bogg brothers, cam, dist, coil, leads, manifold

[Nobby]

imo dont bother biggest waste of £600 ive ever spent use proven twin 40's

[Saloony]

Best thing ive ever done, but i done it at an early stage in its popularity.

[phunkynova]

imo dont bother biggest waste of £600 ive ever spent use proven twin 40's Sorry but I payed £250 and the best £250 I ever spent on a carb set up
AND I've used both 40's and bike carb's, and 30 years of rally sport behind me if you set them right they work just as good END OF STORY.