I'm looking to bike carb my '89 1.3 Golf to go alongside a Polo GT cam for a bit of extra poke. Manifold etc I can fabricate and weld up no problem. However I have three minor questions to help on my quest 1) Which carbs are best suite, 600/1000 & any particularly manufacturer (R1 carbs seem the most popular but R6 seems to be suggested for 1.3s)? 2) What jetting would I need for above carbs, again it seems 600cc carbs would be best suited and won't need rejetting? 3) Are there any bike carbs that have an auto choke or will I have to run a choke cable through the bulk head and behind the dash?
R1 carbs are meant to sit at quite a steep angle, so the float chambers are not ideal when mounted in a more horizontal plane like when fitted on the small block Polo / Golf engine. I found Suzuki GSXR cabs were ideal and come in 34, 36, 38, and 40mm sizes. The outer 2 carbs were in perfect line with cylinders 1 and 4, it only require slight angling of 2 and 3 runners to mate to the centre 2 and 3 carbs.
That covers my first question nicely. Assuming no rejetting is required am I likely to need to run a choke cable or will the car start over the winter without choke? If not whats the best way to run a cable through
Some bike carbs have a choke cable facility so that would be ideal. You will need the choke in the winter months. There should be various holes in the bulkhead to fit a choke cable through. I would expect some re-jetting would be required, but this can only be done once the engine is up and running.
600cc carbs work well on the 1300s. R6's are also good ones. I never needed a choke on bike or twin 40's on my 1300s. Once its running you just have to feather the throttle for <1minute. They run with standard jetting, but you will need to change it.
Can you offer any more information as far as jet sizes are needed for a standard 2G engine, gives me a a base to work from as the carbs will be the first addition. As far as starting with a choke did they struggle or we're they easy enough to get going. I'm also looking at a piper fast road cam rather than a standard Polo GT one of a little more poke, and the exhaust manifold will be mated to a Magnex twin 2.5" system. If I get brave enough and can find the correct information then I'll eventually run it on a Megasquirt?ECU and look into forced induction She's already a goodun' for the 100 quid I paid
1.6mm = 160 jet sizd as far as im aware, i carried out this conversion over the weekend. 1.3 gt polo, boggbro's manifold, cbr600 carbs, unsure of jets used, was already set up by boggbro's. U need to think more about throttle linkage as that takes a bit of thinking. Good luck and its a great mod. Oh yes, get bike pump to match carbs makes things easier.
The carbs from a Bandit 600(GSF600) seem to be going for a more desireable price any ideas if these would be suited?
they should do it, google 'cbr600' and compare the sizes and compare to the ones u have seen. U want 34mm from memory.
Im good enough with a welder to knock together a manifold myself, besides Bogg bros are the other side of the country.
Get on clubpolo.co.uk, there's a massive thread on bike carbing smaller VW engines, fair few people there with some very decent knowledge that could help you. Here you go: http://www.clubpolo.co.uk/forum/index.php?showforum=55
I ran R6 carbs on a 1300 polo with a p&p'd head. The standard jets are 1.5mm and are if anything abit rich. its ran smooth as an needed only balancing to get it going lovely. recommend R6 carbs for any 1300-1600, and R1 for 1800-2000.
Does anyone remember the Red MK2 Golf 1.3 Twin carb'd monster which was featured in PVW a few years ago. Iirc, was tracked out, with rallye spots on the front. From what i can remember it was quite a detailed and impressive build, and was running some serious power from the 1.3.
There was a polo in PVW on bike throttle bodies or carbs producing 175bhp. I think it had a fair amount of work though, maybe even a bike engine's head.
Went for bandit carbs in the end, here's some progress shots of the manilfold I'm just waiting for work to sort me out with a KK600 baseplate for my Pipercross airfilter, then I've gotta make up some velocity stacks to mount the filter
