twin 40 carbs

[holmes]

hi as above iam looking for a set of twin 40 carbs either weber dellorto or solex not really bothered ideally set-up for a 1.8 engine but i think iam right in thinking i can get them rejetted anyway. name your price regards

[no such user]

40’s belong in the stone age. and don’t fit golf 2 8 valve very well, downdraft are a bit harder to find but a much better solution . they’ll need jetting to your enigne

[ld50]

RE2 is using downdrafts on his as far as I know…check his handiwork:

http://www.vwsyncro.co.uk/data/forums/topic.asp?TOPIC_ID=275&whichpage=2

[re2]

the best solution is to get a crossflow head and then dcoe’s. If i was doing this again (and hadnt have found my kit) thats what I would have done. This soln allows even better access to nice cold air and a reduction of the intake temp. Easy to do these days too. You will be lucky to get all of the componants that ive collected, as it took over 3 years to do and a lot of badly phrased German. Im just an idiot to myself and do things the hard way! My brother also has the same kit as me but the parts are rare even in Germany

Dont bother with dcoe on a regular head as it wont breath and therefore wont perform. There is a lot of material on the net about this being a less favourable conversion. However, you could fabricate a manifold and fit what you like- throttlebodies, or a host of carbs, or even a dirty great big carb and no balancing issues

[holmes]

chris is supplying me with a a crossflow head hence the dcoe’s.i didn’t think about using one big carb, wot sort of size do you think would work and how easy are they to come by?

[re2]

you have a crossflow, so use 40 carbs (dcoe best for spares and tuning knowledge) and get get silly and fit 45’5 as you dont need them (i dont on my engine). Use the torque as thats what gets a syncro moving

[no such user]

id say go bike carbs every time they outperform 40’s time and time again, a 40 well 39mm bike carb can drive like twin 40’s but give more power than 45’s.

[holmes]

all stuff to think about but have no experience with bike carbs wot sort of thing am i looking for ie wot would i search for if i was to search on ebay etc?

[re2]

personnally im a bit dubious of bike carbs as they are designed to run on lower caopacity motors and within a greater rev range. I know they work, but why mess about when dcoe’s are so readily available.

[holmes]

trouble is dcoe’s are fairly expensive whereas bike carbs are a fraction of the price, i have had a look on the vw polo boys sites and golf sites and there using them with good gains it seems and they are also easier to fit the only real question is these are carbs right? so i have seen injection holes on some of the guys bike carbs, i was assuming they were like ordinary carbs ie attatch the fuel line to the back and away you go? if they have injection surely you need an ecu? i may be wrong hence why iam enquiring.[]

[no such user]

bikes can have throttel body’s or carbs. if you have throttel body’s need an ecu to control the fuel as a minimum, i carbs do not require and ecu just the correct jets. bike carbs a quite a lot more advanced than Webber’s as they manage to get a small enigne to idle with a relatively massive carb. when you compare choke sizes 600 bike carbs normally have roughly the same choke sizes to what Webber 40’s carry and 1000cc carbs simalr sizes to to 45’s. the bike carbs also flow better compared to the same size Webber so they are actually a better carb. alto they were not designed to fit big engines they lend themselves very well to been fitted. at the end of the day the air flow through the carb is similar and that’s all they really care about. jetting them isn’t that hard ether as quite a lot of people have looked into it a lot. all the grass track boys i know have switched to bike carbs and haven’t found a downside

[re2]

sounds a promising option. All my experience of bike carbs are on bikes, so there you go. Remember that the polo boys are running 1300 or less and less weight, so i supose it depends on you and you engine choices really

[holmes]

well iam definatly going to be getting bike carbs me thinks. So what i think i need is a manifold fabricated, 4 bike carbs, maybe an electric fuel pump or will it run on the existing front mounted engine pump,( mine is a 1.8 8v carb not injection)and a new set of fuel jets or i think i have heard that you can drill the existing jets? am i missing anything?

[no such user]

it has been known to drill existing jets, probably be looking at somewhere between 0.70 and 1.00 mm . new high quality drill bits are a must it’s not that brass is hard to drill it’s just so it drills a hole the size it says it will

[re2]

best off with a better low pressure pump like facet, and a fuel pressure regulator like filterking. Let us know how it goes!

[Author]

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