Here's one setup: Build thread can be found here, carby bits 1/4 of the way down: http://forum.performancevwmag.com/viewtopic.php?t=45195&sid=77e1c5076f4deeb30678c47ec734921e
I've just remembered where I've seen twin downdraught carbs on an 8v Click me EDIT: It's the same bloke as the link James Mk2 has put up.
looks like holley 4 barrels are not suitable for size and tune of engine so its back to webbers - that downdraft looks ace but DCNF's dont come in 45mm so that isn't going to work so it looks like DCOEs are the way forward and I think 45s with about 38 chokes - anyone fitted these (or 40s) to a Mk2 ? I'm not going to cut the bulkhead or rain tray as this is going to be a semi sensible car - so if space is too tight then a custom mani will be the way over the top of the engine maybe one made from silicone......
quite interesting - seems there are a lot of downdraft carbs in the beetle tuning world.... http://www.cbperformance.com/catalog.asp?ProductID=1210 dual 48 IDA's..... http://www.cbperformance.com/catalog.asp?ProductID=1430 51.5's ! custom inlet manifolds: http://pickard.engineeredbydesign.co.uk/ probably others out there also - like my local exhaust shop.....
48 IDA alloy carb flange http://www.piercemanifolds.com/accessories.htm now need to find a 8V alloy head flange - could always chop off the ends of a standard pnenum though and graft this flange on....
did you not see that skoda crossflow manifold i posted somewhere, comes in half and looks like the IDA manifold, would need an adaptor plate, but may work
hmm - it seems there are no downdraft manifolds for bigger than 40mm carbs, and even they are very rare making one is going to cost too much for the worth of the project - so it may be game over on this one
Thats nothing that a die grinder wont fix ! Do you know the bore of the downdraught manifolds ? Even if you went for a 42mm inlet valve, the port runners in the manifold wont need to be as big as you think. As long as there's enough thickness in the casting, the inlet side of the manifold maybe able to be opened out too. If the inlet is 40mm to suit the carb (though they are normally a little bigger anyway) it should take an increase to 45mm without to much trouble, though 44mm is more IDA size. The port runners where it meets the head will only need to be 34mm with a 42mm inlet, smaller if the inlet valve is smaller. I'd imagine it should accept that. All you need now are the measurements from a downdraught manifold and see if the above will go.
what about twin sidedrafts 40's cut away the rain tray and slot them in there. heat sheld & clearance issues sorted in one!! what do you think?
