Ill get Weber carbs for my mk1 cabby (1.8 8v DX year 1992) and I have some questions about it.My thoughts are to set a 272 camshaft and a 4-2-1 polished exhaust manifold,apart from the Webers. The parts I need: A pair of Weber 40 DCOEs Carbs manifold for VW 8v Linkage/cables for twin carbs Air filter for carbs Electric Fuel pump Is this enough or need something else to fit them correctly??Any other suggestions? If I use FACET fuel pump or CARTER fuel pump,do not need pressure regulator,right? What are the differences between this two tipes of linkage??In my case,what is the best option? The standard jetting of the carbs are: * 30mm Venturi / Choke * 115 Main jet * F11 Emulsion tube * 200 Air corrector jet * 50 Pump exhaust valve * 45F9 Idle jet * 40 Pump jet * 1.75 Needle valve. Any mods to this set up or it is right.The car use,road/fast road. Thanks
You'll need a regulator to set the pressure correctly, even the basic lowest pressure Facet pump produces more than the 3 psi you'll need to set for the carbs not to flood. You'll also need some Misab plates, the gaskets that seal the carbs to the manifold, and the mounting rubbers & cups which allow the correct tension to be had so the carbs can still move, the carbs must not be bolted up tight. The best throttle linkage by far is the genuine Weber item. It fits properly and is adjustable to fine tune the set up when ballancing the carbs. The off the shelf manifolds in the UK are normally Mangoletsi's. The casting leave's a lot to be desired on the quality front, and as cast, the holes (port runners) are too small. This can be sorted with deft use of a die grinder and carbide burr to open out the holes to the correct size, dependant on the valve size/port runners in the head being used. There is a possiblity that you'll break into the bolt holes (you ALWAYS do when used on a race engine), this is'nt a problem as the bolt heads will seal off any leaks up through the holes, as long as the boss that the head contacts against is square shouldered, which may involve some fileing to correct (you'll probably have to do this anyway due to the poor quality casting). If you dont open out the ports in the manifold, a lot of the potential gains from the carbs will be lost. The choke and jetting will be an... ok starting point, but some changes will no doubt be needed. To go with the 30mm chokes I would start will something like... 120 mains 170-180 airs F16 tubes 50F11 idles 40 pump (so at least thats ok!) 1.75 maybe a bit small for the above, 2.00 maybe a better option. The pump bleed back (pump exhaust) will be ok to start with at least, maybe even ok in general. Speak to someone like Southern Carburetters & Injection (020 8540 2729) for supply and advice on the above, not some e-bay/internet bandit. A 270-ish cam is fine for road use, but would work better with a modified head. If you do both then the 30mm chokes will be too small, you could "just" get away with them with the cam only. Use a vernier pulley to enable the cam to be set up on the rolling road at the same time as the carbs.
Ok,so a regulator and misab plates are needed too.The gaskets I think they are included with the manifold.What are you refering to when say Mounting rubbers and cups?? Im not from UK,so my english is not so fluent I have been watching this website http://www.dellorto.co.uk/default.asp So if you could tell me with examples from this web what are the parts you are refering to (mounting rubbers and weber genuine linkage kit) and any other parts if needed. The jetting is clear but what you explain about the manifold holes,I have understood that the holes are not bigger enough to work well with carbs so need to make them bigger.If I get ones from Pierce or Rowlands,do I have to do the same or these have not this problem? Thanks for everthing.In my country is difficult to get info about this kind of mods.
