hi there.
just starting out. confused by 750mc regs on carb venturi widths.
it says they can be 23 and 24mm on a twin choke model but most commonly fitted DGAV seems to be 32/36.
what carbs are you allowed to use? any tips on the best one?
cheers.

Ok, firstly just to clear up a common bit of confusion DGV and DGAV carbs are the same basic thing but the A in DGAV stands for automatic choke so you have more rubbish to take off if you're fitting it in a car built purely for racing.

32/36 carbs are relatively easy to pick up new or second hand (Burtonpower will be able to sell you a new one off the shelf for example) but is a LOT harder to buy a new 23/24 twin choke webber and to be honest the cars will run better with the bigger carb BUT it's not legal and it takes a matter of minutes to measure the venturis (and anyway the sizes are stamped on the linkage side of the carb for good measure).

Having said that a twin choke webber is the only carb worth having but it's worth noting that the regulations don't say it has to come from a Ford engine. I believe that some Volvo 340s used 23/24 Webber carbs and if I remember correctly there were one or too other makes that did as well. Well worth checking out because they wont be as expensive and will probably be a good few years younger than one off an Escort

Dave, having got the carbs, what can be done to get the most out of them whilst remaining legal?

Also, I noticed at the race, most have electric pumps for fuel supply. Is there a suggested psi / pump rate that is a suggested minimum for this carb?


ta

You can't do much....but remove any/everything to do with an automatic choke and then remove anything and everything to do with the choke flaps from both inlets of the carb. Then get the car to a rolling road and have it tuned - you'll definitely be suprised at the difference (it'll cost you no more than 100 quid and trust me, value for money wise it is the best 100 quid you'll ever spend on the build of your car). I know people worry about starting the car if the choke flaps are removed but if there's any problem (ie first thing in the morning) a bit of metal plate held over the primary ventury (the one towards the outside of the engine) will get it going.

Fuel pumps....lets face it it's not a massively tuned engine so the standard mechanical pump would do the job. There are pros and cons for each obviously but if you go for an electric pump the cheapest solid state facet pump does a fine job in our experience and I can't see any use whatsoever for a flow regulator.

Many thanks.