Carb Conversion

[Kindsvater Flat]

What has to be done to convert a carb from a naturally aspirated to a blown setup?

[Blown 472]

Originally posted by Kindsvater Flat
What has to be done to convert a carb from a naturally aspirated to a blown setup?
Well this is my set up, I plugged the power valves due to pulling 30 plus inches of vac at idle and not being in the range of them to work so I plugged them. I had to drill holes in the throttle blades to get more air into the motor to idle other wise I was into the transition slots and it was rich as hell. Dont use the tube type discharge nozzles as they will weep, dont use the crappy barry grant gaskets and alum needles for the discharge as they will lift up and weep, if you plug the power valves make sure the round part of the plug is filed flat as it will hold the metering block off the main body and seep fuel and run rich.
I am going to up grade to the roundy round floats, oh and dont use the big ol steel ball needle and seats as they dont seal for shit. I use the biggest rubber needle and seats.
This might not work for all but this was all the stuff I ran into and how I fixxed it, your results might vary.;)

[Fiat48]

A lot depends on which model carbs you intend to use. The carb works the same as unblown but you do need more fuel since you're putting air in the engine. Larger jets and possibly larger accelerator pumps and shooters. Some carbs don't have power valves. If the carb does have a power valve, then generally you block that off but must increase jet size big time to compensate.
Fuel demand is greater with blown also so you need to check your fuel system is adequate.
List the carb numbers and I'm sure the carb guys will jump in here shortly.

[Kindsvater Flat]

I haven't bought them yet but if I buy new then I have the choice for application. If I come across a good used set then I can have them converted.