Fuel Regulator

[1293gt]

Hello all,
can somebody please tell me why Fuel Regulators are used in normally aspirated cars?
I assume from the name that it is to "regulate fuel" pressure but wonder why you would want to do this.
Thanks in advance.

Edited by 1293gt on Wednesday 14th January 10:28

Edited by 1293gt on Wednesday 14th January 10:28

[Dino42]

They're generally used to limit the fuel pressure.
SU carb float chamber needle valves can only handle relatively low fuel pressure before they leak and cause carb flooding.
Many of the 'uprated pumps' available, in addition to supplying a greater flow which is why you'd fit one, also supply greater pressure and can cause flooding....so you limit the pressure down just before the carb.

Edited by Dino42 on Wednesday 14th January 14:23

[Cooperman]

With twin Facit pumps on a rally car, in parallel for reliability, the fuel pressure would be far too high for SU's and would fllod out past the needle valves.

[1293gt]

Ahhh, is that why my 1430 runs fine, but really doesn't like ticking over (it starts to miss due to a wet spark plug after a while)?
It has been rolling roaded and is properly set up, it just does this now and again, normally when I've just got it going and don't drive it straight away.

Edited by 1293gt on Wednesday 14th January 16:26

[Dino42]

Well quite possibly.
If the needle valve is leaking the first thing that happens is that the fuel level in the float chamber rises making the mixture richer, depite there being no obvious external leak.

[1293gt]

Okay,
no we've established that I need a fuel regulator, a couple of additional questions please...
What items do people recommend?
What pressure should I set it at?

Thanks Everyone.

[CarsOrBikes]

Simple regulator with a dial is inexpensive, and 4psi will work with twin SU's.

My car has two regs, one if i have the carbs on, the other for spi, a very fine tweak when on the rollers is worth 5-6 bhp on its own on the latter.

[guru_1071]

the filter kings with the built in filters are probably the best to go for, its very rare you even have to fiddle with the pressure (on a carbed car with a facet pump)

its not the regulated pressure thats the most handy thing provided by a regulator, rather its the constant stream of 'straight' petrol - rather then the spurting air filled supply that will upset the floats and needle seats normally.