Twin Weber 45's

[danny_samb]

Hi all just purchased some twin weber 45's I'm running a 2litre pinto standard, but eventually want fast road cam, do I need to upgrade fuel pump to run the webers only runing mechanical at the min, do I also need a fuel pressure regulator

Thanks

[Longboarder]

The standard mechanical pump will happily run the webbers. Probably wont need a regulator as long as the carb needle valves are in reasonable condition. My pump was fine on a fairly well tuned silvertop and didn't need a regulator.

 

Nigel

[Shandylegs]

No, not if standard or a relatively standard state of tune, the mech pump will be fine. Depending on how far you want to go with the engine 40's may have been a better choice.

 

Thanks.......

[Shandylegs]

Damn, not fast enough!

[Snapperpaul]

40's have a maximum choke Venturi of 33mm fine for a standard Pinto but as soon as you upgrade then the 45's are needed as they will take up to 38mm venturies, good for high 170 to low 180 bhp.

Depending on your tuning plans choke sizes of 34 to 36 are most likely.

[Bob Tucker]

I had 36mm chokes in my DCOE 40s. These ran fine with a standard 2.0 & eventually with a large inlet valve head, & FR32 cam.

No doubt the 45s with 37 or 38 may have got more HP, but would probably have lost some tractability.

 

IIRC there is a series of articles by a guy (name forgotten, like so much else!!) about suggested setups for DHLAs & DCOEs someone will remember his name...got it....Dave Baker at PUMA race engines.

HTH Bob

[Snapperpaul]

Weber recomend max choke in a 40 should be no more than 33mm or there is not enough Venturi effect.

Edited January 12, 2012 by Snapperpaul

[danny_samb]

On the carb I have now there is a return to the fuel tank. What happens to the return line when put the twin 45's on

Thanks

[Ian & Carole]

_{Either blank it off and forget about it or use it as an extra tank vent provided the end is high enough not to allow fuel to syphon out.}

[danny_samb]

What do I put over the pipe then to vent it, surely can't just have an open ended pipe

[miikae]

I fitted a non return valve so that it could still act as a breather just incase i turned it over:)

[danny_samb]

Think I'll put a non return valve in and a little breather on the end stop any dirt getting in, where you get the non return valve from

[miikae]

I got it of ebay i think, its been quite a while now since i bought one.

 

One 10mm just like this ebay Item number: 350524076202