10 replies to this topic

[paul munday]

Hi
I have a 1293 stage 2 engine from Jon Speed but I can't remember what camshaft I have in it but will find out. ( http://www.jonspeedr...=14523&cID=2095 ) I have recently got a weber 40 with 5 inch manifold. I have cut and fitted a box in the bulkhead for room and I am looking for some advise on a general setup for the same size engine or similar engine so I can get it to a rolling road?

The weber at the moment is setup with:

Auxiliary Venturi (45)
Main Venturi (30)
Pump Jets (35)
Pump Exhaust (50)
Mains (165)
Air Correctors (140)
Float Level (Unknown) but they are the bass floats
Emulsion Tube (F14)
Idle Jets 45F4


Any help would be great.

[paul munday]

The cam is a kent 276

[Bungle]

eurocarb are good at sizing jets , give them a ring they are normally very helpful

[paul munday]

Thanks for that.

[KernowCooper]

There are a list in Vizards Book, but remember these will only be a guide to get it in the ball park and to get the best a rolling road session is the best way if you have one nearby?

[paul munday]

Is this the book you are returning to? http://www.amazon.co...?pi=SL500_SY125

I have been to Mini Bitz in northampton and they said they could fit the carb and getting running for a rolling road, so I don't no if it would just be easier to do that if it doesn't cost to much. I would prefer to spend the money on the rolling road.

I have two rolling roads by me:
http://www.rollingroadtuning.co.uk
http://www.northamptonmotorsport.com

[KernowCooper]

yes thats the book refered to here as the Yellow Bible in many posts, always worth having but a rolling road session is whats really needed as all those recommendations are only a starting point as every engines different.

[Bungle]

yes that's the book

do the rolling roads above stock webber jets to be able to try a few or will they just make the best of what you have ?

[paul munday]

I have ordered the book to get me started. I contacted Eurocarbs to and they have suggested sizes of chokes and jets which I can compare to the book when I get it.

Im not sure if the rolling road places stock the jets yet, Im going to give them a call over the weekend to see. I just looked up the parts Eurocarbs suggested, which will cost around £50 to get which is a lot if they are wrong, so if the rolling road places do stock jets for testing that going to save me on maybe getting the wrong parts.

[crock]

Your pump jets are too small. Use 40 or 45 with 45 certainly being plenty rich. By "main venturi" do you mean the big round thing that we Yanks call the choke? If yes, then a 30 mm will be too small. You will need anything from 32 thru 36. I can only guess from here, but I would start with 34 mm with 32 mm my next best guess. The chokes are expensive. The size of the main jet is related to the choke size. Chances are excellent that 165 is much too big. A 130 will be rich for 32 mm choke, and 145 rich for 34 mm. Just to get the car on the road use a 125 with your 30 mm choke. Don't worry about the emulsion tube, aux venturi, pump exhaust, or air corrector unless you are on a dyno with a Weber specialist as these are fine tuning items.

[Wright&Wright]

If you're looking for a Mini specialist that can jet a Weber on a rolling road, I'd recommend Southam Mini and Metro Centre just the other side of Daventry.
Our club has always used them and they definitely know their onions.

I think the estimated cost was around £80 for a setup and power runs but don't hold me to that.