This is what happens if U use T40's without a Regulator

[Snowface]

I'm using the standard mechanical pump on my T40 setup and have found it pumps between 6-8psi.

This is too much and after taking trumpets off and using a torch and mirror to see down the barrels of the carb's you can see the effect of this excessive pressure is.

Basically the needle valves in the float chambers can't close very well so my float chamber overfills and thus fuel drips out of the venturi.

This means that the dripping fuel doesn't get burnt during combustion and can wash the oil off the walls of the bores if there's too much. This can lead to other problems e.g. piston rings.

It also makes the engine run too rich and causes flat spots.

Plus this fuel pouring down the inlet manifold and inlets doesn't allow the head/inlet manifold to 'coke up' which means you are loosing a bit of power there also. (my inlet manifold/head has no coke build up (just damp) and i've been running it for 3000miles.

I've just got the regulator sorted and the car runs noticably better. it also starts better and before it used to sometimes stall at junctions; it doesn't anymore.

All i need to do now is do a few more thousand miles to get it coked up and then r/r again. Hopefully i will of gained 1 or 2 ponies.

My advise to anyone without a regulator running T40's (or even a 32/34) is to get one. about ?10-20 depending on what type u get. You will get that money back within 4-8 weeks just on the fuel you save.

Snow.

[Ste_Nova]

did you have a return.... i had masses of problems with my 32/34 till i fitted a 1.3sr type return setup

[Snowface]

its weird. i had a return (t-piece) when i was running my 32/34, but it had a similar problem with too much pressure.

I tried using a return (same t-piece) on my T40's and the car wouldn't start. I took the t-piece off and it started fine.

weird huh. perhaps its something to do with the two float chambers/needle valves on T40's. And the fuel finds it easier to go straight down the return lol.

i don't know.

Works fine now though.

[dunova]

Do you think i might possibly have any trouble like this using a facet red top pump and no regulator on t40's?

[Ste_Nova]

i used the vapor can not the T

[benji]

i've run my t40's for over a year now without any regulator and had no problems

[Snowface]

perhaps your fuel pump isn't as wild as mine or perhaps you havn't noticed it being bad and thought thats the way its meant to run.

[snapper]

funnily enough, the 32/34 on my SR used to do the exact same thing. i eventually got the t-piece with the restrictor in it from webcon and everything's much better!

of course the restrictor is just a cheap and nasty version of a regulator.

[namkeaps]

perhaps your fuel pump isn't as wild as mine or perhaps you havn't noticed it being bad and thought thats the way its meant to run.

assuming the 1.4 mile times in his sig are his:

108 bhp @ 6300rpm, 100 ft/lbs @ 4500rpm, SQM - 15.9 @ 85mph.

for the car with T40's i assume he knows what hes doing lol :wink:

[benji]

perhaps you havn't noticed it being bad and thought thats the way its meant to run.

true

[Snowface]

just take one of the trumpets off and get a mirror and shine torch into mirror to see if you can see fuel dripping slowly from the venturi.

there was a small pool of it settled in that small pipe of the venturi on mine.

[benji]

i get fuel dripping out of the carbs on to the floor.

would fitting a regulator fix this? or will i have to adjust the needle valves aswell?

[MechaT]

I use the vapour seperator and I get no noticable probs with my T40's. No stalling, flats spots or any other signs of richness.
I'm still gonna check with a mirror tho. Could explain why the cabin smells of fuel when i get in.

No point being halfarsed with T40's. Where do I get a regulator for 10-20 quid?

[Snowface]

i got mine from www.burtonpower.com for ?23. its got a filter built in also.

https://www.burtonpower.com/prodpics/large/FSEFPR004%20Filter%20King_1.jpg

You can get them without filters for a bit less.

benji: fuel dripping out of carbs onto floor would probably be a result of too high pressure.
regulator should sort it and you shouldn't need to adjust needle valves.

[m.d.]

i have a small fuel king that was about 30 quid but works a treat, anyone know where i can get a guage to measure my fuel pressure as i cant find one that reads low enough,

i think im running at 3.5psi but not mega sure to be honnest

[benji]

https://www.burtonpower.com/prodpics/small/FSEFPR007G%20Filter%20King.jpg

i'm gonna order one of these tomorrow. ?39.95

[Snowface]

i have a small fuel king that was about 30 quid but works a treat, anyone know where i can get a guage to measure my fuel pressure as i cant find one that reads low enough,

i think im running at 3.5psi but not mega sure to be honnest

www.burtonpower.com

i suggest benji, to get the regulator pictured (it has a place to put a pressure gauge, although in the pic it don't) and buy a fuel gauge seperate.

burton power item numbers are:

Regulator - FSEFPR004
gauge - FSEFPG001

about ?35 in total and they post it special delivery (about ?5).

when i had probs with mine leaking i phoned them up and they are real nice guys and helpful. know their stuff.

[CP]

3 points:
T40's only require 2 - 3.5 psi fuel pressure - std fuel pump will deliver enough fuel regulated down to this level except maybe absolutely flat out on track - slight question mark? Cheapest easiest solution i found was a Perolator adjustable pressure regulator. D. tweeks etc used to do them.

The presence of petrol in the carbs and dripping/ blowing back out of them isnt necessarily an indication they are leaking etc . Maybe just how you been using them before/after switching off. Dont forget the accelerator pumps literally squirts a stream of petrol into the inlet manifold if you press the throttle fairly firmly. Free petrol in and around t 40's is normal

You may have a problem with the tension of the steel tabs on the needle valves that shut off the fuel delivery into the float chamber. You take the cover off complete with the float and hold it at a right angle and measure the the float setting -should be 8.5 mm from top of float to underside of the cover with needle valve fully closed. You can adjust the tab by bending it slightly so the ball valve is fully closed at this measurement. Very easy and straight forward thing to do. Whilst you are at it check the floats aren't leaking and flooded with fuel otherwise they wont work!

[Snowface]

i put a gauge in mine without out the regulator and the needle was flicking between 6 and 9psi even at tick over.
can't be good.