Fuel pumps/regulators with twin 40's

[Dillett]

Which should i use? i seen alot running facet ones with filter king regulators, is it ok to run them on the normal pump on the back of the head and use a pressure regulator or to just get new?
Cheers dave

[Adam]

You can just use a standard mechanical pump and a fuel pressure regulator yes.

[dunova]

I may be getting mixed up with something else, but don't the mechanical pumps 'pulse' rather than delivering a steady flow rate? If so, then this could cause you hassel.

[Adam]

I may be getting mixed up with something else, but don't the mechanical pumps 'pulse' rather than delivering a steady flow rate? If so, then this could cause you hassel.
Hrmm, not sure.
The way the pump works would suggest it pulses the fuel.
But i know a few people using a mechanical pump when they are running T40s, even on 1.6 engines etc.

[Stuart]

jim runs the mechaical pump on his 1.6 blah blah and has no problems with it. obv has a regulator inbetween

[dunova]

I think i read that the mechanical pumps 'pulse' on some website selling 'performance' pumps, so it was probably just sales gumf lol

I haven't heard of people having trouble with them, but when i was getting my stuff together i went for a facet red top pump and an adjustable regulator. Mechanical pump should be fine though.

[DIY*VALVER84]

as mentioned above yes you can use the standard pump but you will be needing a regulator due to its pulsing effect you should be looking to run it at 16-20psi thats nearly as much as my xe,carbs are bad....no they are good gargle gargle pop bang snort bang pop!!!

[Stuart]

lmao


the weber/dellotroe 40's/45's carbs need between 3 and 4 psi.... not fecking 16-22 :rolleyes:
think about getting usefull info before posting

[dunova]

16-20psi would flood the 40's to feck!! :roll:

[Dillett]

Cheers. So anything from 0-10psi regulator will do?

[S_Gault]

3.5 at idle no more

[Nick]

mine currently run with no regulator on a 1.6 with T40's

I run the standard Mech fuel pump, what Pressure would this be at ?

[Dillett]

it just pulses as said above, wont give a set pressure. be different everytime i would've thought....
My engine is doing my tits in, won't start now.

[Nick]

it just pulses as said above, wont give a set pressure. be different everytime i would've thought....
My engine is doing my tits in, won't start now.

but it should give a average pressure, after all every pulse will be of similar force

[Dillett]

Yeah but no-one is bored enough to want to measure an average pressure of a standard pump! You'll get anomylies aswell i.e one really strong pulse followed by a really weak one hence irratic tickover on 40's etc....

[dunova]

it just pulses as said above, wont give a set pressure. be different everytime i would've thought....
My engine is doing my tits in, won't start now.

but it should give a average pressure, after all every pulse will be of similar force
It will give an average pressure, but not a steady pressure.

Nick, i would get a regulator on there asap. Iirc the standard mech pump runs at about 30 psi :!:

[Nick]

christ - i was under the impression it was ever so slightly higher i.e 5 PSi

would someone like to clear this up ? 30psi is nearly the pressure required for injection (40-45psi)

of course it's a fairly regularised squirt, it's operated by a mechanical lobe.

[dunova]

Oops, just realised i was getting confused lol, yes it is just over 5 psi!! Still too high tbh and could cause flooding, but isn't disasterous.

[Riggy]

iirc std mech fuel pump is 7 psi

[Dan]

you should still run a regulator nick, the filter king variety is my chosen type and never had a problem with it. As mentioned before in the thread you should never run anymore than 3-4 psi on idle. If the carbs have had alot more than that shoved through them just giving the float levels a check wouldnt hurt. Mines set to 'about' 3psi on the regulator

[Nick]

cheers dan - i've been meaning to get one, but i'l make sure i do now

[lj]

so u can run twin carbs with no regulator and on normal fuel pump?

[Dan]

yes you can, but its not right and can/will cause problems along the line, and to be honest, for the sake of a 30 quid regulator is it really worth the hassle?

[Nick]

tbh dan mine runs pretty well really ! no FPR and the carbs aren't even jetted :-D

but take his advice mr.Lj

[mikey14sr]

I bought a regulator just for my 32/34, it was flooding the float chamber without it and set at 3.5psi it also idles a lot smoother. It's also one bit I wont have to buy when I finally get my 40's on.

[Dan]

oh i agree nick, it will run but nothing like when it has been jetted and set up properly. It 'could' go on and be lucky, but where do you think all the bad tales of carbs and all the rubbish come from lol, and for such simple things how do you think i have managed to keep mine off a r/r, even with all the abuse it has had for these few years and still be kinda close to peak performance back at the end of the summer.

Even something simple like having the throttle cable set right can help maintain tune imo lol.

[lj]

i've been told to get a red top/silver top fuel pump and regulator...is this bullshit then? thinking of fast road cam to on the 1.3 lump with head work and maybe big valved head..... any info on doing this?

[Dan]

i run a facet redtop pump, always have done but my engine started life as a gte engine on carbs and was fed by the injection pump prior to that.

[Snowface]

When i measured my standard mech pump it was (pulsing) between 5 and 7psi. And it was flooding the float chamber on my 32/34 Weber even though i had a T-piece.

If you are running Webers you need 3.5psi and Dellorto 3psi. Much more than this and it will be overfueling.
I ran my Dellorto's without a regulator for a bit and noticed i got 7-10mpg more when i put a Fuelking regulator on there.

Wonder where all the excess fuel went? :roll: Probably giving the cylinder bores a good wash.

[Nick]

and also, i'd imagine with a regulator on there, apart from your improvement in MPG you probably noticed an improvment in performance ?

I know mine bogs down alot (they're not jetted tho) but i hope a regulator would improve that slightly untill i can get it to an RR

[Adam]

What are your carbs jetted for Nick?

[Nick]

they are jetted for a 1.3SR i think... was skoobs old engine.

It's definetly running rich