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EFI pump to bike carbs?
coozer - 5/8/13 at 03:24 PM

Is it possible to use the intank EFI pump to feed bike carbs?

What I was thinking was running the high pressure up to a swirl pot and using the bike pump to feed the carbs.

Or, is there a way to limit the pressure from the EFI Pump (its a Mk5 Fiesta job)

As with OEM tanks they are top feed so a gravity feed to a bike pump aint possible..

AND, will 1 bike pump feed two sets of ZX9R carbs?

big_wasa - 5/8/13 at 03:45 PM

You really don't need a swirl pot as the carbs have a float bowls.

I would be looking at an in tank landrover /range rover low pressure pump. A pump designed to feed Su carbs.

Some people get regulators to work but dropping the pressure to 1~2psi and keeping the flow isn't easy or reliable with a regulator.

The way I would do it is with a webcon Huco pump. Its designed to pull fuel from the tank with the pump in the engine bay like an Su pump and is low pressure. For your tank you just need a dip tube to pick the fuel from the tank. Or dual bike pumps side by side. Done the same as above Or the v8 landy in tank pump.

coozer - 5/8/13 at 04:01 PM

Cheers Warren, its for a pair of ZX9 carbs on a 4l V8.

Shame I'd gone to the expense of fitting the Fiesta pump then changing me mind!

[Edited on 5/8/13 by coozer]

coozer - 5/8/13 at 04:10 PM

Is the Huco the same as the SU types fitted to Mini's Morris's MG's etc?

Just looking at this and following the part numbers..

http://cat.hueco-automotive.com/index.php?searchkey=133010&dialog=1&contentmode=3&lang=uk&PHPSESSID=45e76bf0867e0dcd119194e708363574

big_wasa - 5/8/13 at 04:44 PM

The old su pumps I am told had points in them where as the Huco is electronic. All I can say is that it will suck from the tank no problem and flowed plenty at sub 2 psi.


edit looks like the specs have changed a little since I bought mine.

eBay Item

[Edited on 5/8/13 by big_wasa]

blakep82 - 5/8/13 at 04:58 PM

the EFI pump pressure would be too high wouldn't it? or am i missing something?

best to maybe have a pair of bike fuel pumps, one feeding each set of carbs. as for a swirl pot, a cheaper and easier set up would surely be welding a small sump to the bottom of the tank, say 4" diameter, 2" deep, and a 2" diameter hole in the tank to feed it, and the tanks outlet out of the sump?
will always be filled with fuel by gravity alone, unless the tank is VERY empty, in which case you're kinda stuck anyway. 1 outlet with a T to both pumps, or even 2 outlets. much more simple than swirl pots, HP pumps, all the pipes work etc

big_wasa - 5/8/13 at 04:59 PM

The defender pump prc7020 is designed to feed twin su's on a 3.5L v8 and they are very cheap.

eBay Item

coozer - 5/8/13 at 05:22 PM

Excellent, thanks Warren.

Blake, the tank is plastic out of a boat... top feed, it had a pipe hanging down for suction pickup when I bought it and before I spent ages and tons of wonger fitting the Fiesta injection pump, then changing my mind and going over to carbs..

blakep82 - 5/8/13 at 05:33 PM

Aw, right! So efi pump to get the fuel out the tank into a swirl pot, the bike carbs from there to the carbs?

coozer - 5/8/13 at 05:56 PM

quote:
Originally posted by blakep82
Aw, right! So efi pump to get the fuel out the tank into a swirl pot, the bike carbs from there to the carbs?


Aye, thats what I was thinking but Warren has done the best for me

jacko - 5/8/13 at 06:03 PM

quote:
Originally posted by coozer
Excellent, thanks Warren.

Blake, the tank is plastic out of a boat... top feed, it had a pipe hanging down for suction pickup when I bought it and before I spent ages and tons of wonger fitting the Fiesta injection pump, then changing my mind and going over to carbs..


I am using zx9r carbs and the fuel comes out the top of the tank i am using a bike pump its been like this for 5 years
Jacko

BaileyPerformance - 6/8/13 at 08:55 AM

Got to ask, why did you go for carbs? all you need is the stock 3.9 inlet manifold, injectors, fuel rail and throttle and megasquirt.

The bike carbs will not be right anyway, you'll need to get them jetted. Plus you have lost the advantage of the mappable ignition unless you use megajolt with the carbs.

Unless your engine is tuned (big cam, goods heads) the bike carbs will NOT give you any better performance over a pair of stock SUs, nor will a weber or Holley. The stock SUs are good for 220BHP.

If you want to stick with carbs you need a metro turbo fuel regulator, these are designed to be fed with an EFI pump and regulate down to suit an SU, there is a boost reference pipe but you would leave that disconnected. You will need a return line back to the tank.

iank - 6/8/13 at 09:05 AM

If you're planning IVA then check the regulations on plastic fuel tanks, if it doesn't have the right standards numbers then it's a no-go iirc.

40inches - 6/8/13 at 04:17 PM

quote:
Originally posted by jacko
quote:
Originally posted by coozer
Excellent, thanks Warren.

Blake, the tank is plastic out of a boat... top feed, it had a pipe hanging down for suction pickup when I bought it and before I spent ages and tons of wonger fitting the Fiesta injection pump, then changing my mind and going over to carbs..


I am using zx9r carbs and the fuel comes out the top of the tank i am using a bike pump its been like this for 5 years
Jacko


Same here, works fine.
Fuel pump mounting
Fuel pump mounting

coozer - 6/8/13 at 04:33 PM

quote:
Originally posted by BaileyPerformance
Got to ask, why did you go for carbs? all you need is the stock 3.9 inlet manifold, injectors, fuel rail and throttle and megasquirt.

The bike carbs will not be right anyway, you'll need to get them jetted. Plus you have lost the advantage of the mappable ignition unless you use megajolt with the carbs.

Unless your engine is tuned (big cam, goods heads) the bike carbs will NOT give you any better performance over a pair of stock SUs, nor will a weber or Holley. The stock SUs are good for 220BHP.

If you want to stick with carbs you need a metro turbo fuel regulator, these are designed to be fed with an EFI pump and regulate down to suit an SU, there is a boost reference pipe but you would leave that disconnected. You will need a return line back to the tank.


In the past I have in the past spent thousands on ECU's, spent ages trying to get them working properly (with the exception of the Omex 600 £££).

So, in hindsight putting the carbs on looks easy, jetting is easy (Dave @ Boggs). I already have 2 sets of ZX9 carbs, the engine is already equipped with a trigger wheel and 2 ford coil packs, I have a MS2 that I'm going to use for spark only. Engine is a simple upgrade and no IVA is needed.

jacko - 6/8/13 at 06:30 PM

35l fuel tank over diff
35l fuel tank over diff
I have just found a photo of my fuel tank as you can see the fuel comes out the top
Jacko

BaileyPerformance - 6/8/13 at 09:13 PM

quote:
Originally posted by coozer
quote:
Originally posted by BaileyPerformance
Got to ask, why did you go for carbs? all you need is the stock 3.9 inlet manifold, injectors, fuel rail and throttle and megasquirt.

The bike carbs will not be right anyway, you'll need to get them jetted. Plus you have lost the advantage of the mappable ignition unless you use megajolt with the carbs.

Unless your engine is tuned (big cam, goods heads) the bike carbs will NOT give you any better performance over a pair of stock SUs, nor will a weber or Holley. The stock SUs are good for 220BHP.

If you want to stick with carbs you need a metro turbo fuel regulator, these are designed to be fed with an EFI pump and regulate down to suit an SU, there is a boost reference pipe but you would leave that disconnected. You will need a return line back to the tank.


In the past I have in the past spent thousands on ECU's, spent ages trying to get them working properly (with the exception of the Omex 600 £££).

So, in hindsight putting the carbs on looks easy, jetting is easy (Dave @ Boggs). I already have 2 sets of ZX9 carbs, the engine is already equipped with a trigger wheel and 2 ford coil packs, I have a MS2 that I'm going to use for spark only. Engine is a simple upgrade and no IVA is needed.


If you already have megasquirt why don't you use the fuelling side too? You already have the Efi manifold so your all set? Tuning a rover v8 on megasquirt is straight forward, we have done at least 10 in the past few years. Bike carbs will never be as accurate, fuel efficant or make as much power as fuel injection. The common misconception is if you have 8 carbs your engine will breath better, it will not, the stock Efi manifold as a large throttle body as standard, most bike carbs are less than 45mm, the cylinder is only been fed by 45mm, on and injection plenum each cylinder is fed by a common 65/70mm throttle.

I tuned a pinto recently that used zx9 carbs, thay where too small for mild tuned 2.0, in fact I have seen same results with stock weber (after jetting), we did a x flow on same carbs and it make good power, so I think the zx9 carbs are more suitable for smaller engines or a stock 2.0 (just)

So, if your engine is bigger than 3.5 you may end up losing power over Efi or SUs

coozer - 6/8/13 at 09:38 PM

In the past I had a St170 on bike carbs, it gave 166bhp on a RR.. then I went up to a MS2.. I couldn't get it running properly so switched to a Omex 600. It run much better straight away and after a RR tuning it made 178bhp. So in all an extra 12bhp for £2K.. doh!

And, with the carbs set up at Boggs it gave me 40mpg, once I had the Omex setup the best I got was 26mpg, it was awful with the MS!

All I wish is I'd stuck with the carbs, spent £500 on some new cams and got 200bhp?

Problem is round here theres not a descent RR thats any good with MS.

So you reckon the carbs are too small? Thats 8 carbs with a 40mm diameter, one for each runner. Without getting the calculator out that looks a lot bigger than the EFI TB diameter. The EFI inlet runners are 38mm diameter..

I'm thinking that as its a 3.9, the carbs are up to it, one set for each 2L.

I'm not sure what you mean by a ZX9 carbs are too small for a pinto? I've seen pintos make good power on 600 carbs at 36mm (Same as 45 webers with chokes in them)

And finally, 8 x 40 is no good compared to 2 x44 (SU's)??

Your welcome to prove me wrong but I dont want to spent another grand on setting up injection. Unless you can point me in the right direction with the MS. Its an MS2 from Phil @ efiextra but the LR4x4 forum reckon its far too complicated for a Rover V8.

BaileyPerformance - 6/8/13 at 10:39 PM

When you have individual carbs for each cylinder, it's only that carb that feeds the cylinder.when you have a common plenum you have that cylinder been fed by a big single throttle. As the engine only really sucks from one cylinder at one time you will get more airflow from the single throttle over a small carb.

As you said the stock rover has quite small ports so big carbs aren't going to help, but the point I'm making is 8 bike carbs are not going to help airflow over a stock Efi inlet or a pair of 1 3/4 SUs. Don't forget the 2 SUs are in parrell so the engine pulls from the 2 at the same time.

Not sure how you have spent so much on Efi in the past, I'm not sure what other companies charge but we charge £1400 for a full Efi conversion on a rover including all parts labour and mapping. Or just £250 to map it.

I have a customer with a 4.6l Tvr who sees 30 plus mpg on motorway, on ms2, makes well over 300bhp.

My own cosworth on ms2 will do 35mpg (normal driving) and makes 360bhp 400lb/ft.

Megasquirt is not complicated, it is less complicated that a Lucas hot wire system.

I would love to compair a weber 45 with a 36mm choke to a zx9 on a flow bench, my money would be on the weber as its only the choke that is 36mm, the rest of the air path is 45mm.

I'm convinced you should stick with Efi, so much so I will set it up for £200 (£50 off)

Scuzzle - 7/8/13 at 12:17 AM

Is drilling a hole in the bottom of the tank and fitting a screw in fuel pipe fitting not the easiest and cheapest way round this. You can get tight fitting screw together pipe fittings where you just drill a hole in the tank and bolt the fittings together with a smear of fuel resistant silicone sealer like Dirko seal.

You empty the tank right down, fit 2 pipe outlets at the bottom of the tank and have a bike fuel pump on each one feeding each set of carbs at bang on the right pressure.