42 replies to this topic

[Chris1992]

Ok, if you are using the std tank with a 6mm/1/4" outlet you can't feed the high pressure pump from it, they don't like to suck only push, it's recommended that the inlet of the pump is no less than 12mm/1/2". So unless you are going to weld a new outlet on the bottom of the tank, you will need a swirl pot, then you can put a low pressure pump on the existing outlet on the tank and feed the pot.Im going to presume that you want to run stainless braided hose as per the photo above, something I would be very wary of is cheap braided hose a lot of it not more than shower hose. Due to the ethanol content of fuel today it will rot it out in no time best stick with the well known motorsport vendors not eBay cr#p. The obvious easy way to plumb the F.I system in is to fit an MPI tank, this uses an in tank pump and has the return fitted already

Shooter

 

I'd like to avoid using a swirl pot as I never plan to track my car, so I don't think I'll see the benefit. I was under the impression that as long as I mount the pump below the tank then it will be gravity fed? That's what the internet told me anyway lol. 

 

The only reason I'm using the 044 is because I got it dirt cheap and it's almost new. So I'd rather use what I have if I can to keep costs down.

[PoolGuy]

Just so I'm clear on this, we're talking about the SC £10,000+ engine with BWM injection etc?

[Chris1992]

Just so I'm clear on this, we're talking about the SC £10,000+ engine with BWM injection etc?

 

Yes indeed 

[PoolGuy]

Sorry to be blunt, but you need to do this properly. Saving a few quid on the proper fuel supply for a £10k engine is just crazy imo. Get the proper LP pump, swirl pot and filters and plumb them with decent fittings and hose.

[Shooter63]

Flog the pump and start again, it's miles too big for what you need anyway. You've spent a lot on the engine etc, a few hundred quid on the proper fuelling system is peanuts

Shooter

[Chris1992]

Sorry to be blunt, but you need to do this properly. Saving a few quid on the proper fuel supply for a £10k engine is just crazy imo. Get the proper LP pump, swirl pot and filters and plumb them with decent fittings and hose.

 

No worries, I had no intention of cutting corners, I was just under the impression that swirl pots were for cars that are tracked often. John at SC also never mentioned a swirl pot, but I plan to give him a call when he's back from holiday to discuss a few things so I'll get his thoughts. 

 

I'd already mentioned that I intend to use proper AN fittings and hose.    

[Chris1992]

Flog the pump and start again, it's miles too big for what you need anyway. You've spent a lot on the engine etc, a few hundred quid on the proper fuelling system is peanuts

Shooter

 

Which pump would you recommend? 

[72hump]

Hi Chris, I've only read some of this post, if your after a fuel pump, I'm like most of the guys on hear that are building/running the Twincam engine from SC have fitted the MPI pump, this will give you more than enough pressure, as you will have a fuel pressure regulator set to 3.5bar.

Cheers, Paul.

[Northernpower]

I would agree, if you're not going to track the car there's no need for a swirl pot, it's over the top for a road car. As 72hump says, the MPI pump in the tank (with it's filter fitted) is more than adequate for your set up. If you're only going to use the car on the road there is a strong argument for mounting the regulator in the boot, the reason is as follows. If you run a supply to the regulator in the engine compartment (which with your set up will be running a very high ambient temperature) and then run it from the regulator through the fuel rail and back through the return side of the regulator to the tank, the fuel will slowly increase in temperature, run it long enough and the fuel gets very hot leading to potential vaporisation and mixture issues. If you install the regulator in the boot, the pump delivers the fuel from the tank, through the regulator, onward through a single line at the correct pressure and the excess straight back to the tank at roughly the temp it originally came out of the tank. the benefit is, you only need a single line to the engine compartment and the fuel is cooler. There is a proper stop end available for the return connection on the fuel rail . I also agree with the need for a rigid 8mm fuel rail from the boot to the engine compartment.

[Chris1992]

I would agree, if you're not going to track the car there's no need for a swirl pot, it's over the top for a road car. As 72hump says, the MPI pump in the tank (with it's filter fitted) is more than adequate for your set up. If you're only going to use the car on the road there is a strong argument for mounting the regulator in the boot, the reason is as follows. If you run a supply to the regulator in the engine compartment (which with your set up will be running a very high ambient temperature) and then run it from the regulator through the fuel rail and back through the return side of the regulator to the tank, the fuel will slowly increase in temperature, run it long enough and the fuel gets very hot leading to potential vaporisation and mixture issues. If you install the regulator in the boot, the pump delivers the fuel from the tank, through the regulator, onward through a single line at the correct pressure and the excess straight back to the tank at roughly the temp it originally came out of the tank. the benefit is, you only need a single line to the engine compartment and the fuel is cooler. There is a proper stop end available for the return connection on the fuel rail . I also agree with the need for a rigid 8mm fuel rail from the boot to the engine compartment.

 

Mounting the regulator in the boot would definitely be a much easier solution, and I had thought about that, but for some reason I had got it in my head that it wasn't the best method. I may try this first and if I suffer any issues due to it then I can always relocate it and then simply run an extra fuel line for the return. Very interesting what you say about the temperature of the fuel circulating through the engine bay, it certainly makes sense.

 

I remember having an up-close look at the shorty that SC built, and that does seem to be set up with the return end of the fuel rail capped off. There seems to be a variety of ways to set up the fuel delivery for these conversions from what i've seen. 

 

I'll hold fire on any decision making until I've spoken with John at SC, as he built the engine. If he says the 044 pump is a bust then I'll begin weighing up my options for either a smaller capacity pump, or an MPI tank.

 

Regarding the need for a rigid fuel line running the length of the car, is this down to holding the correct fuel pressure? Or is this purely a safety thing? Both would be valid arguments in favour, I'm just curious. 

 

Hi Chris, I've only read some of this post, if your after a fuel pump, I'm like most of the guys on hear that are building/running the Twincam engine from SC have fitted the MPI pump, this will give you more than enough pressure, as you will have a fuel pressure regulator set to 3.5bar.

Cheers, Paul.

 

Cheers Paul, like I mentioned to Northernpower, depending on what John at SC advises I may be on the hunt for one.

[hazpalmer14]

On turbo engines most people with a saloon tank either use the MPI tank makes things easier because it has the in built pump and return. Other common option is gravity feed a metro turbo (or simial injection pump) and T the return into the low pressure side between the tank and pump. This also has the effect of effectively increasing your feed to the pump. I have a turbo estate and i'm using a swirl pot but thats becuase of the shape of the LWB tank and where the pick up is.

[Northernpower]

.

 

Regarding the need for a rigid fuel line running the length of the car, is this down to holding the correct fuel pressure? Or is this purely a safety thing? Both would be valid arguments in favour, I'm just curious. 

 

It's twofold and you're correct on both counts, some of the flexible hose on sale today is poor quality in terms of it's integrity to take injection pump pressure and also it deteriorates at an alarming rate (restricting the flow considerably), this includes some of the well known braided types. If you're not running inboard, flexible hose needs a lot of support to fix it to the underside of the vehicle to stop it becoming a snag hazard. The lessor problem relates to using poor flexible hose and as a result you do get fluctuating pressure, admittedly this is less of a problem on a road engine but constant flooring of the throttle in race conditions did lead to a slight weakening of the mixture as witnessed on the lambda reading but it shouldn't pose a problem for a road engine. On a personal level I just think it's good practice to fit a rigid line. 

[Chris1992]

On turbo engines most people with a saloon tank either use the MPI tank makes things easier because it has the in built pump and return. Other common option is gravity feed a metro turbo (or simial injection pump) and T the return into the low pressure side between the tank and pump. This also has the effect of effectively increasing your feed to the pump. I have a turbo estate and i'm using a swirl pot but thats becuase of the shape of the LWB tank and where the pick up is.

 

I am beginning to sway towards an MPI tank, especially as I have to remove my tank soon anyway. I'll give it some thought over the next few days. Does the standard MPI fuel tank have it's own regulator built in too? Or can I run the SC regulator with this tank?

 

It's twofold and you're correct on both counts, some of the flexible hose on sale today is poor quality in terms of it's integrity to take injection pump pressure and also it deteriorates at an alarming rate (restricting the flow considerably), this includes some of the well known braided types. If you're not running inboard, flexible hose needs a lot of support to fix it to the underside of the vehicle to stop it becoming a snag hazard. The lessor problem relates to using poor flexible hose and as a result you do get fluctuating pressure, admittedly this is less of a problem on a road engine but constant flooring of the throttle in race conditions did lead to a slight weakening of the mixture as witnessed on the lambda reading but it shouldn't pose a problem for a road engine. On a personal level I just think it's good practice to fit a rigid line. 

 

 

 

Ah right I see, I've been running flexi hose under my car for a few years now but I have always been a bit paranoid about, so I think now is as good a time as any to make the change over to a rigid line.

Edited by Chris1992, 03 October 2020 - 06:29 PM.

[Northernpower]

 

On turbo engines most people with a saloon tank either use the MPI tank makes things easier because it has the in built pump and return. Other common option is gravity feed a metro turbo (or simial injection pump) and T the return into the low pressure side between the tank and pump. This also has the effect of effectively increasing your feed to the pump. I have a turbo estate and i'm using a swirl pot but thats becuase of the shape of the LWB tank and where the pick up is.

 

I am beginning to sway towards an MPI tank, especially as I have to remove my tank soon anyway. I'll give it some thought over the next few days. Does the standard MPI fuel tank have it's own regulator built in too? Or can I run the SC regulator with this tank?

 

It's twofold and you're correct on both counts, some of the flexible hose on sale today is poor quality in terms of it's integrity to take injection pump pressure and also it deteriorates at an alarming rate (restricting the flow considerably), this includes some of the well known braided types. If you're not running inboard, flexible hose needs a lot of support to fix it to the underside of the vehicle to stop it becoming a snag hazard. The lessor problem relates to using poor flexible hose and as a result you do get fluctuating pressure, admittedly this is less of a problem on a road engine but constant flooring of the throttle in race conditions did lead to a slight weakening of the mixture as witnessed on the lambda reading but it shouldn't pose a problem for a road engine. On a personal level I just think it's good practice to fit a rigid line. 

 

 

 

Ah right I see, I've been running flexi hose under my car for a few years now but I have always been a bit paranoid about, so I think now is as good a time as any to make the change over to a rigid line.

 

The MPI tank and MPI pump is just that, it doesn't have the regulator but the SC regulator is a great match to it.

[Northernpower]

Don't forget the SC ECU controls the fuel pump earth, not the feed. I would also suggest an inertia switch as well.