I'm thinking about changing over from and Edelbrock 600 Carb to a Holley Sniper EFI setup whilst my build is still under progress. I need to fit a return line so now's the time to do it whilst the tank is empty and out.
I have an existing Aeromotive inline pump and am going to continue on with a Holley Sniper compatible inline pump. I do not have enough room between the bootlid floor and the top of the fuel tank for an in tank pump also I want a flat bootlid floor as well.
1/ Holley sell the kit with a pre and post pump filter, will my existing fuel water separator be sufficient or do I need something compatible with the efi inline pump?
2/ Also anyone got 1st hand advise on the Sniper?
Hi Meeksie
Have a look at some of the other brands available as some do not require a return fuel line as they are a direct replacement for a carbie, later model Commodores have a single fuel line.
Your existing fuel pump may not be up to the required pressure, have a look at efihardware.com and speak to Ian at Cruising Automotive as he deals in injection systems for Street Rods.
34 tub wrote:Hi Meeksie
Have a look at some of the other brands available as some do not require a return fuel line as they are a direct replacement for a carbie, later model Commodores have a single fuel line.
Your existing fuel pump may not be up to the required pressure, have a look at efihardware.com and speak to Ian at Cruising Automotive as he deals in injection systems for Street Rods.
Thanks David
Thanks David, I realise that I will have to change the pump but I'm more interested in understanding if a filter needs to match the pump or can I use my existing fuel water separator?
Thanks for the link to efihardware.com I'll get in touch with them as I will never spend another $ at Crusin Automotive.
You can use your existing filter and pump but your existing pump will make the EFI pump output a higher pressure than is should. This is because the fuel going in the EFI pump is under pressure rather than gravity feeding into it.
The usual set up is Low pressure pump -> swirl pot -> EFI pump with the return line running to the swirl pot. The swirl pot then has an overflow back to your fuel tank.
As your tank doesn't have any fuel in it why not take it out and alter it so you have a bottom feed for an external EFI pump and do away with the water trap (never seen one in use on a petrol engine) and low pressure pump. Whilst altering the fuel tank you can have a return line installed. Put the fuel pickup at the rear of the tank and if possible have it surrounded by a low baffle to hold fuel there. It would need holes to allow the fuel to enter the baffle.
If you don't want a return line from the engine back you could use a Corvette fuel filter that has a built in regulator. This could be installed next to the tank and after the EFI pump so the return line would be a few hundred MM long.
Never argue with an idiot, they will drag you down to their level and beat you with experience.
I helped install one on a mates early 60s Chev. It went in with a new motor. I did the wiring.
The system was installed with their fuel pump and filters and was setup with the return fuel line. Thermo fan was wired to be controlled by the unit and provision was made for when the AC is reconnected.
The unit was impressive, we punched in the basic setting for the motor, didn’t touch the idle and had the timing around TDC and it fired up and sat there and idled. First rev it stalled, after a quick check of the plug leads one was pushed on properly and it was fired up again and all was good considering the timing...
The cars been back on the road since late last year and so far so good.
I’ve been told that the injectors can be a little noisy but it wasn’t the something that I noticed.
I have one running in my wife's 56. I put it in the weekend before lake Mulwala rod run and has been going prefect every since, jump in turn the key and off it goes, she drives it a minimum of 2-3 times a week.
You only need a 100 micron pre filter and a 10 micron post filter, if you are going to modify the tank put a sump in it and pull fuel from the bottom this will mean that you wont get the fuel surge when cornering. then you can use the current position in for the return line.
My only advice, make sure those filters are relatively easily accessible. Mine isn't and I had one clog. Tilt tray home rather than 5 mins side of road remove filter and go job.
I'm using Tanks Inc conversion in my Hudson. After doing an external EFI fuel pump on the Vicki and on my 36 Plymouth Coupe, I vowed I would put the fuel pump inside the tank for the next one. The external ones are just so bloody noisy!
This conversion is way cheaper than other conversions for older, carb tanks, like the Aeroflow Phantom, and is piss easy to install. It comes with all the gear you need, a fuel pump, supply and return inlet/outlet. You'll still need another hole for the fuel gauge sender, but I am just using the factory hole.
Choco Munday, Technical Author, Hot Rod Handbooks
Ph:0412 883 235
Hi All
If you use a late model Ford of Commodore in tank pump they come as a complete unit with fuel sender, tank filter and do not require swirl pot, they are spring loaded so they remain tight on the bottom of the tank, some models are designed for single fuel line eg no return required. Various models between Ford and Holden have different tank depths. ref efihardware.com SKU 850-130A Complete Kit or SKU 850-120A Complete Kit
Thanks for all the advice guys it was good to hear from those who have fitted and been using the Sniper systems without any troubles.
I think at this stage I'll put the tank back in the car and see if there may be clearance to fit an in tank pump like 34Tub suggested. If not possible then I'll go for an inline pump just have to figure out how to mount it down low and modify the tank outlet.
Thanks again greatly appreciated.
Whilst I'm not using a Sniper, I'm using Professional Products (PP) in-tank pump with an external swirl pot. I'm running a pressure return line to the tank from the pot; the feed line then goes to an external PP pump on the chassis and up to a regulator near the engine. With EFI you'll need to upgrade your pump, 45psi (EFI) is a lot more pressure than 5psi (Carb).
6AN up to 550hp, 8AN over 550hp and 10AN when getting serious.
Definitely run an in-line pre-pump filter (100 microns) and a post-pump filter (35 microns). I'm using AN8 line from tank pump to external pump and then AN6 line up to engine as well as return line to sump built into the PP in-tank pump assembly. I've also an in-line fuel on demand sensor that actually slows the pumps down as it works off TPS and through ECU etc etc. Mine has a base map and not self learning. It can be fine tuned. As I run 6xEFI 97s I had to upgrade the injectors to 50lbs each, the original injectors just wouldn't cut the mustard.
That water separator might be OK for low pressure however I'd check that it can safely handle 45psi, constantly! An old trick when I was an apprentice was to add methylated spirits to the tank to remove the water.
