View Full Version : Fuel System Questions
cnutting
08-25-2016, 07:25 AM
I will be using a 289 with a carburetor and mechanical fuel pump in my FIA build. I didn't think that I needed to run a return line, is this a valid assumption? Also, I installed the kit supplied fuel pickup in the tank, but this is designed for a fuel injected setup correct? Do I need to switch over to something else, or can I just use the existing pickup and cap the return?
Chris
mikeinatlanta
08-25-2016, 08:24 AM
Return systems are superior to non-return, so the question is how authentic do want your build to be? As long as your mechanical pump is designed for a no return system, you can use the existing pickup and cap the return, just make sure and keep the fuel line away from heat sources.
If I were doing a authentic looking build I would gut the mechanical (but keep it), use a low pressure electric at the tank, and put a return style regulator just out of sight near the motor. Best of both worlds, authentic looks and modern reliability.:)
CraigS
08-25-2016, 01:59 PM
On the other hand I have 38000 miles on mine w/ an old school mechanical pump. Never a single problem.
edwardb
08-25-2016, 03:08 PM
The fuel pickup supplied with the tank from Factory Five can be used in a non-EFI setup. You can use it for your carb'd setup. In addition to the pickup tube, there is a return tube. But it should be either pinched shut or capped. The OE pickup for an EFI setup includes an electric fuel pump. Unless you think it's possible in the future you may switch to EFI, IMO there's no reason to install a return line. Assuming your engine has the right timing cover with a mounting point for a mechanical fuel pump plus the eccentric installed on the end of the cam, I would install a mechanical pump. They're simple and reliable and only require a single feed line. Worked for decades for a reason. The industry changed to electric pumps, higher pressures, return lines, etc. with the advent of EFI. It that's not in your future, keep it simple. Two builds to date with carbs and mechanical fuel pumps. > 12K miles now between the two. Zero issues.
JRL16
08-25-2016, 04:23 PM
I agree with Edwardb. I didn't feel comfortable capping shut the return line on my carbed/mechanical fuel pump 427 build though so got the single fuel tube pickup from breeze. A little pricey but gives some peace of mind.
cnutting
08-26-2016, 07:26 AM
Thanks for the input. This was one of those second guessing, "oh crap" moments. Now that all the aluminum is on I started thinking about having to go in and change everything out.
Gumball
08-26-2016, 08:05 AM
Another carb'd FFR here - using the Breeze pickup and a mechanical pump. Remember to watch out for the pressure at the carb - e.g., a Holley only needs 4 - 6 PSI - and an electric pump may need a regulator.
Blue MK3
08-26-2016, 08:47 AM
I have a SBF with a carb and mechanical pump. The pump had to have a regulator installed to get the pressure down to ~5-6psi. Works fine. I can't see any reason to change over to an electric pump and all the required extra plumbing and wiring, relays, etc. Adds too many complicating issues.
Avalanche325
08-26-2016, 04:50 PM
There is no issue with capping the return. It is just a tube in the pickup with no pressure. It DOES need to be capped in case of a rollover. There is also a vent in the tank, but is has a check valve for roll bar testing.
Don't worry if you need to pull the tank. I timed it once........12 minutes, not counting jacking the car up.
Bueller83
10-21-2016, 03:19 PM
I have a SBF with a carb and mechanical pump. The pump had to have a regulator installed to get the pressure down to ~5-6psi. Works fine. I can't see any reason to change over to an electric pump and all the required extra plumbing and wiring, relays, etc. Adds too many complicating issues.
Do you have any pictures of your setup? I am looking to do the same thing for the same reason.
Mark Reynolds
11-10-2016, 09:28 AM
Here are the Breeze stainless steel fuel pickups for use in carbureted applications:
with bulge outlet for 3/8" ID Fuel Hose:
http://www.breezeautomotive.com/details.php?prod_id=300
with 06AN outlet fitting:
http://www.breezeautomotive.com/details.php?prod_id=1103