electric fuel pump

[monzadon]

i am installing a Clarks electric fuel pump on my 63 monza and i have read where a return line was installed some times i am wondering if i need to install a return line because it looks like it might be hard to do and i really don't know how to do that

[RexJohnson]

The only factory cars that came with a return line were turbo charged cars from '63 thru '66. Smog cars also had them but I'm not sure if they were on the '66 smog cars or not. For sure all '68 and '9 cars had them.

[Lane66Monza]

Don't need return line unless you already have one installed by the factory. Just be aware that if they are still using the Airtex E8016S pumps, the pump may have a output pressure more than a carb can handle. My friend John bought the kit and pump was delivering 9 psi. He tried a regulator from a flaps and it failed. Finally changed to a suitable pump.

Carb acceptable input pressure is 2 - 4.5 psi. Do yourself a favor and check its output pressure during engine operation. Remove engine fuel filter behind lh rear wheel and install a t-fitting with adapters to fit filter's 5/16" hoses and a 0-25 psi gage.

[monzadon]

thanks for all the information it really helps me with this installation, i restored a 66 and installed a Clarks electric fuel pump and didn't have any problem wit to much pressure

[66vairguy]

Don't need return line unless you already have one installed by the factory. Just be aware that if they are still using the Airtex E8016S pumps, the pump may have a output pressure more than a carb can handle. My friend John bought the kit and pump was delivering 9 psi. He tried a regulator from a flaps and it failed. Finally changed to a suitable pump.

Carb acceptable input pressure is 2 - 4.5 psi. Do yourself a favor and check its output pressure during engine operation. Remove engine fuel filter behind lh rear wheel and install a t-fitting with adapters to fit filter's 5/16" hoses and a 0-25 psi gage.

First --- the old QUALITY AirTex electric pumps are NO LONGER MADE as the new units are by a China company who bought the AirTex name. The new pumps have been reported to be PROBLEMATIC - DO NOT USE.

Second the OLD AirTex E8016S pump pressure rating was 2 - 4.5PSI or always 4.5 except at maximum flow of 30GPH (if you Corvair uses that look for a BIG leak ) Some vendors sold the AirTex E8012S pump rated at 5 - 9 PSI which actually delivered 9 PSI in the Corvair. IGNORE the lower pressure number on fuel pumps as it is a bogus number to allow for a claimed higher volume flow of 30GPH which the Corvair will NEVER demand unless the fuel line broke off the carburetor(s)!!!!!

Bottom line is the shop manual wants 4-5 PSI at the Rochester carburetors (the exception is the Carter carburetor on the Turbo cars that the consensus agrees runs best at 2-3 PSI).

[jimbrandberg]

While a return line is a nice thing to have it is difficult to accomplish.
It's nice, although probably not necessary, for an electric fuel pump to keep fuel running through it for cooling.

I believe the turbo had it for 3 reasons.
High underhood temperatures liked keeping the fuel circulating.
Carter YH is more sensitive to fuel pressure and it helps alleviate it somewhat.
It gives a place for residual fuel pressure to go when you shut the engine off. The Carter YH can be persnickety about hot restart flooding.

The original rubber tee in the gas tank vent line gets hard and cracks before its time. California Corvairs has a special steel tee that is much better.

[monzadon]

do i need to remove the original fuel pump when installing a electric fuel pump

[Dennis66]

There are 3 options:
1. just leave it, and re-route the plumbing to the carbs
2. buy the "dummy" fuel pump body that replaces the center body in your existing pump (some disassembly and reassembly required - note that the 5 screw holes only line up one way) and allows you to keep all original plumbing and have it look original (around 60.00 - what I and many others have done)
3. install an inexpensive "plug" (available from Clark's, and possibly other sources). This fits in where the base of your existing fuel pump was, attaches witht he same screw, plugs the hole, and probably makes getting to the oil pressure sender and maybe fan belt adjustment a little easier.
Personally, after investing in an expensive Facet pump, I opted to get the Ted Brown IN TANK electric fue pump (<200.00) that also came with a new sender unit and kept all my plumbing original looking.

[66vairguy]

There are 3 options:

3. install an inexpensive "plug" (available from Clark's, and possibly other sources). This fits in where the base of your existing fuel pump was, attaches witht he same screw, plugs the hole, and probably makes getting to the oil pressure sender and maybe fan belt adjustment a little easier.

If you are not into the "original" look (many are and that is fine), then as Dennis said you remove the fuel pump, put in plug. I'll add that you can rotate the fuel lines 180 degrees to put the "T" up toward the front of the engine compartment and add a "home made" line to connect to the original fuel line behind the bulkhead. Looks cleaner and MORE importantly keeps the fuel cooler so you DO NOT need a fuel return line. I did that and even in 90 degree weather I have had no issue with vapor lock. Your choice.

[RexJohnson]

With an electric fuel pump pushing from the front you should never have vapor lock. If the fuel ever vaporizes the vapors just get pushed into the bowls.

[66vairguy]

With an electric fuel pump pushing from the front you should never have vapor lock. If the fuel ever vaporizes the vapors just get pushed into the bowls.

Agree - but sometimes the bends in the fuel lines trap a bubble that causes odd flow problems - like "soft" pedal brakes with an air bubble in the line. The fuel pump, even with a dummy plate is a HOT SPOT and today's fuels vaporize easily - even the non-ethanol blends.

[Wittsend]

As I see on Google images the '63 looks like it still has the dual air filter arrangement (unless you have replaced them with something aftermarket) that will get in the way of the configuration that 66vairguy posted an image of. But, you can still do the mechanical fuel pump delete arrangement it just needs to be towards the rear. Plug was made on a lathe with an o-ring groove.

Engine noise area.JPG (54.88 KiB) Viewed 111 times

[66vairguy]

As I see on Google images the '63 looks like it still has the dual air filter arrangement (unless you have replaced them with something aftermarket) that will get in the way of the configuration that 66vairguy posted an image of. But, you can still do the mechanical fuel pump delete arrangement it just needs to be towards the rear. Plug was made on a lathe with an o-ring groove.
Engine noise area.JPG
20221006_174835.jpg

Thanks for pointing that out. Mine was a LM 140HP and there are TWO versions of fuel lines. You need to use the 1965 model year with BOTH lines to the carburetors are toward the outside of the car. The lines that can be rotated 180 degrees.

The 66-69 passenger side 140HP fuel lines were changed to clear A/C or smog pump. rotating the 65 model year lines works fine as there is will be no fuel line around the A/C compressor (both my cars have 140Hp with A/C using Sanden and Clark's bracket).

[jimbrandberg]

When rotating the fuel lines I actually prefer the 66 style that runs inside the carburetors. You would think it would interfere with the throttle rod but I think it's fine.
The 65 style that runs outside the carburetors is a little cramped against the frame rail.
Both styles will work and I tend to use what I have since they're not cheap to buy.

When making a new fuel inlet line at the front of the engine I come in sideways using a 1/8 NPT 90 degree 5/16 flare fitting but bending the steel line to come in from the top like in the picture above looks good too.
I think the first few I did years ago were original lines I rebent to fit and even when I started making new ones I just stayed in the same vein without even thinking about it.

I like seeing how other folks do things.

[RexJohnson]

For the vapor lock comparison, The brake system is completely different than the fuel system so the soft pedal with air bubble doesn't apply. To plug the fuel pump hole I machined off the top of the pump and used an 1/8" pipe plug in the hole. It fits like it was meant to be.