Two-Port Fuel Pump

[64convertible]

I need a new fuel pump, but I’m told I have to get a 3-port, as there aren’t any kits or replacements for what I have.

Also, I know nothing about fuel pumps.

So if I give my mechanic a 3-port pump, what modifications do I tell him he needs to make to the fuel system? Where does the third port go?

[action]

The third port is a return line back to the tank.
This prevents vapor lock by having some fuel return to the tank

Moving fuel is less likely to pick up heat
Lower heat less likely to vapor lock


Action

[JCSLOCUM]

I have a 2 port (brand new from PO) on my '66, which I know isn't right but it works. Is there any big reason to change it out, other than authenticity?

[action]

I
Is there any big reason to change it out, other than authenticity?

To prevent vapor lock.

Vapor lock is only going to occur under a limited amount of circumstances.
Longer periods of idling and/or slow speed driving with AC on in the summer.
My location gets to triple digits for high temps during the months of June to September.
I need all the help I can get even if I don't drive during those times.

Authenticity ain't a thing if the car don't go.

Action

[TonyC]

Actually, Action, from my own experience with those two-and-a-tree pumps that have been dominating the aftermarket since the '80s, I've learned it's more than merely vapor lock. It's so much vapor lock that it can literally render the pump internally inoperative. Because of the absence of that separate vapor-return port, nearly every pump of that kind I've dealt with has popped its internal valves out of their places, killing the fuel distribution. The only good thing about those pumps was that the aftermarket design still retained screws holding everything together, so a tinkerer like me could still get into the pump and secure anything that got dislodged...but only temporarily, until the vapor buildup caused them to dislodge again. All that I learned the hard way with my grand's Man-Of-War. With Frankenstein I swore from the onset that I'd never use a two-and-a-tree pump, sticking only with the proper OE 3-porter, and any malfunctions would be remedied by repairs only...or in the case of a replacement, it would only be with another properly-designed 3-porter.

Last week, in fact, that was one of the major showstoppers for me. We finally got the engine to fire, and it held on its own without "help," although the distributor showed to be a tooth off alignment...but when I shut it off to do some more distributor adjustments, I saw fuel leaking out of the return line onto the water pump. Somehow the fitting for the hose broke inside the valve, and was loose. I had my J B Weld on hand, but you know how long that takes to cure...and being that it was on Sunday, that halted any more progress on the revival. Hopefully, four days of curing will fix that; I'll find out come Friday. I do have a spare pump on hand if it comes down to that.

---Tony

[Ken Stevens]

On my 61 I’ve owned since ‘93, my 3-port works great since it’s rebuild. There are 3 additional issues that work to still encourage vapor lock in my Lincoln:

1) I know the eccentric on the cam gear (that operates the pump push rod) must be worn as the bronzite tips on the pushrods only last a year. As they wear, the pump stroke is reduced which will cause vapor lock on hot days. I would like to upgrade to the ‘63 eccentric and pushrod, but that requires major surgery and the inevitable “as long as you’re in there” expenses. Eventually I will, though.

2) The car came with an Airtex supplement fuel pump in the rear by the tank that will not only keep the carb fed but also fill the carb bowl when starting after a long rest. When the pushrod wears, I need to use the pump constantly. A hint things are still not perfect.

3) This year I started using ethanol-free fuel (higher boiling point) and, along with the auxiliary pump, has combined to eliminate vapor lock so far this year. Also healthier for various rubber parts