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Fuel Pump '71 LM318 Fuel Flow Direction?

Okay, this one doesn't sound right. Fuel pump (mechanical) is located starboard side, forward on the engine. I removed the pump about a year ago. I do not remember which was the inlet or outlet. The barbed tube (5/16") is on the aft side of the pump pointing aft. I assumed this tube was the outlet to the carb as it pointed in that direction. The other threaded tube (3/8") I assumed to be the inlet as it pointed to the gas tank. Now on a vendor's site I read the following:

[h=1]"Fuel Pump Marine for Chrysler Small Block 318-360 V8 1964-1987 Carter 2495527Fuel Pump for Chrysler Marine 318-360 without Flume Tube.[/h]Has a Hose Barbed Inlet and a Threaded Outlet
Fits Small Block Chrysler 318 340 360 c.i.d. engine. This was used from 1964 thru 1987.
This item replaces OEM: 2495527."


Inlet/outlet are reversed from what I assumed. If this is correct the inlet and outlet lines will have to cross over the pump and do a 180 back to their respective inlet and outlet tubes. The carb is a Carter AFB 4 barrel. Also, what is a flume tube? There are no other attachments on the pump besides the inlet and outlet tubes.

 
Okay, that helps. I think my pump predates flume/fume tubes.

I looked at some pictures of my carb prior to rebuild. The fuel inlet port has a has a steel line attached to the carb. The line makes a 90 degree turn forward a couple of inches from the card. It then proceeds along the valve cover and out of sight. That would make it feasible to approach the pump from the forward side as the vendor's description states. I am going to guess that original equipment in 1971 was a bent steel line from the carb (threaded port) to the threaded port on the fuel pump. Anyhow, hoping someone else has something to add about this. Carter AFB.jpg
 
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In the pic it looks like the original steel line has had its fitting pulled back and an excessively long rubber hose pulled over the flange. Should be hardlined to a metal filter. The plastic filter in a pressurized fuel line has got to go. Is the original steel line to the pump still there? One of the previously posted links shows two metal lines and a metal filter.
 

Yes..... the in-line plastic body fuel filter must go. It is not only un-safe, it is not legal and could cost you a citation should you be inspected.
Also, the filter media is far too small to be of any value. You need a Marine style fuel filter.... RACOR being one of the best for your use.

As for the OEM metal fuel line from the fuel pump to the carburetor...... as long as the appropriate barbed fittings and band clamps are used, the J1527 USCG A1-15 ISO fuel line is legal.

trient_hose_mod.jpg



If the fuel pump body parts cannot be disassembled and re-indexed, the A1-15 hose may allow for re-routing.


By the way...... it is not adviseable to adapt a fuel hose to a cut metal fuel line. Requirements call for a barb or beaded portion.
 
Thanks shipmates! You are right about the potential bomb and no-no plastic filter, but as I said the picture is prior to carb rebuild, the way it came to me. Here is the way it looks after rebuild:New Fuel Line.jpgCarb After Rebuild.jpg But my main question remains: Which is the inlet and outlet on the fuel pump? I tend to think I have it backwards. Several vendor web sites state the barbed tube is the inlet. I guess it would not be to difficult to rig up some test tubing and crank the engine.
 
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Don't want to pull the pump again. This looks exactly like mine. You know, the more vendor ads I see the more I believe them. I think I may have made a wrong assumption. I am going to hook it up the way the ad says and crank the engine.

Has a Hose Barbed Inlet and a Threaded Outlet

Fits Small Block Chrysler 318 340 360 c.i.d. engine.
This was used from 1964 thru 1987.

This item replaces Chrysler Marine # 2495527.

CARM6866.jpg
 
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The one on the right feeds the carb. To verify put a vacuum gage on the inlet, see if it pulls when engine is cranked.
 
The fitting with the tube-and-bulb (in lieu of actual threads) is the suction port.
This will be supplied from your Marine Cartridge style fuel filter system, and from the "outlet" port only.
(these filters are directional)

The threaded fitting will be the supply to the carburetor.
It may be set up for an inverted flare style steel tube..... but it will accept a special hose barbed fitting for use with the approved A1-15 fuel line.


.
 
Thanks for the help. Did not have a vac gauge. I used a gallon jug as input and a jar as output. Cranked the engine and it worked as you said it would. Thanks again!
 
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