Cam lobe position for mechanical fuel pump

[renjaminfrankln]

I have not seen any decent pictures of this on any of the write-ups I read. Currently the pump is out of my truck and I have turned the engine over a bit to get the lobe in the right spot.

First pic is of the lobe hanging down. You want this lobe to be up and out of the way when installing the new pump. 2nd pic is after I rotated the engine by jumping the starter solenoid. You can no longer see the lobe hanging down. This is the

Can anyone confirm that I have this right? If so, let me know, and feel free to add these pics to a write up in the tech section.

Also, does anyone know off hand the fittings needed to convert the mechanical pump to fuel filter line to a regular fuel hose (barbs, thread sizes). Or a source for a new hard line. My hard line was so corroded to the brass fitting that it just twisted right off with the brass fitting.

 

[renjaminfrankln]

Pics

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Cam hanging down (pic above this text)

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Cam rotated up and out of the way

 

[renjaminfrankln]

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[david85]

I just did this job on my truck a couple nights ago. Short answer is yes, you have it right regarding the camshaft position.

The pump arm slides UNDER the cam lobe so that the smooth part of the arm rides against the camshaft. You want the lobe to be at its highest point when the fuel pump is installed. Do this by rotating the crankshaft to TDC and check the cam position. It will either be at the lowest, or highest spot. Another 360 degrees of crankshaft rotation will be required if the lobe is low.

I wasn't able to see inside the engine like you did. A quick dry fit was enough to tell that the pump didn't want to sit flat against the block without putting stress against the arm. That was the clue I needed to rotate the engine over by one full turn of the crank (15/16" socket). After that, it went in easy.

Sorry, I don't know the fitting info but I bet if you were to put the old pump in a vise, you could get the fitting out with a pipe wrench and use that as a sample at the parts store. Nothing to lose at this point.

I also didn't realize there were different styles of fuel pump that fit this engine. The one I took out and the one I replaced looks the same as the new one you have. I haven't seen the short arm style before.

 

[Oledirtypearl86]

Your cam is on the right position iv changed the bolts out for studs and so it doesn't matter anymore if I got the cam lobe in the right position I slid it under the cam up to the studs and then tighten the nuts and it m not sure on the fitting either

 

[IDIBRONCO]

You could take your pump into a parts store and they should be able to get you a fitting to go in there. I wouldn't try a box store like Auto Zone. Maybe NAPA would be your best bet. If there's a carburetor repair shop somewhere around, they would probably be the best one to try. Still take the pump in with you since they probably would have no idea on the size by description.

 

[Randy Bush]

The fitting on the pump is not going to be a problem, it the one at the fuel filter that you are going to have figure out, being that one is the olive seal one. One on the pump should be an 3/8 inverted flare fitting.

 

[Randy Bush]

I just did this job on my truck a couple nights ago. Short answer is yes, you have it right regarding the camshaft position.

The pump arm slides UNDER the cam lobe so that the smooth part of the arm rides against the camshaft. You want the lobe to be at its highest point when the fuel pump is installed. Do this by rotating the crankshaft to TDC and check the cam position. It will either be at the lowest, or highest spot. Another 360 degrees of crankshaft rotation will be required if the lobe is low.

I wasn't able to see inside the engine like you did. A quick dry fit was enough to tell that the pump didn't want to sit flat against the block without putting stress against the arm. That was the clue I needed to rotate the engine over by one full turn of the crank (15/16" socket). After that, it went in easy.

Sorry, I don't know the fitting info but I bet if you were to put the old pump in a vise, you could get the fitting out with a pipe wrench and use that as a sample at the parts store. Nothing to lose at this point.

I also didn't realize there were different styles of fuel pump that fit this engine. The one I took out and the one I replaced looks the same as the new one you have. I haven't seen the short arm style before.

both pumps are interchangeable, just different made by different companies.

 

[renjaminfrankln]

Looks like this will work for the pump. 3/8 inverted flare to 3/8 hose barb

https://www.summitracing.com/parts/edd-821660

I'm going to confirm here in a minute, but I think the filter head connection (the 90 deg elbow) is just a 3/8 tapered pipe thread.

 

[Randy Bush]

I have always thought one could use a high quality braided line to get rid of the olive seals. Pretty sure it is 3/8 pipe threads on the filter head.

 

[renjaminfrankln]

New pump is in. Got the block heater plugged in. Waiting on the RTV to dry overnight.

The edelmann hose 3/8 inverted flare to 3/8 hose barb fit perfectly. The threads on the filter head were 1/4" pipe thread. Local ace hardware had a 1/4" pipe thread to 3/8 hose barb fitting in stock.

 

[IDIBRONCO]

Good. Now to drive it.

 

[renjaminfrankln]

Drove great today. No leaks. Ran like a sewing machine. I need to go on a more extended drive to see if my problem was solved, but very glad to have a new pump on there regardless.