[lluciano77]

I am switching my 5.0 back to a mechanical fuel pump. I have a box with mixed Ford parts. I had parts for a couple 2 piece eccentrics, and one or two of the 1 piece designs.

I had to take my timing cover and water pump off to add a fuel pump eccentric. I opened up the front of the engine. I looked in my box of parts, and I used an eccentric that I thought was a one piece design. Then, I reassembled the front of the engine.

Now, when I spin the engine, there is very little fuel pump action. I put my finger over the vacuum side of the pump, and there isn't enough suction to maintain adequate pressure. I am using brand new stock pump.

I removed the fuel pump and moved the pump arm by hand. By hand, I can generate more than enough, so I would imagine the pump is fine.

Is there a way to tell if I may have used part of the one piece eccentric by mistake?

Could the new pump be bad?

I have to use a two piece eccentric. The Cloye's timing chain requires it.

Is there something I am missing?

[lluciano77]

Anyone?

[KULTULZ]

I don't understand the question. If the application requires the two piece eccentric, why didn't you install it?

[lluciano77]

My timing chain requires the one piece eccentric. Aftermarket timing chains are designed for either one or two piece eccentrics.

I have a box full of mixed Ford parts. There are some 1 piece eccentrics in it, and some 2 piece.

I did my best to find the one I thought was a one piece eccentric. I installed the fuel pump. It doesn't seem like the eccentric has the amount of throw needed to move the fuel pump arm enough to supply adequate fuel pressure. I was pretty sure I used the one piece eccentric, but the problem may also be with the pump itself.

When I move the pump arm up and down by hand on the bench, it seems to push and pull a lot more than when installed on the engine.

I am asking if there is a way to tell for sure if I used the 1 piece. Is it possible that I used one part of the two piece? Would the round part of the two piece only lift the pump arm slightly, or not at all?

[lluciano77]

What happened to all of the Ford guys?

Hey 4 Jaw, this aught to be one you would know. Wouldn't you?

[crazy larry]

the only fp eccentric i ever saw on a 302 or 289 has been a one piece. looks like every other eccentric i've seen, a round bowl with perpendicular sides.

[KULTULZ]

I have to use a two piece eccentric. The Cloye's timing chain requires it.

My timing chain requires the one piece eccentric. Aftermarket timing chains are designed for either one or two piece eccentrics.

The SBF is is a two piece...inner and outer. You are missing something.

[onebadmerc]

I had the same problem with my 289, I tried to use a 2 piece fuel pump eccentric from a 71 302. The timing chain gear was too wide and stuck out too far. The pin that retains the eccentric was too short. It stuck out far enough to bolt it on but when I fired the motor up the eccentric slipped off of the pin. Try checking the pin on the end of your camshaft.

[KULTULZ]

Camshaft Dowel Pin/Fuel Pump Eccentric

Two different length dowel pins were used in the front of the
cams in 221-351W engines. In 1972 and earlier engines, a
longer (1.375”) dowel pin was used so that it would extend
through the one piece fuel pump eccentric used on these
engines. The 1973 and later engines utilized a two piece fuel
pump eccentric which required a shorter (1.125”) dowel pin. If
no eccentric is used, a thicker than standard retaining washer
must be used to make up for the thickness of the eccentric.

(NOTE: Earlier Electric Pump Conversion or Later F.I Engines)

The cam gear MUST be pulled tightly against the snout of the
cam. If the gear is not tight against the step at the front of the
cam the bolt will come loose and engine failure is sure to
occur.

Dowel pin failure is fairly common in Small Block Ford
engines. This is almost never the result of a defective or soft
dowel pin. It is most often caused by the bolt in the center of
the cam coming loose and allowing the dowel pin to be loaded
and shear. The center bolt should always be torqued to the
manufacturer’s specification, and a suitable thread lock used to
prevent the bolt from coming loose.

There is a mix-match of one and/or two piece eccentric useage. One piece to 1972, two piece from there. One piece in the 82/84 HO and an upgraded inner eccentric starting in 1988 so you have to use the same system throughout.

[lluciano77]

I want to run a one piece eccentric. That is what the timing chain set requires.

I will see if I can tell whether or not the pin slipped out, but I doubt it. I spun the engine using a bump starter, and left the fuel pump loosely bolted in. You can definitely feel the eccentric spinning. When the eccentric is at full lift, I can't get the fuel pump bolted on. So I'm sure the eccentric is working. It just doesn't seem to be working enough.

All of my Ford small parts are mixed up in a big box. I had 1 and 2 piece eccentrics in it. The 1 piece eccentrics were from early 289/302s, and the 2 piece ones were from 70's 302s.

[lluciano77]

Does anyone know how to tell the difference between the part of the 1 piece eccentric, and the parts to the 2 piece?

[onebadmerc]

On the two piece eccentric their should be a tab on the back that holds it in place. The older 1 piece eccentrics are held by a dowl pin protruding through the timing gear.

[lluciano77]

Originally posted by KULTULZ


The SBF is is a two piece...inner and outer. You are missing something.

I am sorry. I meant that I have to use a 1 piece eccentric with my Cloyes timing chain.

Originally posted by onebadmerc
On the two piece eccentric their should be a tab on the back that holds it in place. The older 1 piece eccentrics are held by a dowl pin protruding through the timing gear.

The one I put on had two hole. The one for the camshaft, and a smaller one for the dowel pin. Are you saying the outer race of the 2 piece has a rectangular, or square hole?

Originally posted by onebadmerc
I had the same problem with my 289, I tried to use a 2 piece fuel pump eccentric from a 71 302. The timing chain gear was too wide and stuck out too far. The pin that retains the eccentric was too short. It stuck out far enough to bolt it on but when I fired the motor up the eccentric slipped off of the pin. Try checking the pin on the end of your camshaft.

Did the eccentric lift the pump just a little when the pin fell out? I am trying to avoid removing the timing cover unessesarily. I am getting a little bit of fuel pump arm movement, but not enough.

[onebadmerc]

It was a weird situation, I had to pull the cover and pull the eccentric off and get the right pin, plus I changed the retainer. The pin was only protruding above the gear .020-.030 of a inch. It stuck out just enough to hold the eccentric on, but when I cranked the motor over, it fired up; then it died, I lost fuel pressure. It loosened the eccentric bolt, I should have used thread lock, but it wouldn't have helped. The one piece retainer that was with the 289 but I lost it, so I used one off of a spare motor I had. The motor was a 71 302 and it was a 2 piece eccentric that still used the pin for retainment. Later two piece eccentrics have a tab on the back side that fit in the hole in the timing gear, they use a really short pin. Ford really screwed around with the eccentrics in the early 70's so I guess there could even be more different combinations of them. What I eventually did was I snagged a 1 piece eccentric from a friends junk 289 and got the right retaining pin.

[brainsboy]

I normally know alot about fords but I have never used those pieces, I cant even remember what they look like, I always throw them in the trash and run an electric fuel pumps.