87 LX - strange fuel pump eccentric

Spooky21

Member

Feb 27, 2019

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Czech Republic

Feb 27, 2019

#1

• Feb 27, 2019

• #1

I've taken apart my engine which I'm converting to carb and discovered this eccentric installed:

I believe it's a 2-piece unit from which someone took the outer part and slapped it back in the engine, am I wrong? There's "2A" stamped on it and the pin is not going through.
So, the question is, can I run my pump on it? The outside diameter is 59.6mm (2.35"), does anybody know what OD should it have for a pump to work properly? If I'd know the correct dimensions, I can probably fabricate a new eccentric to solve this problem. I'm in the middle of Europe so i can't go for a junkyard hunt. )
Thanks for your insights!

 

Last edited: Feb 27, 2019

General karthief

wonder how much it would cost to ship you a pair

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Feb 28, 2019

#2

• Feb 28, 2019

• #2

I'll guess the reason you are getting no response to this our efi does not use this part, we know what it is and what it does we just don't have them. So to get an answer for you lets call on a classic member, no because he is old but he works with classics that would use one of these.
@horse sence
He may need a hall pass to get up here so be patient.

 

horse sence

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Feb 28, 2019

#3

• Feb 28, 2019

• #3

I am not sure but i dont think the EFI motors use this because they use an electric fuel pump .
65 and earlier motors use a one piece excentric ,they also have a different timing cover and water pump. I think the 2 piece excentric started in 69 but i am not sure about that ,i know the early one piece excentric is a taller piece and will rub the inside of the later timing cover .
I would think you could run a fuel pump off of the one pictured if the pin catches the excentric so it cant spin loose .
An electric fuel pump may be your best bet though

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

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Feb 28, 2019

#4

• Feb 28, 2019

• #4

The EFI motors have an oil slinger in that location.

I did pull apart an '85 Mustang motor that had the same fuel pump eccentric as pictured from the factory. However, i'm not a carb guy (EFI is just easier for me to understand) so not sure what it would take to get a mechanical pump working.

What is the source of that engine?

 

Spooky21

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Feb 27, 2019

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Feb 28, 2019

#5

• Feb 28, 2019

• #5

5L5: It's an original roller block from my 87 Fox. It also had a provision for mech. fuel pump and threaded holes in the timing cover.
And I've already purchased a mech. pump, so electric pump is out of the question, more reasons besides...

horse sence: Do you know the outside dieameter of either eccentric? I think its an original 2-piece unit which is missing the outer ring (the one on the right of this pic) for whatever reason, and i think the pump would not get full arm travel if I run it like this.

 

horse sence

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Feb 28, 2019

#6

• Feb 28, 2019

• #6

I dont have a roller type here to measure ,but the non roller is 2 1/2 inches and 7/8 tall

 

Spooky21

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Feb 27, 2019

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Feb 28, 2019

#7

• Feb 28, 2019

• #7

Thanks!

 

Spooky21

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Mar 12, 2019

#8

• Mar 12, 2019

• #8

Solved it my way.

 

Reactions: 90sickfox

JD1964

there is enough sticking out to grab on to

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#9

• Mar 12, 2019

• #9

Is that a bearing type ecentric? I've never seen one of those. Who makes that?

 

General karthief

wonder how much it would cost to ship you a pair

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Mar 12, 2019

#10

• Mar 12, 2019

• #10

So what's the reasoning here?

 

Spooky21

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Mar 13, 2019

#11

• Mar 13, 2019

• #11

It's my own design, but there are some out there. Well the reasoning is easy, it saves friction and it was chaper for me to make this one than buy a stock unit.

 

JD1964

there is enough sticking out to grab on to

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#12

• Mar 13, 2019

• #12

At age 54 I’ve owned more than a few cars with mechanical fuel pumps. I never had a breakdown because of one. I like their simplicity. Now, the bearing design eccentric does add some complexity. As we all know, complexity can result in more things that can fail.

You obviously have machining skills and tools available to you. You had to make the offset bushing for the center portion. How did you figure the beating diameter and offset and it’s relation to how far it moves the fuel pump arm? Beyond the need for durability, I suppose that is a very critical thing to get right.

 

Spooky21

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Feb 27, 2019

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Mar 13, 2019

#13

• Mar 13, 2019

• #13

Well, yeah, it adds complexity...in a same way roller rockers add complexity.
I had to work with standard available bearings, i chose the same bearing that HiPo parts uses (68mm OD), then i just had to calculate how much closer to the center to move the offset hole so the arm travel would be the same as with stock eccentric. I drew circles in cad, one of the stock eccentric diameter, second of the bearing diameter, than the stock position of the offset hole. I could measure the lowest and highest points of the pump arm in relation to the cam. +/- thou aint no concern here, the pump can take it. Sorry my english is short for this. )

 

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