Fuel pump spacer for Fhead?

Bought a new fuel pump with the vacuum pump. P/N 9562, I seem to recall seeing a spacer called out for proper pump pressure, for an Lhead. Would a spacer be required for my Fhead?:hurrican:

Does anyone use a spacer with their fuel pump?

 

Don't know if you've seen this or not, but here is a link to an article on the CJ3B Page. Scroll about half way down the page to the fuel pump mounting spacer. I bought a new fuel pump from Walcks (not the vacuum kind) and I'm not using a spacer. Hope this helps some.

http://www.film.queensu.ca/CJ3B/Tech/FuelLine.html

 

one of the m38a1's i bought had the spacer, not sure why, the other a1 had/has a L head its not orignal, but i do belive it is a leftover crate motor, neither had many miles one had 13k and the one with the f head had 38k, but it did have the spacer you are talking about, so yes to your question i do have a spacer on a f head, dont know exactly why but i do have it

 

From what I understand the spacer is used to lower fuel pump pressure, the article I read says to add gaskets to further lower pump pressure, it makes sense to move the pump farther away from the cam eccentric to so it doesn't have as long of stroke on the pump.

 

I've seen them and have one or two lying around, I guess it does make sense to me that it would lower the fuel pressure.

 

I'm gonna go fer it and install it with out as the pump on my fhead doesn't have one now just rtying to get everyone thoughts on using it.

 

Watch the carburetor when the engine is idling. If the fuel pressure is too high it can overwhelm the needle and float, and overflow the carburetor bowl, you might see fuel dripping out the hole for the accelerator pump arm. In that case you either need the spacer, or a fuel pressure regulator.

Eric

 

My m38 has the spacer for the L-head, reason it has it on the m38 is not only for fuel pressure but also to clear the engine mount.

 

Ok, So did the factory ever use a spacer?

 

Looks like the spacer is needed for the vacuum/ fuel pump I have. With the cam positioned to have the least pressure on the lever coming out of the pump it takes way to much pressure to get the bolt holes lined up. By holding it about 1/4 away from the block and the lever touching the cam the bolt holes line up.

So any one have an extra spacer?

 

It's good to see opinions concerning the function of certain parts but I hate to see those estimations promoted in place of fact.
I have previously researched and touched upon this topic concerning fuel pump spacers; which was previously noted upon the CJ3B Page.

Two similar double acting pumps were used.The AC pump model number is located on the mounting flange edge.
Those pumps are AC # 4080 and 4693. The 4080 was replaced by the 4693 in 1960 or 1961.
These same pump models were also used on CJ-5,6's of the same time period.
Other universal models will also incorporate the use of this same spacer, even though it was not used on all universal jeeps.
This part is identified as W/O # 647669.
It is shaped nearly identical to the mounting flange pattern of the pump body. It is constructed of steel. It is .140" (approx 1/8") thick.
The purpose is to correctly distance the pump in relation to the camshaft centerline.
Shortening of the distance by spacer omission increases the pump stroke.
This only slightly raises pump volume,it does not effect pump pressure.
Fuel pump pressure is regulated by two identical, spring loaded, one way check valves. One valve for inflow and one valve for outflow.
Therefore the pump creates equal fuel suction and output pressure.
Upon installation of the "spacer", two fiber gaskets are needed.

Many F-134 hurricane engines have been fitted with other pumps, either AC pumps intended for different W/O applications or aftermarket pumps of other manufacture.
Most if not all aftermarket pumps have a shorter pump stroke.
There fore in relation to fuel pump mounting for the model CJ-3B,"spacer" omission has sometimes occurred.