Conventional fuel pumps on older crossflow V6

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Hi,

very familar with v4's as i have been rebuilding them.

im gonna work on 2 v6's. One is an 81 with with 2 conventional pumps..the other appears to have been vro at one point, but now also has 2 conventional pumps.

i typically use the 438556 or 438559 pumps comonly available(either block mounted Pulsed or via hose)

I realize the v6 requires 2 (1 motor has them mounted already but look pretty crappy)....

question is this:

The book shows 2 different part numbers that sub to unique upper and lower fuel pump "kits". The only apparant difference is the position of the outter cap and nozzle under the screw. One is positoned up while the other is down for hose routing.

am I able to use the familar 438556 or 559 and rotate that cap/nozzle to the needed orientation? They rotate easy enough but i dont know if it affects proper fuel flow etc.

i can get the 559 or 556 relatively cheap, this would be a great setup.
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Or, was thinking using either of these pumps without movinf the cap/nozzle at all, and just complete the plumbing. I have plenty of Formed omc gas line to use.
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Thoughts on this? Thinking I can mount 2 438559 pumps and be good
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Z






Was thinking of putting something together like this. Assuming I can use the standard 438559 std fuel pumps I normally get, plumbed together.

Thoughts?
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
woops, trouble with the image, trying again:

pumps.jpg

I'd be using 2 438556, standard pumps I am familiar with and not expensive.
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
Messages
15,931
On the 81 they are different as one is low and other is high pressure.
 

racerone

Supreme Mariner
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Dec 28, 2013
Messages
38,685
Myself I have a supply of the older 75 / 100 HP fuel pumps.------Have a filter and sediment bowl too.------Very little money spent on my part.-----Easy to rig up a pair or even 3 of those pumps.
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Faz, thanks...just to clarify, the front casing has 2 pressure port connections

Ive got the '81 and '85 side by side. The 81 8s missing ita pumps. But you are saying one is a higher pressure that the other?

the running '85 has 2 older pumpa that appea4 identical.

was hoping I could use the readily avail and cheap pair of 438556/559 type

Racer, you say 70-100 older motor pumps...would a pair of these rigged up do ok for the 150? I will research..if you wouldnt mind me asking where to procure, pm?

thanks all...sorry to beat this one up! Been on the v4's awhile.
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
I pulled every conventional pump back to 1968 on 85, 90, 115 etc...they all sub to latest 438556

just double checking 1 last time, I can go with a dual setup with that or the 438556. Commonly avail.

or I have plenty of spare VRO units that are good, those should be fine to run mix, correct?
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
Messages
15,931
The picture of pump you posted only has 1 pulse port....other one is fuel out to carbs.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,685
I would say that one pulse port operates both pumps as that is how they are mounted on that bracket.
 
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