Looking for this part, Have one for sale?

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Hambone
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Re: Looking for this part, Have one for sale?

Unread post by Hambone » January 7th, 2023, 11:05 am

Was that fitting modified(drilled and tapped) to except a fuel return line? Horst mentioned the Holleys didn't have a fuel return?

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Lou
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Re: Looking for this part, Have one for sale?

Unread post by Lou » January 7th, 2023, 11:09 am

Hambone wrote:
January 7th, 2023, 11:05 am
Was that fitting modified(drilled and tapped) to except a fuel return line? Horst mentioned the Holleys didn't have a fuel return?
The fitting photo came from an original unmolested mutt in original motor pool condition. It was not modified and came from the factory that way. I know, it was the first time I saw a holley with that fitting as well! :)
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Horst
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Re: Looking for this part, Have one for sale?

Unread post by Horst » January 7th, 2023, 11:27 am

Interesting. How on an A1 set-up could that even be routed back to the tank?

Don’t get me wrong , I’m not questioning your statement, I just wonder…
Horst

1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga

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Lou
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Re: Looking for this part, Have one for sale?

Unread post by Lou » January 7th, 2023, 11:57 am

Horst wrote:
January 7th, 2023, 11:27 am
Interesting. How on an A1 set-up could that even be routed back to the tank?

Don’t get me wrong , I’m not questioning your statement, I just wonder…
I get what you are saying and have no problem with your question. We are all here to learn. :wink:

I have never seen that set up and visit lots of MV shows. That photo was taken from a site where the owner described his mutt as such. Maybe he stretched the truth? That may not even be a straight 151 or A1 because I do not see the voltage regulator to the right. So it maybe in the realm of possibilities that it is actually an A2 with a factory return line and bubba cobbled together an official looking return to connect to it.

What do you think?
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Horst
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Re: Looking for this part, Have one for sale?

Unread post by Horst » January 7th, 2023, 12:08 pm

Not only is the voltage regulator missing, it actually has a 60amp alternator installed. My best guess is therefore that this is a nicely made installation of an Holley in an A2. As discussed, the fuel return is not compatible with the fuel filter in the carb, therefore I have another doubt that this is factory.

I had installed also an Holley and had improvised a fuel return in a similar fashion as yours with some sort of T. I did not experience any significant improvement over the Zenith and removed it again, later sold it.
Horst

1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga

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Lou
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Re: Looking for this part, Have one for sale?

Unread post by Lou » January 7th, 2023, 12:49 pm

Horst wrote:
January 7th, 2023, 12:08 pm
Not only is the voltage regulator missing, it actually has a 60amp alternator installed. My best guess is therefore that this is a nicely made installation of an Holley in an A2. As discussed, the fuel return is not compatible with the fuel filter in the carb, therefore I have another doubt that this is factory.

I had installed also an Holley and had improvised a fuel return in a similar fashion as yours with some sort of T. I did not experience any significant improvement over the Zenith and removed it again, later sold it.
Thank You for your assessment and agree with your conclusion. So the next step (as you suggested) is to drill and tap a hole in the plug. The plug is not thick enough to have a restriction hole and have enough "meat" to safely thread enough of the elbow to hold it in. So the threads will have to be tapped all the way to the bottom and restriction made in the elbow.

Was thinking about soldering the very end of the elbow closed and then drilling a hole through the solder for restriction, what do you think?

Have to admit I am very curious if not having any restriction at all would work. Thinking that since the fuel comes into the port, the needle and seat are right there. Excess fuel would have to travel through the elbow and the long line back the tank. Certainly the length of the return line would have restriction and I would think the fuel would choose the path of least resistance and enter the needle and seat and what is not used would go back to the tank.

Cannot imagine that so much fuel would go past the chamber into the return line and not leave enough fuel for the carb. Any opinions on that?

I have driven other mutts than mine, and had 3 different Zeniths on my mutt. If you are not driving the mutt off road, the zenith is fine (except for the flat spot at 2,500 rpm). So agree the holley is not necessary for the average mutt owner. Where the holley shines (and why we need it) is the real accelerator pump the holley has. Driving off road and then approaching very soft sand, when punching the throttle with the zenith, there is a delay before the vacuum operated accelerator pump dumps extra fuel in the carb and the engine bogs down.

With the holley the accelerator pump immediately dumps extra fuel in the carb with no delay and no bogging down. This makes a huge difference for us. With the zenith we had to downshift a gear when approaching soft sand (we call it Sugar Sand here in NJ, and it looks exactly like beach sand because that's what is was thousands of years ago and it is very deep and soft). So with the holley there is a lot less downshifting and smiles on the drivers face when he punches the throttle. :D Think holley double pumper carbs we had in the 70's. Yea, will admit as a kid had souped up cars with big block motors. :lol:
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Horst
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Re: Looking for this part, Have one for sale?

Unread post by Horst » January 7th, 2023, 12:56 pm

thanks for the information Lou. My Zenith does not have a flat spot and I have driven my 151 off-road. When I had the Holley installed, I did not see much better performance on the street but I have to admit that I did not off-road with it to see the difference you are describing.

I would put a defined restriction in the return, for example as you are suggesting.
Horst

1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga

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Re: Looking for this part, Have one for sale?

Unread post by rickf » January 7th, 2023, 6:14 pm

Here is a picture from the 1960 Tm. It shows the factory fittings which include the blank fitting on the fuel channel and the bowl vent fitting.
Untitled.png
There was never a vapor return on the Holley carb. This was something they came up with once they went to the closed fuel system with emissions. I am sure you van make this idea work but you have to be sure to keep the metering hole small enough that you can maintain 3lbs. minimum fuel pressure to the carburetor at wide open throttle. Measure the hole in the A2 fitting and do not go any bigger than that. Remember, these setups are designed to return vapor, not liquid. So if you set it up to return any volume of liquid you may starve the carb for fuel.
Jeep Cj's used a fuel filter that did what you are looking to do, it had a pass through for the gas to go through the filter and a separate fitting off the side for vapor/fuel return. I run one on my CJ-7. I don't know how much gas they bypass but it might be worth a try for the price of a filter.

https://www.amazon.com/WIX-Filters-Comp ... 3109347797
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1964 M151A1
1984 M1008
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Mark
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Re: Looking for this part, Have one for sale?

Unread post by Mark » January 7th, 2023, 8:41 pm

I have a holley carburetor on my 151, A2.I'll post some pictures asap, have alot of snow to shovel1st. The reason I did I read that the holley carburetor was the caddy of carburetors
mark


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1960 m151
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Mark
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Re: Looking for this part, Have one for sale?

Unread post by Mark » January 7th, 2023, 8:42 pm

I have a holley carburetor on my 151, A2.I'll post some pictures asap, have alot of snow to shovel1st. The reason I did I read that the holley carburetor was the cadillac of carburetors
mark


1968 m274A5
1960 m151
1981 m151A2
1964 m416
1971 m416

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Lou
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Re: Looking for this part, Have one for sale?

Unread post by Lou » January 8th, 2023, 5:52 pm

Thank you all for your input on this issue. Yesterday removed the cap from the Holley carb and drilled and tapped a hole for an elbow. Then filled the elbow with solder and drilled a 3/32 hole through the solder. This hole is twice the size of the return hole in the zenith return.
new return and restrictor in elbow.JPG

Here is the finished product.
New return 1-2023.JPG

Concerned that the return hole maybe too large, we took the mutt for a 30 mile test ride, 6 miles of that on the Garden State Parkway. We normally do not drive on there as I hate to drive the mutt over 50-55 mph. So after 10 miles of holding the pedal all the way to the floor the engine never starved for fuel or bucked. Also set a new speed record for the mutt 69 mph sustained. Since we have a tach installed that equals to 3,800 rpm for the curious. You could never do this in the summer as the temperature starts to climb to 190 around 55 mph. :!:

Would never ever run the mutt at this speed or rpm but wanted to ensure the carb would not run out of fuel with the enlarged return. We stopped for 10 minutes and the mutt started right up and did not have the flooding issue we have been having for a long while. :shock:

Now here is the crazy part. After the mutt sits for 10 minutes the fuel filter becomes empty. It never did this before. First thing I thought was maybe the valve in the fuel pump was leaking down, but the fuel was emptying toward the carb. So then thought the needle and seat must be leaking so took the air cleaner hose off the carb looked and felt and no fuel was found in the throat.

Put the hose back on and the mutt started right back up and the filter was full in a few seconds. So the fuel is apparently being sucked back in the tank through the new return. My theory it is being sucked back in the tank by the fuel cooling and creating a vacuum.

A normal mutt fuel system would not do this because of the one way valve in the fuel vent on the tank. It normally lets air in the tank, but not out. I removed that valve so the tank can “breath” and not become pressurized. As mentioned previously vapor pressure build up while off roading was forcing the needle valve to open after engine shut off and flooding the engine.

So for now this appears to have resolved my issue, the real test will be on a summer day when this was a major issue. Hope all this helps someone that has a Holley and experiences similar issues. Another positive benefit is that the plastic fuel filter is not pulsing back and forth like an accordion any more! :lol:
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Louie
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Lou
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Re: Looking for this part, Have one for sale?

Unread post by Lou » January 8th, 2023, 5:56 pm

Rick,
In 1985 owned a 79 CJ5 and it had that crazy fuel filter!
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Hambone
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Re: Looking for this part, Have one for sale?

Unread post by Hambone » January 8th, 2023, 10:23 pm

Glad it worked out for you.

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Lou
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Re: Looking for this part, Have one for sale?

Unread post by Lou » January 8th, 2023, 10:24 pm

Hambone wrote:
January 8th, 2023, 10:23 pm
Glad it worked out for you.
Thanks! :D
Take Care,
Louie
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