Marvel carburetor

howie123

howie123

Senior Member
I am planning to try a Marvel carburetor on my speedster this spring. I made one carburetor out of two. I have a question about the GAV. One of the carburetors had a stiff spring, a brass washer and some sort of packing or fiber washer under the GAV nut. One of them had nothing. There was nothing in the gasket set that appeared to fit. Does anyone know what was originally there? Thanks for the help. Howie
 
The marvel is unusual in that it has a "hex" top on the GAV needle. I think I remember a small washer (that the needle sticks through) and a spring.

Spring first in the hole, then washer, then needle going through the washer/spring.

The object of the spring/washer is to act as a sort of "detent" to prevent motion of the GAV unless it's turned by the handle. IIRC, the Model B Zenith carb has a similar spring arrangement which can be seen at Vince Falter's site at http://www.fordgarage.com/pages/bcarbassembly.htm (the Model A Zenith has instead it's GAV bushing with it's "fingers.")

I don't remember any fibrous washer or packing, but it might make sense that the GAV Bushing/nut should be gas-tight. Maybe pass on the packing and use teflon sealant or Permatex No. 2 where the bushing screws into the body?

As to leaving the spring/washer out? I suppose this is OK as long as engine vibration doesn't make the GAV needle move. Likewise, a prior owner of the carb may have found adjustment at the dashboard to be too hard - and removed the spring/washer.

Play around with it. This is something you can do in idle moments when you've eaten your ice-cream and waiting for the girlfriend to finish hers.

Wimmen love the smell of gasoline on a man's hands.

Joe K
 
Play around with it. This is something you can do in idle moments when you've eaten your ice-cream and waiting for the girlfriend to finish hers.

Wimmen love the smell of gasoline on a man's hands.
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That is pretty funny! :D
Thanks for the rundown Joe K.
 
Ichecked one of mine and there is a spting under the nut but no washer or packing. I haven't tried either of these I just stuck them on the Vortex intake for tie pic.

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Thanks for the information. I have the carburetor installed, just need to connect the fuel line. I will probably try it without the spring first and go from there. I will post an update when I get that far. Purdy, I sure like the looks of that manifold. Thanks again. Howie
 
Thanks Howie. As usual, I mostly agree with Joe K , except the part about the wimmen loving the smell of gas on a mans hands. That was a good one though. I figure you will need the spring but it will be easy enough to put back if needed.
 
Hi Howie

I took a some pictures of an unmolested Marvel carb. There is a felt washer/seal at the end of the GAV. The brass washer and spring apply pressure on the felt to form a seal for the GAV.

Jeff
 

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Interesting that MS GAV has a "key." The ones I've seen have a "hex."

See Purdy's pix above. The hex is visible.

Do you have the driver and can you show the inside?

Joe K
 
Interesting that MS GAV has a "key." The ones I've seen have a "hex."

Do you have the driver and can you show the inside?

Joe K
_
Click to expand...

Joe

I have one in the car and this one, each of these have a keyed GAV. Just put things away but I'll dig it out and get a picture.

Jeff
 
Joe

Here are a couple of pictures of the MS keyed GAV driver.

Jeff
 

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Aha. I see they have inserted a "pin" to catch the groove in the GAV needle.

DON'T lose that driver. It probably can't be duplicated except by exceptional means.

The hex driver reproductions are sold on Ebay and at Renners and they want $40 each.

And thanks for the look see on the Carb GAV. I have two of the MS carbs, one I've looked at (as reported) the other still barn virgin.

Joe K
 
I have 1 in my collection of 10 marvels that has the strange needle on it like Jeffs picture in post #8 . I will need to look closer and Take more pics The one with the strange style needle is the only one that won't turn. I removed the nut, needle and spring on the front carb pictured in post #5 there was a spring that came out with it. The carb was mounted to the manifold and may have the washer and packing still in the carb . I was a little quick with my inspection and should have checked a carb that was loose and shook it upside down, the washer and packing may have fallen out, then.

I don't know if the carb with the different needle is a canadian model or if it is just a later version. My first thought was that somebody had fitted it out with a Zenith GAV needle. I remember Ben Neiman talking about such a conversion on the old barn.

Except for the missing fuel line fitting, mine mostly looke like this, better when they are cleaned up.

4870916-T400300.jpg
 
I run the Marvel carbs more than any other carburetor in the sixties. Back then we didn't worry much where the GAV was set. I just put it where it run best and left it there all of the time.The biggest problem that I had with the Marvel carbs was stripped threads at the mounting flange. Ijust got back in from the shop. I checked five more of my Marvels and they all have the springs under the GAV nut but no washer or packing on any of them. It makes sense the purpose that the washer and packing would serve but five out of ten of mine definately doesn't have them. I Will check the others tomorrow. I've got one that I tested on my september 29 and it ran good and didn't leak, it doesn't have the washer and packing either so I figure that the washer and packing isn't necessary. I figure that the spring is needed to hold tension on the needle so it will hold the adjustment..
 
Heh. You make me feel sane, Purdy. It's been a while and while I noticed the spring and washer, I never saw a fiber or soft washer. One wonders if it got missed in my haste.

I checked a few of the Marvels over on ebay. There are a couple of straight/grooved GAVs over there too. On pretty good looking carbs - like maybe Marvel's newest stock? Older looking ones seem to have the hex.

Now if someone like MrTexas could dice up a Marvel and figure it out.

Well, it's not like there is a shortage of Marvels.

Joe K
 
If you could take a picture for posterity - it would aid the hobby. Just looking may reveal how it was done.

Right now the hex driver is available - but at a price. The GAV needle in any style is not available but the GAV hex bushing (with threads to match the Marvel GAV) IS.

9467173.jpg


From Renner's Corner.

Joe K
 
Joe and Jesse , It appears that both styles of the Marvel GAV needle are interchangable and will thread into the common Marvel GAV bushing-nut. The needle drivers are not interchangable . Both styles of Marvel GAV needle is different and longer than the needle used with the model A Zenith carb. When I first saw the different shaped needle , I thought it was a conversion with the Zenith needle untill I looked closer. I think that Ben Neiman used both the Zenith needle and needle housing in his conversion. Ben also had a conversion to use the model A zenith GAV assembly on the B carb.. Deb worked late and hasn't taken any pictures yet. I was about to go back out and bring in parts for pictures but its storeming outside right now .
 
Well just to chime in, I have a marvel that came off a parts car I own, it has a hex GAV needle with driver. While taking it apart for cleaning, it does have what appears to be a thick felt washer at the base of the housing. I'm assuming they came with these, and over the years weren't replaced. Apparently they aren't absolutely necessary.
 
Jesse, The storm passed without any harm here. I really enjoyed the sound of the rain on the roof, last night.

It sounds like your carb is good. I would run it. I will try and put some more pictures up maybe tonight when we get home. I've got parts layed out. I've just got to get the pitchers took and stored where I can post them. As far as the hex style GAV needle, I think with a little grinding work a Zenith needle driver could be used. Later, Purdy.
 
This isn't much to add but here is a pic of the hex drive needle at the top , the round drive with slot needle Is second and the Zenith GAV needle at the bottom. This shows the difference in design and length of the needles. The top two are interchangable with the marvel carbs but the needle drivers are different. In other words the needles and drivers need to be a matched set. The Zenith needle is too short to use as is on the Marvel carb. There may be a way to fit the zenith needle housing, needle and driver to the Marvel carb . I'm going to be looking at possibilities with some of my stuff. I got this gasket set a few years back I would think that this kit is still available, somewhere. Mikes Affordable use to, maybe still sell rebuilt marvel carbs exchange. Mikes in Georgia or Smith and Jones in Columbia SC. are both worth a try for gaskets and maybe some parts.
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