carb question

carb question

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By tarheel - 15 Years Ago

Hey Guys:

I've been following several topics on the technical forum and must say that I'm impressed by the knowledge of Y-Blocks and mechanics in general. Hopefully someone can help me with my question.

I have a '56 Victoria with a 312 that I would like to update with a later carb and distributor. I have a "B" intake manifold and a rebuilt '57 distributor from Auto Zone, and I've come across a Holley 4150G from a '60 Ford truck with a 292. However, the carb has a governor on it and a manual choke. Can the governor be removed and the carb be fitted with a electric choke? The carb is cheap, looks to be in really good condition and money is as tight as always, so I'm hoping that it can be done. Any information will be appreciated.

Larry Fuller

By joey - 15 Years Ago

tarheel (10/22/2010)

I did the opposite a while back with the Holley 4160 on my 312, went from electric to manual choke. Anyway I know Holley sells both electric and manual choke conversion kits for their carbs including the 4150s, they can be bought brand new for about $50 plus shipping. You need to tell them if your vacuum source is external or internal.

Regarding vacuum, you may have already incapacitated the governor function in changing the distributor setup from what was originally intended. I think the 4150G was often used in medium sized trucks, and so the spring inside the secondary housing may be of a higher tension so as to delay the opening of the secondaries when fitted on a heavier vehicle. If I read you right you may want them to open up sooner, and so want to go for a lighter spring. There are spring kits available online or at auto parts stores and they are relatively cheap.

Hope this helps a little. BigGrin And yes, the folks here are ridiculously smart and can probably explaing things a lot better than me.

By tarheel - 15 Years Ago

Thanks, Joey. It sounds like I can use the carb without much problem. When you said that I may have eliminated the governor when I changed the distributor from original, is that how the governor worked, by changing the timing advance?

Larry

By Y block Billy - 15 Years Ago

I don't think you want a truck governed carb. They work on vacuum only, not to say it won't work, but the primary throttle plates work from vacuum also. If you hold the carb in your hand and turn the throttle lever the plates don't move, you have to have the carb on the car with vacuum for them to work. Its a matched set with the distributor and is better to stay with the distrbutor. If I remember correctly the Idle screws are in the rear metering plate instead of the front.

By joey - 15 Years Ago

tarheel (10/22/2010)

No, the governor worked by vacuum. What I meant was that the governor was originally set up to work off the vacuum line of a particular distributor. Now that the distributor is out of the picture, the governor function is probably disabled, which is what you're wanting. Beyond that, there are mechanical things you can do to make the secondaries open quicker than was the case when that carb was on a heavier, slower truck. A lighter spring is certainly one. If there was a vacuum line to the secondaries housing from the governor, maybe that port could be blocked off. Or, if it had a check ball in the secondaries housing, which some of them did, you could try it without that to see if that encourages the secondaries. You may have to do some tweaking.

By tarheel - 15 Years Ago

Joey:

Thanks for the information. I looked the carburetor over a little more closely and it sure operates differently from a regular carburetor. The primary butterflies are spring loaded to stay open, not closed. If the linkage pullrod is held in the closed position it holds the primaries closed, but if you pull the linkage rod back you can still hold the primaries closed. (I'm assuming the primaries are in the front part of the carburetor, even though the idle screws are in the rear metering blocks like you said.) So you are correct that both the primaries and the secondaries are vacuum operated, although it appears that vacuum holds the primaries closed and pulls the secondaries open. I'm guessing that when the engine is running and the throttle is opened, the springs open the primaries as far as the available vacuum (and the throttle linkage's position) allows.

A lot of motorcycle carburetors use a similar principal to operate the slides in their carburetors. We used to call them altitude compensating carburetors because the slides would only open as much as the available vacuum would allow, maintaining good mixture control at different elevations. They worked well and it's interesting to think I could use this carburetor in the same manner (I live about 3500 feet above sea level), but I think I'd better just get a regular carburetor.

Thanks again for your help.

Larry Fuller

By joey - 15 Years Ago

tarheel (10/25/2010)

I think I'd better just get a regular carburetor.

Yeah, I tend to agree, at least from this distance.

I know some folks don't like to go the ebay/hemmings/craigslist route, but I have found if you keep your eyes open you can often find a pretty good deal. Or you might be able to get a lead from somebody on these forums. I had a nice 390 cfm Holley 4160 that would have been fine on a stock 312, but I traded it. I know that doesn't help you right at the moment, but the point is there are a lot of guys out there who could probably help you.

By Y block Billy - 15 Years Ago

Believe it or not I tried one of these truck carbs on my car with the matching distributor, it was the strongest carb I have ever run off the line, I mean stomping on it rolling down the road it would start baking the tires or slipping the clutch, but the 3800 rpm cutout just wouldn't do along with the richest jets I have ever seen in a carb fuel would run out the exhaust and it wasn't very economical, but strong off the line I have never seen nothing like it.