Tractor Carbs for Turbos?

[Lazy JW]

We know that carbs used on turbos need to either be used as a draw-through or put in a pressure can to equalize pressures on a blow-through system. Having worked with old tractors for years I know that the carbs on most of them are internally vented for the purpose of having only filtered air in the system. Would these carbs be able to be used in a turbo application as-is on a blow-through system? It seems to me that the internal venting would be like a built in equalizing pressure can. I have no intention af actually doing this but am just curious. Any thoughts?
Joe

 

[addo]

I have no intention of actually doing this

That ranks with "I'm just going to the swap meet to have a look. Not to buy anything."

 

[Lazy JW]

I was hoping that Fiorelli or someone else in the tractor pulling game would chime in. Surely I'm not the first one crazy enough to think of this one I know that these carbs aren't normally thought of in the context of high performance, but they made them in pretty big bore diameters and they fit into such nice, small spaces. Just the ticket for stuffing too big an engine into too small of a space. Like a 300 six in a British sports car 8)
Joe

 

[Fiorelli]

You got your wish! but I'm not much help I'll add my two cents. My uncle wants to try this except with out the turbo to try to get better milage. He is hoping some how the updraft carb will increase his milage. I don't think it will work but why not try you can't learn if you don't try.

I really don't know if it would work like you think or not. You don't have an acclerator valve to give it that shot of fuel to make it come to life. I also don't know if you could find a big enough carb on an old tractor. The gas tractors I have the venturie (sp) is smaller than an inch they would make that stock 300 carb look like a heck of a preformance upgrade. There are lots bigger carbs on some of the gas pulling tractors I run with if you are serious about trying it I can find out how big and where to get them. One of my friends is using a carb off an allson aircraft engine along with the 5.5 bore pistons from one of those engines but it is also over 1000 cid.

The more I think the more I wonder. I'll have to grab one of those carbs and look at it a little closer.

If you have a small turbo put it on the tractor and try it. It can't get any easier or cheaper. I may try that next summer at an outlaw pull on a stock little tractor. Now I need to watch e-bay for a turbo as if I wasn't looking for two for the 300 any way.

 

[Lazy JW]

Thanks for the reply. I'm mostly just curious if my theory is sound or not. I really doubt that there is much practical application for this, partly because of the limited sizes available. But my John Deere Model A has a fair sized carb, and I am sure that the Model D used a bigger one. They had to feed 250 cubic inches per cylinder and the John Deere carbs are true side draft. And when you pressurize with turbo boost a lot more will fit through the same hole compared to N/A. I don't expect an updraft carb will get better fuel mileage as a direct function of the updraft feature, but those fully adjustable main jets might help somewhat (didn't Henry have that feature on his "A" Model?) Most tractor carbs used what is called an "accelerator well" to provide extra fuel on acceleration, it is pretty puny compared to a fully adjustable accelerator pump on an automotive carb, but they seem adequate on a relatively slow revving tractor engine.
Joe

 

[Fiorelli]

I really wonder how big those carbs get. I know of some big NA pulling tractors that have to use an updraft carb. I'll tell you this just to get you an Idea of how big some of these carbs must be. I pull aginst a five star Minneapolis Moline they are a four cylinder tractor mine is a Six cylinder GB Minneapolis Moline. We are both running the same heads He has the right blocks for his tractor orginaly 4.25 bore and I have the 800 CID blocks orginaly 5.319 bore I can run 100 Rpm's faster than he can. He is on gas and beats me everytime. I've heard of some of these fourcylinder engines bored and stroked to 713 CID and running at 2145 RPM's. I don't know if he is that big or bigger but I don't think it hurts much for air. There are 1000 CID sixcylinders he is beating. Very impressive tractor. I am getting closer all the time. I wish he would come out over the summer so I could run aginst him.

I'm mostly just curious if my theory is sound or not. I really doubt that there is much practical application for this

You can't learn if you don't think, ask, and try.

 

[Lazy JW]

I really wonder how big those carbs get. I know of some big NA pulling tractors that have to use an updraft carb. I'll tell you this just to get you an Idea of how big some of these carbs must be. I pull aginst a five star Minneapolis Moline they are a four cylinder tractor mine is a Six cylinder GB Minneapolis Moline. We are both running the same heads He has the right blocks for his tractor orginaly 4.25 bore and I have the 800 CID blocks orginaly 5.319 bore I can run 100 Rpm's faster than he can. He is on gas and beats me everytime. I've heard of some of these fourcylinder engines bored and stroked to 713 CID and running at 2145 RPM's. I don't know if he is that big or bigger but I don't think it hurts much for air. There are 1000 CID sixcylinders he is beating. Very impressive tractor. I am getting closer all the time. I wish he would come out over the summer so I could run aginst him.

I'm mostly just curious if my theory is sound or not. I really doubt that there is much practical application for this

You can't learn if you don't think, ask, and try.

Those Minnie-Mo's must have been bodacious gas hogs They weren't very popular out here but my wife's uncle used to run them. He was always proud of how well they pulled. What model are you running?

Joe

 

[Fiorelli]

The MM engine is accually about the same as everything else on effecency. If you think a tractor has to run wide open all the time even if you arn't working it hard you will use a lot more fuel than if you can idel it back and shift up a gear and that is when you really save fuel over the other tractors. The power is great they were large engines but they ran slow and have a very good torque expecally at the bottom end. I'm pulling a six cylinder GB. We have most of the MM's that were built that we use on our farm, they are slowly being retired from some of the jobs they use to do simply becaues they arn't big enough a 110hp just isn't enough for the tilage anymore but it easily will run the bailer. MM did sell some 250HP small belhousing HD800 engines that were built just for the later tractors but that engine is very hard to find and most MM people would love to have one. Below 1000 RPM's the 100HP MM's will eat our 217 HP Maginum. We have a White with the 585 MM diesel engine about 150 hp it will run right with that Maginum if you are on very hard ground working both tractors for all they are worth traveling about 3.5 MPH where it can get good traction. Do something where you run about 5 to 6 MPH and you can't get as good of traction and the Maginum will easily out pull it.

I'm sure the pulling tractors are lots harder on fuel. The 283's in the U's and five stars and the 403's in the G's are getting over 700CID most about 440 CID that is a easiy build for the fourcylinder tractors. The tank on my pulling tractor holds 4 3/4 gal of LP and we have pulled it seven times at one pull with out filling it up but the engine is still stock.