Carburators

[Ohio-H]

What is the difference between the E4 and E2 carbs, which one is better for a 300?

 

[BarnyardEngineering]

IH used the same carburetor body for the 300/350/400/450 tractors. Basically the same body as the Farmall M. Honestly I have not heard of them referred to as E2/E4, so I couldn't tell you which is which.

I'm not familiar with the internal differences, if there are any, but I would imagine that one has a smaller venturi for the smaller engine displacement. That would be the one to use on the 300. The larger venturi may cause running issues due to low vacuum and insufficient fuel atomization.

Remember we're talking about a 70 year old tractor here, not a drag car. The chances of there being any discernable performance difference between the two is in reality, slim to none. It's not like one carburetor is going to have twice the HP of the other.

So maybe, the answer is more pragmatic: The one that's not leaking and makes the tractor run best.

 

[used red MN]

What is the difference between the E4 and E2 carbs, which one is better for a 300?

I have never heard of such a designation, do you have more details about what they were used on originally?
Had this typed up last night and didn’t hit Post.

 

[Ohio-H]

It appears to be a slight difference in venturi size, I didn't know if there was any difference. That number is stamped on the neck of the upper half of the carb.

 

[used red MN]

It appears to be a slight difference in venturi size, I didn't know if there was any difference. That number is stamped on the neck of the upper half of the carb.

Is this information from a tractor puller? They might know (or make up things) that the normal IH mechanic knows nothing about. Unless it is a modified engine with a big cam and trick rocker arms be spun way up I doubt there would be much need for a carb that is something bigger and better than stock.

 

[Ohio-H]

It appears to be a slight difference in venturi size, I didn't know if there was any difference. That number is stamped on the neck of the upper half of the carb.

I stand corrected, the letter prefix is "S" .

 

[Ohio-H]

S-2

 

[D Slater]

What is the difference between the E4 and E2 carbs, which one is better for a 300?

IH used E-12 designation on some of that body size Carburetors. All not exactly the same. Use the carburetor number found on small round piece near were throttle tube bolts to carburetor. Gasoline number would be 361525R1 or R2. All R1 were supposed to be recalled early on and changed to R-2. Some didn't. R2 used on 350 also. Those carburetors have a 25/32 venturi if I remember correctly. Depends on what you want to do as to best. You can get carburetors or changes to those to flow more air and fuel but most times need engine changes to benefit. E-10 was used for H carburetors.