allis chalmers 262 compression ?

[Anonymous-0]

I was reading on the tractor data web sight that the allis chalmers 262 gas and diesel engine both has the same bore and stroke, yet the diesel is 14.1 compression and the gas is 8.1.Can someone explain to me how this works?Thanks in advance.

 

[r aiken]

The combustion chamber in the head is about 1/2 as big for the diesel as the gas engine.

 

[steve(ill)]

yep, you know how you raise compression in most old motors, mill the face of the head.. same as the B-C motor, makes the combustion chamber smaller.

 

[Anonymous-0]

I have 45 diesel (230) that I pull with my problem is that I can get plenty of fuel to the engine but I can't get the air to the engine (must stay non turbo). I do not think that there is room for larger valves in the head the way the head is set up right now, could head work be done that would allow for direct injection (remove the combustion chambers in the head completely) like the 301 and then use pistons made for direct injection? Would this allow more air flow and bigger valves?

 

[steve(ill)]

dont know that much about the 230 diesel. i think i would first look at the intake and exaust manifolds to see if porting and enlarging can be done to help. Your theory on the direct injection sounds good, but your past my knolwedge on that specific motor.

 

[Chris (swIA)]

The compression ratio can be changed by moving the wrist pin. Lower the wrist pin in the piston and the compression goes up without changing the bore or stroke. That is how the compression ratio increased from the WD-45 through the 170. Same engine. Just higher compression and higher rpms to get more horsepower.

 

[TractorNutt]

I see there is a nice set of injection lines on ebay #1904-3404-9934 for a Buda WD45

 

[Brian Jasper co. Ia]

The main difference in the 262 gas to diesel is the piston crown height. Both heads are flat. The combustion chamber is in the area between the piston and head. A diesel piston rises .002 to .029 above the deck of the block. A gas engine piston stays about 1/4" below the deck. Milling a gas head has no effect on compression. Milling a diesel head would have a minimal effect. What helps most is having a new valve and seat installed. A valve seat ground deep into the head lowers compression.
Doing port work on the head will help. The intake manifold flows poorly at best. Spend some real time opening the manifold up and remove the preheater. I saw a 45D pull 61hp on the dyno once. The owner stated he had built up the manifold runners with brazing rods to enlarge them. It also had a custom cam.