MH 44 EFI Tuning day 2

David G

Well-known Member
I ran the tractor about 3 hours tonight.

It is a lot easier to tune with the dyno, I set it at an RPM, then started loading it up. The auto tune took about 5 minutes at each step to get it right. I then move to the next RPM range and do it again

The timing tables I loaded make it sound quite a bit better, and the throttle response is also.

The engine runs out of snot right at 44 HP, adding fuel does no good at that point. I did not check to see if the governor opened it all the way up, so will do that next time. If it is open, I will remove air cleaner and see if that makes a difference. The next step after that would be to bore out the throttle body to the next size throttle plate I can get. I am thinking a JD 3020 might be a good fit.

The good news is that I am only up to 10ms second on fuel at full load. I would like to go to sequential injection so I can balance the outer cylinders to the inner ones on fuel. A siamese intake will always run one pair of cylinders leaner than the others. I have about 16ms of total fuel time with the cam that is in it now, so I have a little safety factor. Does anyone know if the 44 special or 444 had a different grind cam?
 
The late 44 and 444 gas, kerosene, and LP had the same cam, part # 760 180 M1. I'll try to find the MH cam spec sheet chart I have, but all it listed was the open and close specs if I remember right.
 
Just curious what is the throttle body bore now ? I would not think a tractor engine would be turning enough rpm to need a very big throttle bore , as generally smaller bore means higher velocity for the intake charge and better low end torque . A bigger bore throttle body would definitely allow higher HP for a high rpm engine , but could mean less low end lugging power . I am curious to see how this aspect plays out in your project. The Zenith carbs used in the old F-Series Farmalls had several different venturis for use depending on application and I have wondered about swapping different ones in the same tractor to see the results.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top