105 octane gas

I have a Farmall H that I use only for pulling, its seems I am about 5H.P. short when I am pulling. I am always running short of power when I am hooked up. I have a cam grind and I am running about 2400 RPM's and I was wondering if 105 octane gas would help me out in the H.P. dept. Chad S I know you do a lot of pulling and I was wondering what your thoughts are. The sled we pull is a hard pull and it also gives you a lot of traction.

how many pounds of compression do you have?


Andrew

140 to 150

Octane doesn't give you a power boost, it allows you to tune the engine more aggressively for more power.

If you go 105, you could probably dial in a degree or two more timing, which might help you on the power front.

Mix in some E85 with your pump gas. At 150 psi, you can mix in a quart of E85 to 1 gallon 93 octane pump gas and pick up 2-5 more hp. You will have to retune the engine, mainly timing adjustment, and a bigger jet in the carb if you cannot back the main load adjustment screw out and make it run rich now. If your pulling it to its knees, then you need to think small on the carb venturi, a #25 will be good to enhance low end torque, a 27 for more of a high rpm setup. (if your running the M style carb) Dont worry about the E85 and the carb parts, it wont hurt it. Timing will be a bit more retarded once the E85 is dialed in. A #23 venturi will help the best for low end torque, when you run rpm, you do need more air to flow, but thats not whats going on here,, your lugging way below, even below rated rpm 540, (1815) so if your running it way down, you need to tune it on the dyno under 540,, but no lower than 400 on the pto speed and tune it to get the best results. Your tuning it on the wrong side of the rpm spectrum, where the high rpm is good for bigger, more powerful engines that can manitain the rpm, all your looking to do is enhance your low end pulling torque by tuning it for the lower rpms to make it live a little longer. It could go 2 inches farther, or 10 feet farther, depends on how much you can improve the low end torque curve. ChadS

We do have a M carb do not know the venturi size but have have drilled the main jet so we are able to get plenty of gas