Allis Chalmers 301 injectors

The pump guy should Match them to your pump

What is the stock pop psi?

Heed what the good doc sez, I say that a lot...  we did this back in the 70's in farm stock pulling.  There are 3 AC inj tips - the 180   xx218  the 190 x044 and the 903? tips (last 3 part digits w/o looking then up.  However I would take a different route - I would go with the late BOSH injectors. You are going to have to atomize the fuel as much as possible because you will suffer from lack of O2 to burn it.  AS your rpm drops , so will air flow unlike a turbo engine. As your rpm drops the torque will increase but HP doesn't. At this point if you want more torque you will have to have more 'air'.  This will have to be accomplished by more cubic inches ,  a better cam grind, porting of the head and a  scavenging exhaust system .   You can do thousands of dollars of work here to gain just a few horse power.  There have been reports of 185's set at 100 pto hp - I have never seen it - I think Doc will agree - it ain't happening.  IF I were to attack this again I would get a set of bosh injectors and lines as in a early 6080 or F3, let Ed rework the pump-match the injectors to as high pressure as possible (think bust up that fuel this thing is not turbo'd)  stock pump -  and get the CAM reground.  You need quicker lift, more lift, a cam grinder knows this stuff when you tell him your use.  Cut the parasitic loss - water pump hyd pump just use a single gear pump for ps and pd  and do some mild head porting  .  Then do some dyno testing as to fuel pump timing with some cetane  (sp?) booster.  Anyway to get more O2 into the intake the more hp as the rules allow hint hint...

The Bosch brand injectors would be the best choice, agreed. On the late great 8000 series, their pressures were set up as high as 4300 psi. I don't think the baby RoosaMaster would like that number....3300 is better.  This would be a great place to experiment with my under the hood 4bbl Holley carb dialed in to use methanol. I have felt that this would vaporize in the airstream enough to allow a good burn when the diesel fuel starts the fire. I know spraying methanol into the airstream doesn't work on NA engines like it does on turbo engines.

Right now on 18.4 28’s it’s around 2.9 mph according to a speed board. Way too slow. Pulls great but never gets to use any power. 3/4 of the track then blow the tires off. I’ll have to look into those late style injectors. 3300 psi sounds like a go then

we know for a fact that the set up with the bosch nozzels results in more economy, torque, and better starting. Doc has an intriguing ideal of putting a non restrictive large 4bbl carb on top of the intake running methanol - pluses are a cooling effect on the air stream, extra slow burning fuel over what diesel  is supplied - a dyno and some work would be a fun ideal to experiment with.  Pullers in the 70's used propane or other gaseous fuel - even O2 in the intake before it was ruled out.   There were some pretty good rumors of hidden nitrous oxide supplies that would be unleashed at the end of the run that gave one a sudden push  from us bush pullers to the big boys....  btw we ran 18.4 -30 that held 3th gear sometimes 4th (2nd high) in the 7000 # class with just a turned up pump - and 4th gear after some engine work - cam, 190 injectors.  9000# class 3d gear even with 23.1x26 a size that was std and allowed.

Edited by tbran - 22 Feb 2020 at 10:23am

So the Bosch uses its own nozzle I assume

Ed, it has great power. The engine is 300 hours off a fresh overhaul so it’s healthy. I spoke to you about a month ago about it. For sure need to feed it some more fuel though, the pump is turned up and it doesn’t even haze out the exhaust. I am gonna build a custom intake set up and an ice box for it. Won’t be like a turbo but I’m gonna do all I can to eliminate restrictions and feed it all the air I can.

not really. If your going to get rid of the seats so they don’t fall out might as well fill it with a bigger valve 2 birds with one stone. Don’t think it’s necessary is all situations