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[TJones]

I was thinking the same thing LarrBeard after measuring but I didn’t want to send it out and have it done then have to trim it up later after it was powder coated.
As far as the motor, he sent it down to get it line bored, decked and bored the cylinders 30 thousandths. He’s changing the pistons to flat tops and putting a bigger cam in it, Not much change to the motor other than doing it right this time.

On a another note:
I’m running 538’s in it now, a friend said the overdrive will change the 538’s to 373’s does anyone know if that’s correct or does anyone know the formula to the conversion?
Seems like a big jump to me.
It’s a Warn OD.

[LarrBeard]

On a another note: I’m running 538’s in it now, a friend said the overdrive will change the 538’s to 373’s does anyone know if that’s correct or does anyone know the formula to the conversion? Seems like a big jump to me. It’s a Warn OD.

I’m running 538’s in it now, a friend said the overdrive will change the 538’s to 373’s does anyone know if that’s correct or does anyone know the formula to the conversion? Seems like a big jump to me. It’s a Warn OD.


I looked at the description of the Warn OD in the KWAS catalog and it is described as a 25% Overdrive. The question is "What does that 25% mean?" If I go back to the '48 Mechanic's Manual and look in the overdrive section, the description of the Borg Warner OD is "When overdrive is used the engine speed is reduced about 30% at speeds over approximately 30 mph". (In this case 30 mph is where the electrical governor kicked in, but this would be when you shifted manually.

I would assume that the Warn OD, being a 25% OD, would give you a 25% reduction in RPM for a given road speed - or the engine will be running at 75% of its original rpm for a given pace down the road.

I'd multiply 5.38 x 0.75 to find the effective drive train ratio - and when I do that I come up with a number close to 4.035. Not the 3.73 your friend predicted, but still a significant gain. I would suspect that OD will be the predominant driving mode.

[bmorgil]

[I]I'd multiply 5.38 x 0.75 to find the effective drive train ratio - and when I do that I come up with a number close to 4.035. Not the 3.73 your friend predicted, but still a significant gain. I would suspect that OD will be the predominant driving mode.

That's the formula to use alright LarrBeard.

TJ, we had a little discussion about this before with Kmorris. https://willysjeepforum.kaiserwillys...ight=overdrive