The Ford Barn - View Single Post - 3.54 Gears in a 32-34 rear end...

JSeery · 04-19-2017, 05:55 PM

You are not turning that many rpms at 55 mph! It is not going to hurt the engine!

rpm = (mph X gear ratio X 336) / tire diameter

(55 X 3.78 X 336) / 28 = 2,500 rpm

(55 X 4.11 X 336) / 28 = 2,700 rpm

(65 X 4.11 X 336) / 28 = 3,200 rpm

If any of these rpms levels are going to hurt your engine I would be looking for a new engine!!

04-19-2017, 05:55 PM	#33
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 3.54 Gears in a 32-34 rear end... You are not turning that many rpms at 55 mph! It is not going to hurt the engine! rpm = (mph X gear ratio X 336) / tire diameter (55 X 3.78 X 336) / 28 = 2,500 rpm (55 X 4.11 X 336) / 28 = 2,700 rpm (65 X 4.11 X 336) / 28 = 3,200 rpm If any of these rpms levels are going to hurt your engine I would be looking for a new engine!!