En-401 & En-402

[DMorgan]

Hey, I just got the build sheet on my 1963 B-421 "S" & it says that the engine is an EN-402. The serial tag is gone off the engine so there is no way of telling if it has been changed out or not. Anyway my question is whats the difference between the mack EN-401 & the EN-402? I always thought that all B-42's had En-401 engines in them. Thanks for the help, Daniel

[bullhusk]

D.B.Macks, I'm pretty sure there the same motor 4 1/16 X 5 5/32 150 hp @2800 an 330 @ 1400 torque. Don't know why there one digit off. Ernie

[Speed]

And my EN354 has even less power. Fortunately,with its 6.86 axle,it pulls a load okay,unless I want to go over 35 mph.

Speed

[Maddog13407]

most of the en401's and en402's had the option of an oil cooler. only main difference was 2 more added head bolts on the en402's on the outside left corners, front and back. as someone else said, barely enough power to drive a truck around empty let alone loaded, and if you got 80,000 miles out of one, you were doing good. ~Matt

[Yoos Brothers Construction]

most of the en401's and en402's had the option of an oil cooler. only main difference was 2 more added head bolts on the en402's on the outside left corners, front and back. as someone else said, barely enough power to drive a truck around empty let alone loaded, and if you got 80,000 miles out of one, you were doing good. ~Matt

In 1971 somebody solved the no power problem in my 1959 B-421. They took out the EN-401 and replaced it with an EN-414[AKA Chrysler 413 industrial V8], which means more power and less gas mileage , Josh.

[Speed]

Josh,what kind of mileage would you have expected with the other engine? Mine has a best of 7.1,flat towing my '62 Chevy one ton duallie loaded with spare parts,but that was relatively flat 4 lane,and I discovered later I was only going about 40 mph-my speedometer was waaaayyy off (Showed me averaging 55),and the noise in the cab,square tires,rattles and squeaks,gear noise etc. mis-led my senses at telling what I was really running at.

I still seem to get quite a lot of driving out of a tank of gas though,even just moving stuff around locally . I pulled an old 40 foot fifth wheel RV trailer about 15 miles yesterday,and figured out if I can work up enough power,I should be able to run 60-65 mph,without crowding redline on the old beast. I was clocked by a friend on this job at 45 on flat ground,at 1800 rpm,so using that info,and my changing from 9.00-20's to 10.00R-20's when I get it back to town,should get me the 60-65. Re-sealing the Brownie and axle pinion yoke,filling the boxes with a little lighter oil,and fixing the brakes so I'm not fighting 2 dragging brakes will help a lot too.

Speed