Mack engine in 5tons

[dennisallen]

Anyone know much about Mack motors put in 5 tons?i

 

[pmramsey]

The Mack engines were the ENDT-673 of which there were three versions produced over the production years.
#1-had five-ring pistons, 9/16-inch cylinder head studs, and metal bearings in the IP governor.
#2-had four-ring pistons, 5/8-inch cylinder head studs, and Teflon bushed IP governor.
#3-added improved cylinder head and crankshaft main bearings.
The earliest version produced 205 HP with the final version found in the 70s depot rebuilds producing 220 HP.

 

[pmramsey]

The Mack 5-tons were produced 1965-70. Depot rebuilds ceased in 1975.

 

[dennisallen]

We're they very dependable ?
I'm looking at a truck with a Mack engine. It's in a 5 ton dump

 

[pmramsey]

Dependable is a moving target. In my opinion, they were far better than the Continental gas engines and the M54A2 and M52A2 multi-fuel versions of the trucks. Like any other truck engine much depends on the driver(s). The Mack ENDT-s faired best when pushed hard and worked at the top of the designed opening range. They are delightfully simple engines and most of the older mechanics still on the job today grew up on these and the commercial versions of engines.

 

[sandcobra164]

I've driven an M54A1 powered by a Mack engine many times. Quite an enjoyable ride and way more power than a multi fuel powered truck. I've never driven a multi powered 5 ton but I can't imagine it would be fun. I owned a deuce for many years and towed many things behind it. 10,000 extra pounds and 6.44 vs 6.72 gears would seem to push things in the wrong direction. Not sure how I would compare the Mack to the NHC-250 but I do like that the Mack has a turbo and gives something of a familiar sound when pushed.

 

[AMGeneral]

+1 on what pmramsey said, the ENDT 673 was basically a commercial design,modified slightly to meet military requirements.

Dependable almost to a fault,with 1 weakness, they run a flat tappet cam vs a roller cam follower as most "modern" diesels do,and are prone to cam lobe wear.

Having owned several(6+) 5 tons that were or are powered by the Mack, they are an absolute blast to drive,with power to spare and not overly noisy.

1 point pmramsey did not touch on,the ENDT came with 2 different turbos installed,usually(but not always) based on whether or not it was the newer design engine or not.

The video below is a Mack powered 5 ton wrecker with the later style,smaller turbo.
https://www.youtube.com/watch?v=hViTa8h-Y7I&index=17&list=PL2E2B54ADAF9BC71A

 

[wheelspinner]

Wow, power to spare is an understatement it looks like.

 

[acesneights1]

I have an M52a1 with a Mack motor. It was sold to me as a 1974 AM general. I did not get to drive it yet but anxiously awaiting....

 

[acesneights1]

Anyone know the part numbers for the Oil Filters on a Mack powered 5 ton ? I can't come up with anything.

 

[AMGeneral]

Anyone know the part numbers for the Oil Filters on a Mack powered 5 ton ? I can't come up with anything.

Below are all the filter numbers,WIX numbers are indicated,any good parts house should be able to cross them over.

Full flow oil 51133
Bypass oil 51503

Primary fuel long canister 33511
Primary fuel short canister 33080

Secondary fuel 33090

 

[JDToumanian]

Dependable almost to a fault, with 1 weakness, they run a flat tappet cam vs a roller cam follower as most "modern" diesels do, and are prone to cam lobe wear.

Mack engine owners probably already know this, but... Engines with flat tappet cams benefit greatly from engine oils with a high TBN and low sulfated ash content, like Chevron's DELO 100 (not 400) or Shell Rotella T1, in a straight 30-weight. Modern multi-grades, like 15w-40, may not protect these older engine designs!

Jon