Mack 300 engine.. pros and cons?

[krismoriah]

I am double posting this in another section.. I have to move fast on this deal on a truck im looking at.. just trying to get as much info as i can before i purchase.

I just got a call about a 1980 superliner dump for sale. Talked to the guy says it has a EM6 300 that was rebuilt. Says it has pictures of a bulldog on a rebuild plate on the engine. Says it has a 13 speed road ranger with 4.17 mack rears. Radiator is leaking pretty bad..dont know how much that will cost..if i can even find one.

Are the EM6 300 motors pretty good? I have a 1995 mack 400 and it does really well.. just wondering how gutless this truck will be in comparison...?

Seller says it will do 85mph no problem. but its the hills that I have to haul that i am wondering about.

Will be packing 25 ton regularly. Just wondering if this 300 engine can handle 77000lbs up hills without falling on its face.

[GearheadGrrrl]

1980 sounds a bit early for a "300", it might be a 285 HP Maxidyne or 315 HP Thermodyne. Neither engine has given anyone much in the way of problems. Performance at 77k pounds should be adaquite, though crusing speed is more likely to be 65 than 85. And you're right about the radiator- better find out what a replacement will cost before buying the truck. Best of luck!

[Rob]

Last month I had a new copper and brass five row radiator built for my R795 and it was right at $1400.00. This used the bolt on tanks top and bottom.

All of the engines in that timeframe were good in my opinion. The "300", and the 300+ engines were just getting to the point of being a very good balance of power and durability. Much more power and the lifespans were shortened, especially with a hired driver.

Rob

[EWB555]

First truck I ever drove was a 78 R Model with a 300+ and 2 stick 6 Speed. I would say power was good for what it was, especially since it had that tiny intercooler box. This one may do better with the 13 speed, but given that its geared to run 85 I'd say its not going to pull too well. The truck I drove would run 63 @2300. My 1995 E7 400 (when its not in derate mode) runs SIGNIFICANTLY stronger, and its only geared to run 73.

[krismoriah]

The engine rebuild or swap might have replaced whatever engine was in it with a 300. Owner says it has no jakes which is not going to work for what the truck will be doing on a daily basis. Called up a friend who has a 300 mack with jake heads, new fuel pump and turbo for cheap..so that fixes that problem. The guy with the engine says he has run 300 macks for years and he could leave 425 cats and 400 cummins like they were standin still on the hills... but you hear alot of those stories. I think a good game plan is get her going for pretty cheap and work her on a daily basis until something major goes wrong with the engine.. she will pay for herself in a short amount of time... then repower with a 350 later on..