How's It Gonna Pull:

[Rob]

Now I'm gonna ask a question cause I have no experience.

Here are the givens:

1962 Mack B-67ST.

Somewhere between 5.73 and 5.77 ratio rears.

Nine speed overgear transmission.

END673T series engine, (looks to be 1966 vintage due to casting dates).

11RX22.5 tires.

What kind of road speed should I be able to maintain on the flat pulling a 13,000# trailer, with about 30,000# on the deck, (antique trucks)?

I have no idea as to horsepower of the engine but surmise it's about 225-250.

Thanks,

Rob

[Lmackattack]

looks to be geared for 55-60MPH depending on the overdrive ratio. HP in that range will pull fine on the flats but you will be downshifting in the hills. the 250 HP thermodynes did good for there time but the maxidynes soon took over.

[Rob]

looks to be geared for 55-60MPH depending on the overdrive ratio. HP in that range will pull fine on the flats but you will be downshifting in the hills. the 250 HP thermodynes did good for there time but the maxidynes soon took over.

Supposedly it will run 65 empty. I'm wondering if I'll be able to keep up to 60 with a load on....

Rob

[Lmackattack]

My B model with a Quad and 5.73 is geared for 62MPH. I think thats at 2100RPM. I could likely get 65MPH @2300 but its never left the yard! LOL

Trent

[b61fred]

I think you will be shifting alot and slowing down on hills when loaded like that.

[theakerstwo]

Rob i am almost sure that the ENDT 673 is a 205 or 211 HP. Now the ENDT673B is a 225 and the C is a 250HP. the B and C is a complete different engine than the ENDT673. The B and C will have different head and block with piston cooling nozzles. The engine you have will not have the piston cooling nozzles and it should have 18 heads bolts instead of 20.I think if i am right the 18 will be 9/16 and the 20 head bolts per head will have the 5/8 bolts. The will be studs and nuts on both engines. I think the cap screw head bolts came out after the maxidyne was introduced in 67.I am going on my memory and have no old manuals no more.The oil pressure regultor block on the side of the block will have 2 regulator valves in the B and C were the ENDT only had one regulator in it. There was a ENDT 673 but i have never seen one so i dont know what it is but i would think it is in the B and C family.

[Rob]

Hoping to drive it again this weekend. Kicked a couple of cars out this past week and having some time free up. I received the "O" ring and gasket kits for rebuilding the cooler so took the old one apart this evening although it did not leak with testing. Pretty cruddy in there so leaving it soak overnight in the washer. Will pressure wash it clean tomorrow and rebuild, then pressure test again. I've still not been able to get the old cooler apart that was originally on the engine.

I have about 15 gallons of clean drain oil that will be used to verify the coolant in the oil problem goes away. Also bought a box of Cascade soap as suggested. If the oil contaminates again, I'll pull the pan and do the pressure test as has been suggested. I've not pulled the compressor lines loose as they are very stiff and sure to break with disturbance. A good portion of the lines on the engine are replacements. What are original are very stiff and will need replaced before the truck operates much.

Don't mind getting someplace slow with this truck's anticipated usage, just want to get there. I have more powerful engines around here and will use one if need be but I'm not sure if I'll keep this one or not. Too much belly, not enough cab syndrome. Big feet get in the way too with the cramped cabin.

Rob