Mark T

Some older Diamond Ts used that cab, I think Hendrickson and maybe even a couple others.   How about that repair on the cab corner ???  Pretty nice work (along with the rest too)

Sounds like what would be called a blown head gasket from combustion passing by it .  

Why is the head off it and what damaged the liner ?  Not much of a chance of it ever sealing as it should with the liner damaged, no matter what fire ring or gasket.....and why is the liner damaged ?????

Those trucks have IH  Comfo Vision cabs (or some name like that)  Used by Diamond T, but not REO

4 hours ago, Vladislav said:

The thread turned out as an interesting discussion and I heave read it whole to this point but still don't see the answer to the matter of ability realizing the Maxidyne concept.

I understand the lower RPM torque rise was done by fuel and turbo settings. That's fine, Ok, the engine would pull at 1000RPM. But to me it's nothing else but extreme lugging. You add fuel and add air to burn it out and the engine pulls. But I can't figure out how the crank and the block withstanded those high stresses and a similar made Thermodyne could not? Or Mack engeneers just used the actual sturdiness of the components which could work for Maxidyne but just were not stressed up really much in Thermodyne version?

I could be wrong on this, but I think some of the old Thermodynes had hollow crank throws. (along with no oilers)  As the Maxidyne evolved and horsepower went up there was some kind of update that added bracing from main cap to main cap.  So much got better and better over time. Another thing that was huge in accomplishing all this was higher injection pressure (made by a pump that could have a life)  

659  

6 hours ago, 67RModel said:

That is kind of nuts when you think about it. Could you imagine the carnage if you flipped the switch to engage Husky Drive and for whatever reason only one of the differentials went into high range? Were they air operated or electric 2 speeds? All the 2 speed Eaton "Double Duty" axles I drove in medium duty ford F700s were electric and I remember several 2 speed motor failures. 

(lol)   I have a '21 Peterbilt with the same set up, except I use a 10 speed 

7 hours ago, fjh said:

When the E9 was introduced I was offered in a 400 hp maxidyne Version there was no change in oil pressure no physical changes to  the engine other than the fuel pump and turbo! These would pull there asses off right down to 1000 RPM you could use a 9 speed transmission  behind them ! I believe that they did away with this concept for emission reasons due to the smoke! (opinion)  If they had VGT back in the day imagine the power and fuel efficiency if they were able to dial up the air to burn that extra fuel properly !  As soon as they dropped the use of maxidyne they increased the RPM and HP to 440 then 450 then 500 all had a far less rpm  range and had to have a multi speed trans to keep them in the zone for power and efficiency! That said The maxidyne  theroy only worked for a bit longer In the E6 Lineup for a few years after this before they converted to  econodyne  again the engine needed  the multi  speed Trans and the higher RPMs because of the smaller working range ! All of these changes were all gifted to us By the What is now Known as the EPA !

just a mix of observation and opinion!

I had 2 MP7s   one was a Maxidyne and one Econodyne.  Far as I know it was only a software difference One was a 395 and the other a 405.  Those little engines were sorta like you suggested about the V8 using everything for power. In my opinion ???? cubic inch for cubic inch ...not many run like them. (and yes I know they don't leave a trail of fire, but they're a tiny engine compared to even a 13 liter) and they're actually fairly close to the same displacement as a 237

Live tandem twin screw. Little 34000 pound Eatons with the round housing I believe

Multi speed transmissions gained popularity as axle ratios became faster.  A truck with a 3.7 axle grossing 80K would have a hard time starting out on black top even with a 6 to 1 first gear in the transmission. Newer engines all made much more torque than engines common in the mid '60s

Back to original question. Maxidynes didn't get their grunt from some mystery valves . 50 years ago, they engineered away lots of shifting, and now they do that with the M drive .

Fuller jumped in on the concept. A PowerTorque Cummins worked with a five speed Fuller. Husky Drives and TO 95ALLs were made just for that.  Of course that was years after Mack had a good foothold on the less shifting idea

38 minutes ago, tjc transport said:

that is true, but those trucks also were usually washed at the end of the day, and parked indoors. 

i know a guy that has a three year old truck that looks like it is 30 years old. 

on the same lines, my old 99 R model still looks like it rolled off the showroom floor.

We all know the guy with the 3 year old truck that looks 30 😂 and they're getting more popular than ever cause that's about when good warranty runs out 

I think see'n how as that pickup is all dolled up and ready to go ?  Might be a good vehicle to try a low altitude girl in a car picture 

39 minutes ago, tjc transport said:

i don't think so Larry. ain't no way a dump truck will run the roads here for 50+ years without falling apart and being completely rebuilt 5-6 times. 

IDK ???  I don't have to put much thought into a few old ten wheelers from NJ that were in pretty nice shape.  Lots of those old big DMs and Autocars ?  they weren't exactly a rarity , and some were pretty well preserved.

All the work is done on top of the piston ( timing injection pressure , matching of turbo cam and fuel delivery ) and more important than any of it ?

Someone figured out how to do it for a reasonable amount of money .   Think many people realize one of those old constant torque Maxidynes were never anything bigger than what would be called an 11 liter today ? 

I can't believe how much the front springs look like something so much newer .

It kinda looks like the same red as the tractor you drove ??  

That probably was a dump truck at one time.

Timmy set you right up. 👍

If the spring in it is that busted, it likely doesn't have much fight left in it. !!! but still gotta be careful !!!

Now I feel like a pecker head (lol)   Thanks for posting.  It's an interesting truck, and I doubt it's only me who thinks that.

This guy's a tease....he's making us wait way too long for more info and pictures of this truck 

vent line is all