Production of V-8 Maxidyne under way by Mack Trucks

[kscarbel2]

The Daily Mail (Hagerstown, Maryland)  /  October 12, 1970

ALLENTOWN, Pa. -- Mack Trucks, Inc., has added another chapter to the success story of its revolutionary "constant horsepower" Maxidyne engine with the production of an even more powerful model, a V-8 Maxidyne delivering 325 horsepower.

Announcement of production of this newest turbocharged Maxidyne, which is coupled with the proven five-speed Maxitorque transmission, was made today by Walter M. May, executive vice-president of engineering and product, and Gerald F. Jones, executive vice-president of marketing.

May and Winton J. Pelizzoni, chief engineer of power trains, developed the basic Maxidyne principle.

Although production of the original 237-horsepower Maxidyne, a six-cylinder in-line engine, began only three years ago, it already accounts for more than 60 per cent of all Mack engines sold.

May and Jones stressed that the V-8 Maxidyne, designated ENDT865, is designed to supplement, not replace, the original Maxidyne.

"Mack's new V-8," they said, "is the perfect answer for the truck fleets and owner operators in need of an engine in the 325-horsepower range which provides all the advantages of the original Maxidyne, a drastic reduction in the shifting of gears, better operating efficiency, less driver fatigue and a reduction in maintenance costs."

Zenon C. R. Hansen, Mack chairman of the board and president, said the newest Mack engine "will further entrench Mack in the Number One spot among all manufacturers of diesel-powered trucks.

"Reports on the 23 prototypes we've had running in all sections of the nation for the last two years prove there is nothing else like the Maxidyne V-8. It's another 'first' for Mack, another quality power train from a company known around the world for the durability of its products," said Hansen.

Development of the V-8 Maxidyne was under way when Mack introduced the in-line Maxidyne in 1966 and started production of that six-cylinder model the following year. A number of the V-8 prototypes, pulling up to 160,000 pounds gross combination weight, individually have logged more than 200,000 miles.

Results showed the Maxidyne made the run with up to 83 percent less shifting of gears and finished about 11 hours ahead of one truck and close to six hours ahead of the other, and provided a substantial fuel economy advantage.

The Maxidyne concept of constant horsepower over a broad working range of 1,400 to 2,400 revolutions per minute and a 56 percent torque rise in that range, make the difference.

May and Pelizzoni slated: "Through most of its speed range, the Maxidyne actually puts out more power than higher rated engines, which exceed it for only the top 200 rpm. With a Maxidyne, the horsepower increases as rpm drop. Since the engine runs at lower rpm most of the time, it also consumes less fuel.

[HeavyGunner]

How did they accomplish more power with less rpm?  I've always wondered why some diesels don't lug very well and others pull like hell and will eventually settle in at an rpm and stay there rather than constantly down shifting until you in the bottom end of the low range?  Thanks for sharing Ks. 

[fjh]

The first year  or two of the E9 400  was offered with Maxidine  Frigin awesome  power house The thing would pull tree stumps!

[HeavyGunner]

2 minutes ago, fjh said:

The first year  or two of the E9 400  was offered with Maxidine  Frigin awesome  power house The thing would pull tree stumps!

So is/was maxidine an option?

[Outbehindthebarn]

8 minutes ago, HeavyGunner said:

So is/was maxidine an option?

Mack museum says my 1005 V8 (predecessor to E9) was originally to be equipped with a 6 speed. Has decal on the dash calling it a Maxidyne.... Somewhere during production they decided to intercool it, and forced the original purchaser into buying the 12 speed.. . he said he didn't have a choice!

[fjh]

I'm Not positive but I believe mack pioneered chassis mounted charge air the E9400 superliner was the first of anyone's chassis I  saw with a cooler  on the rad! before it became common place! No one else's  hood was designed to accommodate it at the time! 

KS may know a little on this subject!?

Edited August 26, 2016 by fjh

[kscarbel2]

ENDT865      14.19L  325hp @ 2,100   1,491 N.m @ 1,350                                   Maxidyne (5 or 6-speed Maxitorque)

ENDT866      14.19L  375hp @ 2,200   1,410 N.m @ 1,600                                   Conventional torque-rise for multi-speed transmission

ETAZ1000     16.36L  400hp @ 1,900   2,060 N.m @ 1,230                                   Conventional torque-rise for multi-speed transmission

ETAZ1005A   16.36L  400hp @ 2,100   2,060 N.m @ 1,230                                   Maxidyne (5 or 6-speed Maxitorque)

EM9-400        16.36L  400hp @ 2,100   2,061 N.m @ 1,230  (55% torque rise)      Maxidyne (5 or 6-speed Maxitorque)

EM9-400R     16.36L  400hp @ 1,700   2,061 N.m @ 1,230  (23% torque rise)      Eco-spec conventional torque-rise for multi-speed tranny

E9-440          16.36L  440hp @ 1,800   2,027 N.M @ 1,300  (16% torque rise)       Conventional torque-rise for multi-speed transmission

E9-400          16.36L  400hp @ 1,900   1,796 N.m @ 1,300  (20% torque rise)       Conventional torque-rise for multi-speed transmission

E9-450          16.36L  450hp @ 1,900   2,027 N.m @ 1,300  (20% torque rise)       Conventional torque-rise for multi-speed transmission

E9-500           16.36L  500hp @ 1,900   2,251 N.m @ 1,300  (20% torque rise)      Conventional torque-rise for multi-speed transmission

 

The 865 was a high torque-rise Maxidyne spec V-8, and the 866 was set up for multi-speed transmissions.

When the E9 first came out in the early 1980s (evolved from the ENDT1000/1005) at the same time Cruise-Liner production shifted from Hayward, California to Macungie, you had the EM9-400 Maxidyne V-8 governed at 2,100rpm (55% torque rise), the "Econodyne" spec EM9-400R for multi-speed transmissions governed at 1,700 rpm (23% torque rise), and the E9-440 V-8 for multi-speed transmissions governed at 1,800rpm (16% torque rise).

The EM9-400R offered maximum fuel economy in a V-8, while the E9-440 was aimed at the owner-operator segment.

Then in the mid-eighties, the Maxidyne spec V-8 was dropped, and the product range became the E9-400, E9-450 and E9-500 (US market) which all had a 20% torque rise.

[41180]

Which of the old v8 865 866  held up better ? The  325 or 375 ? I've heard horror stories of guys that ran them back in the 70' s having to change head gaskets and heads every  6  months.