Maxidyne 300, E6-350 Coolpower Etc.

[ThaddeusW]

I was wondering what the major difference between the maxidynes and the E6 is. I also want to know which one was called the cool power. I am slowly trying to educate myself in Mack engines so I need all the help I can get.

This is a maxidyne 676 and there is an ENDT 676 and a ENDTB 676. What is the difference and is it air to air and air to water aftercooled or just air to air? Also the 676-300 had the aftercooling and the 675-237 did not, right?

Now this is an E6. I herd there was a 2 and 4 valve version. It has air-to-air and air-to-water aftercooling and uses the same block as the 675-237 and the 676-300. Is this the same E6-350 that I commonly see in superliners and other R's? Also what was the difference between the 2 and 4 valve sersion?

Will the 676-300 or the E6 fit into a B or will the aftercooler get in the way? Oh and did they have jake brakes or a dynatard? how effective was the dynatard?

Thanks all!

[Packer]

Just happen to have a dynatard. Took it off my 237. Looks good and clean! Make me on offer!?!

Packer

[Superdog]

Too make things very simple,the biggest difference between the early Maxidyne 300,300+,and early 350 and the E6 engines was the aftercooling,the early ones used the side mounted aftercooler and a tip turbine fan,E6's were air to air mounted in front of radiator.I believe your 2nd pic is a 678 (early 350),not an E6.

The difference between a ENDT676 and a ENDTB676 is the B means it has a Dynatard engine brake.Dynatard's require a special cam and can't just be added to any engine without changing the cam also,were a Jacobs Brake doesn't need to.

[mackmaster]

E6 is on this picture: http://community.webshots.com/photo/540961...540961016wxOGpJ

in an old MH613. I readed everything on the net, but not too much info can be found. Superdog has right, both pics showing an older model. I dont know in my wreck is a 2 or 4 valves engine?!

[rick harper]

i do believe that all MH's came with four(4) valve heads. the MH was produced starting in 1984 and that is the same year as the four(4) valve head came into production. look at your valve covers, you will be able tell from them.

[Lmackattack]

I think an easy way to tell if you have a 2 v or 4 v head is to look where the injector lines enter the head. my 2v 285 hp has the injector lines on the driver side on the top of the heads next to the valve covers. I think the 4v head has the lines that incert into the sides of the heads?? could be wrong but thats what I have noticed on my companys trucks.

or just pop off the valve covers...

[fullfuel01]

some MH have 2VH because they start it in 1983 and 4vh wasn't in production. all 4vh got the air to air in the front. 2vh get 'cold' air with prestone...

[b61mack]

The top picture looks like air-air, the bottom looks like it has cooler lines going to the intercooler,it is a series intercooler, i have a late 1983 titled 1984 MH and it has the 2VH 350hp with charge air cooler, the intercooler fits great in the B model, i have a 300+, 13 speed roadranger in my 63 B model. Ron

[TRUE GRIT]

IS THERE A DIFFERENCE BETWEEN E6, AND EM6, MY 84 R MODEL SAYS EM6 300 ON THE ENGINE TAG AND ECONODYNE ON THE HOOD

[b61mack]

I think the EM6 is a maxidyne the E6 is set up to use more than 5 speeds, the engines are basicly the same, if you go to mack and buy a basic engine whatever pump, injectors,turbo,intercooler,you can have a 237,285,300,315,350 HP.

[TRUE GRIT]

THANKS, MY TRUCK IS A 5 SPEED, DO YOU KNOW WHAT ECONODYNE IS SUPPOSED TO MEAN ? I HAVE HEARD IT WAS A FUEL PINCHER.

[Superdog]

the EM6 was a Maxidyne version of the Econdyne E6.It was a low rpm engine.Your truck might have had a different hood put on it or someone might have just stuck the emblem on.I've seen both EM6 and E6 300's with 5 speeds.

[Mack Doctor Jr.]

THE 6 CYLINDER MACKS WERE OF THE SAME BLOCK WITH THE DIFFERENCE OF A COUPLE OF CUBES. THE ONLY THINGS THAT CHANGED FOR MORE HORSE POWER WERE THE TURBO, INJECTORS, PUMP, INTERCOOLER. MY DADS WORKED ON THEM FOR 30 YEARS HE SAID THAT THOSE FEW CHANGES IN CUBES DIDNT AMOUNT TO A HILL OF BEANS. MACK WAS ALWAYS KNOWN FOR BAD CAMSHAFTS( DYNATARDS) THATS WHY JACOBS BRAKES WERENT TO POPULAR. I THINK THE 4V HEAD WASNT MADE TILL 88. I GOT AN 87 WITH 2V HEADS AND HAD AN 88 WITH 4V HEAD AND TRENTS RIGHT THE BEST WAY TO TELL IF ITS 4V IS TO SEE IF THE INJECTOR COME IN THE SIDE OF THE HEAD (PASSENGER).

HOPE THIS HELPS JOE

[David]

I purchased a new 85 model MH in the fall of 84. It had a 2V 350 with chassis mounted air to air. It also had round headlights.

[Lmackattack]

I was talking with a friend a week ago and he was telling me that there was 350HP mack with the tip turbine side mount charge air/intercooler...how were those engines?? I would think that at 350HP the side mount would be to small to cool the intake air???

and another question I always wondered with tip turbines... If the tip turbine pushes air across the intercooler/coolant fins.. where does that air go after it makes it way across the intercooler??I cant hear it escapeing under the hood... but cant see if it has a way back to the intake??? whats the story

Trent

[scott]

thad i've been fooling with this stuff for a little while now and i'm still a little hazy about years and applications. the easiest way for me to spot a 2-valve motor is by the stamped steel valve covers. E-6 4-valve motors have cast aluminum covers. yes they fit in B's with the engine mount air coolers. scott

[Mack Doctor Jr.]

HEY GUYS I GOT THE BIBLE OUT NOW.HOE TO IDETIFY YOUR ENGINE SERIAL # IS

E = MACK TURBO CHARGED DIESEL ENGINE

M = MAXIDYNE ENGINE (HIGH TROQUE RISE ENGINE)

C = CALIFORNIA CERTIFIED

6 = FIRST DIGIT INDICATES CUBIC INCH DISPLACEMENT ( 672 I.E.)

NEXT THREE NUMBERS MEAN PEAK GROSS HORSEPOWER (BHP)

THE LAST 2 LETTERS COULD BE AN L OR AN R

L = LOW SPEED MAXIDYNE

R = REDUCED ENGINE SPEED

[Packer]

I worked at Mack's Salt lake City, UT dealership in the late '70's. One thing that I noticed is that on the air cooled engine, if you lost one turbo, the other shelled out also. Never had much good to say about the two turbo system but - - - I have no idea what may have caused the turbochargers to come apart.

Was it poor oil?

Too many miles?

Bad air cleaner?

Bad turbo?

I may never know the answer to the question. At the time I was just a youngster and was the Cummins mechanic in the shop. Did some work on Mack engines; rebuilt several, but didn't take the time to find out why the air cooled seemed to have that problem.

Packer

[TRUE GRIT]

HEY GUYS I GOT THE BIBLE OUT NOW.HOE TO IDETIFY YOUR ENGINE SERIAL # IS

E = MACK TURBO CHARGED DIESEL ENGINE

M = MAXIDYNE ENGINE (HIGH TROQUE RISE ENGINE)

C = CALIFORNIA CERTIFIED

6 = FIRST DIGIT INDICATES CUBIC INCH DISPLACEMENT ( 672 I.E.)

NEXT THREE NUMBERS MEAN PEAK GROSS HORSEPOWER (BHP)

THE LAST 2 LETTERS COULD BE AN L OR AN R

L = LOW SPEED MAXIDYNE

R = REDUCED ENGINE SPEED

thanks, great info.

[b61mack]

Today i was looking at at some engine blocks that i bought awile back and found out that i have a 1981 350, it has a tag on it E6 350, i was wandering if 81 was the first year for the 350 ,i think it came out of a criuseliner.

[mudslut28]

THE 6 CYLINDER MACKS WERE OF THE SAME BLOCK WITH THE DIFFERENCE OF A COUPLE OF CUBES. THE ONLY THINGS THAT CHANGED FOR MORE HORSE POWER WERE THE TURBO, INJECTORS, PUMP, INTERCOOLER. MY DADS WORKED ON THEM FOR 30 YEARS HE SAID THAT THOSE FEW CHANGES IN CUBES DIDNT AMOUNT TO A HILL OF BEANS. MACK WAS ALWAYS KNOWN FOR BAD CAMSHAFTS( DYNATARDS) THATS WHY JACOBS BRAKES WERENT TO POPULAR. I THINK THE 4V HEAD WASNT MADE TILL 88. I GOT AN 87 WITH 2V HEADS AND HAD AN 88 WITH 4V HEAD AND TRENTS RIGHT THE BEST WAY TO TELL IF ITS 4V IS TO SEE IF THE INJECTOR COME IN THE SIDE OF THE HEAD (PASSENGER).

HOPE THIS HELPS JOE

Your Dad is correct. I had one of the first 4 valves in my 88. The damn thing had constant valve train trouble for the first 2 years and since i rebuilt it completely after it wiped the cam out in 91...it hasnt been opened again. The 4 valves made a lot more low rpm torque as well. Mine pulled hard down to 1000 rpm's....whereas my 2 valves is dead in the water below 1400. The 2 valve I turn to 2300 and the 4 valve turns about 1950-2000 tops. I like the driveability of the 4 valves (lazy shifter here) much more than the keep it wound up style of the 2 valve.

I might be wrong here but I cant remember for sure...but the first 4v motors had the L designation on them. I think the EM6 is a 2v as well isnt it? The 4V is an E6-300L or E6-(insert hp rating here)L. E7 was a little bit more cubes ( 720something I THINK)and a wet liner motor. E6 was a dry liner (no water circulating around the outside of the liners) and was in the 670something cubic inch range. The 4v motors also had the charge cooler in front of the motor and the side mounted cooler or the god-forsaken tip turbine were GONE. Those 2v motors were a pain in the azz to take a valve cover off to run the valves or to swap the heads on due to the weight of the front one with the cooler attached. Assembling the valve pans and jake spacers without leaks is also a nightmare where the 4v has the valve covers slotted so the gasket fits right in them. MUCH better design on the valve pans. The others who mentioned the side mounted injector lines are correct also.

Sorry to be long winded but I am bored and new to the site I wont swear to all of the above but it is true to the best of my memory..lol.

[kscarbel]

i do believe that all MH's came with four(4) valve heads. the MH was produced starting in 1984 and that is the same year as the four(4) valve head came into production. look at your valve covers, you will be able tell from them.

MH's produced in 1984 (first year initial production) had 2-valve engines. Production from 1985-on had 4-engines. The MH went through a lot of last minute tweaking during 1984. From 1985 on, it was smooth sailing. The 1985 4vh 350's I sold were, understandably, much better performers than the 1984 MH's with 2vh 350's.

Some FYI about late model 2VH engines. In 1988, the 2VH EM6-275L was the standard engine in the DMM-600S and DMM-6006S because that model had not been designed to accomodate chassis mounted charge-air cooling (CMCAC). The 2VH E6-350 (governed at 1950rpm rather than the 4VH's 1800rpm) was the optional engine in the DMM.

[theakerstwo]

THE 6 CYLINDER MACKS WERE OF THE SAME BLOCK WITH THE DIFFERENCE OF A COUPLE OF CUBES. THE ONLY THINGS THAT CHANGED FOR MORE HORSE POWER WERE THE TURBO, INJECTORS, PUMP, INTERCOOLER. MY DADS WORKED ON THEM FOR 30 YEARS HE SAID THAT THOSE FEW CHANGES IN CUBES DIDNT AMOUNT TO A HILL OF BEANS. MACK WAS ALWAYS KNOWN FOR BAD CAMSHAFTS( DYNATARDS) THATS WHY JACOBS BRAKES WERENT TO POPULAR. I THINK THE 4V HEAD WASNT MADE TILL 88. I GOT AN 87 WITH 2V HEADS AND HAD AN 88 WITH 4V HEAD AND TRENTS RIGHT THE BEST WAY TO TELL IF ITS 4V IS TO SEE IF THE INJECTOR COME IN THE SIDE OF THE HEAD (PASSENGER).

HOPE THIS HELPS JOE

So no one misunderstands the 2V block is different than the 4V block. The engines up to a E7 will be all same cubic inche. That would be 672 and that is from a 4 7/8 bore.Your dad is probably like me and has only seen the worst of them but the truth of it is they have no more cam problems than any other engine unless you are talking about the 2002 and 3and 4 engines.I think the 4 V came out in 84 or 85. But if a 88 had a 2V it may have been put in after the fact.I have a 85 4V and a 86 4V