Evolution of the E7 Engine

[kevgibbs]

Can anybody give me somewhat of a detailed history of the E7 engine? I'm more concerned about how the fuel system on the engine changed over time. I'm aware that a full mechanical engine was made and that a ECM controlled engine was made. However I've recently found another model for sale that uses the mechanical fuel injection pump but utilizes what looks like a electronic stepping motor to run the throttle. We have a full mechanical E7 in our fleet and we're convinced that it is the best engine to ever roll off of Macks assembly line. I would just like some history on how the E7 changed over time and what models proved to be the most powerful and service free over time. 

[Joey Mack]

The E-7 mechanical is great!!!, the last of the million mile engines. The electric governor housing on the Robert Bosch pumps were great too. yes there is a small computer,,, the F.I.C. module.. The most common repairs i've made on those, is the Duetch connecter for the governor housing. the contacts get loose, especially if the connecter is not secured. I have also gained respect over the years for the E-Tech. It's fairly simple, and can run a million +... lifters were an issue, engine brake was nothin to write home about,..... Top oil feed update, high pressure oil pump, new re-set screws, and a lash change on the engine brake helped, .....Mack went with vendor parts on this engine, and quality was compromised. but, it is still a good engine, Once again this engine still does a good job. around 2003-2006, they started to screw up, with the A.S.E.T. C.E.G.R. However,  The "Powerleash" engine brake, made by Mack... did a good job... I have done compression skids with power leash during road tests..... there's a ton more to say, but I  have never written a book before....🙂... Jojo   Ok Vmac3+"F"... Fill in the blanks....  😅

[Vmac3]

Okay here it goes.....

In the early 90s Mack released its first version of their electronics called VMAC (Vehicle Management and Control). The first generation was called VMAC1. The fuel system was a partial authority system where it had 2 modules. 1 module was called the FIC (fuel Injection control module) and the other was the vmac module. Each module had their own functions, the fic controlled fueling to the pump and the vmac module controlled vehicle electronics.  They both communicated via j1587 datalines. Both modules where located on the passenger side kick panel. The injection pump as JoJo mentioned was built by Robert Bosch. The FIC sent commands to the pump for fueling. There were a couple of electronic components, a rack actuator, rack position sensor and a timing event marker sensor. As JoJo mentioned the pins on the pump would get loose and had to be replaced. In the front on the pump was the timing mechanism, Mack called it the econovance. This was controlled  by a actuator that allowed for oil pressure to actuate the econovance. This worked by two helical gears that would allow for advance and retarded timing. This engine was a breakthrough for Mack because now you can have specific customer data programming, better fueling and fault diagnostics. Vmac2 was the same where it was still a partial authority fuel system but with the use of 1 module. This allowed more programming features. In my opinion this was the best Mack engine ever built, 2 million was no problem for this little 12litre engine. These engine produced more hp than what was advertised. I have dynoed several of these and they produced 20% more than what was advertised. These push rod  engines had two peice pistons, that were full floating. The engine brakes were nothing to write home too. They used Jacob's engine brake and an exhaust brake that Mack called a stealth brake. It was an air actuated exhaust brake that sounded like the engine was being muffled. Lifters were a flat tapped. 

The new emissions standard came out in 1998 (I believe) which called for a reduction NOx and particulates. Mack introduced Vmac3, it was still an E7 engine but the engine block was reworked to allow for a new fuel system redesign. Mack used Robert Bosch components to make up their fuel system. They used the infamous EUP (Electronic Unit Pump) system, it is still considered to be a pump line nozzle system but each cylinder had their own individual pump that was mounted in the engine. So any cylinder to cylinder variation can be corrected at anytime, where as the partial authority it cannot. These pumps were driven by the engine camshaft, so you can imagine how heavy this cam would be. The injectors were pretty much the same, they sat in the cylinder head in between the valves. So you may ask why did they come up with this fuel system? Well the reason is the partial authority pumps were only able to produce around 20 thousand psi of injection pressures. The eup fuel system brought it closer to 30 thousand. This is a big deal for deisel engines because when diesel fuel is injected, it is injected as a mist and not vapor. So the smaller the fuel droplet the less time is needed to compress the fuel to reach its injection pressure, inject it, heat it, turn it into a vapor  and oxidize the fuel in which combustion occurs. Getting away from the science, the engine itself was the same, it was still a 12litre with a lacklustre engine brake. It was still a push rod engine with the same piston design, except the bowl of the piston was a little different. Lifters were steel rollers, then they switched to ceramic rollers with spring loaded push rods. No egr yet. The electronics gave way to a full authority fuel system, the engine ecu was mounted on the right side under the eups and under a heat shield. Later on they moved it to the left side mounted on the intake. Mack called this engine LSR (Left side redesign). 

Vmac3 had two modules the engine ecu and the vehicle ecu. The vehicle ecu was mounted on the passenger side kick panel. They both communicated via the datalinks, j1587/1708 and j1939. These are a set of languages and physical characteristics of the modules. JoJo mentioned the issues with valve trains  and engine brakes with several updates they released. In 2002 mack introduced the CCRS engine Contantly Controlled Rate Shaping System). The fuel system was anle to produce  a pilot injection before main injection. This allowed for lower particulates and NOx emissions. This is why these engines have a different camshaft compared to its earlier version. Mack started to loose their fame as a built proof engine, but what customers didn't realize that the grass was not greener on the other side. Most manufactures started to transition to egr/vgt engines. By late 2003 the end came for the non egr engine.

The EPA mandated for further reductions in emissions for 2004 model year. This time they especially targeted NOx, and there you have it the egr was installed on the E7 Etech engine.

ASET AC and ASET IEGR engines were introduced late 2003. The engine was still the same e7 12 litre engine. But now they changed the camshaft, piston bowl design, turbocharger, more electronics egr system and a better engine brake. Well at least some good came out of this with their engine brakes.  Really strong and enough to put you tight agianst the seat belt. The iegr engine did not have all the mumbo jumbo compared to the external egr. The iegr was fitted into offroad/construction vehicles, simply for space. The iegr used an extra bump on the exhaust lobe to push exhaust gases into the intake during the intake stroke, so the exhaust valve would open during the intake stroke. This is not new technology, Honda used this in some of their cars. Anyway the issue with these engines are they always had exhaust gasses being dumped in the cylinder and this caused a lot of grief in the beginning. Sludging of engine oil, worn rocker shafts worn pistons and liners and blow by. So Mack introduced software updates to change the fueling. Anyway no need to discuss about the external egr engine. I'm sure everyone knows about this abortion of an engine. The engine itself was good, it's just what was attached to it caused all the grief. 

Sorry for the long winded post but I was walking down memory lane on this one. These engine taught me so much and it taught me how much I really did not appreciate the original Etech engine. Looking back the Etech was an excellent engine. I'm sure I missed out on a lot of things here but thanks for allowing me to share.

V

Edited December 22, 2020 by Vmac3

[kevgibbs]

Thank You very much VMAC3! I have been searching for this exact information for a week and nowhere on the web can I find any literature or history on the E7 engine. I have just purchased a 1997 CH613 Gold Dog Mack with the E7-400, T2130 13-SPD, and 3.78 Mack rears. The truck has 425,000 original miles. I believe that the engine is a VMAC2 but I have not ran the VIN or engine serial number to verify that yet. It is by far one of the nicest 23 year old trucks I have ever seen. 

 

I should preface this with we have owned a 1996 CH613 with the Full Mechanical E7 for over 20 years now. It has been turned up quite a bit and it will run circles around our 450HP Cat 3406E's. This 1997 Mack that I just bought will be our first Mack with any electronics on it. I was somewhat familiar with the VMAC3 engines but was totally unaware that Mack actually produced an E7 with a electronically controlled In-Line Bosch Pump until recently. 

[Vmac3]

5 hours ago, kevgibbs said:

Thank You very much VMAC3! I have been searching for this exact information for a week and nowhere on the web can I find any literature or history on the E7 engine. I have just purchased a 1997 CH613 Gold Dog Mack with the E7-400, T2130 13-SPD, and 3.78 Mack rears. The truck has 425,000 original miles. I believe that the engine is a VMAC2 but I have not ran the VIN or engine serial number to verify that yet. It is by far one of the nicest 23 year old trucks I have ever seen. 

 

I should preface this with we have owned a 1996 CH613 with the Full Mechanical E7 for over 20 years now. It has been turned up quite a bit and it will run circles around our 450HP Cat 3406E's. This 1997 Mack that I just bought will be our first Mack with any electronics on it. I was somewhat familiar with the VMAC3 engines but was totally unaware that Mack actually produced an E7 with a electronically controlled In-Line Bosch Pump until recently. 

I am glad I can share my experiences.

Vmac2 was a fantastic model. The best by far. They did have some issues, but the time 1997 came around they sorted most of the bugs out. If we look at the contrasting differences from 1997 to today's vehicles, you cant dispute the fact that today's vehicles are safer and more comfy to drive. The EPA drives the industry for change. Some would argue for the worse others would argue for the better. The big deal is if someone is to get into a 2021 vehicle and treat it as if was a 1985 truck, they will surely be disappointed. Another big issue is training today's techs. Anyway I hope everyone here has a safe and happy Christmas holiday. All the best in the new year. Stay safe.

V

[Vmac3]

Hey Jojo your turn. 

[Joey Mack]

Your too funny... I'm good, I couldnt agree more with you,, nor could I explain as well as you did... Jojo

[Lmackattack]

you said you dynoed some of the VmacII E7s and they would put down 20% more than advertised. was this with the mechanical pump and injectors?

 

The full Mechanical E7 macks I have driven always outperformed the electronic versions. They pulled and you could feel it. the electronics were all very sleepy.  I know the later E7 may have been better on fuel but they were guttless in the hills.

[Vmac3]

These were the vmac2 vehicles 1996-97. Partial authority fuel systems. Really good engines. 

Edited December 23, 2020 by Vmac3

[Joey Mack]

"L"    I know what you are saying about "Sleepy"  In some case's I changed the "governor" setting from Min-Max.... to" All speed" and it would perk it up some, However< you are at the mercy of the E.C.M...... I drove 427"s and 400's.. 13 spd. and 18 spd.  puling over loaded dump trailers... The 400 with 18 spd, (Didn't know the rear gears at that time). did a heck of a lot better, country road hills, mabey, drop 1 gear then split down 1 time was enough to pull the hill and not be a rolling road block. I was a young driver back then, 1999,, But that was my experience, I came out of a 79 R model, 350/ 9speed.. and nothing else... well, it had power steering...  Jojo..

[kevgibbs]

On 12/22/2020 at 6:54 PM, Joey Mack said:

"L"    I know what you are saying about "Sleepy"  In some case's I changed the "governor" setting from Min-Max.... to" All speed" and it would perk it up some, However< you are at the mercy of the E.C.M...... I drove 427"s and 400's.. 13 spd. and 18 spd.  puling over loaded dump trailers... The 400 with 18 spd, (Didn't know the rear gears at that time). did a heck of a lot better, country road hills, mabey, drop 1 gear then split down 1 time was enough to pull the hill and not be a rolling road block. I was a young driver back then, 1999,, But that was my experience, I came out of a 79 R model, 350/ 9speed.. and nothing else... well, it had power steering...  Jojo..

Hey Joey, I'm curious what tools do I need to change the governor setting from Min-Max to All Speed? What's the difference between the two settings?

[Joey Mack]

Pro link 9000.. hand held programmer...  with the V-Mac II "Card"... There was no internet connection then... I am rusty now, I would have to be there with the tool and "Wing it"... There are plenty of Guy's here that can help better than me..  Go Bulldog! Jojo

[theakerstwo]

I have a pro link and the VMAC 11 card but i can not remember seeing that but will go and connect it up sun eveing and let you know.

[Joey Mack]

Glenn, I dont remember if it's in there either. The MIN-MAX setting I Know is in V-Mac III..  I only posted the Pro-link because of the year of the truck. Like I said.. I am rusted when it comes to the Pro-Link, however, I would love to own one with an assortment of cards..  Jojo

[fjh]

Yup pretty sure its in there I know they moved things around a bit in the vmac 2 card how ever the setting things should be in tact in one of the heading! Switch status comes to mind!

[theakerstwo]

I went to the shop and found that mine and connected it up and i found the info in governor information.Mine was set at min/max and i set it to all speed not know what that means.I know what other engines means when you set it to VSG.I will know if this helps any in the response.

[Joey Mack]

Min-Max was related to the cruise control settings.. and fuel management for power demands with your right foot.  All Speed is supposed to act like a mechanical pump, all in the right foot...  I think i got that right...  Getting rusty sucks!!!

[Bullheaded]

I also loved the mechanical E7. My memory is fuzzy on the years, but I pulled dump trailers with a CL that had a mechanical E7 400 and it pulled every bit as good as the E7 454 and two  2000 E7 460's I ran. And it was bulletproof.

It's just too bad that when I had my 2000 CH E7 460 it was a nightmare but now we all know all the fixes for them and it could have been a great engine.

It cooked 5 air dryers and compressors from the casting sand issue, dropped a valve and had that bad mass ground issue that no dealer at the time could ever figure out.

But like I said, when it decided to run, it pulled great and got awesome MPG's.

Knowing all the fixes now, I'd love to still have that truck.

[fjh]

16 hours ago, Joey Mack said:

Min-Max was related to the cruise control settings.. and fuel management for power demands with your right foot.  All Speed is supposed to act like a mechanical pump, all in the right foot...  I think i got that right...  Getting rusty sucks!!!

correct Joe ! The way I understood it at the time was for driver feel ! the min max setting Made the engine brake respond as if you were driving a cummins or mech engine  , You had to have your foot all the way off the pedal for the engine brake to engage (NO Fuel position) .The all speed setting was as if you were driving a Mack with a normal dynatard instant response as you let your foot up even a little on the throttle the brake would come on ! Just my thoughts on this ! As mentioned  above we were encouraged to set min-max for best  the throttle response!

[theakerstwo]

I set mine to all speed and i have not found any difference yet.I may have to set it back and watch for any difference a few times but the response has not changed to me.I do know it started faster this morning.

[theakerstwo]

I have mechanic engine that i just rebuilt i would like to put in but i would miss the cruze and engine protection if i did that.

[james j neiweem]

What years did the mechanical E-7 run.

[Joey Mack]

90-97, with the last ones having an electronic governor housing. still miniscule compared to the next era. E-Tech..

[Mackch613]

I have a question, I have a 2005 Mack ch613 dumptruck with a e7 aset with a 427 I believe, any recommendations that will help with some more power and speed I’ve noticed it does sound real quite anything to give it back that growl? 

[Joey Mack]

fuel filters, re-run the valve's, change governor setting to 'allspeed'..  if you have the big turbo, make sure the VGT actuator moves properly, replace the air filter for the VGT...  clear out all MID128 codes...  jojo

[Mackch613]

How do I go about changing the codes