Jody Scott Posted 17 hours ago Share Posted 17 hours ago Hello All, I came down the hill yesterday loaded and was not impressed, the truck ran great, lots of torque, climbing with the 18 speed is a dream but going down hill is the problem, no engine brake. I have read all the articles written on here and other places that i could find but i am not completely satisfied with the answers when it comes to the Jacob’s performance or converting the E7 to the Power Leash. I already have a set of 690 Jacob’s that have been updated and i am willing to purchase a set of Power Leash brakes to see if can be done. I would like to know the thoughts of the knowledgeable pros on this site and settle this debate and document this process. Quote Link to comment https://www.bigmacktrucks.com/topic/76688-2002-mack-e7-engine-brake-power-leash-or-jacobs/ Share on other sites More sharing options...
Mackpro Posted 14 hours ago Share Posted 14 hours ago The Powerleash engine brake is only for the ASET family of engines and wasn’t even available on the first year of those engines. Jacobs was still the only option till halfway through 2004. Lots and lots of service bulletins on updating the Jacobs on the pre-ASET engines. The high volume oil pump and external oil line kit helped a lot. Putting a Powerleash brake on a pre-ASET engine might work but I know it takes a totally different camshaft profile that is only available on the ASET cams. 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76688-2002-mack-e7-engine-brake-power-leash-or-jacobs/#findComment-596349 Share on other sites More sharing options...
Jody Scott Posted 4 hours ago Author Share Posted 4 hours ago I was looking at that the cams part the other day and I was scratching my head over it. A cam normally is just a question of lift and duration but Mack has a strange grind on their cams that causes the valve train to get loose on the back side of the lobe, i dont understand why they do that but i dont think that has anything to do with the operation of the engine brake. They even put springs on the push rods to help with keeping the noise down on the valve train and other reasons i guess. So with the cam and engine brake operation it comes back to lift and duration on the exhaust lobe right? Don’t get mad at me over this, i am just trying to understand how and why this can or can’t work. Quote Link to comment https://www.bigmacktrucks.com/topic/76688-2002-mack-e7-engine-brake-power-leash-or-jacobs/#findComment-596365 Share on other sites More sharing options...
Jody Scott Posted 3 hours ago Author Share Posted 3 hours ago I found this on a retrofit kit. Quote Link to comment https://www.bigmacktrucks.com/topic/76688-2002-mack-e7-engine-brake-power-leash-or-jacobs/#findComment-596366 Share on other sites More sharing options...
Joey Mack Posted 2 hours ago Share Posted 2 hours ago So basically you need a cam shaft, rocker shaft assemblies, EECU, valve covers with the stud for the engine brake celenoid, high volume oil pump, rocker shaft bolts,, thats all i can think of of the top of my head. As far as cam timing, im not sure if the EECU will take care of that, or if you will use an offset cam gear key. Quote Link to comment https://www.bigmacktrucks.com/topic/76688-2002-mack-e7-engine-brake-power-leash-or-jacobs/#findComment-596373 Share on other sites More sharing options...
Jody Scott Posted 1 hour ago Author Share Posted 1 hour ago I am curious if the cam will work just as it is? Quote Link to comment https://www.bigmacktrucks.com/topic/76688-2002-mack-e7-engine-brake-power-leash-or-jacobs/#findComment-596381 Share on other sites More sharing options...
Jody Scott Posted 52 minutes ago Author Share Posted 52 minutes ago My thinking is that both the Jake and Power Leash work the same it is just that the Power Leash does it better. Nobody that I have read about or come access has been able to explain why the Power Leash works better other than being designed/ engineered to work with low volumes of oil. Quote Link to comment https://www.bigmacktrucks.com/topic/76688-2002-mack-e7-engine-brake-power-leash-or-jacobs/#findComment-596382 Share on other sites More sharing options...
Jody Scott Posted 27 minutes ago Author Share Posted 27 minutes ago The EECU works the same between the Jake and the Power Leash correct? Quote Link to comment https://www.bigmacktrucks.com/topic/76688-2002-mack-e7-engine-brake-power-leash-or-jacobs/#findComment-596383 Share on other sites More sharing options...
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