nasty51ford Posted August 19, 2014 Share Posted August 19, 2014 Looking for a little info on turning the pump up a little on my "58" Mack, it has the END673 in it, I just want to turn it up a little to get a little more power, but not enough that it will melt a piston, or wash down the cylinders, does anyone know how to go about doing this? I have been a mechanic all my life, but have never worked on one of these, I've only had it for about two weeks, and can it be turned up higher than 2100 RPM ,or is that the highest it will safely turn? It will be used for my own personal use, and will occasionally haul a car, either on the bed, it has an 18-20' tilt bed, or on a 20' car trailer that I have. Thanks Keith Quote Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/ Share on other sites More sharing options...
theakerstwo Posted August 19, 2014 Share Posted August 19, 2014 Don't raise the rpm.You can add just a little rack to it.Pull the governor cover and you will understand were the rack stop is inside.The rack goes forward for more fuel but is limited by the stop.The is a screw on stop that will alow the stop to be moved forward for more rack travel.one and a half turns of the srew is enough to do damage if you don't know how to drive a hot engine.Just remember pistons and liners may not be found for that engine any more. 2 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-256645 Share on other sites More sharing options...
nasty51ford Posted August 19, 2014 Author Share Posted August 19, 2014 Thanks, yeah, I'm use to running hot engines, that's all I ever had, lol! But I never played with an old Mack. Is there anything to do to the injectors to get a little more out of it? Quote Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-256647 Share on other sites More sharing options...
theakerstwo Posted August 20, 2014 Share Posted August 20, 2014 give it one and a half turn on the rack screw and thats all you need. If you want more than that screw some more and I can tell you for sure you can get more fuel in that engine than it can handle.Old timers would set them till they could get a small red cone out of the stack and you could not do that long. 2 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-256663 Share on other sites More sharing options...
thomastractorsvc Posted August 20, 2014 Share Posted August 20, 2014 where is the rest of the pictures? If you want more power look for a different engine if speed put in an aux trans 1 Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-256670 Share on other sites More sharing options...
nasty51ford Posted August 20, 2014 Author Share Posted August 20, 2014 Thinking of changing the differential, just needs a little taller gear, I won't be hauling any thing heavier than a car, or pickup truck, once in a great while maybe two, would like to see a little fire out of the stack at night, I remember seeing that when I was a kid riding with my dad. Before I was born he had a "51" A-Car DC100, that he went through from the ground up, and built the engine also, it had a 200 Cumins, he painted it Apache red and Sheridan blue, with real gold leaf lettering and scroll work, had "Bimbo" painted across the front bumper, because my older sister, who was only two at the time, use to go around singing that song "Bimbo Bimbo, where ya gonna goeeeeo......Bimbo Bimbo going down the roadeooooo" Lol. He had the pump set, and injectors set to where he had a little convex mirror on the passenger side aimed at the stack, she would throw a one foot flame, and he could use that mirror as a tach, he would know to downshift when that flame got down to 2" ! Lol. He swore till the day he died that that old "200" Cummins would out pull the trucks he was driving at that time, he was driving till 2000, lost him in 2003. Well.....I'm rambling....Lol Quote Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-256676 Share on other sites More sharing options...
nasty51ford Posted September 8, 2014 Author Share Posted September 8, 2014 Well, I finally got to take it for a short drive a couple days ago, I still have the grin on my face! Lol. She drives SO MUCH BETTER than I had anticipated! There is a miss at high RPM though, could this be a weak injector, or maybe it needs the overhead run? It doesn't do it at idle, or low RPM's, just when it gets up over somewhere around 15-1600, and it doesn't sound like a dead miss, more like a weak injector. I know nothing about adjusting the injectors, or valves on these 673's, is there a website that explains it? Thanks Keith Quote Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-259127 Share on other sites More sharing options...
gearhead204 Posted September 9, 2014 Share Posted September 9, 2014 nasty: does it have a dynatard eng. brake? if not its the same as a gas eng. for the valve adjustments firing order the same so if the clearance is listed on the valve cover grab any automotive manual and follow the inline 6 valve adjustment procedure. if it has a dynatard some one on here I'm sure will help you out. Quote Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-259182 Share on other sites More sharing options...
nasty51ford Posted September 16, 2014 Author Share Posted September 16, 2014 I was just wondering if there is an injector adjustment on these, but no, no Dynatard. Quote Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-260015 Share on other sites More sharing options...
gearhead204 Posted September 16, 2014 Share Posted September 16, 2014 no injector adj. only Cummins and Detroit have inj. adj. during that era. Mack injectors are bench set. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-260016 Share on other sites More sharing options...
nasty51ford Posted October 1, 2014 Author Share Posted October 1, 2014 Thanks Pedigreed, so an end 673 won't live long at 2300 RPM huh? Quote Link to comment https://www.bigmacktrucks.com/topic/36758-end673-pump/#findComment-261779 Share on other sites More sharing options...
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