MaxPinJT Posted March 14, 2019 Share Posted March 14, 2019 Hi guys I'm new to this forum and owning trucks also. I bought a 1995 Mack RD690 with a 300hp EM7 engine. It's machanical pump E7 engine and I'd like to turn it to a 350hp or maybe a bit more? How do you turn up the 300 to a 350? Is it just injectors or it's way more than that like a pump injectors and a turbo? Thanks for any help given. Quote Link to comment https://www.bigmacktrucks.com/topic/56144-1995-rd-300hp/ Share on other sites More sharing options...
Maxidyne Posted March 14, 2019 Share Posted March 14, 2019 What transmission does it have? Quote Link to comment https://www.bigmacktrucks.com/topic/56144-1995-rd-300hp/#findComment-418178 Share on other sites More sharing options...
Popular Post JoeH Posted March 14, 2019 Popular Post Share Posted March 14, 2019 I have a 95 RD688S, which is a 350 hp e7 engine. I will bet your dog outpulls my dog. Your dog is a Maxidyne engine, which means it has a broad power band. The older em6 maxidyne makes at least 90% torque in the entire power band. Our maxidynes we own that are pre em6 (endt676) pull from 1200rpm all the way to 2100rpm. Not sure about what the em7 does, never driven one. My e7 350 only makes that much power for like 3 or 400 rpms. It's probably just fuel pump adjustments and watching your EGTs, but I've never tweaked a fuel pump. Only read what guys post here. Maxidynes are great because of that powerband. It may only be a 300, but comparing a Maxidyne to a cat or Cummins of similar hp is like apples to oranges. Or cats to dogs. 1 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/56144-1995-rd-300hp/#findComment-418182 Share on other sites More sharing options...
fjh Posted March 15, 2019 Share Posted March 15, 2019 14 hours ago, Maxidyne said: What transmission does it have? This question is important! That being said! All the above comments are true you should leave well enough alone and be happy! Your engine is reliable as is and will make you a big bag of money if you just work it! Its not a Race out there, its just Get the job Done, at the end of the day, they pay you to get the load from A to B! JOE H Made the right comment ! You could possible tweak the pump if its not VMAC Yes! The Big Question is However is it worth it! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/56144-1995-rd-300hp/#findComment-418231 Share on other sites More sharing options...
MaxPinJT Posted March 18, 2019 Author Share Posted March 18, 2019 The trans is a 2070 seven speed. I just would like the engine to pull harder. I drove a 94 back in the early 2000's and it would pull real good with an easton fuller 8LL in it. It would make 24lbs of boost and the stack temp never went up over 900. I'm just hopping I can make this engine pull like that 94 did? Quote Link to comment https://www.bigmacktrucks.com/topic/56144-1995-rd-300hp/#findComment-418504 Share on other sites More sharing options...
MaxPinJT Posted March 18, 2019 Author Share Posted March 18, 2019 The engine is an all manual pump engine with a ReMack pump in it from Mack only a few thousand miles ago. But the pump was put in a couple years ago by the guy I bought it from who used the truck only a little bit. The engine has 24000 plus hours on it, mostly idle time 139000 miles. Quote Link to comment https://www.bigmacktrucks.com/topic/56144-1995-rd-300hp/#findComment-418505 Share on other sites More sharing options...
Maxidyne Posted March 19, 2019 Share Posted March 19, 2019 6 hours ago, MaxPinJT said: The trans is a 2070 seven speed. I just would like the engine to pull harder. I drove a 94 back in the early 2000's and it would pull real good with an easton fuller 8LL in it. It would make 24lbs of boost and the stack temp never went up over 900. I'm just hopping I can make this engine pull like that 94 did? That's a wide ratio transmission that won't work with the narrower powerband of a 350. Quote Link to comment https://www.bigmacktrucks.com/topic/56144-1995-rd-300hp/#findComment-418540 Share on other sites More sharing options...
JoeH Posted March 19, 2019 Share Posted March 19, 2019 7 hours ago, Maxidyne said: That's a wide ratio transmission that won't work with the narrower powerband of a 350. He's wondering about just juicing up his maxidyne to make it like a 350hp maxidyne, not changing to a different fuel pump. Quote Link to comment https://www.bigmacktrucks.com/topic/56144-1995-rd-300hp/#findComment-418548 Share on other sites More sharing options...
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