Mikesbucketlistmack Posted October 25, 2013 Share Posted October 25, 2013 I know this may be a dumb question to the old timers, but what is the proper rpm for upshifting a 1981 R 611 ST with a 250 horsepower engine and 6 speed tranny with an extra low deep reduction gear ? Thanks ! Quote Link to comment Share on other sites More sharing options...
Lmackattack Posted October 25, 2013 Share Posted October 25, 2013 You can do it 2 ways.Run it up to 2100 then shift. It will fall back to around 1300 and start pulling againOr run them up to 1800 then shift. It falls back to 1000These engines don't pull real hard past 1950. And they make most of their power around 1200rpm...Thats how I drive em Quote Link to comment Share on other sites More sharing options...
jakebrake86 Posted October 25, 2013 Share Posted October 25, 2013 I used to run it up to around 1600, pop the go pedal, knock it in neutral, and wait on the needle to pass 1100 or so, and stick it in the next hole. That was on the few trucks I drove that had a tach that still worked. It seemed to be about the same on a 5, 6, or 7 speed. Somebody on here made me laugh the other day. They said run up the RPM's, knock it in neutral, pull out your favorite book, read a paragraph or two, then grab the next gear. Lol 2 Quote Jake Link to comment Share on other sites More sharing options...
mackdaddy Posted October 25, 2013 Share Posted October 25, 2013 You said it right. You have to wait until you see that rpm needle drop at or below the 1300 or it wont go in. 1 Quote Link to comment Share on other sites More sharing options...
Green Dash Posted October 25, 2013 Share Posted October 25, 2013 A 611 with 250 hp... Is this a 673 with a turbo or was the engine replaced with an EM6-250? Quote Jim Link to comment Share on other sites More sharing options...
Mikesbucketlistmack Posted October 26, 2013 Author Share Posted October 26, 2013 Jim. it says 250 hp on the engine plate. It used to be a former State truck from MA. Quote Link to comment Share on other sites More sharing options...
bulldog man Posted October 26, 2013 Share Posted October 26, 2013 @ Trent & Jake yall took the words right out my mouth cause I was thinking pretty much the same thing .& Jake ive herd my pop (granddad ), great Uncle (who worked for pops buddy) & 2 of our drivers say the same thing about pulling out a book ... Quote You Cant Fix Stupid. But You Can Numb It With A Sledgehammer. Link to comment Share on other sites More sharing options...
Green Dash Posted October 27, 2013 Share Posted October 27, 2013 Jim. it says 250 hp on the engine plate. It used to be a former State truck from MA.Any other letters, i.e. ENDT, E6 or EM6? The reason I ask is that the factory engine on a 611 should not be lugged down that far. The fact that it has a 6 speed is why I thought the engine was changed. An EM-250L can be lugged a little lower than an EM6-250 but I don't remember the specifics. Quote Jim Link to comment Share on other sites More sharing options...
sllimec47 Posted November 29, 2013 Share Posted November 29, 2013 I believe the L motors will pull from 1000 rpm Quote Link to comment Share on other sites More sharing options...
doubleclutchinweasel Posted November 29, 2013 Share Posted November 29, 2013 Same thoughts... Is this an E6 or an EM6. Or, what is the ENDT- number? It should be stamped on the timing case. A Maxidyne version pulls fine down low. If you have the non-Maxi, basically a Thermidyne, it prefers to run a bit higher RPM, & not be lugged.Mine is the ENDT-673C. It's a 250-horse Thermodyne, but has oil-cooling jets on the undersides of the pistons, & the extra head studs in the corners if the heads...like a Maxidyne. So, it can tolerate a LITTLE more lugging, due to the extra cooling, but still won't live at 11-1200 like a Maxi.I've seen engine/transmission swaps which result in impractical combinations. But, if it's a factory 6-speed Maxitorque, & a factory Maxidyne, do what Lmackattack & jakebrake86 said, & keep the revs down in the 11-1900 RPM range.Oh...and keep a sandwich or book handy to pass the time! Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment Share on other sites More sharing options...
jeff20878 Posted December 27, 2013 Share Posted December 27, 2013 We used to say "pull it out of 4th gear, go get a cup of coffee, then come back and pull it into 5th gear"! LOL 1 Quote Link to comment Share on other sites More sharing options...
doubleclutchinweasel Posted December 27, 2013 Share Posted December 27, 2013 We used to say "pull it out of 4th gear, go get a cup of coffee, then come back and pull it into 5th gear"! LOLI hope this doesn't start a brawl...I HATED driving the original Maxidyne/Maxitorque trucks!Having to wait that long to downshift drove me batty!You had to get in a whole different frame of mind to drive them. We used to call them a "lazy man's truck."Just personal preference, I guess. Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment Share on other sites More sharing options...
57 bcr Posted December 27, 2013 Share Posted December 27, 2013 It's throwing me off :tease:a little bit! An R611ST (were they E-6's by then or still ENDT673C's?) either way,what in the hell is it doing with just a 6 speed behind it? Like the "weasel" says,Themodynes & Maxidynes are 2 different animals. An R685 with a 6 speed, okay.But a 611? HMMMMMMMMMMM?? Of course,trucks can be modified over the years.I know of a guy that put a E-6 in a Superliner that had come from the factory with an EM-6 in it.Lasted about 4-5 months.Couldn't take the lugging. 1 Quote IF YOU BOUGHT IT, A TRUCK BROUGHT IT..AND WHEN YOU'RE DONE WITH IT, A TRUCK WILL HAUL IT AWAY!!! Big John Trimble,WRVA Link to comment Share on other sites More sharing options...
leversole Posted December 27, 2013 Share Posted December 27, 2013 If you turn your engne brake on that 'ill bring the RPMs down fast! Sounds cool too! Quote Link to comment Share on other sites More sharing options...
Gmerrill0516 Posted December 27, 2013 Share Posted December 27, 2013 I'm told I have an E6-250 turbo with the original quadbox behind it. I think he drove it like that for 25+ years hauling dirt and doing paving (judging by how much is stuck to it). So I assume that's ok...Right? That's in the B-815 with 7.49:1 rears. Quote Link to comment Share on other sites More sharing options...
Mike Posted December 27, 2013 Share Posted December 27, 2013 We used to say "pull it out of 4th gear, go get a cup of coffee, then come back and pull it into 5th gear"! LOLYou guys are just too nice. I thought someone would have said get out and take a whiz and step back in the cab. Quote Link to comment Share on other sites More sharing options...
rickykarenpr Posted December 27, 2013 Share Posted December 27, 2013 exelent Quote Link to comment Share on other sites More sharing options...
doubleclutchinweasel Posted December 28, 2013 Share Posted December 28, 2013 I'm told I have an E6-250 turbo with the original quadbox behind it. I think he drove it like that for 25+ years hauling dirt and doing paving (judging by how much is stuck to it). So I assume that's ok...Right? That's in the B-815 with 7.49:1 rears.Yep. That's the classic Mack setup. And you don't have to wait long to shift...especially if you split all the ones you can! 1 Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment Share on other sites More sharing options...
57 bcr Posted December 28, 2013 Share Posted December 28, 2013 Over the years,I have heard of guys using multi-speed transmissions with a Maxidyne(high torque rise) engine with success.Not so much luck, using a 5 or 6 speed with with a Thermodyne or for that matter,an Econodyne (or conventional torque rise engine),unless geared super low (like 5.something rears & direct trans,where it won't hurt 'em). And Mike,there are no dumb questions here.Remember that! Quote IF YOU BOUGHT IT, A TRUCK BROUGHT IT..AND WHEN YOU'RE DONE WITH IT, A TRUCK WILL HAUL IT AWAY!!! Big John Trimble,WRVA Link to comment Share on other sites More sharing options...
doubleclutchinweasel Posted December 28, 2013 Share Posted December 28, 2013 Over the years,I have heard of guys using multi-speed transmissions with a Maxidyne(high torque rise) engine with success.Not so much luck, using a 5 or 6 speed with with a Thermodyne or for that matter,an Econodyne (or conventional torque rise engine),unless geared super low (like 5.something rears & direct trans,where it won't hurt 'em). And Mike,there are no dumb questions here.Remember that!I've also seen multi-speed boxes torn to shreds by a Maxidyne.Look at the torque ratings...the old boxes just weren't built to take that much torque.It mainly depends on how you load & drive them. If running a Maxi hooked to a Quad, for instance, don't let the Maxi lug down into that maximum torque zone. Treat it like a Thermo, & keep the rpm up in the 18-2100 range. The torque up there is more in line with a Thermo.And, you're right; a 5-6 speed is just too widely spaced to run behind a Thermodyne without ridiculously low gearing. Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment Share on other sites More sharing options...
rickykarenpr Posted December 28, 2013 Share Posted December 28, 2013 do you have a pic of the truck?? Quote Link to comment Share on other sites More sharing options...
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