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cruising rpm #1567169 01/22/14 06:31 PM 01/22/14 06:31 PM
Joined: Feb 2009 Posts: 1,274 Ontario.Canada C can.al OP pro stock
can.al OP pro stock C Joined: Feb 2009 Posts: 1,274 Ontario.Canada	what would you say is an acceptable rpm to cruise at for an extended trip? ..would 2800 - 3000 be pushing it on a 2 or 3 hour period?

Re: cruising rpm [Re: can.al] #1567170 01/22/14 06:36 PM 01/22/14 06:36 PM
Joined: Aug 2012 Posts: 1,574 Lakeland FL F floridian pro stock
floridian pro stock F Joined: Aug 2012 Posts: 1,574 Lakeland FL	Which engine.. I would think that is a bit high for a big block, but I am kinda anal....

Re: cruising rpm [Re: floridian] #1567171 01/22/14 06:46 PM 01/22/14 06:46 PM
Joined: Jan 2003 Posts: 32,910 Grand Prairie,Texas stumpy I Win
stumpy I Win Joined: Jan 2003 Posts: 32,910 Grand Prairie,Texas	That range should be fine for any engine.

Re: cruising rpm [Re: can.al] #1567172 01/22/14 08:04 PM 01/22/14 08:04 PM
Joined: Oct 2009 Posts: 440 Canada D Dons Dart mopar
Dons Dart mopar D Joined: Oct 2009 Posts: 440 Canada	Quote: what would you say is an acceptable rpm to cruise at for an extended trip? ..would 2800 - 3000 be 28 would make me feel better + save on gaspushing it on a 2 or 3 hour period?

Re: cruising rpm [Re: can.al] #1567173 01/22/14 09:05 PM 01/22/14 09:05 PM
Joined: Apr 2010 Posts: 10,570 Sunny South Florida Golden-Arm I Live Here
Golden-Arm I Live Here Joined: Apr 2010 Posts: 10,570 Sunny South Florida	at what speed do you see that number? if you see it at 45 mph, that's going to be an awful ride. if you're doing 75, that's what the number should look like, for a older, non-o/d trans. "When Tyranny Becomes Law, Rebellion Becomes Duty"

Re: cruising rpm [Re: can.al] #1567174 01/22/14 09:36 PM 01/22/14 09:36 PM
Joined: Nov 2003 Posts: 3,426 Dandridge TN D Dabee master
Dabee master D Joined: Nov 2003 Posts: 3,426 Dandridge TN	Shouldn't hurt a thing. Back in the day we ran them at 3000 to 3400 rpm all day long and never hurt them.

Re: cruising rpm [Re: stumpy] #1567175 01/22/14 09:41 PM 01/22/14 09:41 PM
Joined: Feb 2003 Posts: 21,318 Manitoba, Canada DaytonaTurbo Too Many Posts
DaytonaTurbo Too Many Posts Joined: Feb 2003 Posts: 21,318 Manitoba, Canada	Quote: That range should be fine for any engine. doesnt hurt anything to run some rpm for a while. my dd runs 3500 at 75 all the time.

Re: cruising rpm [Re: DaytonaTurbo] #1567176 01/23/14 12:31 AM 01/23/14 12:31 AM
Joined: Oct 2008 Posts: 96 Nampa, Idaho W Wyle E Coyote member
Wyle E Coyote member W Joined: Oct 2008 Posts: 96 Nampa, Idaho	I've heard from a few engine builders that the "optimum" RPM for efficiency is the spot where the HP and Torque curves cross. If you have the cam chart of course. Otherwise, a run like that is good once in a while. For me, I like to stay about 2200-2300 for a big block and 2500-2700 for a small block for long runs. 25 Dodge Roadster 66 D100 440/727 (on 72 D100 chassis) 67 W200 360/727 72 IH TravelAll 1110 4x4 345/727/NP205 76 Scout 2 360/727/D20 '08 Dakota SLT Quad Cab 4wd 4.7L

Re: cruising rpm [Re: Wyle E Coyote] #1567177 01/23/14 12:39 AM 01/23/14 12:39 AM
Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O 70Cuda383 Too Many Posts
70Cuda383 Too Many Posts Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O	Only problem with that, is that since HP is a measure of torque over time, every HP/torque curve crosses at 5200 rpm. I don't know any V8 that cruises best at 5800 rpm... Photobucket sucks

Re: cruising rpm [Re: Wyle E Coyote] #1567178 01/23/14 11:16 AM 01/23/14 11:16 AM
Joined: Feb 2009 Posts: 1,274 Ontario.Canada C can.al OP pro stock
can.al OP pro stock C Joined: Feb 2009 Posts: 1,274 Ontario.Canada	..yes.small cam and 340 i have both 3.55 and 3.23 and i'm thinking 3.23 would be better for this combo

Re: cruising rpm [Re: Dabee] #1567179 01/23/14 11:41 AM 01/23/14 11:41 AM
Joined: Aug 2005 Posts: 5,998 Salem Grizzly Moparts Proctologist
Grizzly Moparts Proctologist Joined: Aug 2005 Posts: 5,998 Salem	Quote: Shouldn't hurt a thing. Back in the day we ran them at 3000 to 3400 rpm all day long and never hurt them. According to someone much older and wiser than I, back in the day a used car with anything over 80,000 miles was considered to be a re-build candidate and was avoided when car-shopping. Today's 1800 rpm OD's easily go 200,000 miles. I did a 5 hour trip to a wedding with a 340 and 3.91's and it fricken' SUCKED. It should have only taken 3 1/2 hours but I couldn't take the 3200 rpm and had to slow it down to 50-55mph. I have no idea how you guys put up with it. In the short-term, no, you won't hurt anything. I have a couple of 833od's to solve my little problem. In the meantime, this, is a little more like it. 8008627-tachvsspeedo.jpg (245 downloads) Mo' Farts Moderated by "tbagger".

Re: cruising rpm [Re: can.al] #1567180 01/23/14 12:03 PM 01/23/14 12:03 PM
Joined: Oct 2009 Posts: 440 Canada D Dons Dart mopar
Dons Dart mopar D Joined: Oct 2009 Posts: 440 Canada	Quote: ..yes.small cam and 340 i have both 3.55 and 3.23 and i'm thinking 3.23 would be better for this combo yep i would take that 355 off your hands lol.looking forward to seeing your Dart one day AL

Re: cruising rpm [Re: Dons Dart] #1567181 01/23/14 12:26 PM 01/23/14 12:26 PM
Joined: Oct 2003 Posts: 3,698 NE Oklahoma V Von master
Von master V Joined: Oct 2003 Posts: 3,698 NE Oklahoma	Some of you guys and your responses.... In any case, 3500rpm all day wont hurt a thing. I do agree that RPMs drive me freakin nuts. Cant stand much over 3200 for a sustained period of time. BTW, some of the DW guys have stones of steel, IMO. One member has made it the last 2 years. 3.91s, 26 inch tires and 3500 rpms for 2400 miles. I bow down, I cant do it. 72 RR, Pump gas 440, 452s, 3800 lbs, Corked, ET Radials,. 11.33@117.72. Same car, bone stock 346s, 9.5 comp, baby solid. 12.24@110.

Re: cruising rpm [Re: Von] #1567182 01/23/14 12:39 PM 01/23/14 12:39 PM
Joined: Jul 2007 Posts: 1,526 North Carolina cjskotni pro stock
cjskotni pro stock Joined: Jul 2007 Posts: 1,526 North Carolina	Yeah I have 3.55's in my Charger with 28" tires and cruising anything over 55-60 gets on my nerves after 30 minutes or so. Someday I hope to go the GV route or Keisler 4sp auto but not in the budget now, sadly. Over 10's of thousand of miles, the higher RPM's will wear the motor more than the 1800-2000 that most modern OD cars cruise at today. However, most of our cars won't see that much mileage. If you do want that old V8 to make it 100K+ miles without a rebuild, than an OD to drop the RPM's down closer to 2K would help greatly.

Re: cruising rpm [Re: Dons Dart] #1567183 01/23/14 02:39 PM 01/23/14 02:39 PM
Joined: Feb 2009 Posts: 1,274 Ontario.Canada C can.al OP pro stock
can.al OP pro stock C Joined: Feb 2009 Posts: 1,274 Ontario.Canada	Quote: Quote: ..yes.small cam and 340 i have both 3.55 and 3.23 and i'm thinking 3.23 would be better for this combo yep i would take that 355 off your hands lol.looking forward to seeing your Dart one day AL ...should be ready for early spring if there are no hiccups.

Re: cruising rpm [Re: can.al] #1567184 01/23/14 04:16 PM 01/23/14 04:16 PM
Joined: Apr 2007 Posts: 2,914 Calgary, Alberta Canada a12rag master
a12rag master Joined: Apr 2007 Posts: 2,914 Calgary, Alberta Canada	Guess it pretty much is going to depend on what you have for cam, convertor, gear and tire . . . In my 74 Duster360 with 727, have swapped out the original 8.25 rear end with 3:55 for a 8.25 with 2.45 !!! Cruising at 70mph all day, running 2600rpm (about 23mpg at that speed too!). . . 360 has tons of torque to roast the one tire . . . 70 Sport Satellite with 360, 727, 3.23:1 . . . no tach, so not sure of rpm, but runs 75 - 85mph all day, no issue . . . Now if the car is a 4:10 rear end . . .RPMS for sure !!! Build it for what you want/how you drive . . . Cheers, Mark

Re: cruising rpm [Re: can.al] #1567185 01/23/14 05:10 PM 01/23/14 05:10 PM
Joined: Nov 2004 Posts: 1,708 S. Il. U.S.A. 5spdcuda top fuel
5spdcuda top fuel Joined: Nov 2004 Posts: 1,708 S. Il. U.S.A.	In my old Duster with 3.23 gears in back and a 727 with a stock type 340 converter I used to turn around 3200 rpm at 70 mph with 26 in. diameter tires. Never seemed to hurt a thing. My 'Cuda with 3.55 gears and .68 overdrive [ final drive is 2.41 ] and roughly the same diameter tires is just under 2200 at 70 mph. Easier on the ears, and probably longer engine life. Both cars used a similar .030 360.

Re: cruising rpm [Re: 5spdcuda] #1567186 01/23/14 07:19 PM 01/23/14 07:19 PM
Joined: Jan 2003 Posts: 27,421 Balt. Md 3 383man Too Many Posts
383man Too Many Posts 3 Joined: Jan 2003 Posts: 27,421 Balt. Md	I run the highway all the time with my 4.30's and 30" tall tires. It runs about 3200 rpm at 60 mph and I drive it the 1-1/2 hr trip to Carlise crusin at 3200 rpm all the way and never no trouble. Ron Last edited by 383man; 01/23/14 07:23 PM.

Re: cruising rpm [Re: can.al] #1567187 01/23/14 07:46 PM 01/23/14 07:46 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: what would you say is an acceptable rpm to cruise at for an extended trip? My first Mopar (that hooked me) was a 68 GTX convertible 440/4sp/4:10 dana/14" wheels I bought in 1975. Next year I went to California & this was back when the speed limit was 70 . It was a buzzin live every 24 hour block of time like it's your last day on earth

Re: cruising rpm [Re: cjskotni] #1567188 01/24/14 12:57 AM 01/24/14 12:57 AM
Joined: Feb 2010 Posts: 18,493 Granite Bay CA Kern Dog Striving for excellence
Kern Dog Striving for excellence Joined: Feb 2010 Posts: 18,493 Granite Bay CA	Quote: Someday I hope to go the GV route or Kiesler 4 speed auto but not in the budget now, sadly. Uhhh... GOOD luck with that Keisler thing....

Re: cruising rpm [Re: Kern Dog] #1567189 01/24/14 12:45 PM 01/24/14 12:45 PM
Joined: Jul 2007 Posts: 1,526 North Carolina cjskotni pro stock
cjskotni pro stock Joined: Jul 2007 Posts: 1,526 North Carolina	Quote: Quote: Someday I hope to go the GV route or Kiesler 4 speed auto but not in the budget now, sadly. Uhhh... GOOD luck with that Keisler thing.... Ummm does this mean their tranny is not as good as advertised? I know it is quite a bit of money but I did like the idea of the lower 1st gear to give some more ommphh to the 3.55's I have now. Oh well, I guess I will need to do some more research as to what path to go down here. I was thinking the A518 route but not wanting to butcher my tranny crossmember to squeeze it in.

Re: cruising rpm [Re: Wyle E Coyote] #1567190 01/24/14 12:50 PM 01/24/14 12:50 PM
Joined: Sep 2007 Posts: 14,889 up yours Supercuda About to go away
Supercuda About to go away Joined: Sep 2007 Posts: 14,889 up yours	Quote: I've heard from a few engine builders that the "optimum" RPM for efficiency is the spot where the HP and Torque curves cross. I do not know where you heard that gem, but ALL engines have their tq and hp curves cross at 5250 rpm, all of them. That is the nature of the formula that derives HP from TQ at a given RPM. As for the RPM, drove San Diego to Memphis, N50's, 4.10's, three speed stick. 70+ mph most of the way, sometimes more, others less. 3500 rpm. They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.

Re: cruising rpm [Re: cjskotni] #1567191 01/24/14 02:08 PM 01/24/14 02:08 PM
Joined: Nov 2004 Posts: 1,708 S. Il. U.S.A. 5spdcuda top fuel
5spdcuda top fuel Joined: Nov 2004 Posts: 1,708 S. Il. U.S.A.	Keisler has filed for bankruptcy and is no longer in business. I don't have any personal knowledge or experience with their 4-speed auto trans, but some may be available used. You may wish to look into a Gear Vendors add on to your 727. The Gear Vendors unit does result in a shorter driveshaft and somewhat more severe driveline angles as the rear axle moves up and down, but your wheelbase is probably long enough for it not to be too big of an issue. Last edited by 5spdcuda; 01/24/14 02:13 PM.

Re: cruising rpm [Re: 5spdcuda] #1567192 01/24/14 05:32 PM 01/24/14 05:32 PM
Joined: Jan 2003 Posts: 5,186 Wherever I am. J Junky master
Junky master J Joined: Jan 2003 Posts: 5,186 Wherever I am.	383ci, 3.73 rear gears, 29" tires, 727 trans, tight torque converter. I run I-5 between 3200 and 3500 RPM quite often. No big deal. 2010 Black Challenger SE <> 3.5 V6 Custom Shift Knobs www.flameball.com Check It Out

Re: cruising rpm [Re: Supercuda] #1567193 01/24/14 07:37 PM 01/24/14 07:37 PM
Joined: Feb 2009 Posts: 1,274 Ontario.Canada C can.al OP pro stock
can.al OP pro stock C Joined: Feb 2009 Posts: 1,274 Ontario.Canada	your maximum lo speed torque must be your cruise rpm for efficiency. ..short duration cams should be more efficient at a lower rpms than long duration cams.

Re: cruising rpm [Re: can.al] #1567194 01/25/14 01:53 PM 01/25/14 01:53 PM
Joined: Nov 2010 Posts: 3,696 jersey S Spaceman Spiff master
Spaceman Spiff master S Joined: Nov 2010 Posts: 3,696 jersey	3.73's and 275/60/15 had no problem turning 3,500 to 4,000 most of the way to Carlisle. 526 cubes of angry wedge, pushbutton shifted, 9 passenger killer!

Re: cruising rpm [Re: can.al] #1567195 01/25/14 02:55 PM 01/25/14 02:55 PM
Joined: Sep 2007 Posts: 14,889 up yours Supercuda About to go away
Supercuda About to go away Joined: Sep 2007 Posts: 14,889 up yours	Quote: your maximum lo speed torque must be your cruise rpm for efficiency. ..short duration cams should be more efficient at a lower rpms than long duration cams. I know that, but that is not what the poster stated. He stated cruise RPM should be where HP and TQ curves cross, that is 5250 for all engines, all cams, all whatever. They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.

Re: cruising rpm [Re: Supercuda] #1567196 01/25/14 03:03 PM 01/25/14 03:03 PM
Joined: Feb 2003 Posts: 21,318 Manitoba, Canada DaytonaTurbo Too Many Posts
DaytonaTurbo Too Many Posts Joined: Feb 2003 Posts: 21,318 Manitoba, Canada	Quote: Quote: your maximum lo speed torque must be your cruise rpm for efficiency. ..short duration cams should be more efficient at a lower rpms than long duration cams. I know that, but that is not what the poster stated. He stated cruise RPM should be where HP and TQ curves cross, that is 5250 for all engines, all cams, all whatever. also, would not peak torq at part throttle occur at a lower rpm? I don't set the cruise at wot!

Re: cruising rpm [Re: can.al] #1567197 01/25/14 03:26 PM 01/25/14 03:26 PM
Joined: Sep 2004 Posts: 22,873 Chicken coop dustergirl340 Chicken Little
dustergirl340 Chicken Little Joined: Sep 2004 Posts: 22,873 Chicken coop	I have 3.91's with 28" tires in the Duster. 2 1/2 hour trip to Woodward netted 3,900 RPM at 70 MPH on the freeway. Guess it's all in what you can tolerate.

Re: cruising rpm [Re: can.al] #1567198 01/25/14 03:38 PM 01/25/14 03:38 PM
Joined: Apr 2012 Posts: 18,880 - R RSNOMO Moparts Torchbearer
RSNOMO Moparts Torchbearer R Joined: Apr 2012 Posts: 18,880 -	Quote: what would you say is an acceptable rpm to cruise at for an extended trip? ..would 2800 - 3000 be pushing it on a 2 or 3 hour period? Ran 85 M.P.H.+ in the 'Power Tour' for 100+ miles in the past... 440 in front of 3:23's... That was an extreme...And the sweet-spot... All things considered out there today, run the 3:23's... Why buzz the engine??? And why limit yourself???

Re: cruising rpm [Re: dustergirl340] #1567199 01/25/14 03:44 PM 01/25/14 03:44 PM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	Believe it or not but I had a new 340 Duster in 71 factory equipped with 3.91 and 4 speed and it got better mileage at 70 and 3900/4000 than at 55/60.

Re: cruising rpm [Re: MoparforLife] #1567200 01/25/14 03:50 PM 01/25/14 03:50 PM
Joined: Sep 2004 Posts: 22,873 Chicken coop dustergirl340 Chicken Little
dustergirl340 Chicken Little Joined: Sep 2004 Posts: 22,873 Chicken coop	I've only calculated the gas mileage in the Duster once, actually on that same Woodward trip. It got 12. So...that's pretty bad.

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