Plymouthy Adams Posted October 19, 2014 Report Share Posted October 19, 2014 depends on where/what you rub that octane onto and if there is an obstacle in your general compass heading... Quote Link to comment Share on other sites More sharing options...
BobB Posted October 19, 2014 Report Share Posted October 19, 2014 My 52 can go 120 'course the units are a bit different . . . 2 Quote Link to comment Share on other sites More sharing options...
BobB Posted October 19, 2014 Report Share Posted October 19, 2014 My 52 can go 120 'course the units are a bit different . . . Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted October 19, 2014 Report Share Posted October 19, 2014 With my gearing I can comfortably cruse all day long at 23.5 leagues per hour. 4 Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted October 19, 2014 Report Share Posted October 19, 2014 That's cruising down I94 through Michigan on my way to the WPC meet in Detroit this past summer. My speedo is a little off though. My actual speed was closer to 78 MPH. This is with 235/75R-15 tires with a 28.75" diameter and 3.73:1 diff gears. If I had the original 4.10 gears that would equate to 71 MPH. If I had 3.54 gears I'd be able to wind it up to around 82 at that engine speed. Maybe I'm more willing to let my engine spin than some are. I do have disc brakes up front that give me some piece of mind at those speeds. The steering could be a little tighter but it's useable. I agree that the truck and I am more comfortable below 60, but I know I can run with the big dogs when I need to. Merle 1 Quote Link to comment Share on other sites More sharing options...
Reg Evans Posted October 19, 2014 Report Share Posted October 19, 2014 Maybe I'm "luggin it" at 60mph's. ;-) The calculator says 2100 rpm's with 28.75" diameter tires. 1 Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted October 19, 2014 Report Share Posted October 19, 2014 Maybe I'm "luggin it" at 60mph's. ;-) The calculator says 2100 rpm's with 28.75" diameter tires. I think it is the old lug behind the wheel 2 Quote Link to comment Share on other sites More sharing options...
dmulhall Posted March 6, 2015 Report Share Posted March 6, 2015 I was reading up on what rpms are "healthy" for a dodge flathead... I cruise along with 4:11 gears at about 50-55mph (but no tach) I always have in the back of my mind how good it is for the engine... then I think...my engine is a ind 251 out of a massey combine and this engine would have been running all day at full throttle for weeks at a time... so I'm trying to come to terms in my head on if it really affects it or not... I did the cheap man rebuild (rings, hone job, bearings) and put about 600 miles on the engine so far doing a mixture of city and highway driving.... discussion? Quote Link to comment Share on other sites More sharing options...
dmulhall Posted March 6, 2015 Report Share Posted March 6, 2015 by way I know sone industrial engines came with full flow oil filtration (or whatever its called) but my engine is just running the standard canister bypass filter Quote Link to comment Share on other sites More sharing options...
dmulhall Posted March 6, 2015 Report Share Posted March 6, 2015 by way I know sone industrial engines came with full flow oil filtration (or whatever its called) but my engine is just running the standard canister bypass filter Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted March 6, 2015 Report Share Posted March 6, 2015 by way I know sone industrial engines came with full flow oil filtration (or whatever its called) but my engine is just running the standard canister bypass filter If your engine block has the raised diamond shaped "boss" shown to the right of the distributor in the photo below it is an easy conversion to full flow oil filtration. If interested I can show you how to do it. Quote Link to comment Share on other sites More sharing options...
dmulhall Posted March 6, 2015 Report Share Posted March 6, 2015 picture Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted March 6, 2015 Report Share Posted March 6, 2015 picture Looks like you are bossless. 1 Quote Link to comment Share on other sites More sharing options...
pflaming Posted March 6, 2015 Report Share Posted March 6, 2015 My dad had a MH grain combine. It ran at full throttle all day in 100 +\- heat. Daddy's a instructions were simple: if the gauges are dirty clean them and don't let them get dirty, watch the temp and oil pressure. The engine never failed. Some use these as power plants c for irrigation and such. I have 3:73 in my truck, travel at ease with the semis, and pass them when I so desire. But it then does have a more noticeable rhythm. I have a Quiet Ride kit which goes in next and that will help. Maybe new body mounts would help as well. Quote Link to comment Share on other sites More sharing options...
NiftyFifty Posted March 6, 2015 Report Share Posted March 6, 2015 First of all....are your brakes all new?? That's what determines how fast you SHOULD go...lol. Your stock set up if it has the 4:10/11 shouldn't be driven much past 45-50, unless it's a fresh motor as well...or in excellent running shape. That sludge that these motors like to build up is a killer at high rpm for long periods, and with a 1000+ mile drive, I'd rather baby it that break it myself. I'm not even going to chance driving mine the 600 miles to Minneapolis this summer, as keeping up on the interstate is going to be tough on the old girl, and it's a rebuilt 251 with 5 speed and 3:73 gears. If even your gear set was a bit lower you could do 60, but the truck just wasn't designed for that kind of driving in stock form. Quote Link to comment Share on other sites More sharing options...
Young Ed Posted March 6, 2015 Report Share Posted March 6, 2015 First of all....are your brakes all new?? That's what determines how fast you SHOULD go...lol. Your stock set up if it has the 4:10/11 shouldn't be driven much past 45-50, unless it's a fresh motor as well...or in excellent running shape. That sludge that these motors like to build up is a killer at high rpm for long periods, and with a 1000+ mile drive, I'd rather baby it that break it myself. I'm not even going to chance driving mine the 600 miles to Minneapolis this summer, as keeping up on the interstate is going to be tough on the old girl, and it's a rebuilt 251 with 5 speed and 3:73 gears. If even your gear set was a bit lower you could do 60, but the truck just wasn't designed for that kind of driving in stock form. How fast do you think we drive here? With your setup you should easily be able to go 70 which as far as I know is the highest speed limit in MN. 1 Quote Link to comment Share on other sites More sharing options...
TodFitch Posted March 6, 2015 Report Share Posted March 6, 2015 First of all....are your brakes all new?? That's what determines how fast you SHOULD go…lol. . . . . . I'm not even going to chance driving mine the 600 miles to Minneapolis this summer, as keeping up on the interstate is going to be tough on the old girl, and it's a rebuilt 251 with 5 speed and 3:73 gears. If even your gear set was a bit lower you could do 60, but the truck just wasn't designed for that kind of driving in stock form. Hmmm. Drove the '33 to Tucson the other year, about 900 miles each way and some miscellaneous driving while in Arizona brought the trip total up to about 2,000. Came back the 900 miles averaging 60 MPH on the freeway with the stock (but rebuilt 25,000 miles ago) 190 cu.in. engine with a 3speed and original 4.375 rear end. I guess we have a difference of opinion how long the engine can safely stay at 3,000 or so RPM. I do agree about the brakes though: They really determines how fast you should go. 1 Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted March 6, 2015 Report Share Posted March 6, 2015 That sludge that these motors like to build up is a killer at high rpm for long periods, What sludge buildup? When an engine runs at full operating temperature for long periods of time there is very little sludge buildup. 2 Quote Link to comment Share on other sites More sharing options...
dmulhall Posted March 6, 2015 Report Share Posted March 6, 2015 all my brakes are rebuilt and new pads...set up fairly well..petal is about 3 inches from the top... kingpins have been done and it drives straight with no play... 50-55mph feels about right Quote Link to comment Share on other sites More sharing options...
Reg Evans Posted March 6, 2015 Report Share Posted March 6, 2015 Well....I guess I need a "Quiet Ride" kit cause Old yeller has a '50 Chrysler 251, the stock 4 speed, and a complete drum to drum 65 T-Bird 3.0 rear end. At 65mph's I'm still reminded why I named it Old Yeller. Quote Link to comment Share on other sites More sharing options...
dmulhall Posted March 6, 2015 Report Share Posted March 6, 2015 according to the gps on my phone I have had it up to 69mph but she was sweating pretty good haha Quote Link to comment Share on other sites More sharing options...
wallytoo Posted March 6, 2015 Report Share Posted March 6, 2015 (edited) i drive my 1.5 ton at 50 mph max, but i'm comfortable with it at 45 mph for long stretches. the tach indicates it's at 2500 rpm at 45, while it pushes 2700 at 50. that's in high range for the rear (5.83) instead of low range (8.11). the tires are 36" in diameter. according to the "book", i should be able to push it close to 55 and be at 3000 rpm, well within its governed limit (3200). Edited March 7, 2015 by wallytoo Quote Link to comment Share on other sites More sharing options...
pflaming Posted March 7, 2015 Report Share Posted March 7, 2015 " . . . within its governed limit (3200)." I've been looking for that RPM. Charts show as high as 3600 but that is probably the safe max upon need, but not the recommended rpm for long time running. Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted March 7, 2015 Report Share Posted March 7, 2015 drive it like you stole it....zoom zoom Quote Link to comment Share on other sites More sharing options...
NiftyFifty Posted March 7, 2015 Report Share Posted March 7, 2015 What sludge buildup? When an engine runs at full operating temperature for long periods of time there is very little sludge buildup. Sure...IF it's had that kind of life and hasn't had a lot of short runs and poor oil changes in its life. I didn't see where it was a rebuilt engine, so who knows what's lurking in the pan and oil gallery...its when your at high rpm that you need the most oil flow to protect everything, and if your even semi plugged...could spell disaster. I was doing 50 mph when mine went KABOOM, threw a rod right through the side of the pan...and I believe because the sludge in my 218 was depriving the bearings of proper oil Quote Link to comment Share on other sites More sharing options...
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