| Author | Message | ||
| Moe Hollow (Moehollow)
Registered Member Username: Moehollow Post Number: 53 Registered: 12-2007 Posted From: 71.102.20.26 Rating: N/A |
I'm about to do some tuning on my 8v71 w/Spicer. What no load speed have you found is optimal? | ||
| Dan West (Utahclaimjumper)
Registered Member Username: Utahclaimjumper Post Number: 104 Registered: 1-2005 Posted From: 208.66.38.115 Rating: N/A |
2250 is normal.>>>Dan | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 564 Registered: 8-2006 Posted From: 76.91.197.153 Rating: N/A |
I'd call 2250 a little high, 2150 on a mechanical engine will still give almost full fuel at 2100, with much less chance of explosion. G | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 476 Registered: 10-2006 Posted From: 208.100.193.217 Rating: N/A |
Running at 1950 will give the best fuel mileage . I have found it easiest to set the 1950 as top speed , so one simply drives floored . Having a extra 200rpm aviliable does not get up hills faster, but requires constant attention NOT to use it . So floored at a lower gov setting is easier on those LOOONG days. FF | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 74 Registered: 7-2006 Posted From: 72.45.68.242 Rating: N/A |
I run mine at 2500 rpm all day. 4-71T | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 19 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
Running the rack and setting the no load and running at that RPM is completely different. On an inline engine, like the 4-71 or 6-71, running all day at 2500 is fine since they have twice the bearing area compared to the V blocks. During the 60's many a trucker turned their 8V-71's up to 2,800rpm for extra power. I have my 8V-71 set at 2,400rpm no load. While I don't go there very often, it's there in case you need the extra speed. Besides, running at 2,500rpm all day isn't going to make that much difference considering the low mileage most put on their buses. Good Luck, TomC | ||
| Larry Baird (Airhog)
Registered Member Username: Airhog Post Number: 144 Registered: 1-2001 Posted From: 71.9.83.67  Rating: N/A |
1950 in my MC-7 is about 85 MPH. | ||
| Moe Hollow (Moehollow)
Registered Member Username: Moehollow Post Number: 54 Registered: 12-2007 Posted From: 71.102.20.26 Rating: N/A |
Larry That sounds really strong. What drive train and rear end do you have? | ||
| Larry Baird (Airhog)
Registered Member Username: Airhog Post Number: 145 Registered: 1-2001 Posted From: 71.9.83.67 Rating: N/A |
I just put in a 8V71T and a RTO 10 speed. I run 3:88 in the rearend and 11R24.5's. I just made a trip to Zion NP from the LA area and pulling my 4700 lb. toad between 70-75 I got 7 MPG. I don't use overdrive much here in CA but it sure is nice when no one is looking. The bus weight is 33,000 lbs. | ||
| Douglas Tappan (Dougthebonifiedbusnut)
Registered Member Username: Dougthebonifiedbusnut Post Number: 66 Registered: 10-2004 Posted From: 75.69.223.64  Rating: N/A |
With regard to rpm settings On most mechanical engines the factoy setting was 2150.In another post I said I had little experience with DD's but I did drive a 8v71 in a cabover Mack for about 10k miles. it had so many miles on it that the gvernor had creeped up to 2400 rpm. The truck had a 4x4 trans in it which meant you always had it screaming.(not mention the fact that I was 23 and the more noise it made the better- that desire has long since changed)The point is that the factory setting of 2150 is to insure they can stay within the terms of their warrenty,I contend you can run a DD at 2400 all day long And see little differance in longevity. |