| Author |
Message |
Bob Baldwin (Bob4106) (66.56.100.54)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 3:56 pm: | |
How will a 6 71 do on the interstate ? I have heard some people with a 8v71 move with speeds like 80 to 90 mph.And pulling a car behind then .I test drove a 4104 with a 6 71 on a road that i could go 35 mph only. And felt like it didn't have power to do what i wanted it to do .With the road speed limit at 35 mph i was shifting gears and in 4th gear felt havey and useing all the power.The bus was empty.And this was a fresh motor. Don't need to got that fast but don't want to be in the way.And be able to pull a hill ok |
two dogs (67.30.23.28)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 4:39 pm: | |
there was something wrong with the 671 when you drove it...lots of times "new" bus drivers don't get the air built up to 100 & get the spring brake released...after you release the parking brake ,press hard on the brake pedal for 60 seconds,IF you have 100 pounds,then, "bump" the clutch & see if it wants to roll...both 671 &871 should do 65 no problem, also "new" people don't realize how important fuel filters are & can't figure out how come it doesn't have as much power as it used to |
John Feld (150.199.209.47)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 6:52 pm: | |
Did you forget to release the brake? My 4104 6-71 is geared at 67 MPH and it does it.
80-90 MPH? I'm gonna get in trouble for saying this, BUT, that's down-right stupid and an accident waiting to happen. Tires are only tested to 75 MPH.
John 4104 |
Peter Broadribb (Madbrit) (65.37.90.139)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 8:17 pm: | |
To cruise at the speed limit of 75 mph on many Interstates, I feel it is only safe to have the ability to attain 85 mph for overtaking. Otherwise one takes forever to pass that 70 mph truck you catch up. It is not safe to be flat out with nothing in reserve.
I think a sustained 85 mph is getting a little too fast as well, but 75 mph tires means a constant speed of 75 mph not a max speed, one can go more for a few miles.
My 2 cents.
Peter. |
Tom Connolly (Tomconnolly) (64.58.196.218)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 8:52 pm: | |
Bob,
I have had the opportunity to run side by side up the interstate many times my 4104 stock 6-71 and a friends 4106 stock 8-71.
The 4106 is faster off the line and gains only about 3-4 bus lengths up to cruising speed (70mph) at the first grade I always win with my 04, maybe I just hit the gears better!
Any way if they are not built up they are not all that much different.
As far as your test drive you shift in to 4th at 45mph if you were running 4th at 35, on level ground she will not be accelerating at a very noticeable rate.
You run a 4104 with your foot in the floor and hold each gear till just below she tops governor speed! and they are faster than they feel, No Dog well maybe an old hound.
Mine does 78mph and gets 10 mpg, Most others claim about the same. The 6-71 is a good power plant & you can get to everything from the outside of the coach!
Tom C |
Phil Dumpster (12.230.214.167)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 8:59 pm: | |
Guys, he didn't say that bus would only go 35 mph, he said it didn't seem to have much power in fourth gear at 35 mph. |
two dogs (67.30.23.56)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 10:00 pm: | |
WHERE ARE THE BUS RACES....NEATO...WAY TO GO TOM |
gabby (67.30.112.205)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 12:05 am: | |
Anyone that is going 35 MPH in 4th gear is really lugging the engine and will damage it. |
BrianMCI96A3 (65.41.249.60)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 8:30 am: | |
My friend's father a diesel field mechanic for 40 years, built an early 60's Madsen bus, in it he stuffed a huge inline 6 caterpillar engine
with a 15 speed fuller road ranger AND, believe it or
not, an air shifted 4 speed brownie box. He claimed it would do 140 mph if he wanted it to, and he raced an empty semi flat bed on the interstate across a dry lake bed and just walked away from him up the mountain on the other side!
Brian |
Jim-Bob (12.46.52.74)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 9:41 am: | |
I have a 4104 with the stock 6-71 & the 3.55:1 rear axle ratio. My shift speeds are 23, 33 & 55mph. The speedo is correct. You run the 6-71 flat out 'till it hits the governor (you'll know 'cause it stops pulling.) Then shift to the next gear. If you are at 35 in 4th you ARE lugging it. Third is a good "city gear". It works from 20 to 50 or so. Detroits are two strokes, they need to rev to make power very unlike 4 strokes. Imagine it is a 2 cycle motorcycle. You won't hurt it running at 2100 against the governor, they run 2350 in boats & 24-2500 in fire service.
You haven't lived till you have run flat out in second for a half hour or so climbing some mountain.
RJ Long has done a great paper you can download to get the hang of the bus transmission. Another thing is that you can't shift these old buses fast like trucks. My trucker brother in law drove our bus & went to shift very quickly like a truck. The bus won't shift that way. You have to time it (count) as per RJ's paper. |
RJ Long (Rjlong) (24.127.74.29)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 8:39 pm: | |
Thanks, Jim-Bob, for the nice comments. That article can be found here on the BNO site, off the main page under "Articles of Interest". Or simply click this link:
http://www.busnut.com/artrjl2.html
RJ
PD4106-2784
Fresno CA |
John Rigby (24.174.239.244)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 9:35 pm: | |
Well there must be something wrong with my engine and tranny because I shift to first hit the gov double clutch as fast as I can ( or i miss the gear ) and put it into 2nd, actually it drops in itself.Same goes for all the gears. This is since s and w worked on the gov, rack and we replaced a slow injector. I figure it will help when changing up on the inclines, I wou,nt loose as much power.
John |
Jim Wilke (12.46.52.74)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2003 - 4:16 pm: | |
John, I had a similar problem when we first got the bus. Could hardly get it to shift. Got so frustrated almost went to automatic.
As we did long neglected maintenance, we found that the accelerator cable was almost bound up. It would only move about 3/4" and the throttle would stick open sometimes (scary!). The previous owner's solution for this was to install 2 large return springs in addition to the original one. This caused the throttle lever to return too quickly & fought with the governor.
We serviced the cable, removed the two big springs & voila! it shifts just as RJ describes. When it is right, it takes the governor a second or two to return to idle which changes the time it takes the gears to come to the proper speed to mesh. It also widens the "window" to get the shift accomplished.
BTW, if you want to shift at other than the shift point, or you miss a shift, you slowly rev up the engine while holding ever so slight pressure on the shift lever till the gears mesh. You can't change the bus speed so you have to bring the engine speed to the road speed. The longer you drive the bus, the easier it gets. I would say it took me about 5000 miles to feel comfortable.
Jim-Bob |