Long time listener, First time caller

[ColoradoCummins]

Greetings from Colorful Colorado!

My name is Jeff, and I have been doing the conversion thing since 1999.
I currently have 3 busses:

1978 Crown-DD671 (NA) - SRA
1993 BB TC2000FE 54psgr. 5.9L Turbo Cummins B series (mechanical) AT545 (junk)
1998 BB TC2000FE 71psgr. 5.9L Turbo Cummins ISB MD3060

Currently only driving the '98 TC2000

I have been perusing Skoolie since '99.
Thanks to all who have contributed! I have learned a TON from you all!

[Carytowncat]

Right on! Glad you called in, it's quite a movement happening here.

[livinthelife]

Welcome. What part of Colorado?

[ColoradoCummins]

Thanks Carytowncat!

Livinthelife

We live in South East Aurora

Which is SE of Denver

Born and raised in Englewood

Anyone near by?

[BusFiend]

Howdy, Jeff!

Ho do you like the ISB in the 71pax?

[livinthelife]

I'm not any more. I was Delta, to Montrose. I know there is one in gunnison and one in springs on here haven't seen them for a while I think there is 1 or 2 probably more in around Denver area too. Any way welcome. Got any pics for your build thread?

[ColoradoCummins]

BusFiend
Thanks!
No complaints! I can only compare it to my '93 B-series 5.9L and my '78 DD671 (non-turbo)
The ISB wraps like a gas engine. Governed at 3200rpm and I've held it at 3200 for many miles (I know, not the best for the longevity of the motor) but I'm still waiting to find an Allison shop that will unlock my 6th gear. BB will not provide a letter of approval to do so....
The B series was great too! I had an issue with the fan clutch/cooling system, so it was always running hot against the overtemp warning. Ran it like that for 5years and she still runs today. (can't say the same for the P.O.S AT545 that was behind it!)
The DD is fun, takes off like a ROCKET! Sounds like a hot rod! Overheated once, and now I need a re-build or re-power....

Livinthelife
I do. It will have to wait though. Getting ready for a trip to the Grand Canyon, and stuck on the rear Fuel Filter replacement at the moment. I loosened the filter to drain it out, and have almost 2gal. drained (not counting the filter capacity) and she's still draining! I have even clamped the fuel inlet and outlet lines upstream and downstream of the filter housing. Where is it all coming from? Will it ever stop?

[BusFiend]

Originally Posted by ColoradoCummins

BusFiend
Thanks!
No complaints! I can only compare it to my '93 B-series 5.9L and my '78 DD671 (non-turbo)
The ISB wraps like a gas engine. Governed at 3200rpm and I've held it at 3200 for many miles (I know, not the best for the longevity of the motor) but I'm still waiting to find an Allison shop that will unlock my 6th gear. BB will not provide a letter of approval to do so....
The B series was great too! I had an issue with the fan clutch/cooling system, so it was always running hot against the overtemp warning. Ran it like that for 5years and she still runs today. (can't say the same for the P.O.S AT545 that was behind it!)
The DD is fun, takes off like a ROCKET! Sounds like a hot rod! Overheated once, and now I need a re-build or re-power....

It's unfair to compare an ISB to a two-stroke Detroit. I'll take the Detroit any day. The 71s were the reason the Screamin' Eagle got it's name. There's just a lot of skoolies out there with old series B Cummins. I think they're under-powered. Now, the ISB 6.7L is a completely different story.

I wonder why Allison won't authorize your tranny reprogram. We've had a few here on the board who received letter from Allison for just that purpose...

[ColoradoCummins]

I have taken the 71pax 5.9L ISB fully loaded (but not towing anything) over Vail Pass, Berthod Pass, Monument Hill (pass), Raton Pass, and back. No complaints (other than the downhill part - thank God for the retarder!)

She slows to between 40-55mph depending on the grade and traffic keeping me from holding my momentum. Not to shabby for such a small motor!

The only real trip I have done in the Crown with the 671 (non-turbo) was when I bought it and drove from What Cheer, IA to Denver. I'll take the 5.9L Cummins any day!!!!!

Really, it all comes down to gearing. The BB was a activity bus from a rural district, so it was built for long highway runs.

6th GEAR

BB said that the driveline could not withstand the RPM's in 6th gear. I told them I didn't want to drive 85mph! I just wanted to run at 2500rpm rather than 3200rpm when on the highway, and that I would sign a release, or whatever they needed, but still no go. I've tried a few different times....

The guys I have seen that have had it approved are all Thomas RE with very short drivelines. Mine is a FE, so the driveline is LONG!!!!

[BusFiend]

Makes sense about the tranny, I guess. They approve someone unlocking. He tries to go down the highways at 80 mph. People get hurt or worse. BB gets sued.

The 71s without a turbo were a little lackluster. The Crowns with the turbo fly pretty well.