Reply
 
Thread Tools Display Modes
 
Old 06-27-2016, 02:57 PM   #41
Bus Nut
 
Join Date: Jun 2016
Location: Orange County, CA
Posts: 385
Year: 1990
Coachwork: integral
Chassis: Crown Supercoach II pusher
Engine: Detroit 6V92TAC, DDEC 2, Jake brake, Allison HT740
Rated Cap: 37,400 lbs GVWR
Quote:
Originally Posted by PNW_Steve View Post
Detroit 671N info?

Hey Everyone,

Thank you for all of the discussion. I love to sit back and listen to folks who are more knowledgeable than I am on a subject discuss it. Educational and entertaining

I have put many miles on DD 2 strokes and they hold a special place for me. However, I have never even seen a "pancake" 671.

I have been searching for details regarding the difference between the regular 671 and the "pancake". I would guess from DD practices that parts commonality would be good. Just guessing though.

How about parts availability?

Is it likely that I may find a Crown with a factory 671T or TA?

Lastly.... I am eyeballing a couple of Crown's that are equipped with 5 speed manual's. Neither seller can identify what transmission it is. I am guessing that it is the Spicer MD 5 speed??? What can you all tell me about this trans? How about swapping in a 7 or 9 speed?
The major difference between pancake and upright Detroits (and presumably also Cummins) is the oil pan and oil pump. With the right parts it is theoretically possible to convert an upright Detroit to a pancake for a Crown or Gillig - however, finding those parts these days may be impossible. It's easier to just find a bus with the right engine.

Crown used both non-turbo and turbo versions of the pancake 6-71 in their Twinkies. The non-turbo has about 215 HP, and the turbo has 270 HP. With a 10-speed transmission even a non-turbo Detroit Crown is reasonably quick, and a 6-71T with a Roadranger 10-speed is a brisk performer. My friend's 40-foot Crown tandem with a 6-71T and RT-910 Roadranger climbed Tehachapi in 9th gear, and his bus is heavier than 35-foot Crowns. There's at least as many turbo Crowns out there as non-turbos, so if you want one just be patient - school districts in CA are beginning to sell off their non-CARB Crowns now.

Remember, no two Crowns are alike. Every one was built to order, and as long as Crown could get the parts the customer wanted they would build it. Some thrifty school districts bought low-spec buses, especially if they are in non-mountainous areas, but some districts speced their Crowns with all the bells and whistles - sanders, extra heaters, Jake brakes or retarders, A/C or power vents, tinted windows, highway gearing, extra baggage compartments, etc etc. For example, Eastern Sierra's Crowns had almost every available option, but they were covering several hundred miles a day. Often the buses from mountain districts are better speced.

John
Iceni John is offline   Reply With Quote
Old 06-27-2016, 03:12 PM   #42
Bus Nut
 
Join Date: Jun 2013
Posts: 252
Quote:
Originally Posted by PNW_Steve View Post
Detroit 671N info?

Hey Everyone,

Thank you for all of the discussion. I love to sit back and listen to folks who are more knowledgeable than I am on a subject discuss it. Educational and entertaining

I have put many miles on DD 2 strokes and they hold a special place for me. However, I have never even seen a "pancake" 671.

I have been searching for details regarding the difference between the regular 671 and the "pancake". I would guess from DD practices that parts commonality would be good. Just guessing though.

How about parts availability?

Is it likely that I may find a Crown with a factory 671T or TA?

Lastly.... I am eyeballing a couple of Crown's that are equipped with 5 speed manual's. Neither seller can identify what transmission it is. I am guessing that it is the Spicer MD 5 speed??? What can you all tell me about this trans? How about swapping in a 7 or 9 speed?
From what I can learn via Google, there appears to be little difference in a 6-71 in a traditional installation versus a 'pancake' installation. It sounds like the engine block was very versatile for a variety of applications including marine use. For that reason I would guess there's probably a large cache of spare parts out there.

As for finding a Crown with a 671T, I can't find any references BUT if you are willing to look at transit buses it appears these were used in city buses made by Flxible and used in markets like Spokane and Portland. Happy hunting!
jake_blue is offline   Reply With Quote
Old 06-27-2016, 03:14 PM   #43
Bus Nut
 
Join Date: Jun 2013
Posts: 252
John beat me to the punch and with better info!
jake_blue is offline   Reply With Quote
Old 06-27-2016, 03:22 PM   #44
Bus Crazy
 
Join Date: May 2016
Location: Pacific North Wet
Posts: 1,335
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
Quote:
Originally Posted by Iceni John View Post
The major difference between pancake and upright Detroits (and presumably also Cummins) is the oil pan and oil pump. With the right parts it is theoretically possible to convert an upright Detroit to a pancake for a Crown or Gillig - however, finding those parts these days may be impossible. It's easier to just find a bus with the right engine.

Crown used both non-turbo and turbo versions of the pancake 6-71 in their Twinkies. The non-turbo has about 215 HP, and the turbo has 270 HP. With a 10-speed transmission even a non-turbo Detroit Crown is reasonably quick, and a 6-71T with a Roadranger 10-speed is a brisk performer. My friend's 40-foot Crown tandem with a 6-71T and RT-910 Roadranger climbed Tehachapi in 9th gear, and his bus is heavier than 35-foot Crowns. There's at least as many turbo Crowns out there as non-turbos, so if you want one just be patient - school districts in CA are beginning to sell off their non-CARB Crowns now.

Remember, no two Crowns are alike. Every one was built to order, and as long as Crown could get the parts the customer wanted they would build it. Some thrifty school districts bought low-spec buses, especially if they are in non-mountainous areas, but some districts speced their Crowns with all the bells and whistles - sanders, extra heaters, Jake brakes or retarders, A/C or power vents, tinted windows, highway gearing, extra baggage compartments, etc etc. For example, Eastern Sierra's Crowns had almost every available option, but they were covering several hundred miles a day. Often the buses from mountain districts are better speced.

John

Hey John,

Thanks for the info!!

That eases my mind. If, for example, I lost a rotor seal and had a runaway then I could find a good running 671 and move the oil pan etc from the dead motor. Not a lot of unique pieces.

As far as the CA school districts go, I have been told that the majority of the Crowns have already been or are about to be crushed.

Any thoughts regarding swapping a 9 or 10 speed for a factory 5 speed?

Thanks again.
PNW_Steve is offline   Reply With Quote
Old 06-27-2016, 03:36 PM   #45
Bus Geek
 
EastCoastCB's Avatar
 
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 11,185
Year: 1992
Coachwork: Ward/AmTran
Chassis: International
Engine: dt466
Rated Cap: 78
Goes without saying, but the 855 big cam would be awesome.
Crowns were some amazing school buses.
__________________
.
Roll Your Own Build Thread
EastCoastCB is offline   Reply With Quote
Old 06-27-2016, 04:54 PM   #46
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 7,195
Year: 1991
Coachwork: Carpenter
Chassis: International S3800
Engine: DT360
Rated Cap: 7 Row Handicap
columbus ohio had a bunch of flxibles and were quickly retired due to many service issues... A/C, electrical and frame cracks were some of the big reasons they were retired before normal criteria and were replaced with mainly Gillig's...

-Christopher
cadillackid is online now   Reply With Quote
Old 06-27-2016, 06:06 PM   #47
Bus Nut
 
Join Date: Jun 2013
Posts: 252
I guess Flxibles were too, well, flexible? Lol
jake_blue is offline   Reply With Quote
Old 06-27-2016, 10:35 PM   #48
Bus Nut
 
Join Date: Jun 2016
Location: Orange County, CA
Posts: 385
Year: 1990
Coachwork: integral
Chassis: Crown Supercoach II pusher
Engine: Detroit 6V92TAC, DDEC 2, Jake brake, Allison HT740
Rated Cap: 37,400 lbs GVWR
Quote:
Originally Posted by EastCoastCB View Post
Goes without saying, but the 855 big cam would be awesome.
Crowns were some amazing school buses.
My friend's Gillig tandem has a big-cam Cummins 855 set at 290 HP, and it moves! He jokingly says it will do 65 MPH up whatever hill you point it at, and that's not far off the truth. One day we took it up to Wrightwood ski resort, and we were having to slow for the curves going uphill! That's what 14 liters and over 1,000 lb/ft of torque does. Then on the way back I don't think he touched the brakes at all, the three-stage Jake holding our speed all the way down. What a beast! If you want the ultimate Crown, get one with a Cummins 855 and turn it up to 400 HP - with the right gearing you'll have a 90+ MPH bus! The articulated Crown/Ikarus 286 transit buses that were used in Portland and elsewhere had 350 HP pancake Cummins engines - apparently they were quite strong performers.

Because Crowns (and Gilligs) were built with standard Class-8 truck parts such as drivetrains and brakes, they can be rebuilt or upgraded just like any heavy truck can. Only your imagination and wallet limit what's possible.

John
Iceni John is offline   Reply With Quote
Old 06-28-2016, 01:50 AM   #49
Bus Crazy
 
Join Date: Jul 2011
Location: Winlcok, WA
Posts: 1,597
Quote:
Originally Posted by PNW_Steve View Post
Hey John,

Thanks for the info!!

That eases my mind. If, for example, I lost a rotor seal and had a runaway then I could find a good running 671 and move the oil pan etc from the dead motor. Not a lot of unique pieces.

As far as the CA school districts go, I have been told that the majority of the Crowns have already been or are about to be crushed.

Any thoughts regarding swapping a 9 or 10 speed for a factory 5 speed?

Thanks again.
\

Swapping in a Road Ranger multi-range transmission in place of the 5-speed is a pretty straight forward swap. Both use the same single shaft gear shift so the hardest part of the swap is just a matter of sliding the shifter into the top of the transmission. You may (most probably) have to have the driveline shortened as the multi-range transmissions tend to be longer than the 5-speeds.

Our church has a 1986 Crown with a 6-71TAC. You have to remember not to floor it from a stand still but ease into the throttle. If you mash the go pedal on the start you throw up a smoke screen that would impress most of those idiots that are always "blowin' coal". But if you ease into it and let the turbo spool up it won't smoke at all. Gearing limits the top speed but it will cruise all day up and down hills at 70 MPH. I can't remember if the HP is set at 250 or 280. I tend to think it is the lower number since it has an MT640 and not an HT740 transmission.
cowlitzcoach is offline   Reply With Quote
Old 06-28-2016, 01:11 PM   #50
Bus Crazy
 
Join Date: May 2016
Location: Pacific North Wet
Posts: 1,335
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
Anyone in the Everett, WA area?

I hear rumor of a Crown tandem parked/abandoned on the flats between Everett & Marysville.

Anyone seen it?
PNW_Steve is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 11:27 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.