Anyone know this one?

[Flyboy]

HI All,

Just looked at a 4905 for sale in Pentiction, BC.  1975, 8V71, Spicer 4sp.  Whoever did the conversion did a great job.  Looks like a Saskatchewan bus (old lettering showing). 

The serial #P8M4108A, coach # 157.  The guy would appreciate any info on the history of this rig.

It got me all fired up to get our bus on the road.  Heading down to Peoria to pick it up and head north in May.  Gonna be fun.

Aron.

[roadrunnertex]

P8M-4108A-157 From GMC to Saskatchewan Transportation Company (Regina,Sask) 10-75.
FYI you stated it was a 4905 and you listed it as a P8M-4108A?
jlv

[Flyboy]

Sorry Nick.

[Flyboy]

Roadrunnertex,

It must be a 4108.  Is that a sceniccruiser?  The floor is stepped up and it has the view windows on the front. 

[roadrunnertex]

It,s not a Scenicruiser this model GM Coach were called Buffalo's because of the hump in the roof.
And in the Northeastern part of the United States some coach operators called them "decks" because of the upper deck.
P8M4108A's were 35 feet long.
P8M4905A were 40 feet long.
The upper deck overhead windows are called "vista windows"
These model coaches were the last GMC intercity coaches built by GMC.
jlv

[Dallas]

To add to Johns post,

PD4501 was the scenic... a 45 passenger, twin deck V-drive, 4 speed wonder of the engineering world.

Too bad they never made a 35' model.. like the Flx Liner or the VL100.

It probably would have completed the corral that GM had on bus transportation. They wouldn't have had to redesign or build the 4104, 06, 07, 08, or 4903-05.

[Flyboy]

Hi Dallas,

Hope all's well with you and yours.  Good to see you in the last BC issue. 

Aron.

[Runcutter]

To expand a little on John's comment.  We called them a "deck-and-a-half", - also shortened to "deck" (northeastern Massachusetts) when I was driving.  Even though I now own a 4107, I still can't bring myself to call it a "buffalo".

Arthur

[Stan]

Dallas: Are you sure the PD4501 was a V drive?

[luvrbus]

I am not a GM person but all 4501 I been around where T drives

[Hartley]

To add to Johns post,

PD4501 was the scenic... a 45 passenger, twin deck V-drive, 4 speed wonder of the engineering world.

Too bad they never made a 35' model.. like the Flx Liner or the VL100.

It probably would have completed the corral that GM had on bus transportation. They wouldn't have had to redesign or build the 4104, 06, 07, 08, or 4903-05.

Dallas,

The Scenicruiser PD4501 is and always a T-Drive machine. It was unique among the GM buses of the day and after. The reason was it came out with TWO 4-71 Engines mounted side by side and coupled together to run the bus. They had to change those out and install 8V71's because the twin engines just didn't work out that well.

I rode on the twin engined buses in their day. They were crude and noisy and underpowered but they were a great ride. That was before Intertstate Highways.
US1 & 301 North through the mountains.... The OLD days... Burma Shave, See Rock City and Stuckeys....

Dave....

[roadrunnertex]

PD-4501 Scenicruiser
When the Scenicruiser came out in August of 1954 it was powered with 2-4/71 Detroit diesel engine's connected to a fluid type coupling for a total of 300 horse power.
The transmission was a 3 speed with a high & low range in each gear for a total of 6 forward speeds.
When the 2- 4/71's were set up right and were synchronized the Scenicruiser was a very nice bus to drive and had plenty of power but let the 2 engines get out of synchronization it was a real underpowered coach.
I have been on the Scenicruisers with the 2-4/71's and they would out run any thing on the road.
When the Scenicruisers were re-powered to a 8V/71 and the 4 speed Spicer transmission the engines were set up to around 276 horse power which was less than when it was powered with the 2-4/71's.
The Scenicruisers were in Greyhound service longer than any other coach in the Greyhound fleet.
To this day the Scenicruiser is still a head turner just ask the folks that own one.
jlv

[Dallas]

Yup, Thanks Dave, I knew that... I chalk it up to Brain Gas...or old age, or just plain stoopidity!

Dallas

To add to Johns post,

PD4501 was the scenic... a 45 passenger, twin deck V-drive, 4 speed wonder of the engineering world.

Too bad they never made a 35' model.. like the Flx Liner or the VL100.

It probably would have completed the corral that GM had on bus transportation. They wouldn't have had to redesign or build the 4104, 06, 07, 08, or 4903-05.

Dallas,

The Scenicruiser PD4501 is and always a T-Drive machine. It was unique among the GM buses of the day and after. The reason was it came out with TWO 4-71 Engines mounted side by side and coupled together to run the bus. They had to change those out and install 8V71's because the twin engines just didn't work out that well.

I rode on the twin engined buses in their day. They were crude and noisy and underpowered but they were a great ride. That was before Intertstate Highways.
US1 & 301 North through the mountains.... The OLD days... Burma Shave, See Rock City and Stuckeys....

Dave....

[Dreamscape]

roadrunnertex,

John, Always enjoy reading your very informative posts. The information you provide is priceless and I learn so much.

Even though I have an Eagle, other brands always interest me.

Thanks,

Paul

[TomC]

The main reason that the 4501 had 2 4-71's is that GM had not come out with the V blocks yet.  The standard practice then was to just add engines as needed-as was the case during WWII.  A larger landing craft was created that needed twin 600hp engines.  Back then, without turbocharging, those engines would have been 8 cylinder locomotive engines that were both expensive and heavy.  Instead they used a bull gear and attached 4 6-71's-two in front and two to the rear of the bull gear. This worked well in that they had 8 engines-just in case one or more quit.  And many was the time after battle that they would come home only on one or two engines total.  They got long life out of the engines since they could get the total horsepower (1200) out of the engines at only 1500 rpm. 
There are many other instances of multiple engines used through a bull gear-mainly in the oil industry on drilling rigs.  So it seemed natural for Grayhound to use it on the 4501.  It was more a transmission problem with the fluid drive to the 3x2 transmission then the actual two engines.  But also, they took off a whole bunch of weight hanging out behind the rear axles also.  2 4-71's weigh in at 3,400lbs compared to the 8V-71 at 2,350lbs, plus the fluid coupling, 3 speed transmission and 2 speed splitter, I bet they reduced the engine/transmission weight by close to a ton.  Now in this day and age-how about 2 4-71's turbo'd and air to air intercooled running through a bull gear with an Allison World Transmission?  That might be unique.  Good Luck, TomC