MC-6

[Mike in GA]

Betting a buddy that MCI only produced 200 of these rare buses. Am I right?
Mike in GA

[RJ]

Mike -

You lost.  MCI built only 100 MC-6s, all of which went to Greyhound.

FWIW & HTH. . .

[wg4t50]

Slight correction, 100 were produced, 1 was totalled in the parkibg lot when it was being hot rod driven and rolled over, so 99 went to Greyhound.
Dave M

[Nusa]

Any bus with a 12v71 is a hot rod. Good luck finding one with that engine still in it.

[wg4t50]

When I installed the12V-71 ib the MC7, it was real clear the 7 was setup in case a 12V went in, once positioned, it was clear hat the opening was right for the 12.  The spacing aroubd the engine gear case and the structure was so equal all around for intake, power steering pump& alternator, used the origional moubt for the damper pulley end, moved the bell housing mount 11 1/2" further and with the 8844 gear box the drive shaft would not been a problem, with the RTO910, the drive shaft had to be 9 3/16" bearing center to center, that became an issue.  Was solved by qn unusual slip joint, about 6" dia spline & about 3" long splines, a good shop was able to make a perfect setup that never had an issue.  The entire MC7 was all fun & games, none like it, was an example of what can be done.  Glad it was the 7 as am told to newer 8 & newer did not have the structure for the 3500 lb 12V.
Dave M

[Mike in GA]

Thanks, guys. I stand corrected!
     Apparently 'rare' doesnt even begin to describe those MC-6s. Wonder how many are still on the road?
Mike in GA

[TomC]

There is no other engine that puts out the sound of the Detroit 12V-71. Make it a twin turbo with straight pipes, and you have a buzzen dozen that will put out 600hp and 1800lb/ft torque-that should get the job done. If I were rich enough, I'd put one in my truck. But, I'm not, so run the Cat 3406B. Good Luck, TomC

[wg4t50]

TomC,
Trust you understand the humor of passing a 465 hp computer Cat with an empty Ravens (aluminum) flat bed, passed him proper, he wanted to know that the hell I had in the old bus, I told him it was a wore out 318, that is when he lost it, he was so proud ot that Cat.
Just glad the mountain was long enough that when he got to the top, I was long gone, out of sight, not a happy camper, am sure he bent the steering wheel,  a very unhappy feller, no humor in him.
If he was more sane, would have confessed the 12V-71 twin turbo 145 injectors at the time and the RTO-910.
That was years  ago when the 465 Cat was the big boy Cat. Guess a 3406E.
The big issue of my setup at the time was traction/wheel spin and tag air bag pressure, carry enough psi in the tag bags to keep from bouncing, spinning was an issue, lower the pressure for traction and the tag would bounce/dribble.  Only had the twin turbo setup for about 2 weeks and removed it, back to normal 12V-71, and N70's.
The 12V-71 was the best sand box toy I ever played with, great memories, some on this forum knew it and rode in it as had it to Arcadia a few times etc.
Dave M

[CrabbyMilton]

Tom C. I remember hearing a DETROIT 12V on YOUTUBE and it sounded alot like the 6-71. They showed the engine itself running at the time. 12 and 6 cylinder engines often sound similar but the 12 is much smoother. Must have been neat to hear in person just the same.

[TomC]

Funny how things evolve. Now the big setup for maximum fuel mileage is the Meritor tag axle setup with air suspension traction control. If the traction axle starts to slip, the tag axle will automatically dump air to add weight to the drive axle. Course with this, the single drive axle is transmitting all the torque. Todays Diesels in general put out 1450-1650lb/ft torque. The tire companies are making special drive tires for single axle drives.

I know in Colorado, there are times when a single drive tractor will have to chain up compared to a tandem drive. I guess I'm old fashioned-I'll keep my tandem drives.

With some of the rigs pulling 3-28ft trailers, you could have a 2 axle tractor pulling 105,000lbs! Not a problem for the single axle-it's rated at 130,000lbs. But all that weight being pulled by just one drive axle! Good Luck, TomC

[wg4t50]

Guess I should mention the radiator/cooling solution with the bigger hp engines, Rigged up a sprayer, using windshield washer fluid and washer pump, with two nozzels set on each side of fan hub, sprayed toward the hub, and it worked better than it looked.  Was able to control temps with both the 12V-71 as non turbo, and the 8V-92, but the dual turbo 12V was a cool damp day kinda toy.  Sure made alot of heat btu. The good part, did not need to stand on it very often nor long.
Had the 4' X 5' radiator across the back using a pusher fan, where the origional radiators and fans were, that became the air filter house for both filters.
Dave M

[TomC]

2 stroke engines have always been the hardest to keep cool-with such a large heat rejection. When I bought my 1980 Kenworth with 8V-92TA, it had the same 1350 radiator they were using on the 600hp KTA Cummins.
More proof of this is when Grayhound pulled some 6V-92TA out of their buses and replaced with the 4 cylinder Series 50. They were able to eliminate one of the radiators and use an air to air intercooler in its place. Good Luck, TomC

[twostick]

TomC,
Trust you understand the humor of passing a 465 hp computer Cat with an empty Ravens (aluminum) flat bed, passed him proper, he wanted to know that the hell I had in the old bus, I told him it was a wore out 318, that is when he lost it, he was so proud ot that Cat.
Just glad the mountain was long enough that when he got to the top, I was long gone, out of sight, not a happy camper, am sure he bent the steering wheel,  a very unhappy feller, no humor in him.
If he was more sane, would have confessed the 12V-71 twin turbo 145 injectors at the time and the RTO-910.
That was years  ago when the 465 Cat was the big boy Cat. Guess a 3406E.
The big issue of my setup at the time was traction/wheel spin and tag air bag pressure, carry enough psi in the tag bags to keep from bouncing, spinning was an issue, lower the pressure for traction and the tag would bounce/dribble.  Only had the twin turbo setup for about 2 weeks and removed it, back to normal 12V-71, and N70's.
The 12V-71 was the best sand box toy I ever played with, great memories, some on this forum knew it and rode in it as had it to Arcadia a few times etc.
Dave M

Nothing adds insult to injury quite like that unmistakable exhaust note telling you that a 2 stroke just snatched a knot in your CAT's tail.

There is no such thing as too much fun but I think a twin turbo V12 in a bus with a 10 over would be pretty close.

What HP rating would it have with those injectors? I looked up some marine specs and they range from 539 gross HP with N70's to 870 with 9215's, an injector number I'm not familiar with. Are 145's bigger?

Kevin

[wg4t50]

The 9215 injectors were newer than what I was familiar with, the N145 was used on some military and some generator sets.  No idea where the 9215 fit, guess it might be slightly more fuel and a better nozzel pattern setup.  Have melted down a few pistons from too much injector advance 
After the 12V, Wound up with the 9200 in the 8V-92 after the 9210 blew the air box covers off, made steel plates to replace the aluminum cast  covers, also found the  benefit of the 6V-92 turbo, it pumped big with the 8V volume of exhaust.  Was lucky I could play some games, a shop with everything needed from mill, lathe, welding, metal cutting, fork lift etc. Not my shop but a close friend whom he & I shared similar thoughts and I worked for Cat, kept him in some 955 small parts.  Today he is dead and I am over the hill.
Can say No one ever had more joy playing crazy games with the old DDC 2 strokers, with all the miles & years, never had one die on the road, always brought me home.
Dave M

[luvrbus]

Is the guy still around that had the 3408 Cat in the scenic that was monster in the rear of the GM