Questions about a MCI 102a3

[TomC]

Two things with S50 idle-they make special soft engine mounts. And S50 has twin counter rotating balancing shafts under the engine in the crankcase. Since the balancing shafts also drive the oil pump, the S50 is the only engine I know that you have to time the oil pump (LOL). Suggested rebuild/replacing of the balancing shaft assembly-300,000mi. In my opinion-S50 is the perfect bus conversion engine. Good Luck, TomC

[J_E]

Thanks for all of the feedback and info guys.  We've decided to get the '91.  We decided to start from a blank slate. I'll get some more pics up when I get everything finalized.  The adventure is about to begin.

Dbldragon: It sounds like we are planning a similar floor plan to what y'all have going.  How did you set up the actual hitch for your toad?  I've read that Prevost built heavier hitched for some of the models that get converted to RVs.  I don't suppose that MCI ever did that.  

TomC: I've read a little about the balance shafts, but missed the oil pump bit.  Is there a way to tell when they are due if you are not sure of the mileage on the engine?  The odometer is showing 323K, and since this is a replacement engine, I think I might be ok for at least a while.

jcdillin: In person, it almost looked like bio growing on the filter.  Servicing/replacing the fuel filter is high on the list of things to address with new to me vehicles. I also figure a dose or two of Bio Kleen from Power Service wouldn't hurt.

Scott&Heather:  I keep forgetting about all of the glass in the windshield when taking a stab at a plan for AC. Using 110V 30A as a power limit for everything is keeping me from getting too creative, which is probably a good thing.

EDIT:  I keep forgetting to ask if anyone has experience with Rush Bus Center or with Americorp Diesel repair on the North side of Houston?

[Geoff]

You don't want 30amp service.  Do 50 amp with a 30 amp pigtail.

--Geoff

[luvrbus]

Watch the oil pressure when the balance shafts are going bad the oil pressure will drop.
They don't idle rough if the RPMS are set a little higher you set it 450 or 500 rpm it will shake the sheets from the bed so will a series 60,2 stroke owners all think they idle rough and they do compared to DD 2 stroke I don't like the idle on my 60 series   

[windtrader]

If you are going to start with a passenger bus, look into the '95-'97 ish  102D3, 40ft Series 60 Allison B500 and DDEC III, pre-EGR 12.7. Since you made the decision to do a full conversion, you've chosen the most costly path. May as well start with the best coach. The difference in the coach cost will disappear once in the entire pile of receipts are stacked up after you've completed the conversion. I would no way start with a two stroke in 2017.

[B_K]

J_E no MCI never did a heavier engine cradle for towing.

If you are going to start with a passenger bus, look into the '95-'97 ish  102D3, 40ft Series 60 Allison B500 and DDEC III, pre-EGR 12.7. Since you made the decision to do a full conversion, you've chosen the most costly path. May as well start with the best coach. The difference in the coach cost will disappear once in the entire pile of receipts are stacked up after you've completed the conversion. I would no way start with a two stroke in 2017.

Don the 50 Series the 91 he is going with is a 4 Stroke just like the 60 Series just lees cylinders!
Someone already retrofitted that bus with that engine.
He'll have a sweet bus when done.
  BK 

[J_E]

jcdillin:  I guess I didn't get where you were going with the fuel filter comment.  I figured it out later when I happened to see a youtube video describing that type of fuel filter.  Never would have guessed that the level of fuel in a filter could tell you how dirty it's gotten.

It's looking like I will just order a set of manuals for the 102a3.  In the mean time, I took a look through the HVAC section of the mc9 manual posted on another site.  Looks like I may have found the tonnage of the A/C compressor, if it's similar to the 102a3.  It's a monster 7.5 tons or 90,000BTU.  My guess was off by about half, even after having seen the compressor in person.

Regards,

[Oonrahnjay]

...  the tonnage of the A/C compressor, if it's similar to the 102a3.  It's a monster 7.5 tons or 90,000BTU.  My guess was off by about half, even after having seen the compressor in person.

Regards, 

      Yep, Aunt Myrtle wants to come out of the casino, slide into the bus seat, and not have sweat dripping between the cheeks of ... umm, her not-face as the bus rolls out of the parking lot.  Air - Cold - Now; that's what we want.

[Scott & Heather]

I'm
Jealous. You're going to love that bus when it's done. And the 50 will get amazing fuel mileage and will have great torque and power and will never overheat. If I could afford it, I'd have one in my coach. But I'm addicted to my 500hp.


Sent from my iPhone using Tapatalk Pro

[jmblake]

So far I'am pleased with the 50 series I put in my bus, No overheating, Good torque, around 7 MPG, even though I haven't had it turned up in HP yet (not sure what HP it set at right now) The hills slow me down but I'am pulling a 6500lb truck, but on the interstates I can run with most trucks and even pass a few LOL. As far as being rough  at ideal mine isn't bad at all. I would like to get it turned up to 350hp - 375hp in the near future. Jason

[J_E]

Well, the deal is done.  I am the proud owner of a 91 MCI 102a3.  I've got a few things that I am going to address before I hit the road and head back home. I have new fuel and oil filters. I also have a couple of gages to see if I can get sorted water temp (need) and fuel (would be nice).  I also have a heckuva lot of learning to do on this bus.  Also, I keep forgetting to ask where I should look on the transmission for an ID plate?  Currently I just know it's a 4 speed Allison.

Engine says it's rated at 275hp.
OTR A/C has been converted to r-134a.  It wont currently freeze you out, but it cooled the bus off ok.  

Pics:
https://drive.google.com/open?id=0B7wToc0YVZbxM2ZibkVFTWNEbEU

https://drive.google.com/open?id=0B7wToc0YVZbxczB0X0NDUklsM2s

https://drive.google.com/open?id=0B7wToc0YVZbxWGNkTXBxckppNTQ

PS: pic are hosted on google drive, but the links should work.  If they do not, let me know and I will get them resized at attach them to a later post.

[jav9956]

Great bus! Depending on how far you go with the conversion you are going to have a lot of work on your hands and a heck of a fun time. Being that it is virtually the same bus we have been working on you may want to check out a few of the videos we have done on our conversion (on youtube). Always good to see what not to do  .

I don't know if you bought the manuals yet but Daveola has the digital copies for a great price; you may have already seen the ad in the classified section on the forum here.

Best of luck! Look forward to seeing the progress you make

[J_E]

Thanks, I bought the basic set of books from Davola, but he didn't have the S50 book and I still haven't figured out the transmission in it.  Except that it is an electronically controlled Allison 4 speed.

Made the 950ish mile trip home with no major issues.  Wrote about it over in the travel section.

I have about a million questions, but want to continue reading the books and search the internet before I begin asking.

Regards,

[Tom Y]

Should be a 748 if it is a 4 speed. Tag on side of tranny. Do you UNDER STAND about going under an air ride bus? SAFETY first, I cut 3" long 3x3x1/4" tubing  and place on the axle stops for safety.

[J_E]

To be honestly blunt, I am pretty fricken ignorant when it comes to working on or around an air ride suspension system. 

I had realized that an air suspension system would settle down some as the air bleeds off of the system.  Well, I say that even though it did surprise me a little when the bus settled down onto the pan I was using to catch my oil.  Luckily, it only made the pan a little difficult to move and didn't create a 5+ gallon headache.