MCI 9 Powertrain options?

TomC · September 08, 2015, 08:00:52 AM

Detroit Series 50 is a GREAT engine-in my opinion the best RV engine you could have. Available up to 350hp and 1050lb/ft torque (about like a strong running 6V-92TA). They are so efficient, when Greyhound retrofitted some of their buses with the Series 50, after taking out the 6V-92TA's, they eliminated one of the radiators substituting it for the air to air aftercooler. Also, driven reasonably, 10mpg isn't impossible.
Three main negatives about the Series 50. One it is very tall. Two, because it is just a 4 cylinder, vibrates at idle-but they also make special soft engine mounts that mostly eliminates that. Three, also because it is a 4 cylinder, it has twin rotating balancing shafts in the crankcase. The key to this is to replace the balancing shafts every 300,000 miles whether they need it or not. The Series 50 has the only oil pump that has to be timed-since it runs off the balancing shafts.
You can run the B400 (3000HS) Allison transmission which is shorter than the B500 (4000HS). Good Luck, TomC

luvrbus · September 08, 2015, 08:49:38 AM

The series 50 is not the only engine that the oil pump needs to be timed fwiw,you can get more than 350 hp from a series 50 also

jmblake · September 08, 2015, 09:24:25 AM

Is the cummins ISM with a 740 going to be longer than the 8v and 740? same question about the C12? My driveshaft right now isn't much more than 12" long, Don't know how much shorter I can go.
Jason

chessie4905 · September 08, 2015, 10:05:32 AM

Don't forget number 4 just to be fair. It is a discontinued engine, just like the 2 cycles (for the most part) with fewer units and years of use.
Would probably be the easiest and least expensive overall to swap, plus the major mileage improvement.

luvrbus · September 08, 2015, 10:19:17 AM

The ISM is 58 inches long the C-12 is 60 inches long your 8v71 is 47 inches long that is why most people use the series 50 in a MCI 9

LuckyChow · September 08, 2015, 03:02:52 PM

Just want to make you aware that we are having a lot of problems getting parts for the Series 50's at work. These are EGR models. Heads and balance shafts are the two hardest parts to get. Detroit seems to be out of them all the time. At the last check, balance shafts were on national backorder according to the dealer. They quoted us 9 months for a reman engine recently.

luvrbus · September 08, 2015, 04:02:49 PM

The heads have been a problem getting ever since John Deere stop casting for DD same with series 60 you buy a new head it says made in Mexico and they look it too

Melbo · September 08, 2015, 04:25:19 PM

I like the L10 that Gary at B&B put in for me. Starts right up even after setting for a spell (like 6 months) came with a big alternator that runs a roof top air with the inverter and I get between 6 and 7.5 mpg. I have the mechanical so there are no electronics to worry about. I don't run the fast lane but I go over 10,000 foot passes here in the mountains and we get along just fine.

Melbo

luvrbus · September 08, 2015, 04:41:05 PM

You have Jakes on your L10 Melbo ? I do remember Gary installing a ZF transmission

Melbo · September 08, 2015, 04:50:22 PM

No jakes. The jakes make the L10 too tall if I remember correctly. The ZF has a retarder that they didn't want set up because I had such a small trans cooler. I installed a trans cooler that is rated for the retarders on the american flyer city buses. So I have a blue ox exhaust brake and the retarder. Between the two we do pretty good in the mountains. Mike put an L10 in his 7 with an allison BR400 I think and had his fuel pump rebuilt and I think he was at something over 300 hp. My L10 is set up for 275 hp so it is comparable to a 8V71. I won't win any races but I don't worry about breaking down or overheating.

Melbo

luvrbus · September 08, 2015, 05:04:12 PM

I was just asking I have a friend looking for a L10E for a upgrade he installed parts from a M11 to have Jakes on his mechanical L10, he had Jakes for awhile now he has a rod through the block my buddy at Coastal Plains Cummins told him it was a no no but he knew better the internet said it was ok

gg04 · September 08, 2015, 05:10:41 PM

Clifford... that's the reason I didn't go with a series 50 ..15 years ago..it was originally an off road stationary, export only engine..and parts were already mostly imported..rdw

jmblake · September 08, 2015, 06:12:29 PM

Is there a transmission that is shorter than the 740 that will work with the ISM or C12 and not need to change my rearend ratio?

luvrbus · September 08, 2015, 06:47:11 PM

As much money have you in the engine I would find the problem and run it they don't give problems when right your guy is missing something that 1 cylinder should not be running hot has a he shot it with a IR gun ?

jmblake · September 08, 2015, 07:02:27 PM

No he didn't, we just put it back together and I took it for a short drive and I heard a pop and looked in the mirror and saw black and gray smoke then lost power so limped back to the garage and he came today and took the inspection plate off and we got another broken liner. This makes the 3rd one. he is stumped, we don't know if we got bad liners or there is something we are missing. I just want something I can go on a trip and not have to worry.