Optional Engines MC 9/12

[Jim Eh.]

Not that I am going to or need to (at the moment) but if I had an option, would I be wise to choose either a Cummins ISL or a late model ISB(6.7) if I could get one of them at a very attractive price?

[Oonrahnjay]

Not that I am going to or need to (at the moment) but if I had an option, would I be wise to choose either a Cummins ISL or a late model ISB(6.7) if I could get one of them at a very attractive price?

      An ISC sort of was my easy way so I really didn't have to get a lot of info but a few people i talked to said that the ISB is too small, not enough power output (without getting weird with it), and would have problems with reliability pushing a bus as big/heavy as an MC12 when it was stock and worse when it was adjusted up on power.  I was told it's just a smaller motor, made smaller in all ways -- thinner gasket surfaces, thinner cylinder bores, narrower main/rod bearings, smaller cam bearing journals, etc.  I don't know if that is someone being cautious but I was glad to get my hands on a good ISC with a less-than-500-miles from replacement new Allison B400.
      An ISL is way bigger but it may be a good fit for an MC12.

[TomC]

Cummins 6.7 ISB is not powerful enough. ISC 8.3 and ISL 8.9 are the same block and size. ISL can be pumped up to 450hp and 1250lb/ft torque-plenty of power-and is about 500lbs lighter than the 8V-71. No reason to go any bigger. Good Luck, TomC

[DoubleEagle]

I used to haul new ISX Cummins engines from the Jamestown, NY plant, and they were very impressive and expensive. Each load was worth over a quarter million. That's a bigger engine, and I had it in the International I was driving. Cummins makes solid engines, but there are cheap quirks that always bothered me. For instance, they would use thinly plated steel band clamps on the various rubber hoses (large & small) that could corrode easily from salt and pop off just as you are climbing a grade when the turbo was working hard. They also initially used a rubber hose from the intake manifold to feed the air compressor intake that could fail and sound like a giant raspberry when it blew. I was at one of the plants in Indiana, and I noticed that the crankshafts came in as raw castings from India to be turned there. With the emissions equipment that is on the newer engines, I don't think you are going to find cheap engines for sale, and I don't think they will be trouble free. I would stick with what the coach came with. 

[TomC]

If you want what is arguably the most reliable engine ever made, use the Caterpillar 3406B. The 3406C is still being made for 3rd world countries that don't want an electronic engine. Can be pumped up to 465hp.
The 3406B is in my truck at 400hp. Only draw back-it is a big block engine and weighs 2850lbs compared to the 1650lbs of the Cummins ISL. Good Luck, TomC

[luvrbus]

Cummins produces the 8.3 and 8.9 in China and they are full of foreign made parts,the ISM is a better engine 

[CrabbyMilton]

So is everything else. I certainly appreciate American heritage but the masses don't care where their stuff comes from just so long as they get it. If some people are so ignorant that they think electricity comes out of the wall, what makes you think they'll know where their engine it's parts come from. CUMMINS no longer offers the C8.3 for buses as of a few years ago. I thought the ISL is the same block as the ISM but I'm only a stockholder CUMMINS puts their name on it so while I would rather they built them here, it's still up to them to make sure it's right.
At least CUMMINS is based here which is more than I can say for DETROIT.

[DoubleEagle]

If you want what is arguably the most reliable engine ever made, use the Caterpillar 3406B.

I second that. I had one in a Mack that had fantastic torque, it would out-pull a 8V92 with a higher horsepower rating easily.

[luvrbus]

I second that. I had one in a Mack that had fantastic torque, it would out-pull a 8V92 with a higher horsepower rating easily.


No one will ever build a engine as good as the 425 HP 3406 drivers could not tear one up,lug it down to 900 rpm push the throttle the black smoke would roll and off she would go to the next fuel stop it was a true million mile engine 

[lostagain]

I have a 3406B in my Peterbuilt dump truck. It pulls like the space shuttle launching from Cape Canaveral. And trouble free too. Wish there was room for it in my bus.

JC

[TomC]

Cummins engine sizes-Pickup truck size-5.9 and ISB 6.7-up to 300hp and 800lb/ft torque, no Jake brake availability, no cylinder liners. ISC 8.3 and ISL 8.9 both the same block with different strokes-available up to 450hp and 1250lb/ft torque, optional Jake brake, light and small-perfect for motorhome. L10/M11/ISM all the same block-available up to 500hp and 1550lb/ft torque. ISX 12 is just about the same size, but heavier since it is a smog engine-available up to 500hp and 1650lb/ft torque. ISX 15 is a big block truck engine weighing just over 3,000lbs-up to 600hp and 2050lb/ft torque (1950lb/ft torque maximum for Allison). NTC, N14 either mechanical or electronic truck engine available up to 525hp and 1850lb/ft torque. KTA 1150-HUGE truck engine weighing 3,600lbs and available up to 750hp and 2250lb/ft torque with twin turbos. VTA-903-V-8 that was produced up to the 1980's. I know of one in a 4106 since it was one of the few Cummins engines that could be run left handed. Still made for various military tanks. Up to 700hp and 1550lb/ft torque.

[CrabbyMilton]

Thanks Tom. I thought the ISL was a revision of the ISM since the ISM evolved from the old L10 in the for of the M11.

[luvrbus]

The torque rating are deceiving on the ISC and the ISL when you take the torque reading after the gear train on the rear wheels they come in around 750 to 800 ft lbs 

[RJ]

The torque rating are deceiving on the ISC and the ISL. When you take the torque reading after the gear train on the rear wheels they come in around 750 to 800 ft lbs.

Clifford -

That must mean that the little 6V71 in my MCI must come in at around 15-20 ft lbs!

Or at least it feels that way when going thru the Rockies!

[luvrbus]

Clifford -

That must mean that the little 6V71 in my MCI must come in at around 15-20 ft lbs!

Or at least it feels that way when going thru the Rockies!

The 6V71 N/A is not much in the mountains but you do have time to smell the pine trees and the rest of forest