BCM Community

Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Singing Land Cruiser on August 17, 2009, 07:54:07 AM

Title: ??? 1987 MCI 102A3 8V92TA ???
Post by: Singing Land Cruiser on August 17, 2009, 07:54:07 AM
1987 MCI 102A3 8V92TA What do these letters stand for? ??? Thanks, M&C
Title: Re: ??? 1987 MCI 102A3 8V92TA ???
Post by: cody on August 17, 2009, 07:58:36 AM
what a great bus TAAAAAAAA-DAAAAAAAAAAAAAA lol,,,,,,,, or it could bean turbo aftercooled but I like ta-daaa
Title: Re: ??? 1987 MCI 102A3 8V92TA ???
Post by: HighTechRedneck on August 17, 2009, 08:02:54 AM
I like your alternate interpretation Cody!  My RTS has a 6V92TA so I guess I have a great bus too.  ;D
Title: Re: ??? 1987 MCI 102A3 8V92TA ???
Post by: TomC on August 17, 2009, 08:53:44 AM
Turbocharged and Aftercooled.  Turbocharging (if you already know please don't take offense of the explanation) is where the exhaust is fed through a housing that looks like a snail shell routing it around and through a turbine wheel that causes it to spin very fast (20,000 rpm and faster).  The exhaust turbine is connected to the fresh air turbine by a shaft so that the fresh air turbine also spins in a snail shell housing to make an intake compressor.  So in a nut shell, the turbocharger takes the exhaust pressure and heat through a turbine powering the intake turbine to push air into the engine under pressure (typically at 15-25psi).  More air-more power, and no loss of power at high altitudes.

All this compressing of air creates heat.  The engines likes to have cool air that is more dense (also for more air), so aftercoolers are used.  On Detroit 2 strokes, two types are used.  The aftercooler you have is a small radiator with coolant from the radiator running through it to cool the intake air.  It sits below the blower in the valley of the V of the engine block.  The cooler is both after the turbocharger and the blower-hence the aftercooler.  The other type is called an intercooler.  This sits between the turbocharger and the blower (or between the turbocharger and the engine in a 4 stroke engine).  This too can be cooled with coolant from the radiator, but virtually all Diesel engines now have them as another separate radiator that is in front of the engine radiator.  This is called an air to air intercooler.  This is what I installed on my 8V-71N.  So now my turbocharged and air to air intercooled engine is called an 8V-71TATAAC (turbocharged air to air aftercooled).  On a 2 stroke to combat further heating of the air by the blower, Detroit came up with a bypass valve on the blower.  When the turbocharger starts pumping out at least 5psi of pressure, the bypass valve in the blower opens and allows some of the pressurized air to bypass through a separate passage way to the bottom side of the blower.  This equalizes the pressure on both sides of the blower making the blower believe it isn't pumping any air-hence it more or less just free wheels and doesn't consume power under turbocharge boost.  Pretty neat.

Hope this helps.  Good Luck TomC
Title: Re: ??? 1987 MCI 102A3 8V92TA ???
Post by: Singing Land Cruiser on August 17, 2009, 09:20:47 AM
Thank you very much. I am going to have a look to see if I can make heads or tails out of this. I'm a carpenter/entertainer. My learning curve is not up to par when it comes to the Mech side of things. :P M&C
Title: Re: ??? 1987 MCI 102A3 8V92TA ???
Post by: Chuck Newman on August 17, 2009, 09:39:45 AM
Michael,

It is 102 inches wide, model A of the series (series A, B, C, D), and it has three axles.  A 102A2 is the same with only two axles.  A 96A3 is 96 inches wide with three axles.  Other than the number of axles and a 6 inch difference in width, they all look basically the same on the exterior, with the exception of C and D series have smooth sides (no fluted stainless) and the D series have a straight up rear cap.

Chuck
Title: Re: ??? 1987 MCI 102A3 8V92TA ???
Post by: Chuck Newman on August 17, 2009, 09:41:43 AM
Michael,

Second reading I realized that isn't exactly what you were asking.  But it's good to know anyway.  I'm going back to bed.
Title: Re: ??? 1987 MCI 102A3 8V92TA ???
Post by: cody on August 17, 2009, 09:42:46 AM
I still like my version, wasn't very informative but much more fun.
Title: Re: ??? 1987 MCI 102A3 8V92TA ???
Post by: Jerry32 on August 17, 2009, 10:01:09 AM
and the 8 stand for 8 cylinder V configuration 92 cubic inches per sylinder Turb aftercooled.