engine rotation

[rcbeam]

I'm still working on the alternator issue.  I understand that 8V71 in a MCI is right hand rotation... facing what?  I am trying to determine which way the rear (flywheel end) camshaft pulley turns... anyone know?

I don't want to get an alternator that spins the wrong way. 

Thanks again,

Russell

[luvrbus]

Facing from the rear, is your pulley on the right hand side cam looking from the rear ?


good luck

[Just Dallas]

RH rotation is when you are facing the engine from the rear looking at the flywheel... the engine is turning clockwise.

If the acc. drive head is on the RH side, the alternator is a RH.

If it's on the left, it's LH.

As far as I know, most alternators (Other than the 50DN) don't care which way they turn. The cooling fan on the alternator however, does.

I'm most probably wrong on that assumption, and if I am, I'm sure I'll be beaten into submission forthwith!

[Don Fairchild]

No Dallas, The engine rotation is always from the front of the engine.  everything else is from the flywheel end. The cams always turn over the top into the blower regardless of right or left hand engines.

Hope I didn't confuse anybody.

Don

[Just Dallas]

Darnit! I knew I'd get that wrongly!

Russell... make a note: never listen to me!

[luvrbus]

Don all accessory drive rotations are taken from the rear is my understanding but after all these years I am still trying to figure out why the fuel pump is left hand rotation lol

good luck

[TomC]

No matter the rotation of the crankshaft, the camshafts, blower and fuel pump all turn the same way all the time.  If you do change rotation of the engine, you also have to change the starter and oil pump.
As to alternators-most spin either way-but make sure of that from the manufacturer.  I know brushless alternators don't care.  Good Luck, TomC

[Chopper Scott]

Luckily for me I put it in D and we head the direction I'm wanting to go!! I do have a buddy that worked on his boat and it ended up going left when he turned right and visa versa and it went backwards when it was supposed to go forwards. I had tears rolling until he hit MY boat!!

[rcbeam]

Luvrbus, the camshaft pulley the alternator will be driven from is on the street side.  Yes, Dallas, some alternators care and some don't care which way they turn, but from what I've read it is because of the fan design.  So, the engine turns clockwise while facing the crankshaft pulley if I follow you guys correctly... but which way will the street camshaft pulley turn while I face the same direction (it is on the other end of the block, flywheel end)?  In other words, I'm standing at the rear of the bus, outside, looking at the crankshaft pulley.

Thx,

Russell

[bevans6]

If you have the alternator pulley driven from the street side camshaft drive position, then it is identical to mine.  On my bus the alternator (50DN) is mounted with it's pulley facing towards the back of the bus.  The drive pulley on the engine rotates with the top of the pulley going towards the passenger side of the bus  (top to middle of the engine).  On the alternator, the top of the pulley also goes towards the passenger side of the bus, so clockwise looking at the pulley from the back of the bus towards the front of the bus.

In other words, the street side camshaft pulley turns the same way as the front pulley on the crank of the engine.

Brian

[artvonne]

  So regardless of which way the crank spins, they just swap which end they drive the cams from to keep them spinning the same direction?  Stuff you dont think about, like the blower would always have to turn the same way. Interesting.

[bevans6]

on a RH engine the idler gear drives the RH "looking-at-it-from-the-back" cam shaft gear, so that gear rotates the same way as the engine, or counter clockwise from the back of the engine looking forward.  On a LH engine the idle gear is moved over so that it drives the left hand cam shaft pulley.  Now that pulley rotates the same way as the engine, clockwise from the back, so the RH cam pulley is opposite to it and is still turning counter clockwise (from the back).

Little pictures and arrows help a lot...  Like the one in the manual!

Brian

[rcbeam]

Brian, thx so much.  I think I finally know which way I'm going.

Russell
MC8