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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: FolkBus on August 23, 2013, 06:36:35 AM



Title: Which End?? 8v-71
Post by: FolkBus on August 23, 2013, 06:36:35 AM
Hi all

I read many times on this board about which way a DD spins. Clock or counterclock.  Looking at the engine, from which end is this determined?  Pulley end or flywheel end?

Thanks

--Mike


Title: Re: Which End?? 8v-71
Post by: Scott Crosby on August 23, 2013, 06:47:45 AM
The rotation direction is what the transmission needs to accept - flywheel end


Title: Re: Which End?? 8v-71
Post by: TomC on August 23, 2013, 07:42:52 AM
Sorry Scott-the rotation is determined from the pulley side. Right hand rotation refers to which hand you had to use to crank start engines, originally. Hence a right hand engine uses your right hand to crank it (since most people are right handed) and spins clockwise when looking at the pulley end. Good Luck, TomC


Title: Re: Which End?? 8v-71
Post by: lostagain on August 23, 2013, 07:48:13 AM
Refer to the first few pages of the DD service manual for your engine. It has a very clear description of how to look at the rotation.

JC


Title: Re: Which End?? 8v-71
Post by: luvrbus on August 23, 2013, 07:56:44 AM
Rotation is from the rear of the engine not the front of the engine page 7 of of the DD bible, but I did like your theory TomC


Title: Re: Which End?? 8v-71
Post by: bevans6 on August 23, 2013, 08:30:47 AM
I just call it normal and backwards, but I am a heathen...   ;D

Brian


Title: Re: Which End?? 8v-71
Post by: wg4t50 on August 23, 2013, 09:04:16 AM
The good part, you can make it go either direction you like.  Change gear position on flywheel end and convert the oil pump, bingo ;D


Title: Re: Which End?? 8v-71
Post by: luvrbus on August 23, 2013, 09:06:14 AM
Not that easy Dave you change the cams also on a V engine and maybe the crank if it has a directional crank


Title: Re: Which End?? 8v-71
Post by: wg4t50 on August 23, 2013, 09:35:05 AM
Yup, never did a V engine, but a few 53 & 71 inline babes.


Title: Re: Which End?? 8v-71
Post by: Ed Hackenbruch on August 23, 2013, 10:10:12 AM
 I am left handed and always used my left hand to crank up the engine that we had on a small jaw crusher in a quarry that i worked in a long time ago.......hated that thing in the winter time.


Title: Re: Which End?? 8v-71
Post by: Chopper Scott on August 23, 2013, 10:36:10 AM
Now I'm confused! LOL ;D


Title: Re: Which End?? 8v-71
Post by: luvrbus on August 23, 2013, 10:54:38 AM
That makes 2 of us Scott the crank pulley will be the only thing turning different the cams turn the same direction right handed or left


Title: Re: Which End?? 8v-71
Post by: eagle19952 on August 23, 2013, 02:29:56 PM
Can we see a video of the guy that can hand cranks a DD.... ;D
I will buy him a ham sandwich....a WHOLE ham... ;D


Title: Re: Which End?? 8v-71
Post by: FolkBus on August 23, 2013, 03:33:29 PM
For now I'll go with the flywheel end.  But I love all of the responses.

--Mike


Title: Re: Which End?? 8v-71
Post by: Scott Crosby on August 24, 2013, 02:22:00 AM
Don't go looking at the pulley on mine for the direction, because on my backwards engine there there is only one pulley and it's on the oposite side as the flywheel but it's not spinning the direction of the engine.  And I never paid attention to the radiator fan but I think it spins the wrong way too. Its not direct drive, though it's a fluid driven torque converter, but at first look it looks like gears from the crank would be turning it.  So back to my original post, it's what the transmission needs to accept, the direction the transmission input will turn. Which I suppose is still backwards if you're looking at a flywheel but you need to "be the transmission" while you at looking at it. I didn't know I needed to look at a book to determine if it turns a transmission left or right.  However my system only works when an engine is running and or turning over, because if I just saw an engine sitting on the ground, especially like a marine version that's not clearly a gm or mci, I wouldn't know unless it was running.  Or what if someone changed the direction of like a GM engine, easy to assume by looks or even if someone put the wrong starter on one, so it cranked the wrong way, so it might run horrible or not at all but it would be turning wrong.  So clearly I don't know the real way, but more oil leaks out on my left hand side, so it must be left hand rotation.


Title: Re: Which End?? 8v-71
Post by: luvrbus on August 24, 2013, 04:22:54 AM
Most marine engines the lefty will have the starter mounted on the right side looking from the rear just like your GM  then there is always the model number on the block if all else fails  ;D  

As I said nothing changes rotation except the crank the blower,fuel pump,water pump and any other accessory turn the same direction on right or left handed engines


Title: Re: Which End?? 8v-71
Post by: TomC on August 25, 2013, 08:45:32 AM
And will have to change the oil pump if the oil pump is mounted on the front of the crank. Good Luck, TomC