821-30 Rotation Direction

[Fred]

Sorry this most likely has been answered 100 times, but what way does the 821-30 rotate looking at the flywheel???
Stupid in Pinehurst
Fred

[Grumblebuns]

Hi Fred,

I checked the online manual on LEC but didn't see the info. I checked the KB and typed in "engine rotation" and according to consensus, looking at the flywheel, the 821 rotates CCW. Please verify this yourself

[jbcollier]

Smart in Pinehurst actually.  Stupid wouldn't have been smart enough to ask.

Clockwise.

[jbcollier]

Dang, wrong again.  Mr. Grumble is right.

[jbcollier]

Now who's stupid?

[Fred]

Thanks when I went clockwise it hung up on the rebuild with just the head, no valve setup. So I believe as our Brit friends say "anti-clockwise" works!!

[GavinT]

Told to me by an old engineer from back in the day . .

Perhaps the easy way to discover the direction of rotation is to observe the timing chain assembly.
Recognising that a chain can only be pulled and not pushed, the chain tensioner will always be on the  trailing (non pulled) side of the assembly because it’s there to stop the chain flailing about.

On our Renault engines, the chain tensioner is on the right when looking at the flywheel.
So . . . CCW would be correct.

Of course, all this assumes one can see the timing chain in the first place!

[GavinT]

Thanks when I went clockwise it hung up on the rebuild with just the head, no valve setup.

G'day Fred,

Just wanted to add a note of caution when doing a dry build.

If you bolt the head down without a head gasket, the head will likely clamp the dizzy drive . . at least on a cross-flow engine.
If you then try to turn the engine over, it'll probably break a tooth or two on the dizzy drive.
Yep . . I'm also stupid. Ask me how I know.

[EuropaTC]

Perhaps the easy way to discover the direction of rotation is to observe the timing chain assembly.
Recognising that a chain can only be pulled and not pushed, the chain tensioner will always be on the  trailing (non pulled) side of the assembly because it’s there to stop the chain flailing about.

Good post Gavin, when I first read it I thought "huh ?" then thought about all the engines I've ever had to work on and yes, it's blindingly obvious. Despite replacing belts and chains I've never thought of it that way and always been checking in the book before setting the timing - every day is a school day !

Brian

[GavinT]

Yes, it should be the same for timing belts as well. But remembering that sometimes cam belts have extra idler pulleys / bearings up near the cams in order to ensure sufficient ‘belt wrap’ around the cam pulleys.

Same thing with those long serpentine belts that drive multiple engine accessories like alternators and power steering pumps etc. . . all with that one belt.

It’s all dictated by the engineering and I recall slapping my forehead when I first heard it too. Ha . .