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Jaws probably dropped at reading the title, but it seems that if you don't know the answer to this question you can't find it on the internet. Everyone already knows but me!
 

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Vintage ducs used bevel gears to drive the cams.

Here's a shot where the cam drive is obvious:



Here's a better shot of the "timing chest". A bevel gear on the crank turns a shaft that spins the cam for the ignition (or a magnet if you're no longer using points). A bevel gear on this shaft drives the cams in the heads:


Singles are the same, but different...
 

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These engine use a LOT of shims! :rolleyes:

My favorite is when a newbie gets his paws on one and pulls it apart thinking he's going to "fix" it when he's too cheap to even buy a shop manual first... um, yeah... those shims you have left over? They're sort of important.

Trivial fact number 347 - the timing dots only line up once every six revolutions of the crank. And if you use squarecase cams in a roundcase engine (not unheard of - I did it) or are timing the cams, the factory dots may never line up! (Hence the yellow dots you can see in the second pic if you look real close)
 

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Singles are the same, but different...
Here's the timing chest on a 160 Ducati. Much simpler:


Only the cam is run off the bevel gear. If you look at the engine cover in the foreground you can see the oil pump, and the gear spins the shaft that actuates the points. The oil pump is driven by a slot in the center of the shaft on the big gear that's still on the engine. Of course that gear spins the gear on the timing cover, which has the points on the other side.

Much less shimming going on... but they're still "bevels" in Ducati-speak.
 
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