With the interest shown for Jim Comstock's new gear drive, I thought I'd post a picture of the arrangement Kenny Dreer used on his ill-fated 961 prototype. Interesting that he drives the cam in the opposite direction of a standard Commando. This was in the early stages of the development, and I don't know what he eventually did for an oil pump, but it's still intertesting to look at.



Ken

Does it really matter which way you spin the cam, as long as the valve events are properly timed?

lcrken wrote:With the interest shown for Jim Comstock's new gear drive, I thought I'd post a picture of the arrangement Kenny Dreer used on his ill-fated 961 prototype. Interesting that he drives the cam in the opposite direction of a standard Commando. This was in the early stages of the development, and I don't know what he eventually did for an oil pump, but it's still intertesting to look at.



Ken

Interesting to see he is using the same alternator I am, it would be cool if you had more pictures.

Jean

grandpaul wrote:Does it really matter which way you spin the cam, as long as the valve events are properly timed?

Off course it does matter, the cams need to be mirrored - not the lobes themselves which are symmetrical in most cases but the spacing of the lobes on the camshaft must be inverted. Just take a look of the two lobes for one cylinder - in order to make for identical timing regardless of direction of rotation they would need to be either on the same position or 180° apart which obviously interferes a bit with how a four stroke works, doesn't it?


Tim

Like I said, as long as the valve timing events are appropriate, you can build a cam to spin any direction you want.

This was NOT taking an old design CCW cam and attempting to run it CW, but an entirely new cam BUILT to run CW.

grandpaul wrote:Like I said, as long as the valve timing events are appropriate, you can build a cam to spin any direction you want.

Yes, that's off course right.


Tim

Note the top mount for the prototype monoshock unit...

[/quote]

Interesting to see he is using the same alternator I am, it would be cool if you had more pictures.

Jean[/quote]

I only have one other picture of this particular bike, shown below.



I do have the following pictures, of a different configuration without the gear drive cam, that show some more detail on the gearbox and primary cover.





Ken

lcrken wrote:

Interesting to see he is using the same alternator I am, it would be cool if you had more pictures.

Jean[/quote]

I only have one other picture of this particular bike, shown below.[/quote]

Were those taken at the shop on 82nd Drive 'cuz they don't look like the old barn.

That's some nifty stuff.

I wish I had a nicely fitted out machine shop and a couple of years of training on it...

swooshdave wrote:

lcrken wrote:

Interesting to see he is using the same alternator I am, it would be cool if you had more pictures.

Jean

I only have one other picture of this particular bike, shown below.[/quote]

Were those taken at the shop on 82nd Drive 'cuz they don't look like the old barn. [/quote]

Could be, but I don't know. Kenny sent them to me a few years ago, and didn't mention where they were taken.

Ken