Yeah, I read that, but you know ......... I took the platform that "it worked for Bill" so it must be good.
I guess I'm not much help here, huh?
The only way that I can figure to check them is to bring the piston to TDC, dial indicate the top of the piston to the top of the cylinder. Then measure the distance from the bottom of the head to the valve, subract the lift of the cam and add the thickness of the head gasket minus a few thousandths for compression. Sound reasonable?

 

.010" More lift, and a few degrees duration won't make a siginifigant difference. If you're concerned, throw a piece of modelling clay on the piston, then do a mock assembly, and run it through 2 rotations. Measure the thickness of the clay to give you the clearance.

 

I just ran mine until it rattled, then backed it off a turn. Just kidding. I didn't check the clearance either, but there doesn't seem to be an issue with it. I am using the 101 grind.

Bill Dragoo
Norman, Oklahoma

 

I also installed the Webcams 101 grind in a stock 300 piston and jug. Put a bit of clay in there and cycled it through. Sadly in Thailand when I was doing this there were no micrometers around. So it was just look at it with a magnifying glass and guess. No idea what the measurement was but it showed no metal to metal contact so I threw it together.

I have a 300 cylinder, Bills 34mm mikuni pumper, exhaust, and filter. Not sure if the cam got installed with the timing off but it was pretty weak off the bottom, but the bike screamed like a banshee in the upper RPM's. I tested jetting from 127 - 155 on the main, and 38-55 on the pilot with all the needle settings and never got enough grunt off the bottom. I had a Thai mechanic experiment with the cam timing. Sadly no such things as degree wheels over there so it was just a pinch of this and that. Know it snaps of the bottom very nice and pulls the front end into the air in first. However the trade off is it signs off too early now. When I'm back over there we will try a midpoint between the two settings. Scary since its all by the eyeball with no degree wheels.

best of luck.

 

you guys - 8 pages all talking about your shafts. [:'(]

 

Here's some updated info on the stock camshafts:

"I'm sorry, their was a mix up somewhere in our conversation. We check
our cams a .050 of lift I'm not sure on the stock numbers in the
service manual. Service manuals can vary, I'm not to sure where they
checked their numbers at and sometimes they check their numbers with
lash or with out lash. I do not have the stock opening and closing
numbers because no one has degreed these cams in for our engine
information. But I do have the stock lift which is .325 and duration
@.050 is 215° on the intake and 212° on the exhaust."

Assuming that the cam lobes are symetrical (I believe that they are) and I got the centerlines right. Then here are the timing numbers for the stock cams @ 0.050" of lift.

Ex opens: 37 deg BBDC
Ex closes: 5 deg BTDC
Duration: 212 deg

In opens: 2.5 deg ATDC
In closes: 37.5 deg ABDC
Duration: 215 deg

No overlap @ 0.050"

Are these numbers more believable?

If they are, then is it probably safe to say that the stock numbers are at zero lift?

I'll wait to update the charts.

 

Yes, this reinforces why I'm leaning towards the #293 grind as recommended by Web Cams. Supposedly, this grind will move the powerband down and increase bottom end torque.

 

Those numbers sound right.
I would not expect to move the powerband down by adding duration, but you can expect a power increase across rhe board witht the increased lift.

 

Here are the updated charts and table:

 

OK, so now we have the data needed for comparison. ...back to my original questions:

Can someone explain what is meant (and the expected effect) by the differences in these numbers. (stock vs. webcams) ..and more specifically, even though the grind #101 and #293 are similar (and similarly different from stock), these subtle differences translate to what effects?

My decision is pretty much made up now, I'm plan on going with the #293 grind, but I still want to learn more about this.