Finally got the stock cam info
Well it's been a long cold winter in Minnesota but i finally got out and tore my bike a part and degreed the cams. It was miserable but right now i'm pretty damn excited. I'm going to share the cam info and explain some of the cam timing events so your not in the dark with the stock stuff.
So here is the stock magic.
Intake Duration is 214.50 degrees.
Exhaust Duration is 217.00 degrees.
Installed Intake Centerline is 98.25 degrees ATDC.
Installed Exhaust Centerline is 107.50 degrees BTDC.
LSA is 102.9 degrees
Overlap is 10.00 degrees.
So what does this all mean?
Well first the intake lobe center line is advanced.
The general rule is;
Advancing cam lobe centerline
Builds More Low-End Torque
Decrease Piston-Intake Valve Clearance
Increase Piston-Exhaust Valve Clearance
Retarding Cam lobe centerline
Builds More High-RPM Power
Increase Piston-Intake Valve Clearance
Decrease Piston-Exhaust Valve Clearance
So as expected this engine builds max torque down low and typically runs out of steam early.
The duration is more than I expected it to be. I was thinking 190ish. Larger motors do tame the cam profiles so maybe I should have expected this.
4 valve heads suffer from exhaust gas reversion due to really good low lift flow. That's why the cams only have 10 deg of overlap.The trick is for me to keep the overlap low to keep reversion at a minimum and pick a new intake & exhaust lobe centerline geared to higher RPM and then determine a LCA (lobe Centerline Angle) that will increase duration.
I am still working on these numbers as I just got in the house from degreeing the cam.
Now, I called Web Cams and they have a grind for the start cams. They basicly increased the duration and left the lobe centerlines as stock. There are a few problems with this approach and i'm not going to pick it a part.
The important thing was the cost It was $840.00 or $880.00 bucks, a lot of friggin money. I would like to do something similar the Brains Airbox Mod. I got 10 people to trust me and split the total cost for the first 10 kits. This got me in the door with the water jet company and those 10, first run people, got their BAMs for cost. I would like to do the same with cams. If i can get some people together and trust my cam spec's i would try to get 10 - 20 sets welded and ground up.
FYI, I still need to call web cams to see if i can get a price break based on quantity. It will also be a week or two before I come up with my cam spec's.
I tend to get a little radical and i'm not going to make some pussy cams that friggin piss me off. I'm also smart enough to realize iI can't go full tilt as i still like to drive across country. I have my cam cores that i bought off ebay for $150.00 bucks. So i'm ready to go for it. If you guys want to move forward your going to need to find some cam cores. They can be straight out of your bike if you wish to go that route. Buy new cams from yamaha or search ebay like i did. I chose to buy cam cores so i can still ride my bike and/or put the stock cams back in if i'm not happy with the Brain Cams. That's my plan.
Anyway, it's supper time and i'm going to go eat and dream about my Stratoliner Deluxe tonight. If your interested in going for cams the easiest way for me to keep track is if you contact me thru my website.
Here is the link.