cam degreing question

I am attempting to degree my new cams from pit-stop-performance on my new 1075 motor. When finding the true TDC I have followed the directions moving the crankshaft both clockwise and counter clock wise till the piston touches the TDC bolt. I have recorded and added the two numbers on the degree wheel, divided by two to get the TDC reading. My question is this, if that reading is 42 degree's and I want to move the pointer or degree wheel to reflect that reading, which way on the degree wheel am i going, clockwise or counter-clockwise from 0? I should know this but I want to be sure and many of you have done this before.
Thanks in advance, Jim

Everything you need to know and then some... Step by step instructions...

kzrider.com/index.php?option=com_docman&...d&gid=451&Itemid=108

lewisj wrote:

I am attempting to degree my new cams from pit-stop-performance on my new 1075 motor. When finding the true TDC I have followed the directions moving the crankshaft both clockwise and counter clock wise till the piston touches the TDC bolt. I have recorded and added the two numbers on the degree wheel, divided by two to get the TDC reading. My question is this, if that reading is 42 degree's and I want to move the pointer or degree wheel to reflect that reading, which way on the degree wheel am i going, clockwise or counter-clockwise from 0? I should know this but I want to be sure and many of you have done this before.
Thanks in advance, Jim

Jim if you are using the postive stop method and not just the dail indacator. Rotate the motor until it hits the stop. Set your degree wheel to "0". Rotate the motor the other direction until it hits the stop again, record that number then divide it in half. Then back the motor up to that number. Then set your degree wheel or pointer accordingly.

May I ask?
Witch cam degreeing method, do you plan on using.

If the cams are those Andrews 3x knock offs, pay careful attention to what you're doing.

They have a lot of overlap lift on 106 centers.

When you have found true TDC, verify it with the stop. You'll get the same stop number in both directions. Then proceed with the rest of the process.

larrycavan wrote:

If the cams are those Andrews 3x knock offs, pay careful attention to what you're doing.

They have a lot of overlap lift on 106 centers.

thats why your building my motor LarryB)

LarryC, Can you quickly explain what you mean by alot of overlap lift at 106? Is this bad, good?
Jim

kzz1p,
I am looking at three different set of instructions and trying to figure out which is best. i have the instructions from Pit-Stop-Performance, they are a little vague at points throughout. I have the Web Cams instruction and I have the Cam Degreeing for Zombies. I am just getting eberything set up for the process. Degree wheel, TDC tool,Dial indicator, etc.
Do you have a perferred method?
Jim

lewisj wrote:

LarryC, Can you quickly explain what you mean by alot of overlap lift at 106? Is this bad, good?
Jim

Jim,

First, look over that cam spec photo I posted.

With a lot of overlap lift [when both valves are open at the same time at TDC] the closer the valves get to tangling with each other and/or the piston.

Low lobe center values on the cams increases overlap lift. That in turn creates less clearance.

With those cams, it's advisable to assemble the head with light springs to degree the cams. You only need valves assembled in one end cylinder to do the job.

By using light springs you can push the valves open with a screw driver to check for clearance problems.

You're probably going to find that the range of least clearance will occur at slightly past TDC on the intake cam [often 5-8 degrees ATDC]

The potential clearance problems are:

a]Intake Cam - It's possible to accelerate the intake valve into the top of the piston.

b]Exhaust Cam - Piston is chasing the valve up the cylinder. Obviously it's important to get the valve out of the piston's way.

To check for clearance problems this works well.

Assemble with light springs [as mentioned above]
Set valve lash to running clearance.
Position Crank at 15* BTDC on Intake Stroke.
Turn the crank in 2 degree increments.
At each point stop and push the valve down with a screwdriver until it touches.
Check the amount of clearance between the lobe and the bucket with feeler guage or use the dial indicator.
Do that process in 2 degree increments moving past TDC until you find the tightest clearance point.
That should be a minimum of .060 valve to piston clearance.

For the exhaust side, generally, 30 - 15* BTDC will be the range of closest valve to piston clearance. On that side it's best to see .080" as the tightest clearance.

If you run into a situation where you don't have enough clearance on 106 centers, you can spread them a couple of degrees to 108. It's either that or machine the valve pockets on the pistons deeper.

Those cams will pull hard for you. They don't leave you a lot of room to play "close enough". Also, I suggest putting a rev limiter on the bike with those cams to be safe.


Pay attention to what you're doing. It's not rocket science but it should't be approached lightly either.

Trickiest parts are finding true TDC and getting your dial indicator to move freely and repeat the numbers. It's a feel thing. You'll get it

LarryC,
Great information, I really appreciate your knowledge and help!
Jim

lewisj wrote:

LarryC,
Great information, I really appreciate your knowledge and help!
Jim

Jim,

One more thing to look at is the clearance between the boss on the cam where the bolts mount and the head.

I just setup a head today for lobe clearances and the cores were dragging in the cam chain tunnel. Had to grind the boss & the head a little.

LarryC, The more I read the more nervous I get. Fortunately, I have a mechanic here in town that was the Int'l. Drag Bike association 'Mechanic of the Year' in 1994, running z1, KZ and 650's. He is very knowledgeable to say the least. i bought my Andrews 3X's off him. I may let him show me the way arounf thiss thing the first time.
Larry, again I appreciate all you help and knowledge and the fact that you readily share it.
Good riding!
Jim

lewisj wrote:

LarryC, The more I read the more nervous I get. Fortunately, I have a mechanic here in town that was the Int'l. Drag Bike association 'Mechanic of the Year' in 1994, running z1, KZ and 650's. He is very knowledgeable to say the least. i bought my Andrews 3X's off him. I may let him show me the way arounf thiss thing the first time.
Larry, again I appreciate all you help and knowledge and the fact that you readily share it.
Good riding!
Jim

You're welcome Jim. That's great you got some good help for this. Many guys are not that fortunate