Degreeing my camshaft

yamahammer

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I've found specs on the 447 cam at http://www.650motorcycles.com/isky.html
What I'm confused about is whether I.V.O means intake valve opening or intake valve open. I guess I'm confusled because it mentions that it was checked at zero lash then it lists various lashes?...

Maybe the dude who made that site is a member here and cam shed some light. I thought I could determine what it meant from context but that proved to be even more confusing. Either my cam sprocket is way off (doubtful, as Hugh was the last one to touch it) or I don't understand what I.V.O means.

Thanks. Kyle
 
Thanks. I only decided to degree it because the head mating surface dosent split the punch mark, its a bit above the horizontal (but less than one tooth off)
 
I had self confusion going on until I paid better attention to the btdc, atdc, bbdc, btdc notations. The various lashes are listed to allow you to check the install at a distance equally away from true TDC. Most common you will find .050 or .040 numbers for openings or closings. If it is a rephase motor cam then check the specs on each cylinder. I made a tool that helps me to keep track of TDC. I bought an old machinists tool box and it had a few run out dials in it. I gutted a spark plug, drilled it to allow the gage to slip in tight. This threads into a spark plug hole and lets me find TDC easy. It takes some getting use to but once you figure it out it saves lots of work. I got tired of wondering if the degree wheel slipped, now I can do rechecks quickly.
 

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That's actually how I find tdc. My dad used to work on/race the old maico 2 strokes so he had a tool lying around that does exactly that. With the pma I lost the stock marks so I leave it in and zero every now and again. It is a rephase, but theres not much I could do if the cam was out of phase with itself, besides to split the difference between cylinders.
 
I think the goal is to get it as close as possible. You will even find specs on intake and exhaust lobes, not that you can change that without a regrind. If your cam was done right it will be on, if not split the difference, or in a rephase, diffrences. I want to go to an adjustable gear cam like Webb or Megacycle so tuning is easier. Modern drag racers use this and can adjust cam timing as needed. As long as it is not out so far that your valves hit the pistons the motor will run. Tweaking the timing can really change your power curve too. Some want peak at 8500 + others ride the street and want grunt at a much lower rpm where the bike is driven most.
 
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