|Topic Review (Newest First)|
|11-28-2017 08:31 PM|
Well, I missed it!
My grade-school teacher knew what she was doing when she marked my report cards, "NEEDS TO READ MORE CAREFULLY."
Surely, you have the adjustable cam sprockets, pdwestman. Would appreciate your first-hand experience and evaluation. I sincerely salute Chris for developing and marketing a needed and wanted niche product.
|11-28-2017 01:13 PM|
Originally Posted by Damocles View Post
He has the tools, the knowledge and the dynamometer to back-up his statements. Lamborghini doesn't let just 'anyone' service or repair there cars.
|11-28-2017 12:58 PM|
A modest question, pdwestman:
What is the DELTA, that is, the DIFFERENCE, in crankshaft degrees between a cam installed using factory witness and index marks, and the stock valve timing specifications?
And, a, "part two" to the question: What is the performance consequence of the angular difference?
|11-28-2017 12:37 PM|
The problem with your argument Damocles, is that due to manufacturing tolerances of the pressed on crankshaft cam chain drive sprocket, the height of the crankcase base gasket surface, the height of the cylinder from base gasket to head gasket, the height of the cam bearing journals above the head gasket surface, the drilled position of the cam sprocket dowel pin holes in the cams, the dowel pin relief in the cam chain sprockets and the actual length of the cam chain All affect the actual camshaft timing.
Plus or minus .0005" here and there causes some engines to run better on bottom and some run better on top. Then lets say 33% actually hit the factory design spec, which was chosen to pacify the EPA.
klrchris took the time to find the sweet spot for the stock and standard KLR650 camshafts, just ask rebar! He is in love with his KLR again.
Hot Cams & Web-Cams have published the sweet stop numbers for their cams. But they never provided any way for the mere mortal to achieve that positioning. So chances are high that if one simply install one of these aftermarket cams with No Adjustment, the engine would perform Worse than standard.
|11-28-2017 12:00 PM|
I'm not as sanguine as some regarding the merits of "degreeing" KLR650 camshafts.
The Service Manuals provide cam timing specifications, the crankshaft degrees when events (Intake Open, Intake Close; Exhaust Open, Exhaust Close) occur. Using as-built timing index and witness marks, I'd expect once comes rather close to these specifications.
Now, unspecificed: Exactly, WHEN does a valve open, or close? A convention in the automobile industry specifies 0.050" valve stem elevation above fully closed position; however . . . don't know what Kawasaki's standard might be.
Let's say 0.050" prevails with Kawasaki also. Set up your degree wheel, indexed at TDC. Put your dial gauge atop the valve stem in question. Rotate the engine 'til 0.050" is read. Note crankshaft degrees, 0.050" valve lift after opening; 0.050" valve lift before closing. That's your valve timing.
How close to factory specifications? And, should you decide to DEVIATE from the valve timing specifications provided by the ol' meanie Kawasaki engineers who don't want anyone to have any fun, WHAT novel valve timing do you want? How much performance increase results from abandoning stock valve timing specifications?
Of course, there's the 15 crankshaft degrees available from advancing the exhaust cam one camshaft sprocket tooth. Some people say such a modification produces 10 % more power from idle to redline. Others, 'specially Generation 1 riders, say, "Not exactly;" some even restore stock valve timing.
Regardless, here's what Clymer says remains Generation 1 valve timing:
IO 19 DEGREES BTDC
IC 69 DEGREES ABDC
EO 57 DEGREES BBDC
EC 31 DEGREES ATDC
This is the valve timing evil Kawasaki engineers have foisted on their customers, robbing them of tremendous "free" power, some say.
Pay no attention to these "factory" valve timing specifications. Gain this power back, with variable camshaft chain sprockets permitting your own custom valve timing!
Hot Cams publishes their own valve timing specifications, if I'm not mistaken; I know WebCam does.
|11-28-2017 11:08 AM|
Originally Posted by carvid View Post
Originally Posted by rebar View Post
As 'Damocles' & 'rebar' suggested, there is more to it than just throwing in a pair of cams. Even the cam company will suggest that they be properly installed to "timing degree specifications".
But until this year it was near impossible for the average mechanic to do that.
'rebar' hesitates to provide a link. But he is using this set of cam sprockets, on his stock cams! And apparently grinning from 'ear to ear'.
|11-27-2017 11:09 PM|
After market cams
Hey Carvid welcome to the site. The stock cams perform very well. I would not give up on them before I was sure that they were properly positioned. Degreeing the cams will tell you if they are in the correct adjustment for performance. That is an easy thing to do and will tell you if adjustment is necessary. Ride safe James
|11-27-2017 10:18 AM|
General comment regarding any "performance" cam.
Cam alone merely shifts horsepower and torque curve rpm peaks; additional modifications (e.g., intake/exhaust/displacement/etc.) required for optimum benefit.
Depending upon how "radical" aftermarket cam might be, extensive valvetrain modification may be necessary for effective operation.
|11-26-2017 09:20 PM|
HotCams for KLR650
Curious if anyone has performed the HotCam set up offered by USMOTOMAN. Any thoughts??