Author Topic: Turning The Motor Over By Hand - Degreeing The Cam  (Read 1930 times)

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Offline stikman

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Turning The Motor Over By Hand - Degreeing The Cam
« on: September 08, 2014, 12:19:37 AM »
I'm setting up to degree in my cam.  I made my piston stop and I made a degree wheel that I can actually put on the points side (despite the lack of threads there).  And I made a super thin wrench to fit on the slotted nut as it is behind the degree wheel.  I tried to find TDC by turning over the motor with that slotted nut but it ends up moving the degree wheel as well.

Only other thing I can think of doing is slotting my degree wheel to fit in behind the slotted nut, then tightening it down as a unit with the small nut on the end of the crank.

So my question is, what's the best way to turn the motor over when trying to degree in your cam?

Cheers!


Edit: Motor is a '77 CB750A
« Last Edit: September 08, 2014, 12:21:31 AM by stikman »
1977 CB750A "High Horse": 836cc, mild porting, custom cam, K5 roundtops, v-stacks...
1973 CB750K D5 plunger frame chopper currently building..

Offline MRieck

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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #1 on: September 08, 2014, 05:06:12 AM »
I mount the wheel on the alternator rotor, numbers facing the points side, and turn with the advancer nut. You will need some spacers (washers etc) between the rotor and the wheel
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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #2 on: September 08, 2014, 05:13:17 AM »
Stickman, I mounted the degree wheel behind the slotted nut and used the alternator nut to turn it.  The bolt on the right side is too easy to bent, better be safe and turn it with the alternator nut, that side can take it.

http://forums.sohc4.net/index.php?topic=115305.150
« Last Edit: September 08, 2014, 05:16:41 AM by 70CB750 »

Offline Bill/BentON Racing

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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #3 on: September 08, 2014, 06:02:13 AM »
I mount the wheel on the alternator rotor, numbers facing the points side, and turn with the advancer nut. You will need some spacers (washers etc) between the rotor and the wheel
I use Mikes method works well! Bill
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Offline MCRider

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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #4 on: September 08, 2014, 06:15:26 AM »
I mount the wheel on the alternator rotor, numbers facing the points side, and turn with the advancer nut. You will need some spacers (washers etc) between the rotor and the wheel
I use Mikes method works well! Bill

Me too. Its really about the only way to do it and have easy access to everything you need. Also, best to use a larger 20" type degree wheel, so you can see it looking thru from the points side to the alt side.
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Offline bwaller

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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #5 on: September 08, 2014, 09:27:02 AM »
Without sparkplugs the engine turns easily so no stress there. I too like the alt side as it can be mounted solidly and it won't ever move.

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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #6 on: September 08, 2014, 10:06:21 AM »
What I appreciated with the degree wheel on the right side was the repeatability. Once you cut the slot in the wheel, you are able to mount it back to the same position relative to crank as before.

To check crankshaft position I guess it does not matter, but to advance F3 camshaft 5 degrees, I spent quite few quality winter evenings working on it, making sure I got it right and that I have sufficient valve clearance too.

« Last Edit: September 10, 2014, 03:30:10 AM by 70CB750 »

Offline stikman

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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #7 on: September 08, 2014, 02:15:04 PM »
Sounds like a couple of decent ways to skin the cat.  Cheers for the help fellahs!
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1973 CB750K D5 plunger frame chopper currently building..

Offline PeWe

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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #8 on: September 10, 2014, 02:24:39 AM »
I use a small degree wheel mounted on the ignition side under the big nut keeping the advance unit. No problem to turn engine with same nut. This with engine in frame and all oil in.

The small degree wheel is not that accurate as the big one that the professionals use as Mike Rieck that has this as profession.

But it works well for me and my bike

« Last Edit: September 10, 2014, 04:10:31 AM by PeWe »
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Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
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http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
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http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
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http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline stikman

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Re: Turning The Motor Over By Hand - Degreeing The Cam
« Reply #9 on: September 13, 2014, 11:22:04 PM »
Thanks again for the info fellahs.  I ended up just tightening up the points side with the degree wheel on it and pulling the alternator cover to turn the motor over from that side.  Worked a treat.

Pulled the cam specs off this custom camshaft I had ground for my matic and got it degreed in.  I think I'm solid!
1977 CB750A "High Horse": 836cc, mild porting, custom cam, K5 roundtops, v-stacks...
1973 CB750K D5 plunger frame chopper currently building..