Cam measurments anyone??

If it's broken or just needs tweaked

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soos
Posts: 57
Joined: Wed Jan 31, 2007 3:09 am

Cam measurments anyone??

Postby soos » Sat Feb 09, 2008 11:41 am

650(1981c)
1.360 Lobe 1.380
1.105 Base circle 1.105
0.255 Lift 0.275

650(1979std)
1.390 1.403
1.110 1.110
0.280 0.393


FIND MORE INFO ON STOCK LIFTS 550 AND 650!!!

650 Manual states
Intake lobe :1.4026-1.4089
Exhaust Lobe:1.3903-1.3966
Wear limit intake :1.40
wear limit exhaust :1.39


Does anyone out there have a 650(or even a 550) cam they can measure the base circle, as well as cam lobe height?

(basically the smallest and largest measurements)


thnx

l8r
-=≡ Soos ≡=-

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Volker_P
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Re: Cam measurments anyone??

Postby Volker_P » Thu Feb 14, 2008 2:37 am

Here is what I measured at an old 63hp camshaft (probably Z-model) with a slide caliper rule from smallest and largest lobe dimensions:

intake 35.7mm
outlet 35.3mm
base circle 28.25mm

It more or less seems to fit what my manual says.

For the 50hp camshaft, the lobes are close to 33mm both. I could find and measure one, too, if it helps.

soos
Posts: 57
Joined: Wed Jan 31, 2007 3:09 am

Postby soos » Thu Feb 14, 2008 9:27 am

Awesome, YEAH!!!!

I would like to have the dimensions for that 50hp cam!
:lol:

It just seems the '81either had a 550 cam stuffed into it, or a 50hp cam.
Not sure how, or why, as this bike has lived it's whole life in the US.
-=≡ Soos ≡=-

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Volker_P
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Re: Cam measurments anyone??

Postby Volker_P » Fri Feb 15, 2008 2:18 am

I try to get the data by next week. but I don't think it is the one you have as I am quite sure the lobes are smaller and almost perfectly equal. In case it is not of the 550, I once read of a CB650 French version with an intermediate power (58hp?, I think it was at http://www.cb500four.com/interactif/phpBB2/index.php). Having a look at your little database, that may come out quite right. So if you don't get ahead maybe it's worth to track this trace.
Here is a picture I took some time ago. Maybe the position of the timing mark to the onset of the second lobe already gives a hint. The data above was measured at the right camshaft.

Image

cb650
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Postby cb650 » Tue Feb 19, 2008 4:19 am

Remember these bikes are 25+ years old. Who knows what or who has messed with them in their past. I still remember seeing a 80 with a drum front brake on it at a swap meet.



Terry

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Volker_P
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Re: Cam measurments anyone??

Postby Volker_P » Wed Feb 20, 2008 1:35 am

Here the 50hp camshaft measurement:

lobes 33.1mm
base circle 28.1mm

Within the capabilities of my slide caliper rule and of myself :lol: , intake and outlet are equal.

soos
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Joined: Wed Jan 31, 2007 3:09 am

Postby soos » Wed Feb 20, 2008 10:04 am

Thnx!!
That will answer a question or two I had.


Sorry for the measurements in US (non-) standard only...
I forget sometimes that besides the US, there is only, what 5? countries that use our measuring system as a standard.



l8r
-=≡ Soos ≡=-


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