Author Topic: Does the tensioner need to be installed for cam dialing?  (Read 1161 times)

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Offline 70CB750

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Does the tensioner need to be installed for cam dialing?
« on: February 24, 2014, 05:10:22 AM »
To measure the camshaft opening and closing I would think the chain tensioner makes no difference, but what do I know?

Opinions?
Prokop
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Re: Does the tensioner need to be installed for cam dialing?
« Reply #1 on: February 24, 2014, 08:13:49 AM »
Simple answer is :sloppy cam chain=sloppy valve timing. The cam and crank must both move at the same time.  A correctly tensioned chain will insure that happens.
Otherwise, your readings will be off.

Offline 70CB750

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Re: Does the tensioner need to be installed for cam dialing?
« Reply #2 on: February 25, 2014, 04:05:12 AM »
Bump.
Prokop
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Offline MRieck

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Re: Does the tensioner need to be installed for cam dialing?
« Reply #3 on: February 25, 2014, 06:16:03 AM »
As was mentioned...it needs to be installed with the correct tension. Check your timing with the lash you will be running too
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Offline 70CB750

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Re: Does the tensioner need to be installed for cam dialing?
« Reply #4 on: February 25, 2014, 06:19:57 AM »
Thank you both, gentlemen.
Prokop
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Offline PeWe

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Re: Does the tensioner need to be installed for cam dialing?
« Reply #5 on: February 25, 2014, 06:40:45 AM »
When you have done it (or not) as recommended...you'll understand why the Pro's on this forum answered as they did :)
I rotated my engine a lot when timing, rechecked everything several times... I want to do it again... The valve train has play that affect the timing, not the valve lash only. The real result will be with the final and by the cam manufacturer recommended valve lash.
Note! Cam specification is often at 0.04-0.05" lift and 0 lash.
my notes when timing: 0 lash need more than no lash between valve and rocker arm, there is a play rocker arm and it's axis too....

True TDC is another thing to find exact 0 for the degree wheel. I did it the complicated way not using a piston stop...
I'll make one for next timing session, bolt thru an old spark plug.
It's easy to implement errors, 1-2 degree here, another degree there. Total 3-5 degrees wrong. My engine runs fine now, but I THINK the cam need to be advanced 3-5 degrees.
« Last Edit: February 25, 2014, 06:48:24 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline 70CB750

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Re: Does the tensioner need to be installed for cam dialing?
« Reply #6 on: February 25, 2014, 06:47:38 AM »
I found my TDC via a stop, amazingly enough it was exactly at T 1-4.  Later, when I pulled the head off, I rechecked the TDC with dial indicator on the piston top and it still matched perfectly.

Still want to go to bigger wheel, I am certain I make some reading errors on the 7" one.
Prokop
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Offline PeWe

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Re: Does the tensioner need to be installed for cam dialing?
« Reply #7 on: February 25, 2014, 06:51:01 AM »
I'll cut my frame and insert frame mod kit to be able to time when I need :) Test different cams and check things.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline MRieck

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Re: Does the tensioner need to be installed for cam dialing?
« Reply #8 on: February 25, 2014, 11:47:36 AM »
I found my TDC via a stop, amazingly enough it was exactly at T 1-4.  Later, when I pulled the head off, I rechecked the TDC with dial indicator on the piston top and it still matched perfectly.

Still want to go to bigger wheel, I am certain I make some reading errors on the 7" one.
T ;)hat is good enough.
Owner of the "Million Dollar CB"

Offline lucky

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Re: Does the tensioner need to be installed for cam dialing?
« Reply #9 on: February 25, 2014, 02:43:00 PM »
To measure the camshaft opening and closing I would think the chain tensioner makes no difference, but what do I know?

Opinions?

The slack needs to be removed from the cam chain if you want it to run its best.