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Location:
Lost in the K hole
Registered:
May 2002
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 Cam adjustment w/ existing dowel pins + holes
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Wed, 27 August 2003 14:44
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just thought id share what i calculated tonight 
7m cam gears have 3 dowel pin locations on each of the cams, AND on the cam gears. theyre designed for 1 step of adjustment in each direction away from TDC, whilst maintinaing the timing mark at 12o'clock... the idiots guide to cam degreeing really
this one step allows a total of + and - 1.5deg cam angle adjustment.
however, i sat down tonight and plotted the angular shifts of ALL combinations of dowel pins and holes. and taking into acount the ability to jump teeth with the cam belt, came up with the following posibilities
you can, effectively ADVANCE or RETARD both IN and EX cams by
0.0deg
1.5deg
2.0deg
3.0deg
3.7deg
4.5deg
5.5deg
6.0deg
7.5deg
9.0deg
9.5deg
10.5deg
11.5deg
and on and on and on
ALL using the existing holes (these are cam degrees, NOT crank degrees)
i figured this was a pretty decent level of adjustment, and for most uses, negates the need for fully adjustable cam gears (you can switch the dowel holes pretty easily at the dyno if you wanted to - and then how often do you want to change it??)
ill describe in detail the combinations of dowel and hole arrangments specifically if someone want to do it. otherwise, itll become a tech article on the site one day, and you can find it there... 
good news none the less...
cheers
ed
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Location:
Perth
Registered:
June 2002
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Re: Cam adjustment w/ existing dowel pins + holes
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Wed, 27 August 2003 15:34
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GOD DAMMIT MAN! have you nothing better to do!  
On a serious note though I had never given this much thought, and I had no idea you could get that kind of adjustment out of it.
As you said, how often would you want to change it??
Good food for thought Ed.
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Toymods Board Member
I supported Toymods
Location:
Turramurra, Sydney.
Registered:
May 2002
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Re: Cam adjustment w/ existing dowel pins + holes
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Wed, 27 August 2003 18:26
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I did wonder about the potential of that a while back, but hey, it'll never look as good as a set of nice polished vernier gears!
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Location:
Lost in the K hole
Registered:
May 2002
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Re: Cam adjustment w/ existing dowel pins + holes
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Thu, 28 August 2003 00:33
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gabe, it took like 20mins to do  
for my budget, ill take the adjustability over the $200 shiny bits any day ...
cheers
ed
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