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Adjustable Timing Gear
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-nick  



Joined: 16 Nov 2002
Posts: 2699
Location: Cambridge, MA

PostPosted: Wed Mar 29, 2006 5:07 am    Post subject: Adjustable Timing Gear Reply with quote

Are they worth picking up? I've seen pics from a couple folks on here who have them. Is everyone just running a little cam retard to bump the top end? Or just using them to degree the cam in to alignment? How big is the effect with our engines? I want to hear from anyone who has played around them on these cars on the street. Especially so if you're running a 931.

My head has been skimed twice now (that I know of). Not sure how much was taken off each time - they were both done during normal head r&r (no warpage reported). I'm sure my cam timing is running a touch advanced (if I'm visually it right...).

It looks like they're around $100 from VW places (basic A1/2/3 chassis 8V adjustable cam wheel).

Thoughts?

nick
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bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Wed Mar 29, 2006 5:40 am    Post subject: Reply with quote

Nick,

I think for a 931 with some head mods, or skimmed, these have to be worth it. If only to dial in the cam timing to the factory spec. However, as you know, it's quite possible to modify the power delivery, in a minor way, with the cam timing.
Remember, the cam is the heart of the engine. Make it beat to the right time.

Steve
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Kenodog  



Joined: 25 Jun 2003
Posts: 2580
Location: Vancouver,B.C.

PostPosted: Wed Mar 29, 2006 3:00 pm    Post subject: Reply with quote

Nick i've played a little with mine and it does make a big difference.Especially if you dial it alot one way or the other.I will assume that they are all pretty much the same design,mine goes 8 deg either way.This is quite helpful if you're running more than stock boost.Inversely,if you are running stock boost then set it to advance and feel the extra low end pull without worrying to much about detonation.
My original plan was to set the cam gear set to full advance for low rev snap and have an MSD BTM retard by 3 deg per psi. when in full boost to spare me the high end detonation.
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morghen  



Joined: 21 Jan 2005
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Location: Romania

PostPosted: Wed Mar 29, 2006 11:53 pm    Post subject: Reply with quote

so to a NA this would be no good ?
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macBdog  



Joined: 16 Aug 2004
Posts: 1110
Location: Brisbane, Australia

PostPosted: Thu Mar 30, 2006 9:57 am    Post subject: Reply with quote

Also what brand are the ones youve got? I have my head off at the moment and wanted to get one but I can't find em for our cars.
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ESC944  



Joined: 21 May 2004
Posts: 747
Location: FL

PostPosted: Thu Mar 30, 2006 2:45 pm    Post subject: Reply with quote

You can make some strides/gains with an ACG on a NA or Turbo car. ACG= Adjustable Cam Gear.

CONTENT DELETED TO APPEASE NICK


Last edited by ESC944 on Fri Mar 31, 2006 4:33 am; edited 1 time in total
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flosho  



Joined: 01 Jul 2004
Posts: 3153
Location: Eau Claire, Wisconsin

PostPosted: Thu Mar 30, 2006 3:10 pm    Post subject: Reply with quote

Excuse my n00bness on this subject. But it is possible to do valve damage if you adjust the cam gear too far one way correct? How much would a person be able to adjust it to the safe maximum?
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macBdog  



Joined: 16 Aug 2004
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Location: Brisbane, Australia

PostPosted: Thu Mar 30, 2006 3:22 pm    Post subject: Reply with quote

Thanks for the write up ESC, good info. Now where can I get one for the 924? You mentioned a company that supplies them for VWs in your post...
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1979 931 with a 350 chev
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ESC944  



Joined: 21 May 2004
Posts: 747
Location: FL

PostPosted: Thu Mar 30, 2006 3:33 pm    Post subject: Reply with quote

Yea bud, you can source the VW units from several vendors...

http://www.eurosportacc.com/camgears.htm
http://www.gprparts.com/brands/neuspeed/camGears.asp
http://www.autocarparts.com/parts/Engine/Cam-~-Cam-Gears/
http://www.performance-cafe.com/index.php?osCsid=a749a6dad6fa1ec978f71c4fdb69f413
http://www.thepartsbin.com/sitemap/volkswagen~cam_gears~parts.html

Of course the internet is a good source..... as search engines go...

You could also get a hold of an original unit made for the 924 and have it reproduced...
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ESC944  



Joined: 21 May 2004
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PostPosted: Thu Mar 30, 2006 3:35 pm    Post subject: Reply with quote

Flosho - I would say it is not in "your" best interest to do anything involving valves - your car snacks on those enough already.

As for actual damage - well anything is possible - but in general practice no.
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flosho  



Joined: 01 Jul 2004
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Location: Eau Claire, Wisconsin

PostPosted: Thu Mar 30, 2006 3:46 pm    Post subject: Reply with quote

ESC944 wrote:
Flosho - I would say it is not in "your" best interest to do anything involving valves - your car snacks on those enough already.

As for actual damage - well anything is possible - but in general practice no.



Yeah that it does. However my 36$ Genuine Porsche timing belt should solve that..right?

I'm hoping to start building a 931 engine from the block up next fall or winter.. I mean I already got an extra cylinder head...
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bass gt  



Joined: 02 Dec 2004
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Location: Johannesburg for now!!

PostPosted: Thu Mar 30, 2006 5:24 pm    Post subject: Reply with quote

Guy's,

Piper in the UK make and sell them.

Steve
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ESC944  



Joined: 21 May 2004
Posts: 747
Location: FL

PostPosted: Thu Mar 30, 2006 7:15 pm    Post subject: Reply with quote

http://www.pipercams.co.uk/NewPiperWeb/redesign/Verniers.html
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-nick  



Joined: 16 Nov 2002
Posts: 2699
Location: Cambridge, MA

PostPosted: Fri Mar 31, 2006 3:26 am    Post subject: Reply with quote

These thoughts don't seem original to me, but you can decide for yourself.

ESC944 wrote:
"The Basic job of the camshaft is to open and close the intake and exhaust valves at the "proper time" relative to engine position (piston travel) - to charge the combustion chamber and expel burnt gasses. "

Sportcompactcar article:
"Basically, the job of the camshaft is to open and close the intake and exhaust valves at the "proper time" relative to engine position (piston travel) - to charge the combustion chamber and expel burnt gasses."

ESC944 wrote:
"Now in any motor once you've bolted on performance parts, milled the head like Nick or some of the other guys on here, or if you install a lumpy performance cam, etc these things alter the optimum cam timing. Well if you consider factory stock optimal. "

Sportcompactcar article:
"However, once you've bolted on performance parts, milled the head or installed a lumpy performance cam, you also alter the optimum cam timing that most sport compacts prefer. What can you do?"


Last edited by -nick on Tue Apr 04, 2006 6:21 am; edited 1 time in total
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Chrenan  



Joined: 15 Jan 2003
Posts: 3899
Location: Canada

PostPosted: Fri Mar 31, 2006 3:29 am    Post subject: Reply with quote

You should always cite the website you are quoting, it is nice for folks to read the original content as they may get more out of the full text.
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