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CVO Technical => Twin Cam => Topic started by: yellow103 on August 09, 2010, 07:53:50 PM
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I see where a lot of folks upgrade to gear drive cams. I have a 05 SEEG 103' with a few upgrades,Rinehart tru duals,SERT,SE air filter,SE 6 speed tranny, changed primary drive to a 21 tooth and am pretty happy with the way it runs, so If I'm not looking to increase HP what are the advantages?
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Gear/gear tooth contact insures dead-on cam timing over the long haul.
Also you'lll never need to change your cam chain shoes again.
You'll want to check crank run-out prior to installation, as .003" is where you want to draw the line.
Scott
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One of the larger dealers in the Milwaukee area STOPPED putting
in GDC's because of all the runout problems.
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The main reason for installing gear drives on the '06 and earlier Twin Cams was getting rid of the chain tensioners that had a bad tendency to fail prematurely, often taking the engine with them. The second reason was that the stock chain setup was so sloppy that cam timing could be affected by as much as 4-6 degrees. That in itself probably isn't a compelling reason for someone who is satisfied with the current performance of his 2005 CVO103 to spend the money for new cams and the gear drives. But if you haven't had the chain tensioners checked/replaced yet, you really should have them inspected. Depending on what you see, you could just button it back up and make a note to check again in another 10k miles, you could just replace the tensioner shoes themselves, you could update the entire cam drive to the new hydraulic tensioner setup, or if you have excellent crank runout (less than .002") you could go for the gear drive. For my money, the new hydraulic tensioners and roller chain setup is the way to go for a street engine. Quieter, less likely to fail if your crank develops a little extra runout, less expense up front.
Jerry