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> Cam Gear Replacement, What bolts to use?
Allan
post Oct 25 2004, 12:25 PM
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Got a replacement cam gear over the weekend thanks to Slits (IMG:style_emoticons/default/smilie_pokal.gif) Anyone recommend the right bolts to use when putting it on the cam? I don't know how much torque they are subjected to or if they need to be a certain size to clear all the stuff inside the case. Also, is anyone familiar with the Eljin (sp?) cams that GPR sells. They are saying they can get me a little more aggressive cam that will work perfectly without changing anything on the fuel injection. Thanks
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Demick
post Oct 25 2004, 12:40 PM
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Whatever cam you buy should come with the appropriate bolts and will specify the torque.

More than likely, you will have to enlarge the holes in the cam gear to fit the bolts. Also, you will probably need to counterbore the holes in the cam gear in order to recess the bolt heads. If they stick up too high, they will hit the oil pump housing.

If you buy the cam from Web-cam, they will not tell you any of this stuff (except for the torque setting). I don't know about other mfg's.

Also, I would recommend using some red loc-tite on the cam bolts. Don't want those to come loose!!

Demick
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Jake Raby
post Oct 25 2004, 01:01 PM
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what oil pump are you running??
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Demick
post Oct 25 2004, 01:10 PM
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QUOTE(Jake Raby @ Oct 25 2004, 11:01 AM)
what oil pump are you running??

I have the stock oil pump. Maybe the clearance from the cam bolts isn't a problem for those running your modified Type 1 pump.

Demick
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Jake Raby
post Oct 25 2004, 01:20 PM
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The Type I Pump is the one that is most important for bolt/cam clearance....
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Allan
post Oct 25 2004, 01:23 PM
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Jake, are you saying that clearance is not a big issue when running the stock t-4 oil pump?
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Demick
post Oct 25 2004, 01:33 PM
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QUOTE(Headrage @ Oct 25 2004, 11:23 AM)
Jake, are you saying that clearance is not a big issue when running the stock t-4 oil pump?

I guarantee you it is a potential issue with the stock pump. If you buy a new cam gear from web-cam, you will notice that the holes are counterbored. The bolts that they supply with the cam also have the bolt head machined down for less height. Using these together is not a problem.

But if you reuse a stock cam gear, it does not have counterbores, and clearance will be an issue.

BTW, the only reason that I reused the cam gear was because you can only now buy one size (-3) new. My cam gear was a -1 size. I figured that if it was important enough for VW to make 7 different sizes of cam gears, that I ought to stick with the original size. But I think most people now agree that an undersized cam gear works just fine (which is why that is the only size available). If I had it to do over again, I would probably just buy a new cam gear. Cost is not an issue, they are very cheap.

Demick
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Allan
post Oct 25 2004, 01:48 PM
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I was under the impression that the different size numbers indicated the distance between the splines. Wouldn't it cause a clearance or wear problem meshing with the drive gear?
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Demick
post Oct 25 2004, 02:11 PM
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The numbers indicate the size (radius) of the cam gear. There were different sizes to compensate for how the case was machined for the crankshaft position vs the camshaft position.

A -3 gear means that the radius of the cam gear is .03mm smaller than the nominal size (nominal size being a "0" gear). A +3 gear means the radius of the cam gear is .03mm larger than the nominal size. The cam gears were available in in the following sizes: -3, -2, -1, 0, +1, +2, +3

A larger cam gear will be a problem. But a smaller cam gear just means that there will be a little extra backlash between the gears. Apparantly this isn't a problem (although the appropriate size is still better in my opinion), but this is why they only make the smallest size now.

Of course, if you have your case align bored, then your original cam gear size is no longer important as the distance from cam to crank has been altered.

Demick
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Jake Raby
post Oct 25 2004, 04:41 PM
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I have never had a clearance issue with a stock pump and an aftermarket gear, but i don't use the same gear that Web sells.. I have had them be close, but still within clearance tolerance before....

I jump straight to a Type I pump on all engines, i haven't used a stock pump in about 5 years!
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Demick
post Oct 25 2004, 04:52 PM
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QUOTE(Jake Raby @ Oct 25 2004, 02:41 PM)
I have never had a clearance issue with a stock pump and an aftermarket gear

Aftermarket gear isn't the problem. Problem is with an OEM gear attached to an aftermarket cam (with bolts). The bolts simply require the holes in the OEM gear to be counterbored.

Demick
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Jake Raby
post Oct 25 2004, 06:00 PM
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Oh, I misunderstood.....

Yes, you are VERY correct!

.140 to be exact!

Just make sure you OEM gear isn't magnesium!
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