[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] [T-3] CAM GEAR SELECTION/MATYCHING , GOOD INFO FOUND


On 31 Jul 2001, at 13:18, Martinez, Leon wrote:

> I aked him about cam matching and he told me that the VW factory does
> this on a routine bases. They start with gears with a pitch and other
> varibles with a deviation  of  0 (zero) then the following
> +1,+2,+3,-1,-2 and -3 . Each number indicates a deviation of 1/100th
> of a mm  from the base zero. All german cams have aluminum gears. The
> new OEM cams only come with the number 0 (zero) deviation so no
> matching

This adjustment proceedure is exactly right, but I thought you 
could still buy cams with the various deviations. I don't think this 
has ever been true of non-stock cams. Yes, all the OE cams have 
alum gears even the aftermarket stock cams. The aftermarket 
performance cams come without gears so you get to remove your 
stock gear and reuse it. I'm not surprised that the steel straight cut 
gears only come in the zero deviation.   

I keep all my old cams and use them to gauge any engine I am 
rebuilding. In the past I have sometimes bought a new cam of the 
right deviation, or just reused a used cam with new lifters. (BTW, 
there are some perfectly awful "Made in W. Germany" lifters out 
there.) The first time I needed a new cam I took the crank, 
bearings, and one case half down to the shop that had a stock and 
tried several until I found a correct one. They knew that this was 
necessary, so they were perfectly happy to let me do this.   

How do you check the fit? place the crank, lubricated new main & 
cam bearings, and cam in the left case half with the timing marks 
aligned properly. Turn the crank slowly in the direction such that 
the gear teeth at the mesh point are rising out of the case half. 
Turn the crank slowly thru 2 full revolutions; if the cam lifts out of its 
bearings at any time then the cam gear is too large and is binding.  
 

You want to use the largest gear that doesn't bind at any point.   

-
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054
USA

-------------------------------------------------------------------
Search old messages on the Web!  Visit http://www.vwtype3.org/list/


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]