About Those Cam Index Numbers............

[hambone]

I think an easier solution would be to buy the camshaft locally and then exchange it for the correct geared shaft if the situation arises.
Ya gotta laff at Chilton et al. and their 12 pages of "engine rebuild"...

[Bookwus]

Hiya Bob,

Yep, that's pretty much my take on it also

[Amskeptic]

I think an easier solution would be to buy the camshaft locally and then exchange it for the correct geared shaft if the situation arises.
Ya gotta laff at Chilton et al. and their 12 pages of "engine rebuild"...

Many replacement camshafts are coming out as bolt-ons. If you ever do replace your camshaft where you are keeping the case, keep the cam gear that works in that case. I wish I HAD . . .
Colin

[satchmo]

I think the concern about which cam to use depends on whether you are using the same engine case your cam came out of. Let me see if I can explain that.

Your OE cam was selected based on the variations in alignment between the crank and cam bores that occurred on the assembly line (remember VW was putting out thousands of these motors every week). So the original cam is specific to THAT case with THAT bore. It was easy to find the right fit at the VW assembly plant since they had bins with every size of cam right there. Type 4 engines had cams from -5 to +5, I believe. Maybe more.

If you are rebuilding your original case in an unaltered manner (no align boring, etc) you need to either use your original cam, find another cam with the same number, or get a new camshaft that will bolt on to your original cam gear. You just can't get away with installing a new aftermarket '0' cam unless that is what your engine had originally.

I don't have experience in align boring, but I suspect once you do that and end up putting in oversize bearings, etc, you have a good chance of altering the original alignment between the crank and cam bores and the original cam number will no longer apply.

And when you get a NEW case, all bets are off. You hope you get a case that had more attention than the VW factory did to aligning the crank and cam bores, and then you can go with a '0' cam, which is good because that is about all that is available new anyway. However, I think it would pay to check any new case for correct alignment between the bores before the build is started, and to do the required tests for cam fit once the cam is in.

At least this is how I understand the cam number issue.

Tim

[Bookwus]

Hiya Tim,

Well, speaking as a an old teacher, I gotta say that you have made the whole issue clear as crystal. I had thought that the index had to do with solely how the crank and cam gears intermeshed. I had not realized (but pretty obvious now it's out there) that the axis of the crank and cam were the determining factor.

Thanks Tim for shining that light in a dark corner!

[Amskeptic]

Hiya Tim,

Well, speaking as a an old teacher, I gotta say that you have made the whole issue clear as crystal. I had thought that the index had to do with solely how the crank and cam gears intermeshed. I had not realized (but pretty obvious now it's out there) that the axis of the crank and cam were the determining factor.

Thanks Tim for shining that light in a dark corner!

"to cover the unavoidable variations in camshaft bore to crankshaft bore dimensions among all crankcases"

We must all endeavor to save up our old gears. If your camshaft is toast, grind the rivet heads off carefully and save the gear. This is important for the future of our hobby iof we want VW engines to continue sounding like VW engines instead of threshing machines with loose ball bearings.
Colin

[Bookwus]

Hiya Colin,

Yep.......agreed there. Eye to the future and all that!

I wandered on down to my FLAPS and I was told that they could not order a cam with a specific index number. However, I know the guys there well enough to get just what I want...........even if it takes a couple of stabs at it. The F in FLAPS is important these days.

But that does make me realize that conservation is getting more important all the time. Good point Colin!