HELP WITH a6 camshaft installation on a4/a1

[JTL_91CB7]

my main consecern is where to set the timing when removing and installing it. If I turn the crank to top dead center will the cam fall into place correctly? If it's too dead center then how would I align the cam with the timing crank? I know I will have to adjust the valves but I don't want to destroy my head!

[Jon]

Best thing to do is set yourself up at TDC. Use the marks on the flywheel (or drive plate if it's an auto).


Pop the valve cover off and check the alignment marks on the gam gear.



Also take a look at your distributor and see if the rotor is pointing at cyl. #1.

Once you have all that wonderful goodness lined up, swapping the camshaft out is easy.
Undo the rocker assembly, pop the cam out, unbolt the cam gear, remove the woodruff key, swap those parts over to the A6 cam (I'd suggest installing a new cam seal too).

Edit: Forgot to mention that marking the cam gear and timing belt also helps keep things aligned when reinstalling.

[deevergote]

The camshaft should be keyed so that it can only go on the gear one way. As long as you install the camshaft on the gear properly, all will be where it belongs. Just be sure to set the timing as jon showed, and you’ll be in good shape.

[CB7_Saloon]

The A1 valve springs are ok to use? I thought those were stiffer to compensate for the extra duration?

[deevergote]

The A6 springs are a different part number, so it is assumed they are stiffer. I don’t believe anyone here has ever measured to confirm. Many people have used the A1 springs with no issue, though. It seems to be safe to use them with the A6 camshaft.

[Jon]

I had a set of A6 springs laying around for testing, but never did. They were used so the testing would have been skewed.

With as many miles as that they have on them these days (after all we are talking about 25-28 year old vehicles), I doubt their pressure variances between the A1/A4 and A6 would be noticeable on a stock-ish motor. Fully built would be an issue.

If you feel like going to the trouble, you can always test and measure the springs (installed height, free height, pressure) to make sure they are square and have proper seat pressure (40-42 pounds I think??).