Adjustable camshaft pulley

[Pisobiker]

As promised here are the drawings and pictures of my adjustable camshaft pulley.
Not 100% finished, though. Only need to drill the holes for the +3°, +6°, +9° and -3°, -6°, -9° settings.

I decided to use the "holes" method instead of the button holes, because I don't have tha machinery for making perfect buttons and I also don't trust theyr tightening capability 100%.


As sayed in another thread I have a 1 coil per cylinder engine with the magnetic camgear pickup (ABY-AAN-ADU engines) stroked using a taller TDi block (~16mm taller).
So, having produced half a theet change in timing, I had to phase the camshafts and the pickup's disk back.
Not having available any source for finding an aftermarket adjustable pulley I had no other solution but building it by myself....
While there I also wanted to be able to chose among different timing advances for later tests.

Here is first drawing: section of OEM camshaft pulley

[Pisobiker]

Here is my adjustable pulley drawing (front view)

[Doug_RS2]

Do you use the original camshaft pulley for the teeth? And cut out the centre to use yours? Or is it all custom made?

[Pisobiker]

As you can see from previous drawing the timing change is accomplished by changing position of the three timing bolts to the corresponding holes. The blue dotted circles show the threaded holes on the center sction.

I choosed the +3°,+6°,+9° and -3°,-6°,-9° solution, which might be eccessive.
+2°, +4°,+6° and -2°, -4°, -6° might be better for some applications.

[Pisobiker]

Let me finish Doug,
be patient a few minutes...

[Pisobiker]

Here is the section view of adjustable pulley:

[Pisobiker]

and latter drawing: exploded section

[Pisobiker]

As you can clearly see from the exploded view the pickup's disk is bolted directly to the outer aluminum disk which is bolted in a fixed position to the gear. This means once retimed the disk will stay the right position with the crankshaft no matter the change in camshaft timing. Its bolts go throug a button hole in the center aluminum part which allow for its movement independently from the disk itself.

not having the machinery for making my own gears I had to cut OEM one.
Some pictures of "ongoing work":

[Pisobiker]

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[Pisobiker]

Then the pulley so far:

[Pisobiker]

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[Pisobiker]

all the parts unbolted:

[Pisobiker]

......

[Pisobiker]

Also will try to find some places where to take some metal off without weakening the structure. At least for ahestetics....

The job was done using a lathe (lots of work, really). A CNC would have certainly produced a better looking piece..... and in a lot less time


Hope I'll find the time to do the last few machining to it. Test fit and road test soon to come.


Ciao

Marco

[Pisobiker]

Any comments good and bad always welcome, as well as tips and ideas for improving the design and functionality