Adjustable camshaft pulley

[Pisobiker]

Marco, it looks perfect man thumbs up!

I think i have the solution to create a design wich isn`t depending on the original sprocket. We also deal with a company that makes custom sprockets out of anything. So if i send up one of my laying around pullys i can let them make an inquiry of totally custom built sprockets with our needs.

For instance sending them some billet material and they deliver billet with the sprocketpatern back so you can make whatever you want out of it. Maybe thats an option.

Just a thought

Cees

Ok for the sprocket (or gear or whatever the name of the "toothed" part is ) but what about the pickup disk?
I mean this one

[Pisobiker]

Anyway what you're saying is very interesting Cees. What about asking them for adjustable internal camshaft gears?
That would REALLY be great. Of course it needs to be top quality hardened steel, but adjustable pulley with adjustable intake cam gear = TOTAL ADJUSTABILITY of camshaft timing ....




Marco

[Dutch_RsBlueS2]

i think i can mill a mold for it, or turn, and then with a big press it out of sheet metal or something, that was my first thougt.

Thats what i`ve been thinking about to make a mold an press sheet metal into that form. Don`t need that much pressure for 0.8mm.

What do you think? i guess thats the way the facture make them as well.

[Dutch_RsBlueS2]

about that internal gear stuff, i think we can manage that with our own machines.

I can buy hardeble steel wich isn`t hard in first but after its fully machined it will be shipped to a company wich will harden it to your own specs. Thats no problem.

There is a lot possible with the right machinery

I`ll make some drawings if i measure my cams and see what kind of possibilities there are. I`ll make some 3D moving models wich everybody can view on its computer.

Indeed it is very wicked and also challange to make that stuff

Cees

[Pisobiker]

Yeah, could work.
If you have the time and the will of doing some tests and research on the subject I think it might be worth.

The internal adjustable sproket is a very interesting thing too. Consider in very many high performance forced induction applications there isn't that big need of super tricky and mega-lift cmshafts. With the right exhaust setup and a few degrees increase in overlap (hence the need for the internal adjustable sprocket) and the right timing (here the adjustable outer pulley...) some 4-5% increase in performances, without hurting low rpm behaviour too much, isn't impossible even with std cams....

[Pisobiker]

For example Catcams sells special camshafts with the adjustable gears for our engines, but I don't think they would sell adjustable gears separately. If someone has infos on this it could be interesting knowing availability and prices.


Marco

[Dutch_RsBlueS2]

I see, well i`ve got some 7A cams does that make a difference ?

And i`ll try to focus on the sprocket and the pickup disc first thats the easiest part

i`ll see what i can do, first i`m going to sleep a bit.

we`ll stay in touch on this one, anyway if you could send me the drawing of the adjustable part of your pully, i can make a fully adjustable one to test it out.

Cees

[Pisobiker]

Ok Cees.

Pretty late indeed.
Let me work out the simpler design pulley I'm thinking at right now, and then I'll send to you both drawings, so you can evaluate which one you like better.


Ciao

Marco

[Pisobiker]

.... about the 7A cams:
AFAIK they should have identical sprokets and mounting specs. just make sure the sprokets are the ones with the full size rounded teeth, 'cause I stepped into some having a sort of cutback teeth. Don't remember if they came out of the NM engine or not...


Marco

[Pisobiker]

The new pulley is performing well so far. Running at OEM timing for the moment.

Cees, I'm out of town till next week. Didn't have the time to make the second drawing. Will do soon and PM you as soon as I have it ready.


Marco

[Dutch_RsBlueS2]

oki, ive got school stuff this week, a whole week of learning

i`ll wait for your PM.

Cees

[elijahallens2]

For example Catcams sells special camshafts with the adjustable gears for our engines, but I don't think they would sell adjustable gears separately. If someone has infos on this it could be interesting knowing availability and prices.


Marco

Marco,
I have a set of fast road cat cams. Here is a picture with the pully. When I bought them I planned to put them on my 94 S4 but I don't know if they are even the right cams since you said the sprocket I have won't work. Let me know if I can help. I'm going out of town for a week but when I get back I can work with you on this.

Elijah

[Tommy200rs]

did you notice during tests that the part numbers for AAN camshaft pulley and for ADU is different. With the adjustable one great timing results can be achieved. Many thanks for you all for a great work done.

[Kartis]

did you notice during tests that the part numbers for AAN camshaft pulley and for ADU is different. With the adjustable one great timing results can be achieved. Many thanks for you all for a great work done.

ADU campulley is different from AAN/ABY, the "triggerdisc" is slightly retarded(or advanced cannot remember) the number is stamped in the gear and the letter B on the triggerdisc

[Pisobiker]

Hi guys.

I'm back from Rome. Car is performing well (will post a small update on my "stroker" thread).
About the pulley, yes, I did notice ABY camsensor disk was slightly advanced compared to the ADU one. I have ascribed this to the fact ADU engine has a smaller waterpump pulley (makes the pump run faster) therefore actually decreasing lenght between campulley and crank sprocket. I actually didn't seem to notice different part numbers, though..... maybe I didn't look at them well enaugh.

Anyway I have discovered a small timing difference in the pickup disk (in my experience about +/- 2 or 3 disk degrees) don't cause the ECU to see any fault. Don't know how far it could be possible to go, though, so I preferred to have the disk placed as close to the OEM position as possible.


Marco