Adjustable Arospeed cam gears questions HELP!?!

[fivestardsm]

I have a set of older Arospeed adjustable cam gears, well they dont line up!! I have tried setting them at several different angles to get the timing marks lined up, but no matter what I do, they are a 1/2 a tooth off. This is bewildering to me, I have done 40 or 50 t-belts over the years, but have never used a set of Adjustable gears.

If anyone has any info on these, or any others that have had the same dificulty.

Thanks...

 

[bigblock4g63]

they had a sh*t load of cams that were f* up from the start

 

[slugsgomoo]

if your head is decked it's likely that they won't line up zeroed out, for what it's worth.

 

[gtluke]

stick on a stock set since you'll never take them off zero anyway

 

[fivestardsm]

Well in my rush, i should have probably clearified the extent of the build. I had planned to run a set of web street grinds, but have moved on to a set of 272's, so I need the adjustables..(well for what I am going to try to do with it, I am going to need them anyway..Dont ask, its just a test that I would rather not get into)
As for the decking, yes the deck has been surfaced by 7thousanths and the head by 2thousanths, and then brought back to with in speck by a thicker head gasket which by all meassurements brings the total loss to only 4thousanths, well with in the specs for mitsu specs by a total of 4thousanths. So I don't belive that 4thousanths is enough to deam a 1/2 of tooth off on the gears. They are set at zero for the necesity of timing, so either I have a sh*t set of gears, or I am missing something seriusly wrong.
Any thoughts on this?

 

[Andy_S]

My old tsi had the head decked. It was off by about that much. I didn't worry about it too much since I was selling the car though.

 

[fivestardsm]

Well, when I get another second on it, I throw a set of stockers on it, and see where they line up. I probably should have done this first, but never thought that 4 thou would be that big of a deal..

 

[curtis]

When the head is milled it advances the cam. Lots of time the head isn't zero'd on all 3 axis's and will have one off more than another. This is definitely apparent when they use the large belt sanders to mill a head. The front or rear or end may loose more material that the other. So this leave you with info but no way to set it up.

First pull number one spark plug. Then a long 1/4 inch extension screw driver etc down the spark plug hole. Take the piston up to perfect TDC. Use a dial indicator. If you don't have one get one. Harbor freight has a cheap one that is digital and works great. Now after its perfect you see the marks in the middle are both down towards center and the top marks that should be straight up are also inward. You should be able to adjust the gears and move them back up to straight starting with one and working back and forth until perfect.

Now for where to set them. Typically engines respond better with advance this is due to the importance of the intake closing point. Earlier intake closing equals increased cylinder pressure and better response and will help low-end torque, but if your engine is dying to soon dependent on rpm turbo installed etc, retarding the cam a few degrees should help extend high-rpm power a bit.

As for yours without a dyno or a way to tell not sure. It may be ground straight up or with advance already, may want to just get them straight up again and make a not that this is now the new zero and then advance maybe 2 on the intake and leave exhaust alone and go run.


Now as for people having there gears at zero and others not just because the gears are at zero doesn't mean they're. Could be the motor has a head thats decked as far as it will go and the motor is really retarded 6 or 8 degrees which is for big top end.

Also make damn sure you don't have a set of the 1st gen /evo ones. I mean the ones that can be used on a early 1st gen/vr4 or a new evo 8/9. My buddy used a set on his evo and the car ran strong until mid range then fell on its face. Ended up he found out at the dyno the next week he had like 12 degrees of advance. Just make sure you use the right dowel pin hole if you have a set.

 

[fivestardsm]

You are a frickin mind reader, Curtis!!
I was going to ask about TDC'n the #1 and adjusting the gears to match..

Also, when the head was measured at the shop, it was said to have already been milled to just under the max servicible limit, this is the reasoning behind the thicker headgasket and the adjustable cam gears. I wanted to be sure, I just never imagined, like stated before, that a total of 7thou would make tha much of a difference. I guess I should have thought about it a little harder...i.e taken the radious of the gears (x2) into the figuring on the missing of 7thou of material to endup at about 1/8"- short on the lines matching.

 

[fivestardsm]

Ok... new discovry, the marks on the gears are not the same as the stockers. The pic of the arospeed show that both of the lines are etched on to one of the TEETH, and the stocker fave the lines on the TOOTH on one side, and the NOTCH on the other. I have tried to contact the manufacture about these, but have not had any luck yet. So does anyone else have this problem with a different brand of adjustables?

 

Take a picture showing both of the cam gears please. Are the dowel pins for both cams up or is one up and one down?

 

[fivestardsm]

I'll put up a few pics later, but just so you know, the dowl pins go up! Never 1 up 1 down, that would be bad..

 

I know that... I wasn't sure if you did /ubbthreads/images/graemlins/smile.gif