I have a Rollmaster double chain timing set. I'm trying to advance my cam but even using the first groove the advance is way too much. There are 44 teeth on the upper gear. One tooth transulates into 8.18 degrees(360/44). The first groove on the lower gear is approximately two teeth so that would result in an advance of over 16 degrees. Don't think I need quite that much advance.

What am I doing wrong? Of course the timing set comes with virtually no instructions.

 

I think the tooth to keyway relationships vary from keyway to keyway. I believe you are assuming you use the dot-to-dot method and use a different keyway. This won't work on that kit.

I know older SBC adj sets have different sets of timing marks that accompanied the different keyway so you could use a dot-to-dot method. Only way I see to do it is change the keyway and use a degree wheel to set it in. EAch keyway should allow for a specific amount of advance/retard but its a guess since I didn't see any distinct markings

 

With the rollmaster, the crank gear will have a few different keyways. The center one is 0 (should have a dot signifying it). Then you have some on either side allowing for advance/retard in 2 degree increments. If you still can't figure it out, let me know and I'll see if I can't find the box that my rollmaster double came in. I had some directions included with mine and I can scan them in.

 

Thanks guys but I got it figured out with the help of a friend.

There are no marks on the lower gear like most adjustable timings gears have. No triangle, square or anything to indicated advance marks so you have to count back three teeth and assume same spacing based on grove(advance)desired.

They did say this in the instructions but it could have been worded a little simpler for the novice like me.