Advancing/Retarding cam gear?

speedracer · Post by **speedracer** » Mon Jul 14, 2008 3:48 pm

What's up guys. I've got a stock bottom end (9.3 compression). I also have a port and polished head, os valves and a #12 crane cam on board. Oh yeah, I have a TTI long tube.

Anyway, I'm trying to improve my idle and overall accelaration. I know with the low compression and all the overlap the #12 has (should have gotten a comp 400). My cam gear is advanced 2 degrees. What's the limit on the advancing before I really f**k something up. Could I go as much as 4 degrees?

I really don't want to dyno the car for a one degree or no degree adjustment. Thoughts? Thanks guys, Paul.

kc2005ptgt · Post by **kc2005ptgt** » Mon Jul 14, 2008 11:47 pm

only a dyno will tell you really what is best, sorry.

speedracer · Post by **speedracer** » Tue Jul 15, 2008 3:12 pm

Yeah, I know I need a dyno it to see where my max tourque curve is. But theoretically, how much can you adjust cam timing? If you move it too far one way or the other, will it run like shit or will valves crash into pistons? Thanks, Paul.

kc2005ptgt · Post by **kc2005ptgt** » Wed Jul 16, 2008 12:58 am

I heard +/-2 max...

Donkeypuncher · Post by **Donkeypuncher** » Wed Jul 16, 2008 2:58 am

kc2002acr wrote:I heard +/-2 max...

That is what I was told as well, couldn't say for sure though. I've read that if you're off by 3 or more notches on the cam sprocket then the valves will contact the pistons. Not sure how many degrees equal 1 notch though.

speedracer · Post by **speedracer** » Wed Jul 16, 2008 6:46 am

Cool, thanks. I was thinking about another degree advance, but I suppose I'll play it safe.

Post by **occasional demons** » Wed Jul 16, 2008 12:33 pm

Donkeypuncher wrote:
kc2002acr wrote:I heard +/-2 max...
That is what I was told as well, couldn't say for sure though. I've read that if you're off by 3 or more notches on the cam sprocket then the valves will contact the pistons. Not sure how many degrees equal 1 notch though.

I think it is eight degrees, cam. But that could be crank degrees. I know I read it somewhere, just can't recall which one it is. A good protractor layed on the cam sprocket will tell you the difference of one tooth. Crank degrees is 2X cam degrees. In my head I can imagine aprox eight tho.