I need a little help, when I installed the cam in my 400 I installed it straight up. Now I what to advance it somewhere from 4 to 8 degrees. It’s a comp cam. My buddy is telling me I need an adjustable timing chain gear set. Why can’t I use a stock type set up?

If you use a stock type gear, the only way to adjust the cam would be to "jump" a tooth. With an adjustable gear set, you have different keyways on the crank gear for the desired alignment. Some sets also use degree bushings to align the gears.

The long and short is that you could use stock gears if you could find a way to guarantee that the setting you want can be maintained. There is nothig special about the adjustable gears themselves, just the alignment features.

Joe,
You can use the stock set-up. Advance it for your best performance until you reach the point where the engine starts hard when warmed up and then back it off a degree.

Thanks for the advice

Not to jump the gun here, but Jim was responding to advancing the timing but Joe was asking about advancing the cam.

Most street motors respond well to about 4 degrees advance for the cam (measured at the crank, of course). It boosts the low end torque a little without killing the top end. An adjustable timing set is really the only reliable way to go.

I use a gear drive wich makes it easy to vary the timing over a pretty wide range. However, it still takes all day to strip the front of the engine and move the timing, then degree the cam to be sure you went the right way.

I stand corrected. I have had a few engines that I built with the multiple key ways on the timing gear but never needed to mess with the timing in this way. Made it into the 11's in a quarter mile with the gears straight up! I'm wondering what you are running to need that kind of an advance? You guys are a little more advanced than I!!

Some cams have as much as 6 degrees advance built in, others have none. Always check the cam specs and degree it to be sure the cam is to spec.

Did you keep the instruction sheet for you timing chain? If so, look at it and se if your chain had an "A" and "R" on the cam gear, if so, just line up the A with the dot on the crank gear. In addition to removing everything on the front of the car, radiator, water pump, it would also be a good idea to loosen all of your rocker arms to take the tension off of your cam (you will have to re-adjust when done, assuming they are adjustable. Advancing your cam 4 crank degrees will lower the hp and torque curves around 300 rpm, a slight but noticabe difference.

You can use a stock-type set-up--provided that you go to advanced auto parts and buy one of their fine double roller chains with a multi keyed crank gear. This chain beats the heck out of anything on GM's shelf or the repro companies.