29Coupe348
Well Known Member
hello, i just bought a roller timing chain, and on the bottom sprocket it has a few different ways to put it on 1. straight up ,2. 4* retard, 3. 4* advance....which way should i install it?...thanks,mike
installing a timming chain
- Thread starter 29Coupe348
- Start date
Timing set?
Bungy is correct with his answer
. I'd like to add that a lot of cams come with advance already ground into the camshaft. Comp cams come with 4 dgs advance straight from the box. Installing their cam straight up would be 4 dgs advanced! 
Bungy is correct with his answer
. I'd like to add that a lot of cams come with advance already ground into the camshaft. Comp cams come with 4 dgs advance straight from the box. Installing their cam straight up would be 4 dgs advanced! 
Firepower354
Well Known Member
You need to degree the cam in to verify where it is before you start moving things around!
We don't drop distributors in without checking the timing, right? Lots of factory cams were ground retarded and aftermarket ones are usually advanced. The timing set you're replacing could be advanced, retarded by design or stretch, or straight up. A couple degrees in the wrong direction can seriously kill your performance and maybe bend valves if you're far enough out of phase with a big cam and piston domes. Bungy nailed the generalization, but you need to degree in the cam. Advancing will increase the cranking compression and help crutch a little too big a cam too. It's every bit as importaint as ignition timing and jetting, but those two are easy enough to change by trial and error on an assembled running car. That wicked-cool highrise aluminum 3x2 is gonna wanna feed a properly phased engine
We don't drop distributors in without checking the timing, right? Lots of factory cams were ground retarded and aftermarket ones are usually advanced. The timing set you're replacing could be advanced, retarded by design or stretch, or straight up. A couple degrees in the wrong direction can seriously kill your performance and maybe bend valves if you're far enough out of phase with a big cam and piston domes. Bungy nailed the generalization, but you need to degree in the cam. Advancing will increase the cranking compression and help crutch a little too big a cam too. It's every bit as importaint as ignition timing and jetting, but those two are easy enough to change by trial and error on an assembled running car. That wicked-cool highrise aluminum 3x2 is gonna wanna feed a properly phased engine
29Coupe348
Well Known Member
ok, i've installed a few cams, but always stright up, how exactly do you degree it, i assume u need a degree wheel, but is it self explainitory from there?
Firepower354
Well Known Member
"Straight up" is based on the accuracy of the camshaft lobes, front drive pin location, cam gear, crank gear, crankshaft keyway position, and even the lifter bore machining. If you're using a new cam from a reputable grinder with the cam card and a quality timing set, you'll be okay with the "line up the dots and burn rubber" method. I've never checked one that was off much more than a degree and a half using quality aftermarket parts. That's acceptable tolerances. If anything is suspect, check it. Besides, you can amaze your friends with your new skills. I add a degree of advance if it's a street driven car that's going to stretch it's chain over tens of thousands of miles. Cheapo's will stretch way more. I've seen them eat through the side of the timing cover!
There's a few ways to do it, and a couple special tools. Here's a recent mag article on it.
http://www.carcraft.com/howto/116_0310_deg/
There's a few ways to do it, and a couple special tools. Here's a recent mag article on it.
http://www.carcraft.com/howto/116_0310_deg/