Thread: I really am idling with 40 degrees advance

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I just swapped cams in my 400 and it runs great. Your cam is installed correctly, no question. The outer ring on your harmonic balancer has probably slipped on you. Common problem. If so it's trash, get a new one. If you use a piston stop and find zero tdc and your dampner doesn't line up to zero tdc, then your dampner ring has slipped or your timing pointer is attached in the wrong place on your front cover.

Originally Posted by K5BlazerGuy

I just swapped cams in my 400 and it runs great. Your cam is installed correctly, no question. The outer ring on your harmonic balancer has probably slipped on you. Common problem. If so it's trash, get a new one. If you use a piston stop and find zero tdc and your dampner doesn't line up to zero tdc, then your dampner ring has slipped or your timing pointer is attached in the wrong place on your front cover.

Don't know how relevant this would be, you're responding to a post from May---hopefully the dude has resolved these issues by now!!!!

So far the TDC has been determined and I guess a pointer was added to point to TDC when the crank was rotated to it. Now by using a timing tape the balancer can be degreed. Attach the timing light, remove the vacuum advance hose and plug it. Run the motor to max advance, probably around 3000 rpm and set it at about 30 deg. Now go back to low idle. You should see an rpm where no further movement of the timing happens or where it just begins if you are going up in rpm. Observe this number on the tape. Subtract this number from the 30 (or what ever you used) This will give the amount of advance in the distributor.

Now you have a set point which is the max rpm before mechanical advance starts. You can set the static timing at this speed. What ever number you choose. The other way is to set the total timing at a speed where all of the advance is in. Say 3000 rpm. Set the total desired at this speed or greater. Either way you must leave the vacuum advance plugged. It will be around 15 degrees additional. Some units are adjustable. The vacuum advance is primarily for MPG. When you tromp on the gas the vacuum advance retards to its 0 point leaving you with your mechanical advance.

One more thing. I spoke with MSD just recently and the man told me to get a cheapo timing light as some of the new ones are so sensitive the will pick up all or most of the multi spark duration and give incorrect timing value. For a change cheapo is better. IE. the cheapo does not pick up the multispark length.