Cam timing

[edbux]

Let's say a friend....installed his cam with a centerline of 106 degrees with the crank sprocket on the timing chain 4 degrees advanced. Would this mess with
the timing? ie the 16 degree initial timing for the distributor when set actually be less?

The answer to this "hypothetical" question for a "friend" is appreciated.

 

[71DartGuy]

Is your friends name edbux b chance??!!!!

 

[edbux]

Ahhhhh...would you believe me if I said no?

 

[lead69]

Let's say a friend....installed his cam with a centerline of 106 degrees with the crank sprocket on the timing chain 4 degrees advanced. Would this mess with
the timing? ie the 16 degree initial timing for the distributor when set actually be less?

The answer to this "hypothetical" question for a "friend" is appreciated.

No,the cam timing is the only thing affected,the cam now has a 102 centerline and if ground on a 110 lobe seperation it is eight degress advanced and you moved the power range down.Changing the cam timing only results in changing the performance of the cam,by retarding or advancing your moving the power range up or down.

 

[edbux]

No,the cam timing is the only thing affected,the cam now has a 102 centerline and if ground on a 110 lobe seperation it is eight degress advanced and you moved the power range down.Changing the cam timing only results in changing the performance of the cam,by retarding or advancing your moving the power range up or down.

Thats what I thought. Back in the 70's and 80's that was the trick...only with an offset key. I was discussing this with a Chevy guy at work and he was saying the dist timing would be off. I told him maybe on his Chevy. Maybe I'll have to take the Dart to work and shut him up, like I did the Mustang guy...just a 65 mile round trip eats up a ton of gas.

 

[moper]

Yes. It will. The cam's intake center line is 106. If he moved the CRANK sprocket 4°, then the CAM was advanced 2°. So it's in at 104°. The crank turns twice as far to reach 4° as the cam has to. So 4 on the crank is 2 on the cam. Any time the camshaft is moved, the ignition timing is changed. Because the oil pump drive is geared to the cam, and the distributor is slotted to the drive. Move one, you move it all. It's not a big deal... 2-4° just means you need to reset initial.

 

[lead69]

Yes. It will. The cam's intake center line is 106. If he moved the CRANK sprocket 4°, then the CAM was advanced 2°. So it's in at 104°. The crank turns twice as far to reach 4° as the cam has to. So 4 on the crank is 2 on the cam. Any time the camshaft is moved, the ignition timing is changed. Because the oil pump drive is geared to the cam, and the distributor is slotted to the drive. Move one, you move it all. It's not a big deal... 2-4° just means you need to reset initial.

If I read it right hes asking about setting the timing after the cams installed and if the timing would be off from the actual numbers on the crank (ie timing light).Obviously it wouldnt because as you said they are all hooked together so the reading would be accurate.Now if the friend was saying you would need to adjust the timing to get the same intial as before the advancement than yes thats correct.