Cam install question

[GBGRIDER]

I installed the cam with the punch mark horizontal and the line vertical to the engine head while the left piston was at TDC. I later read that it must be on the compression stroke when installing cam is this true? Cause apparently i did it on a different stroke.

 

[wallywheels]

That is true but you can switch the wires to fix the problem if you already sealed up the top as long as you have the pistons at TDC and the mark vertical to the cylinder

 

[GBGRIDER]

what wires are you talking about? Ignition? i'm running pamco. also i dont know if it matters but the engine is rephased.

 

[Punkskalar]

It's wrong. Punch mark lines up with head mating surface, and the notch should be vertical while #1 cylinder ( charging system side ) is at TDC

 

[wallywheels]

good catch

 

[GBGRIDER]

It's wrong. Punch mark lines up with head mating surface, and the notch should be vertical while #1 cylinder ( charging system side ) is at TDC

yea thats what i did.... what about what stroke it is on?

 

[5twins]

The engine doesn't know what stroke it's on until you install the cam. It only knows it's at TDC. If the #1 cylinder cam lobes are angled down, #1 would be on the compression stroke. If they're angled up, it would be on the exhaust stroke. I would assume that the cam chain sprocket is mounted so the alignment notch points up when the #1 cam lobes are angled down and that would have you installing it on the #1 cylinder compression stroke.

 

[GBGRIDER]

The engine doesn't know what stroke it's on until you install the cam. It only knows it's at TDC. If the #1 cylinder cam lobes are angled down, #1 would be on the compression stroke. If they're angled up, it would be on the exhaust stroke. I would assume that the cam chain sprocket is mounted so the alignment notch points up when the #1 cam lobes are angled down and that would have you installing it on the #1 cylinder compression stroke.

On the two cams i have with the notch facing up both lobes are facing up.....i'm very confused

 

[5twins]

You and me both, lol. Obviously, I'm not picturing this right in my mind. With the notch up, the left cylinder lobes do angle up but I have no idea what stroke that is. As I said though, when the engine is at TDC, it's at TDC. The stroke isn't determined or "locked in" until you install the cam.

I would just follow Hugh's advice - left cylinder at TDC, install the cam with the notch up. That should make everything right.

 

[GBGRIDER]

lol....that was the answer i was looking for. As long as you install the cam right the stroke will be right. RIGHT? Thanks alot. Peace.

 

[5twins]

Well, in your case (with a rephase), you must be sure the #1 cylinder (left side) is the one at TDC when you put the cam in. Then everything will be right.