How to "rotate" the camshaft?

[Vette76]

Sorry for yet another question on timing these darn 4.0 SOHC camshafts...

Here's where I find myself: The #1 piston is at TDC. The left camshaft is exactly where I need it to be. The timing slot on the left camshaft is below the axis of the camshaft, the timing "nub" is where it needs to be and the timing tools fit perfectly into the camshaft and onto the head. Everything is to spec on that side. All set there.

I had to replace the right camshaft, so right from the start my timing was gone on that side. As I put all the rockers back on, I tried to continually position the camshaft where the timing slot would be in the correct position but the spring pressure "rotated" it to where it wanted to be at rest when I was done. This is about 45 degrees off from the timing slots being parallel to the plane of the head. I've got the new timing cassette, chain and sprocket loosely connected for the next step but nothing is tight nor restricting the spin of the camshaft.

Here's my question: How do I "Position the camshaft timing slots below the centerline of the camshaft" as the instructions require? The timing tool that fits into the timing slot won't fit into the camshaft while it is 45 degrees off from where it needs to be and the camshaft lobes are now receiving spring pressure from the valve train, so it's not as easy as just "free spinning the camshaft" until it gets to where you want it. I have rotated as far as I can with just my hand.

I'm contemplating having to put a flat metal bar into the timing slot of the camshaft and gently rotating it clockwise until it's in place but then what? Because I have a flat bar in the timing slot I wouldn't be able to insert the timing tool into the camshaft because it is blocked by the flat bar being in the slot at the same time? If I was to rotate the camshaft by doing this, the back of the camshaft doesn't appear to have anything to "grab onto" unless I have a friend grab the other timing tool to insert into the sprocket (which would need to be tightened now) on the rear of the head, while I'm turning, and try to tighten that tool in place.

Looking at the lobes of the camshaft I'm having a hard time to believe that you can time it perfectly even if you had all the rockers out (which I had), because of the spring pressure of the valve train. Clearly something needs to be done to overcome the spring pressure being exerted onto the camshaft.

Could someone help me out here? In addition, could I have installed the camshaft wrong (when I replaced it), although I literally took pains to try to keep it "in timing" when I put all the rockers back in. Is the camshaft supposed to rest perfectly in "time" when you put it back in? In other words, is there some "magic" in putting the camshaft back into the head where it naturally ends up in time?

Or am I right that I need to somehow manually manipulate the timing by somehow advancing the camshaft by using force until it is in the right location?

I am literally perplexed at this point...

 

[stoogefan]

According to the manual, you are supposed to time the cam without the rockers installed to eliminate this problem along with valve-piston interference. When I did my chains, I didn't remove the rockers but just used vice grips (between a couple of the lobes) to hold/rotate the camshaft that wasn't connected to the timing tools. Be careful not to crush the oil tube on top! You may need to use a screwdriver or something similar in the slots to get it into approximate position before using the vice grips to hold it in position and connect the timing tool.

 

[Vette76]

So if I understand what you're saying, you literally were close on having the cam's "timing slot" line up (horizontal to the head) and then just clamped onto the camshaft between the lobes and 'rotated' the camshaft until you could fit the timing tools into the end of the camshaft opening?

Man, it certainly looks to me like that's what's needed to be done but all my manual states is that you need to "position" the camshaft...heck if it was that easy I'd have been able to do it with my bare hand!

I tried positioning the cam when I was putting the rockers back on but when I got to the last one (piston 1) I had to remove the timing tool in order to compress the spring and that's when the camshaft turned out of timing on me.

Thanks for your help.

 

[stoogefan]

Yeah. I forgot to loosen the right sprocket bolt before I torqued down the jack shaft sprocket, and it ended up moving. I ended up needing to position it back into approximate position with a screwdriver in the slots and then clamp onto it with the vice grips again to hold it while I got the alignment tool installed. I believe that I saw the vice grips trick in a picture in one of the timing chain threads by 2000StreetRod.

I believe that you can position the cam by hand, if the rockers are not installed, then tighten everything up and put the rockers back in at the very end. I just didn't want to spend an additional $80 on the tool to remove them after already spending about $190 on the timing tools.

 

[Vette76]

StoogeFan...you DA MAN!! Thank you so much for the quick reply.

That's exactly what I thought I should be doing but I tend to put a little too much "meat" on the end of the wrench and always live to regret it

 

[2000StreetRod]

right then left

The reason the camshaft timing procedure specifies to time the right camshaft first is to avoid the issue being discussed. The right will not stay in place but the left will. Using locking pliers seems acceptable to me.