I am having the same issues with my timing .. we have replaced all the tensioners and guide, but when I put it back together it didnt run very well. I think that the cams may have moved when I was replacing the chains. Any idea on how I can reset the timing .. When my crank it set at TDC the timing marks on the cams are off by one link and when I set the timing marks 90 degrees from the Heads my Crank is no TDC. I have the Chiltons manual but it is no much help. Any advice would be very thankful.
On the brighter side I can remove the timing cover with my eyes closed now.

 

Marking the chain is to insure it is installed correctly. Right now you have no chain on the sprocket. Are you 100% positive that the cam timing is correct. I am not and if I was working on your engine I would have to mark the chains and re time the cams.
I also noticed that the timing marks on the cams are not lined up correctly to set the timing. May I ask why the chain is off?

Crash course Engine 101; Every 2 revolutions of the crank shaft the #1 cylinder fires. Because you have an 8 cylinder engine the other 7 cylinders also do so during those 2 revolutions. So, within those 2 revolutions every cylinder will have fired. To open and close the valves a cam is used. It opens and closes the intake valve only once and it opens and closes the exhaust valve only once. It must turn only once for every two revolutions of the crank. So the sprocket on the crank is ½ the size of the sprocket on the cam. To insure that the cam opens and closes the valves at the right time a mark is set in the crank sprocket and a corresponding mark on the cam sprocket. Because your engine is an interference engine when the valves are open the pistons can touch them when they reach the top of their travel. You do not want that to happen. What has to be done is to set the number one piston at the point where it is at the highest part of its travel (Top Dead Center). Once this is done the timing reference marks on the Crankshaft pulleys are set. Then it is a simple matter of lining up the marks on the Cam sprockets. This is how all the cams on all the engines are lined up.

The Triton uses the crankshaft key way as a reference point to help set the cam timing. When a cam is removed the key way is always set to the 12 o’clock position. The cams are then locked in position with a holding tool. If a mechanic was given your engine to set the timing the only safe way to set the cam timing would be to remove the cam followers. This will insure that the valves are all closed. Then set the crankshaft to the 12 o'clock position. Then the cams could be rotated and set to the proper timing. And the chains installed.

JMC

 

JMC,

I just took off my head and noticed that #1 and #7 exhaust valves broke off.

I am going to take this head in and get all the valves swapped from a second head that I have (same head same model).

My question about the timing.

I've set the engine at TDC according to the keyway mark on the crankshaft.. When doing this I also noticed that the #1 piston was at the top of its stroke - that is when the keyway mark on the cam sprocket on the drivers side(head thats never been removed) was pretty close to 12' o clock.. more like 1:15.

Most all of these diagrams show that keyway as being parallel to the inside angle of the head.. this one is like exactly in between 12 o clock and paralell with the inside head which on mine looks about 3 o clock.

When I take in this head to get the valves done, is their instructions that I can give the machine shop? You mentioned that all the valves need to be closed, that is the way it was when I put it on last time.. the first time we put it on we were 180 degrees off and had no interference, then we flipped it around to match the other side and it ran but seemed a little off - so we moved it two teeth and we heard the clicking(snapping of the valves).

Thanks

PS. LOL Tao, I feel the same way about my engine.. removing valve covers, head and whatever else is cake now.. All I need now is to know what I'm doing and I'd be a pretty good mechanic

 

JMC,

So as long as the chain is lined up I don't really need to know which direction the cam is facing right? All I need to do is line up the marks I put on the chain with the corresponding marks on camshaft keyway and crankshaft keyway?

 

As long as the crankshaft keyway is at the 12 o'clock position this will set the pistons in a position so that the cams can be rotated to line up the marks on the sprockets. For the driver side head the mark on the cam sprocket is set to 12 o'clock position and the driver side head the cam sprocket mark is set to 11 o'clock.

The crankshaft is then rotated counterclockwise using the crank tool to roughly 10:30. Halfway between 10 and 11 o'clock. Your manual should show this porcedure. The Crank sprockets are installed and their timing marks should be at the 6 o'clock position.

JMC


crankshaft sprocket marks in the porper position so the Cam sprockets can be ligned up correctly. If you do not do this the links on the Cam sprocket might not line up.

 

I haven't touched the timing on the drivers side.. the chain has not been removed.

It's starting to make sense.. if the keyway on the crankshaft is at 12'o clock that gives enough room for the valves to come down for twisting of the sprocket. But that's not TDC? I just don't understand which factor is most important.. because it seems to me now that if lay the chain out and mark two links on one side and one on the other.. and then have the two links straddle the 6 o'clock notch on the bottom of my camshaft sprocket(It's at 6 o'clock when keyway is pointing at TDC) that all I need to do then is twist the cam until I can lay the chain onto the notch matches up with the marked link on the opposite side of the chain.

Am I getting it?

 

When the Crankshaft keyway is at 12 o'clock the pistons are set in a way that the cams can be rotated to line up the marks on the cam sprockets only. Once they are lined up they stay in place and the crankshaft is then rotated counterclockwise to position the crank sprocket marks to the 6 o'clock position. (The crankshaft keyway is moving counterclockwise from the 12 o'clock position to the 10:30 position, about 1/8th of a turn.) Once the crankshaft sprocket timing marks are at the 6 o'clock position the driver side cam sprocket timing mark should be at the 12 o'clock position and the passenger side cam sprocket timing mark should be at 11 o'clock position.

JMC

 

JMC,

You're awesome.. It's totally clear now.

I appreciate your help.

I'm guessing I may need to use a pair of vice grips to hold the cam sprocket in the position it needs to be at to put the chain on.

One small difference.. when I put the crankshaft keyway at TDC, my drivers side camsprocket notch looks a little off of 12 o' clock.. More like 12:30. I'm pretty sure I have it exactly on top dead center, because I am looking right at the #1 cylinder.

Thanks again for all the assitance.. you've really helped me a ton!!

 

The manual refers to the "o'clock" positions as approximatly so they may be a little off. That may be becasue of the length of the chain and the amount of stretch that would accompany it.

JMC

 

So, in the book it doesn't mention turning the engine over by hand.. but is that always the standard practice? To turn the crankshaft over at least 2 times?

 

So, in the book it doesn't mention turning the engine over by hand after putting the chain on.. to double check that there is no interference.. but is that always the standard practice? To turn the crankshaft over at least 2 times?

 

Never turn the engine over by hand unless the chains are properly installed. It will cause severe engine damage. I don't see where you would need to turn the engine over by hand other than the required amount to set the keyway to 12 o'clock. One more word of caution, never use the camshaft to turn the engine, always use the crankshaft.

JMC

 

JMC,

I've been turning it over alot by hand just to get an understanding of TDC and the timing marks, since one side has the chain on the cam sprocket. I use a socket with a washer on the crankshaft to turn it. I do it slow and it doesn't take much pressure.

The reason I ask is because I'd like to gently double check my work before I turn it over with the starter which broke my valves last time.

Bad idea?

 

If you are turning it over slowly and the parts are installed correctly then you wil lhave no problem. It is definetly safer by hand as you will casue less damage if it is not set up correctly.

JMC

 

JMC,

Put my truck together yesterday... runs better than it has in years. More power.. sounds terrific... no more ticking, just the hum of the fan.. and a real smooth idle.


Thank you SOOOOOOOOOOOOOOO much for your help!!!!!!!!!!!