Headgasket timing question

[JessZ]

I have the motor pulled and head milled and ready to be put back. I'm wondering does the cam gear and chain have to line up with the marks I made. If the camshaft was not turned, nor the crank, the timing should be fine despite which notch the gear goes back on, right? This question is more out of curiosity, what I think really happened is the tensioner sucked of the chain down, which makes it seem like my marks on the chain and gear don't line up. But I'm not sure, this is my first time attempting a headgasket repair. Any thoughts or wisdom here appreciated.

[Swervey McZCar]

I know there are other more experienced guys here but maybe I can help. Did you use a wedge of wood, screwdriver handle or other to hold the chain and tensioner tight in place while you pulled the head? If not, yes you probably lost some length to the tensioner and it will be difficult to get the cam gear back on. If you are pretty sure that the chain has not moved on the crank gear, you can have a friend hold the chain tight while you position the wedge. Perhaps you can regain enough chain to get your cam gear on. If the timing cover is off, don't worry about it, just line uf the marks on the cam gear with the factory dot on the chain and do the same for the crank gear. I'll post a pic in my album.

 

-Stan

Edited March 9, 2010 by Swervey McZCar

[TimZ]

I have the motor pulled and head milled and ready to be put back. I'm wondering does the cam gear and chain have to line up with the marks I made. If the camshaft was not turned, nor the crank, the timing should be fine despite which notch the gear goes back on, right? This question is more out of curiosity, what I think really happened is the tensioner sucked of the chain down, which makes it seem like my marks on the chain and gear don't line up. But I'm not sure, this is my first time attempting a headgasket repair. Any thoughts or wisdom here appreciated.

The timing marks on the chain do have to go back on the same teeth on the sprocket - it does effect the cam timing. If you didn't block the chain and tensioner with a proper tool then there is a 99% chance that the tensioner has fallen out and has wedged itself such that the chain won't go back. Hate to break the bad bad news, but if this is the case you're going to have to pull the front cover in order to put it back together correctly.

 

Also, how much did you shave the head? This will also effect the cam timing - it can be pretty significant depending on how much material was removed.

[Mayolives]

I'm wondering does the cam gear and chain have to line up with the marks I made. If the camshaft was not turned, nor the crank, the timing should be fine despite which notch the gear goes back on, right?

 

Yes, you probably could put it back together the way it is. But I would suggest that you do it the correct way. It's not rocket science. Go back to square one. Find TDC, get the cam in the correct position. Get the timing gear with the tensioner where it belongs, etc. If you don't have a FSM, you can find the correct and simple steps to follow by using the search button. If the tensioner has popped out, you will need to drop the pan in order to get it back where it belongs. Some have been lucky enough to be able to get it back in there using long screw driver, etc. But it's not easy.

Edited March 9, 2010 by Mayolives

[JessZ]

Crap. I've been working to get the timing cover off for 30min and my back already hurts. Anyone have an idea what size the crank pulley bolt is? And what gaskets need be replaced pulling off the timing cover? And am I going to have to drop the oil pan? I'm making a list so I don't have to drive back and forth to the auto shop. I live in the country now and it's more than an hour drive round trip.

As far as the head being milled, they shaved .008in. The head was not damaged, so i guess you'd call it a clean up pass. Anyway, if you say this is too much and it'll affect my timing, I'm marching out and I'm buying a damn Honda!

[wondersparrow]

That much really wont make much of a difference in timing. And really, unless you have an adjustable timing sprocket, there isn't much you can do about it.

[S130Z]

When you pull the front timing cover, I would recomend replacing the two gaskets for that cover. Also, It makes the job a bit easier if you loosen the bolts to the oil pan to allow a bit of clearence when you reinstall the front cover. I believe the crank bolt is a 27mm, but dont hold me to that number.

 

The two dots on the chain should line up with the dots on the cam sproket and crank sproket at the same time. Both dots should be on the right hand side if you are facing the cam chain.(tried finding a pic, but could'nt)

[brokebolt]

I have the motor pulled and head milled...If the camshaft was not turned, nor the crank, the timing should be fine despite which notch the gear goes back on, right?

 

I might be late for your project but here is my $0.02. The cam will have to be removed to mill the head so the cam timing is off for sure. The timing notches will need to be selected based on the amount of milling, with only 0.008" you might be able to re-use the same cam position if the head has not been milled previously and was close to spec before the start of this project. However, being that the position was not checked (or noted that it was checked) prior to removal then you may need to select one of the other two dowel holes that the stock cam gear has bored into the back of the gear (their are three total).

 

If it were me, I would remove the front oil pan bolts, remove the timing cover, inspect the chain guides and tensioner (replace if needed), set crank to TDC using a dial indictor and cam wheel (if not available, then just guess), set cam to TDC using the middle cam gear dowel hole aligning the cam gear with notch on first cam tower, place head onto block, install chain aligning the cam gear with the crank gear and yes they have to match I always use the shinny gold links but you can count them if your unable to find them, install tensioner, check chain for slack, install both guides, install head bolts and torque, turn over engine with 27 mm (1 1/16" 6 point may fit) socket wrench and check for any problems with cam timing. Re-install all of the removed parts and hardware with new gaskets, install motor from where it was pulled...unless it was a junker/donor car...

 

P.S. I have had no luck reinstalling the chain tensioner if the chain has slacked up enough to fully disengage the piston from the tension block. That is why I just remove the front timing cover...to prevent damaging the spring and causing more parts usage then necessary, been their done that!!!

 

Happy wrenching.