Replaced headgasket on my Z24; lost time\tension

[SolidZ24x4]

So I used a vacuum attachment as substitute for the 'datsun wedge' piece of wood to hold the timing chain on the tensioner and bottom sprocket.

 

It worked, maybe. While putting the sprocket back on I dropped the chain into the void, shoot me in the face.

 

I heard it skitter along the teeth of the bottom sprocket so I know it moved. The tensioner had to be wedged back into place but seemed to be still working as it should. I lined up the sprocket best I could, based on the #2 hole in the sprocket that seats the nub on the end of the camshaft. My guide marks were about 5 teeth off when I finally wrestled the sprocket back onto the end of the camshaft.

 

Said f-- it, and put it back together. Took a while to turn over, but when it did there is a little noise like valves running into pistons at idle. Goes away at higher revs, bit I haven't let it run longer than a minute for fear of bending the valves.

 

My question is this, if the cam and main shaft are our of time, is this something that can be adjusted, like timing? Or, will I have to get the engine to tdc, then take off the sprocket, get the camshaft to tdc, and reattach the sprocket?

 

I'm sure a little foresight would have saved me a lot of trouble, but, oops.

 

Thanks for any suggestions!

[datsunaholic]

My question is this, if the cam and main shaft are our of time, is this something that can be adjusted, like timing? Or, will I have to get the engine to tdc, then take off the sprocket, get the camshaft to tdc, and reattach the sprocket?

 

 

 

 

The latter.  The cam timing can only be adjusted by taking the chain off and repositioning the chain on the cam sprocket.  You'd have to turn the cam to get it to tdc as well, if it's off by 5 teeth.

 

But you need to check it first.  So set the crank at TDC and see where the cam lines up with its timing mark.

 

 

Of note, if it was so badly off that the pistons were hitting valves it would be unlikely to run at all.  It will run (poorly) if it's off by a few teeth, though.

[Draker]

Pro-tip: After you change a timing component, rotate the engine by hand 720 degrees and check for binding. 

 

 

As mentioned above, put engine at TDC, check cam timing mark to determine if you are off a tooth.

[SolidZ24x4]

So back at it this morning;

 

I have a habit of preparing for the worst when it comes to these things, hopefully I didn't mess up the tensioner. I dont want to take the front cover off.

 

I'm going to get TDC, take off the cover and see where the cam is. I know theres a dimple on the inside of the cam sprocket, but is there anything to reference that against?

 

Thanks, will let you know

[SolidZ24x4]

[datzenmike]

There's no cam timing mark like the L series because there is no cam thrust plate to put it on, on the Z series heads.. What I do is look straight behind the sprocket at the aluminum casting on the head. There is a faint smooth vertical casting line. Just get the sprocket notch lined up against that.  

[SolidZ24x4]

So I got the sprocket realigned, but it seems as though I've lost tension in the chain. I don't think I let off tension very long while it was off the sprocket, but now it seems like there is less tension in the chain than before. Put it back together with the sprocket and cam at tdc, and started it up but have run into the same problem, pretty bad timing rattle.

 

I really don't want to pull the front cover off, but at this point I'm guessing that will be the next move... Should I start considering this, or does anybody have any more suggestions to try?

 

Before, I was pretty confident the tensioner hadn't been displaced but now I am skeptical.. :|

[datzenmike]

Once the tensioner pops out it's game over.

 

[SolidZ24x4]

Well f--. New plan.

 

Drain coolant and remove radiator.

Remove fan

Hopefully break-free and remove Crankshaft nut.

Drive to parts store and buy puller (maybe new tensioner?)

Remove Crankshaft pulley

 

Go from there... Hurray for poor preparation!

[Lockleaf]

Sometimes you can pull the oil pump and look up through that hole to see your tensioner.

 

Puller for what? Crank pulley isn't pressure fit. A puller will work, but so will a rubber mallet. Couple quick taps usually does it.

[SolidZ24x4]

at the store I'm getting:

 

front cover gasket?

seal for crankshaft?

puller

timing chain tensioner

any other ideas?

 

Thanks

[Lockleaf]

Oil pump gasket. Be sure to pull the oil pump before removing the front cover. There is a cover bolt hidden behind it.

[SolidZ24x4]

The section concerning the fan and fan clutch are kind of vague, do i have take the fan/clutch assy apart to get the waterpump off?

 

Any chance the oilpan doesn't have to come off completely? Something tell me no. This sucks due to the diff right under it....

 

Thanks for the headsup lockleaf

[datzenmike]

Take shroud and fan off for more room. The clutch is integral with the pump and attempting to dismantle it is ill advised. Remove the pump and the clutch together.

[Lockleaf]

Some of the water pump bolts won't come all the way out of the pump. They will hit the pulley. This is ok. They are not meant to come out of there.

[datzenmike]

The tensioner is re-usible, just needs to go back in place. 

Get new crank seal

 

Disconnect battery

Drain coolant

Remove fan shroud.

Remove rad. tip: Pull hoses off the engine not the rad ends.

 

Remove fan belt, alternator, fan and water pump, distributor/wires, oil pump and it's drive spindle.

 

Loosen crankshaft nut don't remove

Loosen cam sprocket retaining nut,don't remove

Loosen the oil pan bolts at the front and 5-6 down each side

Remove the two 10mm bolts at bottom front of head into the top of the timing cover. Or was it 4 of them?

 

Turn engine to TDC using the timing scale.

ENGINE MUST NOT BE TURNED OR MOVED FROM NOW ON!!!!!! tip: Place in neutral and block the tires so bumping against the fenders or pulling on wrenches will not turn the tires and bump the engine off TDC.

 

Remove crank bolt and tap back of pulley forward with the socket. Light taps maybe 30-50 will bring it forward and off the woodruff keys. Look for them they may fall out, or not.

 

Now remove all the timing cover bolts and keep in order.

 

Timing cover should now slide out to the front off it's 2 alignment dowels. Pan gasket and head gasket may grip it. If the pan gasket tears by new one and trim to fit when ready to assemble. Head gasket not near as critical as all it seals is oil fumes and some spray.

 

Remove cam sprocket and chain capture and hold onto the tensioner.

 

Crank sprocket should have a small timing dot or dimple around 4 o'clock

Cam sprocket should be placed on the #2 position and the timing dot should be around 2 o'clock.

Chain will have two bright shiny links with 40 links between them on a Z24

Align these shiny links with the two timing dots on the sprockets.

Slip the chain tensioner back into place.

 

Engine will now be properly cam timed at TDC.

 

Not the end of the world if the engine is turned now.

Put everything back together.

Don't forget timing cover crank seal.

Block and timing cover must be CLEAN........ Do it right and you only have to do it once.

Gaskets go on dry.

Clean oil pan surface with carb cleaner to degrease. Put dab of RTV sealant in corner where block, timing cover and pan meet. May have to smear some on pan gasket also.

Same with head gasket against the top of the timing cover. Just seal it best you can.

 

Drive spindle must be installed in the '11:28 position'. If you only removed the two mounting bolts on the distributor pedestal, the distributor will still be timed properly when put back. 

[SolidZ24x4]

do i have to drain the oil?

[SolidZ24x4]

I apoligize for that last question, I bring my stupid with me some times. I just got back at it and tore off the timing cover.

 

There was lots of swearing, loud music, and sore hands, but I got to the problem and really wish I would have bought or made my own wedge. In case this post is read a few years from now, by someone like myself who is less than prepared, I'll repeat that; ​I really wish I would have bought or made a timing wedge. At least I know how to re-achieve timing once it had been lost. Got lots of pictures too.

 

Anyways, I've got the cam sprocket back on, correctly, the tensioner is back in it's home, and I'm ready to put 'er back together. So, say, just for a topic of conversation, would this thing run if the camshaft were 180 degrees out of time? You, know theoretically...?

 

Now for reassembly...

[Doctor510]

I apoligize for that last question, I bring my stupid with me some times. I just got back at it and tore off the timing cover.

 

There was lots of swearing, loud music, and sore hands, but I got to the problem and really wish I would have bought or made my own wedge. In case this post is read a few years from now, by someone like myself who is less than prepared, I'll repeat that; ​I really wish I would have bought or made a timing wedge. At least I know how to re-achieve timing once it had been lost. Got lots of pictures too.

 

Anyways, I've got the cam sprocket back on, correctly, the tensioner is back in it's home, and I'm ready to put 'er back together. So, say, just for a topic of conversation, would this thing run if the camshaft were 180 degrees out of time? You, know theoretically...?

 

You better hope it does not, bent valves are a bitch

 

Now for reassembly...

[datzenmike]

Anyways, I've got the cam sprocket back on, correctly, the tensioner is back in it's home, and I'm ready to put 'er back together. So, say, just for a topic of conversation, would this thing run if the camshaft were 180 degrees out of time? You, know theoretically...?

 

 

 

Yes it will, but the firing order will be 180 out as well. Just move all the plug wires two positions to the right or the left.

[SolidZ24x4]

I will never do a project like this without comprehensive research first, ever ever again.

 

I'm not a 100% the oil pump went in exactly as it came out, but I did line up the two holes... and I'm not totally sure my sealant job is going to hold up on the oil pan either, but we'll see. If need be, I can always drop the diff and seal up everything on the oil pan properly after the top end is put together properly...

 

Glad to see I put myself in check, I guess; if this works right and doesn't leak I'll still be somewhere like three times past standard rate... but likely will be back at it because I suspect something is going to leak.

[datzenmike]

Oil pump and spindle position is easy to check. Set to TDC and lift the distributor out. You should see this inside....

 

 

 

Notice there is a large (right side) and a small (left side) half moon on the top of the drive spindle. Simple as this.

 

If not this, remove the oil pump and drop the spindle out and re-position until you do have it.

[SolidZ24x4]

So once I achieve this orietation with the oil pump/spindle, the distributor can only be installed in-time correct?

 

Also, I had to cut the oilpan gasket in order to wedge the front cover back in; is it very difficult to pull the oil pan off? I noticed an extrusion on the oil pan itself that prevents access to a few of the bolts on the passenger side, I'm wondering if they get easier to access after pulling the cross member and lowering the diff.

 

All because I didn't use the mf'ing wedge... :poop:

[Lockleaf]

Those bolts are a joke regardless. They are slow and difficult even with the engine on an engine stand.

[SolidZ24x4]

got it put back together, but cant get her to start. I have the oil spindle exactly as pictured, ​exactly, but to no avail. it seems as there's no spark. I'm pretty sure you cant put the distributor cap on backwards... My next move is to rent a timing gun and see if theres anything goin to plug I1.

 

Any suggestions would be much appreciated!! thanks​