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Need help properly aligining crank shaft, cam and distributor. Help please!


cycloid

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Hello

I need help putting my z motor back together. the car is a 1978 280z with 5 speed transmission and it also has ac.

I will try to be as clear and as detailed as possible.

Here is is the low down.

A few weeks ago my car was running. It ran pretty good. The only thing that was wrong with the car was that I could hear the chain slacking when I went above 65 mph. ( I am pretty sure that's what the sound was)

So I bought a timing chain kit. It came with with the cam gear, the crank gear, chain and gaskets. I took the car to a friends house. We then removed the valve cover, we put a mark on the timing cover to note the location of the distributor rotor. then removed the ac bracket, oil pump and then the timing cover.

At that point. everything was good. What messed up was that my friend had had tightened the crank bolt and to put the crank pulley back on he had to unloosen the bolt and basically get the crank off top dead center. He turned the crank around again and tried to get it to tdc. We eventually put the gear and cam gear on the engine without determining what way the cam gear would be installed. We also did not pay any attention to the colored links in the timing chain.

And I believe that the oil pump shaft and distributor were not installed correctly.

when we turned on the car it would not stay on. it had a rough idle and the car would die out.

we also heard some weird clicking noise. I was able to keep the car running and I drove it about 5-8 miles to get it to my house. Since then the car has sat.

I called around a few places and they were telling me that it would cost around 500 dollars to get the engine timed correctly without replacing any parts.

I honestly would rather not pay and try to fix it myself, which I should have done the first time.

If the valves are bent then so be it. But I want to try and adjust the timing first and see how things go before I start spending some serious money.

So now that I have that out of the way, I would like to explain what I have done to the car so far.

I have removed the radiator, timing cover, valve cover harmonic balancer, cam, chain and distributor. I need to get the crank on TDC first. I have no idea how to to do this on this engine. would I be able to tell by the dot and the crank gear? can i tell by the orientation of the crank snout? is there some special trick for getting TDC on a L28?

Secondly. how do I setup my cam? what lobe has to be in what direction? do I have to compensate for a new chain or cam gear? I will also not be running AC either.

after I have my cam and crank timed. How do I setup my distributor? I don't trust the mark that was made on the timing cover. I saw a video on youtube that talks about using the marking on the oil pump to properly set the distributor. Im hoping there is an easy way.

So that's pretty much it.

I would really appreciate it if I could get some assistance. I am eager to get my Z back on the road.

some pics of the car

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img0618m.jpg[img]http://img687.imageshack.us/img687/823/img0617oh.jpg

img0616ps.jpg

img0615j.jpg

img0614au.jpg

img0613lx.jpg

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The timing links have to line up with the timing marks on the sprockets.

Is the chain still on? This will make it easier if it is.

If not. Ideally the head should be off, but,if not, first remove all the plugs.

To establish number one TDC carefully turn the crank till the key at the crank snout is at 12 oclock.

The cam lobes on number 1 cylinder should be at a position so they look like a pair of lazy rabbit ears

If the crank meets resistance it will be the valves hitting pistons, so you may need to turn the cam at the same time, carefully.

Once having established the crank sprocket at TDC. And the cam a described, you can fit the chain.

You should have 22 links including both marked ones, facing the exhaust side of the engine.

Fit the chain on the crank sprocket aligning the mark on the chain with the mark on the sprocket.

Fit the cam sprocket with the mark on the chain aligning with the number 1 mark on the cam sprocket.

Fit the sprocke tto the camshaft and bolt it on.

Fit the tensioner and guides.

Rotate the crank to see if the valves are stuck, and nothing hits.

Fit cover.

Align dizzy shaft mark with mark on oil pump in your first picture. fill pump with oil, and install oil pump.

Tang on shaft should be at around 11-30 oclock position,when viewed at dizzy mounting position, or around 5 degrees from a line drawn through the mounting holes.

There is a picture of this on here somewhere, but I can't find it.

Have I left anything out?

Fit dizzy and plugs, wiring etc.

She should start, if you get the plug wires in correct position.

Firing order 153624

Edited by olzed
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Dave's fail proof timing method. No BS.

1) Put the crank timing pulley at TDC (by hand using the timing marker on the timing cover) Install the cover temporarily.

2) Line the cam sprocket mark up with the mark on the from of cam tower 1. (look through a hole in the cam sprocket to see the marks) There are three marks, with a new chain use mark #1, and dowel hole #1 on the sprocket.

3) Install timing chain, taking care to watch the mark on the cam sprocket. Disregard any shiny or marked chain links they are not important and can go anywhere. If it's off by a few teeth, take off the sprocket and " inchworm" the chain a tooth at a time until it lines up. (chain tensioner keeper tool firmly in place)

4) Place your dist cap on the dizzy and mark where the #1 spark plug falls, on the body of the dist. then remove the cap.

5) Install the dist drive gear, and the dist (with the rotor in place). Is the rotor pointing at the mark you made on the dist? If not, pull down the dist shaft and rotate as needed. (you want the rotor about ten degrees past the mark you made, for the built in timing advance)

6) Done.

Warning: When you rotate the cam and the crank independently, you need to go gently so as not to smack the valves into the pistons. (remember when the first two cam lobes are up, you are near TDC.)

End goal:

Timing Pulley at TDC "0" mark.

Cam Sprocket hash mark is line up with tower hash mark.

Rotor points near the #1 spark plug wire on the cap.

Edited by cygnusx1
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Hello.

I have started re assembly of the timing chain

here is exactly what I have done so far.

I turned the crank over by hand very gently. I did feel some contact with the valves, so I carefully moved the cam a bit until I was able to move the crank over some more.

I got the woodruff key near 12 o'clock. I placed the timing cover on the engine. Then I put on the balancer, and moved it until the woodruff key on the pulley lined up with the 0 mark on the timing cover.

I took off the cover. I made sure the front two cam lobes made a v shape. and the highest peak of cam lobe no. 8 was facing 12 o'clock.

I put the chain on and matched the colored chain link with the mark on the crank sprocket. Then I put the no.1 sprocket hole on the cam.

I then put the timing chain guide that is on the right side. I also put on the part that had the spring. It was really hard to put the spring on

without moving the crank just a little bit. I only moved the crank about 5 degrees clock wise, which also took out the slack on the right side.

I was able to easily put on the spring and the tensioner on the left side. The woodruff key now appears to be at exactly 12 o clock since I advanced the crank those 5 degrees.

I am wondering if I should have moved the crank before or after putting on the distributor? Or maybe not have done it at all? I think by using the timing cover as a guide allowed me to easily put on the tensioners and spring. When I moved the the crank the 5 degrees it completely removed the chain slack and put the woodruff key at 12 o'clock exactly. I hope I'm good to finish up with putting on the distributor.

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Definitely valvetrain sounds as far as I can tell. Could be a missing lash pad? or maladjusted clearance. Turn it over by hand and observe that all the valves are opening and closing by watching them with the cover removed. Compression test results?

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Hello. I turned the crank over by hand did not get any resistance. When I turned the engine back on I could hear the sound again.

I ran a compression test last night and here are the results.

cylinder no.1 =92

cylinder no.2 =0

clyinder no.3 =58

cylinder no.4 = peaked to 120. gradually went down to 34

cylinder no.5 = peaked at 90. gradually went to 30

cylinder no. 6= erratic. jumped between 90 and 95.

how can I check the lash pads? Is there a way to properly adjust valves without removing head?

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