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Discussion Starter #1
First time engine rebuilder question:

I am on the final stages of my 86 2.0L rebuild. Tonight I connected the upper timing chain and set the tension. My question: are the intake and exhaust cams close enough to button the top end up? For a noob, this has been the most perplexing setup to resolve.

Here's the intake cam:


Exhaust cam:


Thanks in advance for any constructive feedback.
 

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No, it's not close enough. Besides, why wouldn't you want it exact? You can set it pretty much anywhere using the holes in the cams and sprockets.

I assume you know that at #1 TDC the #1 intake and exhaust lobes should point away from each-other; not toward each-other as shown in your photos.
 

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as jay points out the cams are set backwards, they should be point out with the crank (#1 piston) at TDC. As you have solenoid cam on the intake, set that side first, then by removing the vernier nut and bolt on the exhaust cam, rotate the cam inside the sprocket, without moving the chain and reinsert the bolt through the hole that lines up. I like to have a new nut and bolt on hand when setting.
 

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Discussion Starter #4
Thanks AlfaJay & rogerspeed,

#1 is at TDC. So obviously, I have really buggered this step of the rebuild.

That's why I posted the photos... seems like I have triple checked everything before I got to this point. I felt a little out in the woods on this portion of the rebuild. Looks like third time will be a charm on this one.

Roger - Does the sprocket nut and lock washer need to be backed off the sprocket before it will rotate freely? And is the vernier nut the tiny bolt that locks the sprocket together (little confused by the terminology)?

again thanks for the feedback... better safe than sorry.
 

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Richard Jemison
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Cam setup

First some clarifications / corrections.

The position of the cams as in your picture with the lobes facing in would be correct for setting the cam timing if the engine is at TDC for the #4 piston. Look at the distributor rotor. Is it pointing to #1 or #4?

The sprocket will Not turn unless the large nut is backed off/loose,( not necessary to remove it) AND with the through bolt removed,

With the small bolt out and the 22mm nut loose the cam can be rotated small amounts (at TDC) to correct minute timing errors.

If your motor is at TDC for #1 and the cams are pointed to center then they need to be rotated 180 degrees (with lobes pointed out) which meand you need to rotate the crank a few degrees to get the pistons anout a 1/2 inch down in the bore. Then the cams can be rotated freely. Then back the crank to its TDC position and set cam timing.

The lock plate behind the 22mm nut isn reusable but it can be left in place. I use red loctite to secure it.

Check timing again after completion as the tighening process can move the cam/sprocket if not locked in place with the through bolt.
 

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If he is at TDC with #1 on the firing stroke, can he just move the HT wires around 2 places on the distributor so that the rotor is now pointing to #4 cylinder? Then make the small adjustments to get the timing marks lined up accurately.
 

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If he is at TDC with #1 on the firing stroke, can he just move the HT wires around 2 places on the distributor?
I think you meant: "If he is at TDC with #4 on the firing stroke..."

Sure, that will work. But, it will confound all mechanics who subsequently work on the engine.

It's so simple to get it right when things are at this stage, that it would be a false economy to just resort to the old "switch the wires around" trick.
 

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Discussion Starter #9
Rather be right on the timing marks (and learn the correct procedure to do so) then fixed by swapping the plug wires. I can appreciate the cleverness of the solution - but, I am highly likely to forget what I did the next time I have an issue. :)

for Richard - #1 is TDC and the distributor rotor is aligned to the distributor mark. I will follow your recommendation to give the valves a 1/2 clearance and realign the cams.

thanks again for the input.
 

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Before the Internet more than one of us learned that lesson the hardway:)
 

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I think you meant: "If he is at TDC with #4 on the firing stroke..."
No I didn't. If he was at TDC with #4 on the firing stroke he would not have to mess with the distributor wires. I don't see the big deal in having the spark plug wires in any particular position on the distributor. Mine are almost certainly not the way they came from the factory but it does not matter because I don't know which way that is. It is pretty easy to see which wires got to which plugs. If a mechanic is confused by that then he should consider another profession.
 

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Hope I'm not saying something wrong here and confusing the issue but if the cams need to be rotated 180 degrees to put the lobes facing out doesn't that put the timing mark on the cam facing down? I'm thinking the cam on the intake side needs to be on the exhaust side and vice versa.
 

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Discussion Starter #15
I will be the first to admit that I thought that stock Alfa cams only fit one way. Last night I rotated cams to be oriented in the correct direction - there where the timing marks. That was the source of my first error: thinking that the stock cams could have a single timing mark.

The other big learning is that the exhaust cam 22mm nut needs to be backed off to allow the sprocket to spin freely (as Alfa7 stated above). Now that I see it work, I am really amazed at this small piece of engineering.

I am back on the road to complete this rebuild and get my Spider running.
 

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Discussion Starter #17 (Edited)
Cam Timing follow-up

Well, the timing is now set correctly on my 86'. Here's a few things to consider if you have an engine with VVT.

First: The correct tools really do make the difference. A big shoutout to Eric (ghnl). He was kind enough to lend my his 55mm spanner (A.5.0232) and camshaft locking tool (A.2.0423) that he purchased from TotallyAlfa.com.

The shop manual states that the lock nut is torqued to 70 ft. lbs - and I believe it. As you can see, I need to use my workbench to lock my 50mm wrench as I loosened the nut. No **** way I was going to do that with an adjustable wrench.



With the nut loose, you can clearly see that it's easy to back off to the lock nut which allows the sprocket to spin freely.



From here, installation of the upper timing chain and setting the tension was so easy it was almost comical. What i have struggled with for a week and a half, i completed in 45 minutes with the correct tools.

Tightening the camshaft sprocket was super easy with the correct tool.



Now the timing is set correctly.

Intake:


Exhaust:


Distributor:


Thanks to Eric for the tools and to AlfaJay for stating the obvious: if your going to set the timing.. why not set it right (I might be paraphrasing, but that's how I took it.)

Now to install the oil pans and get the ol' boy running again.
 

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You are supposed to set the centre of the rotor pointing at point around 5 mm clockwise past the #1 mark on the distributor body when the crank is at TDC.

This is to compensate for the fact that spark is always firing before TDC: And unlike distributors with internal mechanical advance mechanisms, the point on the distributor rotor that will be aligned with the relative pole in the cap will vary significantly. Compare a rotor in a Motronic car with one in a normal car: you will find the rotor blade much wider in the Motronic car.

The wider rotor is to help compensate, but if do not get the setup right, it may cause some ignition issues.
 

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You are supposed to set the centre of the rotor pointing at point around 5 mm clockwise past the #1 mark on the distributor body when the crank is at TDC.

This is to compensate for the fact that spark is always firing before TDC: And unlike distributors with internal mechanical advance mechanisms, the point on the distributor rotor that will be aligned with the relative pole in the cap will vary significantly. Compare a rotor in a Motronic car with one in a normal car: you will find the rotor blade much wider in the Motronic car.

The wider rotor is to help compensate, but if do not get the setup right, it may cause some ignition issues.
That is what you do when setting the ignition later on.
The point of ignition inside the distributor is already set from factory, and can not be adjusted by turning the distributor.
The reason for a wider rotor is depending on ignition advance curve.
 
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