Ferrari 412 - Failed Inspection. High HC and CO Values

These are not the correct definitions of "intake opens" and "exhaust closes". To use these (just touching and just releasing) as the "events", the valve clearance needs to be physically reset to 0.5mm by changing the shim (or the existing running valve clearance + the valve deflection = 0.5mm).

 

This is what you should do:

1. On Cyl 1, you need to replace 1 intake valve shim and 1 exhaust valve shim such that their clerance is 0.5mm
2. Redo your cam timing measurement using those two valve positions.
3. Replace those valve shims with the ones you take out when you are done.

Do the same with the other bank and the cyl on which you are measuring cam.

It's much more accurate with the degree wheel, but this is good enough.

 

When you play with the flywheel, just do not turn it backward as this would make your reading unreliable (in this case you do not rotate the camshafts, you just compress the tensioner).

Are you sure the flywheel is properly line-up and accurately showing TDC?

Same question for the camshafts: maybe they could have been replaced with 400i ones that are cheaper/easier to source and identical (except for the timing marks...).

 

The marks on the cam caps have no relationship to the CS10 and AA16 marks. When the exhaust valve closes (i.e., the exhaust lobe stops touching the shim when clearance has been set to 0.5mm) is when the pointer should be at the CS10 mark, and, likewise, when the intake valve opens (i.e., the intake lobe starts touching the shim when clearance has been set to 0.5mm) is when the pointer should be at the AA16 mark.

PS There are two CS10 marks and two AA16 marks on the flywheel, one set for cylinder #1 and one set for the other bank (not sure which cylinder). Make sure that you are using the correct set of marks for each bank.

PPS The A5/33 mark is where the cyl #1 ignition timing should be (33 deg BTDC) when the engine is at 5000 RPM (with the vacuum line disconnected from the Microplex ECU).

 

Wait, stop. Is there no one else around where you are that can assist with this issue? And, where do you live, again?

 

What is your final lobe separation angle, or in other words how much have you departed from the factory timing marks? If the camshafts timing marks are more than 2mm away from the base setting I would take extra care before attempting to start the engine.

Is this a high mileage car? My own car which is close to 100.000km, does show less wear on the camshafts (there are a few streaks on yours). Maybe this could explain why your settings are so different from the factory base setup.

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It's not clear which camshaft is which: did you advance the exhaust and retarded the inlet (=reduce overlap)? Or was it the other way round?

There seem to be additional marks on the inlet camshaft? Your new timing seems pretty close to these markings.

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By the way looking at the first two photos you posted on this thread, you can see such "marks" in an other camshaft.

 

I saw both were adjusted but on the two pictures you did not say which camshaft is which:

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If my assumption is correct, you did reduce the overlap. Less overlap gives you a bit more vacuum at idle which will make it easier to tune for less emissions.

Assuming also that each "additional marks" on your camshaft are indicating 1°, you reduced the inlet by ~2.5°( ~5° at the crankshaft), so worst case you end-up with a 400i tune. Maybe not the best for performance but this would not destroy your engine.

On the contrary if you retarded the exhaust and advanced the inlet you'd better check everything twice: hitting the exhaust sodium valve would be an absolute pain to fix.

 

The diagram of the 400i WSM manual, section B54, may help (bear with the different timing angle and missing marks compared to the 412) : should give you a better idea of where the timing marks are for the second bank (1-7). This being said, the manual recommends to use a "goniometer" (which is probably how they translate degree wheel from italian)