348 Camshaft Timing Question

The cams are a mile off. In any event, the marks are referred to by Ferrari as assembly marks, only intended to allow assembly without damaging the valves until real timing can take place.

You say engine always ran strong? How many 348s have you driven?
What were the exhaust gas readings on the right and left side, precat?

Who did the major in 2009?

 

Yikes

Did you put a degree wheel on and check the actual timing to see how off it is? Looks like it's 5-10 degrees off. Wow.

 

My calibrated eye ball say 15.8* off.

 

Of course, that is based on the marks, which as Brian noted are for assembly.

 

Without knowing anything else, I would say put a degree wheel on it, find out how far that cam is off, and then go from there.

 

^This^

 

More like 2 teeth.

Hard to see 5 degrees.

 

If you get the factory instructions and follow those they were intended to get the cams properly timed, easily without a bunch of special tools.

 

I estimated around 16 degrees from the mark misalignment. How many teeth is that? Like 1 and 1/2?
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On a 348, the teeth are 10 degrees apart. I think a 1/2 tooth (5 degrees) could be seen...

 

10 cam degrees. Who measures anything in cam degrees...ever?

 

Again CAM degrees. No one ever measures cam degrees.

 

I would not try to forensically figure out what the guy did before. You have no idea the condition of that motor. There could have been non-factory machining, prior service sloppiness etc which could effect what timing looks like. Just note in your head which cam might be off but trust the factory marks until proven otherwise. While assembly marks are not timing marks they are close, often very close and often dead on on unmolested motors. A 348 will run very well at the consumer acceptable assembly marks as just an FYI. Many many have been set up this way pro and DIY although few would admit it. I would do my major and go through the timing exercise and be happy once I confirmed that my timing marks were near the assembly marks. if you get wild results you are probably wrong and I would tread carefully and turn the motor by hand to get a good sense of pistons clearing valves. If the one is still off "some" I would tend to trust it if the car ran well before and I was comfortable with timing technique. It is also not a bad idea to get a baseline compression and leak number set while you are in there and doing that just cements better understanding of motors in general. Consider intake valve cleaning which is easy to do when cams are out and fuel injector service from a good builder like RC engineering in Torrance, Ca..

 

^^^Sage advice from FBB.

Sandy, do you have a copy of the factory repair manual?

 

Heck, you could easily see one degree misalignment in the marks. Knowing it's 1 degree is another thing.

 

Well if one is familiar with those motors and knowing lobe positions you can eyeball the relative positions of the intake and exhaust lobes and see one is quite a ways off even when the marks are ignored. FYI, the marks on the cams and bearing caps are the assembly marks made during part production. The chisel marks on the pulleys were made by the engine assembler so if the motor leaked or went bang on the dyno it could be ripped apart and fixed without going through timing again.

The combination of the assembly marks, the pulley marks and the lobe positions leads me to conclude this motor was last timed by Stevie Wonder.

 

??? The CAM marks are off by about 16 degrees, so that would be 32 on the crank. Is that what you are getting at?

 

Yuuup its off fix it
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