How Much Trouble Am I In If Any ?

I don't see how anybody out in Internet land could possibly tell you if the shavings will or won't hurt the motor. It would depend on factors such as:

• the type of shavings (metal or plastic).
• the amount of shavings.
• the size of the shavings
• The location of the shavings.
• has the motor been run or not?

IMO you have a number of "issues" to over come. Depending on your luck, even a tiny amount metal ingestion could cause an engine failure. The internal structures of the 4.6 intake manifold are very complex and difficult to clean. Hence the reason the "book" recommends getting a new manifold after an engine failure.

IMO if you want to be certain, then all of the debris has to be removed. Otherwise your fate is in the hands of the gear head Gods.

A buddy of mine had a centrifugal supercharger impeller blade explode sending shrapnel all the way through his motor and out of the exhaust. He didn't find all the pieces so he tore the motor apart to both check for damage and try to find the missing pieces. The only thing he found was a tiny little nick on one of combustion chambers. Luck I'd guess.

If any of that made it into one of your cylinders, I'd worry about it getting stuck between the piston and the cylinder wall, scoring the cylinder walls which may possibly lead to destroying the rings and compression. Just sayin...

As WMBurns said, it really is complete luck on what could happen.

On one hand, the tiniest of shavings could get stuck just right between the piston and cylinder and scratch it up, damaging the ring seating abilities and pretty much ruining the motor.

On the other hand, I broke off a 2" x 1" x 1/4" section of the top of my piston a few months ago, bounced it around violently inside the chamber, crushing it up into smaller pieces as it went, before finally shoving it past the exhaust valve and through the exhaust port. All without damaging the ring that was below the part of the piston that broke, or leaving a single scratch on the cylinder wall, or damaging the valves or seats. Just a couple of small nicks in the combustion chamber. Did not hurt one thing and the motor ran fantastic for several hundred miles after that.

Seeing as how relatively easy it is to pull the entire lower intake manifold, I'd yank it off, get everything out that you could, put it back on, and roll on. I very seriously doubt you'll have any problems, but even if you were, what else could you have done before those problems even happen anyway?