Carbon in intake/throttle body due to timing being off?

[SHO SPD]

My dad,was telling me that my timing was just a bit off, or my valves are off causing sme blow back, because I have carbon buildup inside the intake, and throttle body.. He said there should be NOTHING inside there, but yet, every SHO I have seen has had carbon buildup inside the intake... whats the deal?

BTW My engine is out...

<small>[ April 14, 2002, 10:04 PM: Message edited by: SHO SPD ]</small>

 

[sdpatt]

It would be spotless in the manifold if the engine didn't have crankcase gasses vented to the throttle body. There are two breather hoses that allow the vacuum in the intake to scavange the combustion gasses that blow by the piston rings. It is these gasses that introduce the carbon to the intake manifold.

As you had noticed when you took off the oil pan, the engine in your car did not have a good oil history. To answer a question on the Forum, I recently removed the intake's crossover tube to see the diameter of the passages to it, but I also found that my intake was pretty darn clean after a quarter of a million miles. I have never cleaned the inside of the plenums, only scrubbed the runners. The image below is of the inside of the front plenum of my engine. No blackness there. Castrol GTX every 3,000 miles.