Valves diagnosis

[bobdobbs]

Let's say you pull a head and the intake valves are whitish and the exhaust valves are black. Also, there's lots of carbon build-up in the combustion chamber and piston tops, except near the intake valves. What problem(s) does all that indicate?

[trk]

Lean intake conditions .... rich exhaust conditions. ;)

Detonation... ?

[chunky]

Let's say you pull a head and the intake valves are whitish and the exhaust valves are black. Also, there's lots of carbon build-up in the combustion chamber and piston tops, except near the intake valves. What problem(s) does all that indicate?


carbon tends to build up on the exhaust side of the head. exhaust valves are coated black I believe on the k-series head. the intake valves are unfinished metal.

[bobdobbs]

carbon tends to build up on the exhaust side of the head. exhaust valves are coated black I believe on the k-series head. the intake valves are unfinished metal.
So you think it's normal, other than maybe the lean condition?

[Lestat537]

Let's say you pull a head and the intake valves are whitish and the exhaust valves are black. Also, there's lots of carbon build-up in the combustion chamber and piston tops, except near the intake valves. What problem(s) does all that indicate?


Sounds rich to me. How do your plugs look?

[bobdobbs]

Sounds rich to me. How do your plugs look?
Whitish. :confused:

I just looked at the head again and I had it bass-ackwards: The intake valves are black and the exhaust valves are white.

This isn't a Honda, BTW. You don't want to know. :banana:

[PAPITUYO326]

Whitish. :confused:

I just looked at the head again and I had it bass-ackwards: The intake valves are black and the exhaust valves are white.

This isn't a Honda, BTW. You don't want to know. :banana:

my guess...an alfa romeo :winkm:

[Si3]

my guess...an alfa romeo :winkm:


bold guess there..... dobbs with an alfa... who would have guessed!

[BSEVEER]

Fix It Again Tony. Lol :winkm:

[Lestat537]

Whitish. :confused:

I just looked at the head again and I had it bass-ackwards: The intake valves are black and the exhaust valves are white.

This isn't a Honda, BTW. You don't want to know. :banana:

Lean, maybe.

It kind of seems like your timing is off. The reason why i say lean...MAYBE, is because if your timing is off by enough, your spark might come too early before the air/fuel mixture is completely injected, resulting in a lean condition. Then the rest of the fuel enters the fray and is oxidized, but as a result of the preceding detonation. This might produce a fuel rich condition, fouling your pistons and intake valves, whereas the premature detonation would affect the exhaust and plug tips.

Just a speculation though, hope this helps.

[SSMep3]

i dont mean to be a dumbass but what does detonation mean?

[Lestat537]

Detonation is the act of a flammable material combusting in an explosive fashion. =D

The fuel mixture detonates, resulting in a controlled explosion, and the piston is forced downward into the cylinder and turns the crankshaft. If this detonation occurs before the piston reaches Top Dead Center (TDC), this is called 'premature detonation' and as a direct result, causes knock and ping. If you have enough of this, you can say bye bye to a rod. Then your block will say bye bye to you. Then you'll have to say bye bye to your money. =(

[SSMep3]

Detonation is the act of a flammable material combusting in an explosive fashion. =D

The fuel mixture detonates, resulting in a controlled explosion, and the piston is forced downward into the cylinder and turns the crankshaft. If this detonation occurs before the piston reaches Top Dead Center (TDC), this is called 'premature detonation' and as a direct result, causes knock and ping. If you have enough of this, you can say bye bye to a rod. Then your block will say bye bye to you. Then you'll have to say bye bye to your money. =(

hahaha ok cool thanks for clearing that up for me

[bobdobbs]

Just a speculation though, hope this helps.
Yeah, that makes some sense, thanks. I can see some carbonization on TOP of the intake valves, which only makes sense if the charge is igniting too early.