High carbon on valves
 

Good Morning,
My "A" was running great showing light brown / gray color on the spark plugs.
It began loosing power and by shorting out the plugs determined number one cylinder had no power. Pulled the head off and found lots of carbon accumulated on the under side of the valves and a little down the guides. Also the plugs are heavily sooted included the pistons and the head. Shorting out each plug shows a blue / orange spark.
The points were too closed and i found the point block clamp screw was stripped. Reset the points and it started better and ran better.
I re-cored the radiator last year and now it runs real cool
What is the main/sudden cause of all the carbon.
Thanks for your thoughts.
Al

Re: High carbon on valves
 

Wet Carbon?

Re: High carbon on valves
 

My first thought was the engine is running too cool now and that is causing the carbon buildup but since you're in Florida I doubt that's the case. How long since you examined the carbon on the valves? You don't really want to see any orange when checking the spark either, could indicate a weak coil or failed/failing condenser. Do you use any Marvel Mystery Oil in the gas?

Re: High carbon on valves
 

Carbon like you are seeing is running to cool, running short trips, running to rich. Plus maybe using a little oil.

Re: High carbon on valves
 

Daren007 - the best way i can describe the carbon is sticky, maybe that is wet as you ask.

Ryanheacox - The re-cored radiator is so efficient sometimes i don't see any red on the Motometer. I will have to check the coil, and condenser. I don't use any Marvel Mystery Oil. I also installed a Mittchell overdrive 3,500 miles ago.

George, I usually run for an hour or more since most of my club is not very nearby. Too rich is possible and maybe some oil.
I'm thinking about getting one of those thermostats from Vintage Precision I just saw in the MAN magazine.

Thank you all for taking the time to offer your thoughts.
Al

Re: High carbon on valves
 

good idea that might do it, if not I would not worry to much about it.

Re: High carbon on valves
 

Like George says. It is a common and normal condition, exaggerated by running too cool.

Re: High carbon on valves
 

Daren007, I can answer you question better now since cleaning the engine.
The intake ports had wet carbon and the exhaust ports had dry carbon.

Re: High carbon on valves
 

Wet carbon on intake valves point to blow by or worn guides.

Re: High carbon on valves
 

Install a 180° thermostat.