Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 02-16-2020, 08:16 AM   #1
Al 29Tudor
Senior Member
 
Al 29Tudor's Avatar
 
Join Date: Jul 2012
Location: Venice, FL
Posts: 648
Default 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
Al 29Tudor is offline   Reply With Quote
Old 02-16-2020, 09:20 AM   #2
daren007
Senior Member
 
Join Date: Apr 2015
Location: Saint Cloud Mn
Posts: 745
Default Re: High carbon on valves

Wet Carbon?
daren007 is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 02-16-2020, 09:27 AM   #3
ryanheacox
Senior Member
 
ryanheacox's Avatar
 
Join Date: Apr 2013
Location: Northwest CT
Posts: 1,092
Default 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?
ryanheacox is offline   Reply With Quote
Old 02-16-2020, 10:01 AM   #4
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,975
Default 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.
George Miller is offline   Reply With Quote
Old 02-16-2020, 11:26 AM   #5
Al 29Tudor
Senior Member
 
Al 29Tudor's Avatar
 
Join Date: Jul 2012
Location: Venice, FL
Posts: 648
Default 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
Al 29Tudor is offline   Reply With Quote
Old 02-16-2020, 12:03 PM   #6
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,975
Default Re: High carbon on valves

Sponsored Links (Register now to hide all advertisements)
good idea that might do it, if not I would not worry to much about it.
George Miller is offline   Reply With Quote
Old 02-16-2020, 12:05 PM   #7
Jim Brierley
Senior Member
 
Join Date: Jun 2010
Location: Temecula, CA
Posts: 4,066
Default Re: High carbon on valves

Like George says. It is a common and normal condition, exaggerated by running too cool.
Jim Brierley is offline   Reply With Quote
Old 02-16-2020, 09:05 PM   #8
Al 29Tudor
Senior Member
 
Al 29Tudor's Avatar
 
Join Date: Jul 2012
Location: Venice, FL
Posts: 648
Default 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.
Al 29Tudor is offline   Reply With Quote
Old 02-16-2020, 09:13 PM   #9
daren007
Senior Member
 
Join Date: Apr 2015
Location: Saint Cloud Mn
Posts: 745
Default Re: High carbon on valves

Wet carbon on intake valves point to blow by or worn guides.
daren007 is offline   Reply With Quote
Old 02-17-2020, 01:07 PM   #10
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Red Deer, Alberta
Posts: 5,011
Default Re: High carbon on valves

Install a 180° thermostat.
__________________
If you don't hear a rumor by 10 AM, start one!.
Got my education out behind the barn!
katy is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 03:41 PM.