206 carbon issue
- Thread starter harrym
- Start date
steve baker
Moderator
Yes overlap is a factor along with combustion burn quality, ring and cylinder wall sealing and exhaust scavenging efficiency. Remember this camshaft was based on the intek lawn and garden camshaft to operate at 3600 RPM, not specifically designed for racing at 6000 RPM levels.
Steve
Steve
Last edited:
CarlsonMotorsports
Site Supporter
The whole engine was designed to be equal (not necessarily faster,) and very conservative so that it would last a long time. Tight cylinder clearance, hard compression ring, tight oil rings. very rich, low compression, slow timing, etc etc, all made to last. It's not by accident that the rules do not allow us to change the jets or tape the blower housing up to build more heat.
Keep in mind that the intake valve is cooled by the fresh (overly rich) intake charge as well. On alcohol, this tends to wash away some of the carbon; gas in the 206 seems to build up. You see it on top of the piston and combustion chamber of the head as well.
Couple the overlap with some folks running very tight lash settings (.000") and it doesn't take much run-out on the base circle of the cam to have a valve partially open, inviting more carbon buildup.
-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Keep in mind that the intake valve is cooled by the fresh (overly rich) intake charge as well. On alcohol, this tends to wash away some of the carbon; gas in the 206 seems to build up. You see it on top of the piston and combustion chamber of the head as well.
Couple the overlap with some folks running very tight lash settings (.000") and it doesn't take much run-out on the base circle of the cam to have a valve partially open, inviting more carbon buildup.
-----
Thanks and God bless,Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Jimbo
You can fool some of the people some of the time
Do a cylinder leakage test and you just might find that one or both valves are leaking.
Solving that issue will go a long way to solving the carbon problem and making maximum HP.
Another thing you should be doing is turning the engine over to TDC to close the intake valve while the engine is at rest.
Fuel vapor evaporating in the intake track will not help.
For the best valve and head work call me and i'll explain.
Solving that issue will go a long way to solving the carbon problem and making maximum HP.
Another thing you should be doing is turning the engine over to TDC to close the intake valve while the engine is at rest.
Fuel vapor evaporating in the intake track will not help.
For the best valve and head work call me and i'll explain.