racebunnie

Burning up plugs after two races.....any suggestions?

Her engine is nothing too special as the class we run in does not allow many modifications to the engine. She has a 12A carb. engine with '85 manifold. We have used cheap and top of the line plugs but she is eating them up after a race weekend.

specRX7_22

what plugs are you running? Hotter plugs will burn hot, but run the motor cooler. IF you are running hot plugs with too lean of a mixture, the plugs will burn so hot they will actually burn themselves up. SRX7 has almost the same rules as what you are describing (stock motor, carb, etc). what fuel pressure are you running? and how is your timing set?

tims

try running an 11 heat range plug of choice and timing no more than 24*. good to check egt or AF ratio.

specRX7_22

no more than 24º lead and 16º trail.... even that burns up motors. BUT........ we be racin'

tims

with proper engine tuning 24* should be fine and not damage the engine. running a colder range of plug will help.

specRX7_22

the combination of 24/16 timing and 1.5 - 2 pound of fuel pressure, and running hot.... burns up motors after about 2-3 seasons.

racebunnie

Thank you everyone. I going to try your sugestions for my next race.

tims

this is not what I would call a properly tuned engine.

specRX7_22

maybe not, but thats what SRX7 drivers with years of experience, dyno time, and experimentation call it.

tims

I see this is a bit of a jab at someone else then? be careful with so called experts(me included) and verify the "hot setup" on your own. good luck with your engine "tuning".

specRX7_22

ok, this isnt getting anywhere and i really dont wanna fight but.... isnt it a known fact these engines make the most power running hot and lean? assuming stock ports, manny, carb.

tims

sorry, not in my experience. but if you can afford the tear downs and it is working keep doing it.

specRX7_22

well thats what i meant by "we be racin".... it will drastically decrease the life of the motor to the point where it will only last 2 seasons. but its all the price you pay to be competetive with the top drivers.