If an intake valve sticks open on my engine (509 w/ Weiand 8-71) what is the possibility that the gas/air mixture will ignite in the blower? I've seen this happen on the NHRA drag racing and was just wondering (worrying). Thank you in advance for your input.

Odds of it sticking open are not that great (slim to none). That said I have to address the advantage of the poppet vale in the internal combustion engine. Yes the poppet valve shrouds the port until it lifts off the seat approximately 2/3rds of it's diameter. And yes the poppet valve is right smack dab in the middle of the port obstructing flow. But the good news is the poppet valve is self sealing.

The more pressure in the combustion chamber the harder it seals to the seat. Of course that plus starts to go out the window when you start to run a lot of boost. The boost pressure is now trying to force the poppet valve off it's seat with the only force holding it closed is the spring and the compressed air in the cylinder. Depending upon how much boost you are running (at two or three atmospheres), you could over power the spring before the cylinder pressure has a chance to build and blow the intake valve off it's seat.


Larger Dave