Fast Burn, Small Combustion Chamber
I was looking at a 530 head and wondering how to end up with a small CC, shaped and located so that it's mixture would complete the burn more quickly, and be displaced by the piston crown in such a way as to maximize mass flow out of the valve. From what I read a compact CC, designed so that the travel distance of the flame front is significantly reduced, is key to fast burn; and fast burn is key to significantly better performance. In addition, a crown that more fully displaces the volume in the vicinity of the intake valve, corraling the mixture towards the exhaust port, is important to more complete ejection out of the exhaust valve. So, make a piston that's crowned under the intake valve, and if needed, dished under the exhaust valve. But as I looked at the distance from the plug to the farthest extent of the CC under the exhaust valve, it didn't look much different than the distance to a similar point under the intake valve. The CC could be moved and positioned for better ejection, but the propagation distance was essentially unchanged. Would it not take as long to burn the mixture with/without the dome?
If that all makes sense, how can one make a fast burn motor out of a B230? Any way I slice it, I don't see a way to significantly reduce the required combustion propagation distance. Am I missing something?
What else affects combustion propagation speed?
Trying to understand this.
John
I was looking at a 530 head and wondering how to end up with a small CC, shaped and located so that it's mixture would complete the burn more quickly, and be displaced by the piston crown in such a way as to maximize mass flow out of the valve. From what I read a compact CC, designed so that the travel distance of the flame front is significantly reduced, is key to fast burn; and fast burn is key to significantly better performance. In addition, a crown that more fully displaces the volume in the vicinity of the intake valve, corraling the mixture towards the exhaust port, is important to more complete ejection out of the exhaust valve. So, make a piston that's crowned under the intake valve, and if needed, dished under the exhaust valve. But as I looked at the distance from the plug to the farthest extent of the CC under the exhaust valve, it didn't look much different than the distance to a similar point under the intake valve. The CC could be moved and positioned for better ejection, but the propagation distance was essentially unchanged. Would it not take as long to burn the mixture with/without the dome?
If that all makes sense, how can one make a fast burn motor out of a B230? Any way I slice it, I don't see a way to significantly reduce the required combustion propagation distance. Am I missing something?
What else affects combustion propagation speed?
Trying to understand this.
John