Understanding Detonation
Mar 26, 2004 | 08:52 PM
#1
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Range Rover
when your holding the football - people will throw evrything they can at you to strip it away .... including the waterboy at the end of the bench.
when your holding the football - people will throw evrything they can at you to strip it away .... including the waterboy at the end of the bench.
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Mar 27, 2004 | 12:21 AM
#3
Extreme Pro Rider
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Understanding Detonation
I like this description of "squish". I know this is what Pami does to their engines.
It is important to realize the two important functions of reducing the squish band clearance: (a) to enhance turbulence due to rapid ingestion of gas into the combustion chamber, hence increasing the burning rate of the mixture and (b) to reduce the volume of the unburned gas in the boundary layer of cool gas near the piston top and cylinder head surfaces. Typically, gas trapped in the squish area doesn't burn, even if the squish band clearance is relatively large. The cooling effects of the large surface-area-to-volume ratio of this region will prevent any ignition of the fuel-air mix therein, even if the squish band clearance is rather large. Hence any gas caught in the squish band will not be burned near TDC when it does the most good, but later during the combustion process when one cannot extract as much work from the late-burning gases. The amount of gas trapped in the squish band can actually be a substantially greater amount than just the relative volume of the squish band because the pressure wave from the ignition process literally crams a lot of the unburned gas into crevice areas like the squish band. Reducing the squish band clearance will decrease the amount of unburned gas substantially, leading to more complete and faster combustion, lower emissions and improved power. It is one of the few "all gain with no pain" modifications one can carry out on racing or even street motorcycles.
It is important to realize the two important functions of reducing the squish band clearance: (a) to enhance turbulence due to rapid ingestion of gas into the combustion chamber, hence increasing the burning rate of the mixture and (b) to reduce the volume of the unburned gas in the boundary layer of cool gas near the piston top and cylinder head surfaces. Typically, gas trapped in the squish area doesn't burn, even if the squish band clearance is relatively large. The cooling effects of the large surface-area-to-volume ratio of this region will prevent any ignition of the fuel-air mix therein, even if the squish band clearance is rather large. Hence any gas caught in the squish band will not be burned near TDC when it does the most good, but later during the combustion process when one cannot extract as much work from the late-burning gases. The amount of gas trapped in the squish band can actually be a substantially greater amount than just the relative volume of the squish band because the pressure wave from the ignition process literally crams a lot of the unburned gas into crevice areas like the squish band. Reducing the squish band clearance will decrease the amount of unburned gas substantially, leading to more complete and faster combustion, lower emissions and improved power. It is one of the few "all gain with no pain" modifications one can carry out on racing or even street motorcycles.
Mar 27, 2004 | 12:45 AM
#4
Pro Rider - Oldham Racing
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BUILDS THE FASTEST DS's ON THE PLANET!
Want a hot DS, or maybe one of the fastest DS's on the planet? This is the man to contact!
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Understanding Detonation
The three main engine killers are:
1. Improper machining
2. Improper assembly
3. Detonation
Sometimes you can get away with one of these, at least for a little while, but if any two are ever mixed you have a grenade on your hands.
Something else to consider is the fact that the more horsepower your engine makes the quicker one of these problem can rear it's ugly head. A high horsepower engine MUST be machined right with correct tolerances, MUST be assembled right, and MUST be tuned right if it's going to last any time at all.
MrHorsepower
1. Improper machining
2. Improper assembly
3. Detonation
Sometimes you can get away with one of these, at least for a little while, but if any two are ever mixed you have a grenade on your hands.
Something else to consider is the fact that the more horsepower your engine makes the quicker one of these problem can rear it's ugly head. A high horsepower engine MUST be machined right with correct tolerances, MUST be assembled right, and MUST be tuned right if it's going to last any time at all.
MrHorsepower
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