2007-12-31 07:53:58 · 7 answers · asked by mike e 1 in Cars & Transportation ➔ Motorcycles
Ninky is correct about expansion chambers being important when it comes to making 2 stroke power. However, good 4 stroke mufflers are designed the same way so that when the exhaust pulse is reflected the second time, it helps scavenges out the following exhaust pulse.
You're not going to burn valves though. If the exhaust pulse is reflected back into the exhaust port, it's just going to reduce exhaust scavenging out of the cylinder. The intake charge will be diluted with exhaust (that's what ERG valves on cars do), combustion chamber temperatures will be reduced and power will be reduced as well. ERG valves reduce certain emissions by intentionally doing the exact same thing, contaminating the intake charge, reducing combustion temps which in turn reduced certain combustion by products.
It isn't going to make a bit of difference when it comes to heat on the valve because the ONLY time the exhaust valve is cooled is when it seats on the head for an instant. During that instant, heat in the valve is conducted into the cooler valve seat. The only other way is to to have a super radical camshaft that will let a lot of the cooler intake charge pass through the exhaust, but if you were doing that, you'd get fuel mileage equal to that of a freight train.
2007-12-31 14:33:48 · answer #1 · answered by bikinkawboy 7 · 0⤊ 0⤋
You would be doing something foolish.
2007-12-31 11:31:45 · answer #2 · answered by Jon P 5 · 0⤊ 0⤋
Go ahead and try it.
Then come back and tell us what happen.....I hope you got deep pockets.
2007-12-31 10:57:26 · answer #3 · answered by barry m 5 · 0⤊ 0⤋
It would wreck the motor and the exhaust valves would most probably burn.Each time the exhaust valve opens a high pressure pulse would be sent down the exhaust(Two-Stroke exhausts are designed to reflect this pulse back and throttle the exhaust as part of scavenging for the next cycle).With a Four-Stroke there would be nothing to stop the pressure pulse and heat except for the valve,so it would cook.
2007-12-31 10:41:27 · answer #4 · answered by Ninky Nonk---In The Night Garden 4 · 1⤊ 1⤋
it would turn into a 3-stroke bike. ;)
2007-12-31 08:29:17 · answer #5 · answered by ulri6129 3 · 0⤊ 1⤋
Just about all engines are designed with a certain amount of back pressure in the exhaust system, so if you have the necessary free area of exhaust, then nothing will happen, but if restricted, then burnt valves can result.
As a general rule, don't reduce pipe size, and don't go overboard with extremely large pipes or muffler.
2007-12-31 08:06:18 · answer #6 · answered by Anonymous · 0⤊ 0⤋
It would not run right.
2007-12-31 08:03:37 · answer #7 · answered by Dave 7 · 0⤊ 0⤋