emdude
Member
Hi All:
Yesterday I replaced the leaking exhaust gasket on my 66 cc China Girl. In looking at the patterns "embossed" into the old gasket it became far clearer than it had been that the exhaust port (big and square) to header pipe (small and round) match is really pretty bad...or non existent. And I don't think the header pipe can be matched to exhaust port with enough meat left to be safe but would gladly stand corrected by anyone that has accomplished this. I think the header pipes internal area is significantly smaller than even the beginning of the exhaust port right at the cylinder exit.
But this leads me to the following question:
Is anyone aware of ANY aftermarket exhaust that takes matching of the exhaust port and header into any consideration. I've looked but didn't find anything definitive so far.
Seems to me this is a real weak point in the overall design. Even the stock mufflers could provide better high rpm performance if this mismatch were eliminated.
Yesterday I replaced the leaking exhaust gasket on my 66 cc China Girl. In looking at the patterns "embossed" into the old gasket it became far clearer than it had been that the exhaust port (big and square) to header pipe (small and round) match is really pretty bad...or non existent. And I don't think the header pipe can be matched to exhaust port with enough meat left to be safe but would gladly stand corrected by anyone that has accomplished this. I think the header pipes internal area is significantly smaller than even the beginning of the exhaust port right at the cylinder exit.
But this leads me to the following question:
Is anyone aware of ANY aftermarket exhaust that takes matching of the exhaust port and header into any consideration. I've looked but didn't find anything definitive so far.
Seems to me this is a real weak point in the overall design. Even the stock mufflers could provide better high rpm performance if this mismatch were eliminated.