hi, I just noticed that there is a mismatch between the header and engine on my new mvvs 160 gas engine(I guess it is the same case for the glow version of this engine). the exhaust port on the engine is basically larger than the entrance in the tuned pipe header. I suspect this will not give the best gas flow so I wonder if dremelling away a little metal on the intake of the header(chamfering the edges all around) would give measurable improvements on rpm and power. As things is now I see rom for improvement or is there any sensible cause for this mismatch?? I did post this very same question in the gas engine forum, but no replys so far there, so thats why I also place my question here on the glow forum as I think this is more active.

Hi!
It doesn't matter ! Leave it as it is!

Regards!
Jan K
Airracing Products
Swedish MVVS distributor.

dremel away as you like. There is plenty material to make it just perfect. Having said that, I do not think there will be much, if any difference in power. The pressure drop when the port opens just is so large, that the gas will be presed through it, and the port channel shape hardly influences the cylinder discharge. That is why tuners do not turn much attention to the channel shape, but more like to heed the port shape which influences gas discharge big-time.