Originally Posted by
mugenb46
Yes the down stroke and fuel transfer is being done in this proces, but also, high speed fuel transfer is accuring as the case is being charged before the up stroke to TDC, at BDC the port is always open, as the up stroke starts, fuel that is traped under the piston is then releived through the port and charged into the cylender before the transfers and boost close, as the stroke down starts, the port reopens through the transfers and then the releife port.= a charge system thats efficiant and allows the largest boost of fuel and air possible.
Not sure we are talking about the same thing. I'm wondering about the four holes below the exhaust port in the attached picture. They aren't transfer ports or boost ports. I actually wouldn't call them ports at all, because they don't go through into the cylinder.
They may be totally meaningless, but I'm just curious because I've never seen them before on any engine. Thank you for your help.
Scott