What is case porting??? and other porting questions

Porting

Case porting is performed to match the bottom of the cylinders with the top of the case. If the cylinders are opened up a bunch, often the ports are larger than the area in the top of the case where they meet. In therory, when the fuel charge moves from the bottom end up into the transfer ports and the cylinder ports are larger than the case you will get a area of negative pressure where the two parts meet. Matching them elimnates that. Also it eliminates a restriction in the transfer path kind of like water runnig from a 1inch pipe into a 2 inch. Another argument would be that that area left intact would cause turbulance which helps atomize the fuel but I think the loss of flow restriction will make up for that by increasing the flow velocity and putting a bigger charge in the cylinder. Also most case porting smothes out other sharp edges that again can affect flow as well as slightly increasing over all case volumn. Usually attention is paid to the oiler holes too. Again this is done to aid in cutting down restriction of oil/fuel to the bearings. Case volumn isn't going to change that much so I wouldn't be afraid of doing it.
Cut a base gasket to match the cylinder ports and then use that as a template for the case. Careful not to take too much off the sides, if you do you will have a hard time keeping base gaskets from blowing out.

I have heard there isn't much "extra" to gain from these 700's. You might find a little to play with on a case porting mission, but I'm not sure you will feel it when you are done.

As per discussions with several well known porting experts, case porting will not gain a lot of HP (perhaps 2), it will however help with bottom end power delivery, especially with twin pipes, if you get say Carls to do it they will also send you a base gasket that is cut out to match the cylinders and cases so you don't have to fool around port matching the gasket.

thought you were going turbo if so you wont see any gains from porting