Wonder if this has ever been trued on a W engine?
- Thread starter Mr Goodwrench
- Start date
I almost tried something similar, although it wouldn't have been as elegant and well engineered as the way Kasse did it.
Apparently, if you can increase the length of the port in the area between the short turn and the valve seat, the port will flow a lot more air.
If you look at the two pipes in the pictures below, the 90 degree pipe actually flows more than the 45 degree pipe. (flowing left to right) The straight extension on the 90 degree is what allows it to flow more. Take away the extension and of course the 45 degree pipe flows more.
They also say that making the port longer past the short turn allows the air to flow all the way around the valve rather than just skipping over the back of the valve. Apparently, this makes the valve flow better and require less lift.
Here's a mold of a Pro Stock port, you can see that it has a pretty long waterfall area after the turn...
If you were to shorten that length, like shown in this picture with the bottom of the port erased, it would flow a lot less.
Here's a picture of a stock Edelbrock 409 head with some penciled in modifications.
Raising the intake side of the port, Z11 style, certainly helps the flow but I think adding some length to the valve end of the port might be even more effective.
If I ever got ambitious enough to modify another set of heads, I would love to try adding a plate to the bottom of the head.
I would also sink the valve. They say that helps guide the flow past the valve. It would reduce or eliminate the need for valve notches in the piston.
Apparently, if you can increase the length of the port in the area between the short turn and the valve seat, the port will flow a lot more air.
If you look at the two pipes in the pictures below, the 90 degree pipe actually flows more than the 45 degree pipe. (flowing left to right) The straight extension on the 90 degree is what allows it to flow more. Take away the extension and of course the 45 degree pipe flows more.
They also say that making the port longer past the short turn allows the air to flow all the way around the valve rather than just skipping over the back of the valve. Apparently, this makes the valve flow better and require less lift.
Here's a mold of a Pro Stock port, you can see that it has a pretty long waterfall area after the turn...
If you were to shorten that length, like shown in this picture with the bottom of the port erased, it would flow a lot less.
Here's a picture of a stock Edelbrock 409 head with some penciled in modifications.
Raising the intake side of the port, Z11 style, certainly helps the flow but I think adding some length to the valve end of the port might be even more effective.
If I ever got ambitious enough to modify another set of heads, I would love to try adding a plate to the bottom of the head.
I would also sink the valve. They say that helps guide the flow past the valve. It would reduce or eliminate the need for valve notches in the piston.
Mr Goodwrench
Well Known Member
I remember you doing some amazing work on those heads Jim, fascinating stuff! Definitely picks the men from the boys anyone can buy a block, heads and a rotating assembly and screw it together but you people that design, fabricate parts to make a 60 year old engine make that kind of power are geniuses