Speedmaster heads revisited.
Ok guys I won’t be answering many questions today as this head will be totally roughed in so I gotta keep at it. The throat dimension is 1.815 from Speedmaster. My target is 89-90% of valve size so with a 2.02 valve target would be 1.818 so we are good to go. That’s one reason I love going with a 2.055 valve so I can cut the angles on my seat machine. With a 2.02 seat I use my Neway cutters and hand cut my 70-60-45-30-15 on the intake side. I don’t calculate port sizing as I go by airspeed on my bench. But for the numbers guys stock sizing at the pinch is .922 wide by 2.150 high and the pinch is over 1/2 inch because the port continues to move into the port as you port over to the tubes I installed. After just porting over to the tube without touching the common wall yet it measures 1.015 so I gained .093 width so far at “the pinch”. If you look closely you can see where I kissed the tube to know that’s all I can get.
Ok guys I won’t be answering many questions today as this head will be totally roughed in so I gotta keep at it. The throat dimension is 1.815 from Speedmaster. My target is 89-90% of valve size so with a 2.02 valve target would be 1.818 so we are good to go. That’s one reason I love going with a 2.055 valve so I can cut the angles on my seat machine. With a 2.02 seat I use my Neway cutters and hand cut my 70-60-45-30-15 on the intake side. I don’t calculate port sizing as I go by airspeed on my bench. But for the numbers guys stock sizing at the pinch is .922 wide by 2.150 high and the pinch is over 1/2 inch because the port continues to move into the port as you port over to the tubes I installed. After just porting over to the tube without touching the common wall yet it measures 1.015 so I gained .093 width so far at “the pinch”. If you look closely you can see where I kissed the tube to know that’s all I can get.