SBM Edelbrock/Speedmaster Head Data
Here is a picture of a page out of the “Secrets of a 740 HP Winston Cup Engine” by Don Terrell.
He says the top cut on the valve reduces reversion but all of my testing said that valve job on the valve makes reverse flow better.
Smokey Yunik says he did it to shape the flow cone around the valve. I tried that to clean up the dip around .250 lift. It didn’t.
Just something else to look at and consider. I also saw he listed some seat cutters in the book and listed one 55 seat.
I’ve never used that cutter. But it’s very possible that if you used his cutter for a 55 degree seat and a top cut valve it may work.
I know on the 50 and 55 I use the top cut was a reverse flow helper.
Edit: sorry for the sideways picture. I can’t figure out how to rotate it. Maybe @toolmanmike can fix it for me. If he has the time.
Here is a picture of a page out of the “Secrets of a 740 HP Winston Cup Engine” by Don Terrell.
He says the top cut on the valve reduces reversion but all of my testing said that valve job on the valve makes reverse flow better.
Smokey Yunik says he did it to shape the flow cone around the valve. I tried that to clean up the dip around .250 lift. It didn’t.
Just something else to look at and consider. I also saw he listed some seat cutters in the book and listed one 55 seat.
I’ve never used that cutter. But it’s very possible that if you used his cutter for a 55 degree seat and a top cut valve it may work.
I know on the 50 and 55 I use the top cut was a reverse flow helper.
Edit: sorry for the sideways picture. I can’t figure out how to rotate it. Maybe @toolmanmike can fix it for me. If he has the time.