I got the heads back togheter for the shovelhead today. I didn't think to take any pictures before I started, but I took care of some valve shrouding that was going on since the valves are sunk in deep to make TDC clearance with the cylinders shaved down as far as they are. While I had everthing apart I back-cut the valves, in the pictures up above you can see the cut valve on the left and how it started out on the right, you end up with a valve that has a nicer shape that'll flow alot better with just enough seat material to let it run for a long time with no problems. I'm gonna put the bottom end togheter tomorrow and if everything goes to plan I should have it ridable within the next couple days.
2 comments:
Did you use a toolpost grinder or a cutter to cut the back relief in those valves? Have wanted to do it in the past to open up valve-to-valve clearance but haven't tried it.
Thanks.
As far as the actual back-cutting of the valves goes I just did that on the lathe, I did that to improve flow a little bit. The valve to valve and valve to piston clearances came from sinking the valve seats themselves about .070" deeper into the head, when they're deeper they're further apart from each other and further from the piston on TDC, all the work I just did was in the pursuit of a better flowing head. I had the clearance for the cam I was running all along, I was just looking for a little deeper of a breath.
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