daryl bane
Titanium
- Joined
- Mar 12, 2002
- Location
- East Texas
I am putting some ductile iron valve seats into a antique cast iron OHV V-twin (not Harley) motorcycle engine. This will never be a high milage bike, more of a hanger queen, but I want to do it correctly. The original seats were integral to the head and not able to be cleaned up. The valve seat counterbores were cut true, flat and concentric to the valves guides. Due to the rather steep odd hemisphere of the combustion chamber, the now oversized seats cannot fit fully flush all the way around the counterbore. My question is whether to:
1) Cut the new seat so that it sits flush in the counterbore at its deepest and then blend the proud/portruding edge to be flush with the chamber. A PITA, but can do it.
2) Cut the seat so that it sits flush to the shallowest part of the counterbore and allow part of the seat to be recessed into the counterbore. And what would be an allowable tolerance depth for the recess?
Seems alot of the valve seat diagrams show a slightly recessed seat. Thanks.
1) Cut the new seat so that it sits flush in the counterbore at its deepest and then blend the proud/portruding edge to be flush with the chamber. A PITA, but can do it.
2) Cut the seat so that it sits flush to the shallowest part of the counterbore and allow part of the seat to be recessed into the counterbore. And what would be an allowable tolerance depth for the recess?
Seems alot of the valve seat diagrams show a slightly recessed seat. Thanks.