Valve lifter bore grinding
 

For you flathead builders, what is the reason for the tops of the lifter bores being ground down a bit?
Is this to make it easier to check the adjustment with adjustable lifters?
I know about drilling of the bores to ease adjustment using a drift, but am wondering about grinding the tops of the bores?
Thanks for the insight
Jim

Re: Valve lifter bore grinding
 

More wrench clearence when using lifter that requires tool to keep it from rotating. Most likely will have to grind down (thin) wrenches to get them to fit if no extra clearence is provided.

Re: Valve lifter bore grinding
 

Cam regrinds result in a smaller base circle. Smaller base circle results in the lifters sitting lower in the bores. This is compensated for with longer valves. Shaving off the tops of the lifter bores improves access for lifter adjustment.

Re: Valve lifter bore grinding
 

All of the above reasons, PLUS, shortening the life of the lifter bore.

Re: Valve lifter bore grinding
 

Thanks everyone. I get it now