Cutting your own valve seats

For those of you who are interested in cutting or refacing your own valve seats (assuming you can replace the guides yourself). Below are the tools and part numbers you can use. There are other ways to do it and other cutters available from https://www.newaymfg.com/ and you have to take care with Neway cutters and slow way down with lighter pressure to avoid chatter when approaching the finish cut. But they work well.

CUTTING SEATS

Below are some Neway cutters I use. You can use more angles but these are the basics:

Stock and big valve intake 45and 30 deg combo use Neway cutter #645 The 30 deg side will work on the exhaust if the cutters are moved to adjust the diameter.

60 deg stock and big valve intake and exhaust use Neway cutter #205 (move cutters to adjust diameter).

45 deg stock intake and exhaust use Neway cutter #620

45 deg for exhaust only use Neway cutter #608 (or just use cutter #620)

Big valves I refer to are 3mm oversize.

Photo below shows cutters, hand driver and adjustable 5/16" pilot.

Yeah i've wanted to cut my own seats and then did it on a mill because it was all I had. Not on a Norton. I try to do too many things on my own but my experience with seat cutting is its way easier to get them off center as your just dealing a with a few tenthousandths concentricity stem to guide. I watched a friend use a then new tech serdi machine that self located then magnet clamped in position. It's heavy enough you could easily feel a jolt as it locked to the table. I wasn't impressed. I did the lift the valve a little and hold to one side as it drops back to seat test, they weren't any better centered than a good mechanic could do with the tools your showing. I like the T handle to do it by hand as 90 percent of the time I want to see where the cutter first touches compared to where I think it will. On my aircooled 2 valve ducati race bike the bridge between seats heats up and expands down so the seats wear a lot more where they are close to each other. With the neway tools I could lean on it to that side so it seats better hot and less wear longer lasting.

Been using the Neway tools for years and they work well. I also have the tools to clean up the valves if needed. Seat cleanup is a requirement if you install new guides.

Been using these cutters for sometime, though Ii have the 30/45 and 31/46 combo, biggest issue I've found is locating the seat high enough on the valve, the standard procedure described by Neway tends to locate the seat closer to the perimiter of the valve. I prefer turning with finger pressure only for the final cut