SM Head Modifications on a budget
I prepared the valves for the testing this morning. See the pictures below for the redneck back angle riga-ma-jig. This jig took 30 minutes to make and is plenty rigid enough and accurate enough for grinding back angles. It is NOT suitable for grinding seat angles. Each valve took about 1 minute to grind a 30 degree back angle. I tried to get the back angle and the 45 degree seat angle the same width. Each angle came out about 0.070" wide.
As can be seen, the jig consists of 2x4's, conduit clamps and woodworking clamps. The pneumatic die grinder and grinding stone are from Harbor Freight. It's nice to have a drill press like in the pictures because of the rigidity and the ability to move the valve up and down easily. Similar results could be achieved with a hand drill or an electric die grinder. Instead of the stone, a carbide burr or cartridge roll could be used. The important thing is rigidity and maintaining a fairly consistent angle between the valve and the cutting tool.
I prepared the valves for the testing this morning. See the pictures below for the redneck back angle riga-ma-jig. This jig took 30 minutes to make and is plenty rigid enough and accurate enough for grinding back angles. It is NOT suitable for grinding seat angles. Each valve took about 1 minute to grind a 30 degree back angle. I tried to get the back angle and the 45 degree seat angle the same width. Each angle came out about 0.070" wide.
As can be seen, the jig consists of 2x4's, conduit clamps and woodworking clamps. The pneumatic die grinder and grinding stone are from Harbor Freight. It's nice to have a drill press like in the pictures because of the rigidity and the ability to move the valve up and down easily. Similar results could be achieved with a hand drill or an electric die grinder. Instead of the stone, a carbide burr or cartridge roll could be used. The important thing is rigidity and maintaining a fairly consistent angle between the valve and the cutting tool.