This is my first time porting my own motor and i have a question on beveling the edge of the port, I did a bevel on it already but it is very minor, I would like to know how much of a bevel should give it. Also what do you guys do besides a (super steady hand) to straighten out the edges of the port?... as you can see its a bit wavey..



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the steady hand and what i use is a sanding roll on a manderal with my pencil grinder to finish up after using a carbide bur in my die grinder. with a 180 grit roll it will take the high spots off quick and blend any imperfections out with out doin the dig or wave. some shops also wire EDM the ports.



of all the motors i have built , stock remans , turbos motors, street ports , extended porting, 6 port race motors ect ect i have never had a side seal fail , the thing that i do is just take the sharpe edge off with a scotch bright pad wrapped around a manderal in the die grinder. it just puts a very very small radious on the edge and thats it. if i start to see side seal failures i will change that but for now the 70 plus motors that i have out there none came back due to side seal problems.



randy

I roll the closing line over gently with about a .025" radius. Then polish that line to a chrome like finish. In th picture you can see a scratch where the trailing end of the side seal comes aboard the port edge. The leading end stays on the iron, so no problems there. Also a radius at the little end at the bottom so that side seal cannot catch in the port and round the end of the seal or crack it. That happens when the engine is turned over backwards. If you move the open line to get early open then the drooping trailing end becomes a worse problem. This only happens at starting RPM and right at shutdown when the engine is turning very slowly. Assemble a front or rear iron crank and rotor, and ink up the iron around the port. Then scribe the track of the leading and trailing end of the side seal. So long as the leading end stays on the iron the port is still OK.



If you need a straight line, clamp a long lathe tool to the iron along the line you want, and straighten the port with a sanding roll partially against the tool for a perfect line.



Lynn E. Hanover