Hivolt5.0
Senior Member
Here's another article from OleDon.
"In today's world, we read in print and online about guys making huge power numbers on old engines with new technology. Unfortunately, some of the new technology is just above my price range. John Mummert has done wonders with his new aluminum heads, and Ted Eaton has run so many dyno runs, when the two get together, magic happens. I will tell you what some old timers have told me about the old more affordable ways.
A very successful drag racer from Minnesota visited one day and taught me this. Start with a 1/8 ball on a 1/8 shaft, dig a series of 1/8 deep lines in each side of each exhaust port. Near the spark plug, be a little shallow to keep the water on the right side of the iron. Then, make the metal between the lines go away with the bigger 1/4 shaft tools. I use bigger valves on both intake and exhaust. I use 1.94 and 1.6 Chev replacement SS valves with light steel retainers and hard steel keepers on aftermarket springs according to the cam grinders specs. My machinist will grind the seats out and call me to get the heads before he final assembles them. I use the old valves to mark where the new seat is, and pocket port to near that line. Often, there are factory marks in the port where a lot of metal can be removed. The pro head guys use rocket science here, I just make the hole bigger. At the exit of the exhaust, the center of the two center outlets and the far ends of the end ports can be ground away to near the bolt holes. The downside of this is, only one guy makes headers for this type port, and he no longer wishes to do it because of age and health reasons. If you are not afraid of reworking headers, jump in here. These ports have enough meat to end up shaped like a 440 port.
If you look down an intake port, you see the dreaded dog leg. Back to the 1/8 ball on the top dog leg, but go shallow here. If you go into air in the push rod tube, all is not lost. The ID of the push rod tube is the same as the OD of a popular sized tube available at most hardware stores. When you make the metal go away between the 1/8 lines, move to the deep dogleg. I like the cutter shaped like a flame on a six inch long shaft. It will cut nice on both sides of those doglegs. When you are finished, you can see an intake valve that has been hidden around corners for 55 years. It has to make an improvement.
The pictures show the exhaust as cast and opened up. The second picture shows the 1/8 deep lines, and nearly finished. The exhaust can have 1/8 removed all the way around, but be gentle near the spark plug holes. If you opt to make the exhaust opening wider, you wont be using gaskets. I used 12 point SS bolts to about 30 to 35 foot pounds, and they didn't leak in the two years I ran that engine.
If you have questions, feel free to PM or email me any time. An email with Y block in the subject line will always be answered.
"In today's world, we read in print and online about guys making huge power numbers on old engines with new technology. Unfortunately, some of the new technology is just above my price range. John Mummert has done wonders with his new aluminum heads, and Ted Eaton has run so many dyno runs, when the two get together, magic happens. I will tell you what some old timers have told me about the old more affordable ways.
A very successful drag racer from Minnesota visited one day and taught me this. Start with a 1/8 ball on a 1/8 shaft, dig a series of 1/8 deep lines in each side of each exhaust port. Near the spark plug, be a little shallow to keep the water on the right side of the iron. Then, make the metal between the lines go away with the bigger 1/4 shaft tools. I use bigger valves on both intake and exhaust. I use 1.94 and 1.6 Chev replacement SS valves with light steel retainers and hard steel keepers on aftermarket springs according to the cam grinders specs. My machinist will grind the seats out and call me to get the heads before he final assembles them. I use the old valves to mark where the new seat is, and pocket port to near that line. Often, there are factory marks in the port where a lot of metal can be removed. The pro head guys use rocket science here, I just make the hole bigger. At the exit of the exhaust, the center of the two center outlets and the far ends of the end ports can be ground away to near the bolt holes. The downside of this is, only one guy makes headers for this type port, and he no longer wishes to do it because of age and health reasons. If you are not afraid of reworking headers, jump in here. These ports have enough meat to end up shaped like a 440 port.
If you look down an intake port, you see the dreaded dog leg. Back to the 1/8 ball on the top dog leg, but go shallow here. If you go into air in the push rod tube, all is not lost. The ID of the push rod tube is the same as the OD of a popular sized tube available at most hardware stores. When you make the metal go away between the 1/8 lines, move to the deep dogleg. I like the cutter shaped like a flame on a six inch long shaft. It will cut nice on both sides of those doglegs. When you are finished, you can see an intake valve that has been hidden around corners for 55 years. It has to make an improvement.
The pictures show the exhaust as cast and opened up. The second picture shows the 1/8 deep lines, and nearly finished. The exhaust can have 1/8 removed all the way around, but be gentle near the spark plug holes. If you opt to make the exhaust opening wider, you wont be using gaskets. I used 12 point SS bolts to about 30 to 35 foot pounds, and they didn't leak in the two years I ran that engine.
If you have questions, feel free to PM or email me any time. An email with Y block in the subject line will always be answered.
