skullandbones

received my buret from Amazon today so I did some preliminary measurements on the exhaust runners. I didn't expect to get exactly 70 cc for the volume as the valves are not installed. However, I did have a goal of getting a good baseline measurement for comparison of the like runners on each head. So I "poured" the runners after blocking off the ports and guides. I was pleasantly surprised to find a consistency of within one cc (84 to 85). There is a error factor of +/- 1 cc (had to double error factor due to two pours per runner - only a 50 cc buret). The measurements are acceptable though. Next I miced the roof to floor, wall to wall, diagonals, and any other parameter that I could that was repeatable from runner to runner. It was very consistent except for the one runner at the valve seat where I had "ported" the area for smoothness. I use the word porting loosely. I also poured and miced one exhaust runner on the other head to see if I had a consistent set. It was also similar in measurements to the other runners. I am relieved that the data agrees with the "eye test" which was based on experience but no measurements. I must have gotten a 4th or 5th generation head from what I have read in the machinist forums. Their comments tend to favor heads produced 2012 or later. That is consistent with my findings. Next I will continue copying my work for the other three runners then try to duplicate a master runner on the other head to match this head and copy the others to match.

When I have assembled the heads, I will "pour" them again to see if the volume is close to the design specs. As I mentioned before, I'm more concerned about the intake runner volume. I hope they run a little smaller than the published numbers but will just have to live with it if not (until the next shortblock).

Thanks,

WEK. :cool::cool::cool: