OST-034: Noir Crowning

[oldeskewltoy]

Nearly a 2 week delay...

I had a talk with my client, he is hoping for an exhaust to intake flow ratio approaching 80%. This is going to be extraordinarily difficult because the stock Blacktop flows about 61%, and the first attempt at porting the exhaust side did improve things, now 67%, but a further gain of 13% seems a long goal at best.

My first attempt at porting the exhaust was limited because I didn't have a gasket to know where my edges were, and I didn't want to port beyond the gasket, for doing that would cause serious flow issues. So the initial porting on #4 exhaust was from about 33.6 to about 33.7, because not knowing the exhaust gasket left me a bit in the dark.

My client sent me the OEM gasket



Port on far right is #4, even with the gasket in the "down" position, there is still some room available in the port roof, and room all the way around the port.

So now that I had a gasket, work begins on #2 exhaust port. Redline is the gaskets edge.






A bit more dramatic....





The stock Blacktop gasket outlet is 36mm. Port #2 is now out to 34.8mm





Later this week I'll get this on the bench and see what if any improvement there is over the first numbers.


More to come........