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@Jung
Started work on the porting. I’m trying to throw a few tricks at this one, specifically altering the transfer port walls and b port roof to get them more in the modern school (I.e streams colliding with each other in front of the boost port rather than squirting up the back of the cylinder.)
So far, it’s been bloody fiddly - the castings don’t support wild mods without going through to the head bolt counterbores, or breaking through to clean air outside. I’ve been doing some extremely careful plunging with end miles to rough out the shape, then will clean up and finalize with the hand piece.
For anyone super geeky, the exhaust has been widened close to 70% of bore, not really raised at all. The transfers and boost port will be raised 2mm, reducing the blowdown degrees a bit but giving more transfer time area. The boost port gets widened significantly, and the back wall machined back to a 60 degree angle to fire at the plug….porting always seems to take bloody ages and is nerve wracking.
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