OST-034: Noir Crowning

[oldeskewltoy]

oldeskewltoy Wrote:There is one REALLY, and I mean REALLY odd ball bit........ the 3 intake valve seats have NO semblance of an even 3 angle...

http://ost.ebeans.ch/albums/userpics/100...ffset2.jpg


I'll been inquiring with a few people as to the best way to address this....

One thing is certain - the factory put a lot more effort in to making the bowls and seats as smooth a transition as the factory could do... the bowl machining marks you see are not by me... those are all factory machining

I've spoken with a few people concerning the oddly shaped seats, Although oddly shaped, the back cut will aid filling, and so it should remain.... and it shall





I begin on #4, since the bowls already merge pretty well with the seats, my biggest task is a to "build" a short radius, to minimize the intake guides, and guide bosses, and to gently straighten port/bowl mismatches.



#4 is on the left... you can also see where I've done some mild blending, in the chamber, of the factory machining marks.




And to the exhaust on #4(left).... I seem to remember the info "out there" saying the Blacktop had 35mm exhaust port outlets.... I measured these, they come in around 33.6 ish mm.



The ported one is about 33.75mm..... besides the re-taper, I've also "rebuilt" the shape of the guide bosses to minimize their effect on flow past them. I've also added a minor radius to the exhaust guides to further minimize flow disturbances

The view from the chambers...




With #4 mostly finished(right)... #3 has been cleaned, and #2(left) is still a bit "carbon coated". As I did with the SR20 head, I'll be doing with this one. I'll be mounting this on the flowbench a bit later this week so that I can test the 3 chambers/sets of ports all on the same day, and under the same conditions. This will allow me to quantify the port work.


more to come.....