how much did you skim that head Richie? Or has it been welded?
It’s welded and skimmed. That work had already been done in Japan when I bought it. It’s the classic Japanese-style welded big port head format, as commonly used over there for 300hp+ 3.1L and up engines. Skim is around 2mm. Chambers, as shown in the photos, were left rough, although the race size 46/38 seats had been installed already.
The chamber I’ve worked on will be left as is without too much additional enlargement or finishing work until my burette and stand arrive so that I can accurately cc it. The others will be matched and then all mirror polished. The intake seats need more cutting work though- the extra welded material around the sides interfered with the cutter and the top 30deg cut is missing currently. The place that did the work also felt that the intake valves were too big for the seats although I know this to be incorrect - they are definitely the big seats for those 46mm valves. I think it was just a more aggressive setup than they were used to dealing with. Thus, I’m going to get a “second opinion” and have the three angle cut completed elsewhere, which should be easier with the finished chambers and unshrouded valves.
Once done, I can begin mock up and look at lash pad size etc. Still need a new valve spring retainer to replace the one missing from my NISMO set though.