Bit more progress to report at long last!
Some of you may know I spent a good while looking for a good VVC head, preferably with good VVC mechs included. this proved futile as I concluded there are none! In the end I used the VVC mechs and cams from a donor head (which itself was scrap), in a head I got which came fitted with a primitive VVC blanking kit and originally ran in a Caterham.
The head was basically good and had only ever had a light skim. valve-train was also good. I dropped it off for porting with TDR motorsport (right by Brands Hatch) who are k-series specialists. Thoroughly nice chaps and did a great job. They basically opened everything up, particularly on the exhaust side (this being forced induction, less concern for exhaust scavenging as with a nasp). A fair bit of meat was left on the valve guide bosses to help heat dissipation.
I then turned my attention to the lifters. They weren't too bad but the cam-lobe surfaces had some scuffs so I planished them with various grades of wet and dry.
Now to the VVC mechs. I had thought to simply transfer the VVC gear from one cam ladder into the other. Unfortunately they needed synching. An hour of reading later and I had it sussed - whilst daunting, it's actually not that difficult and you just have to be patient and careful not to let the mechanisms fall apart while you're handling them!
Now, some of you will have seen my query on head bolts recently. I elected to use the SAIC developed so-called "n-series" gasket. This was quite literally marketed by x-part as the ultimate fix for k-series head gaskets and is comprised of the SAIC developed gasket, grade 10.9 head bolts (with a slightly revised tightening procedure) and the stiffer oil rail.
I procured the gasket and oil rail separately some time ago and then had serious difficulty getting the bolts on their own. In the end, I had procured three sets of bolts from various suppliers all of whom assured me I was getting the uprated bolts and each time I was disappointed - the bolts I had seen actually have 10.9 stamped on the heads and none of mine had that. Eventually I elected to use the set X-part themselves supplied and which came in genuine MG Rover packaging (they had KX-1 stamped into the heads and I believe these to be made by Kamax in Germany - original oe manufacturer of the head bolts). If I'm correct, these are actually grade 9.8 and I'll have less clamping on the gasket than intended - not ideal especially with forced induction but let's see what happens - I'd already wasted too much time and money trying to find the perfect solution and just had to draw a line under it.
I moved it to 90 degress btdc before I fitted the head - which meant refitting and torqueing the dummy head and old bolts so I could turn the crank!
The gasket compressed to 2mm with the head torqued down. I re-measured the volume of the combustion chamber post porting and skim and I should now have a static compression ratio of almost exactly 9:1. which is what I wanted.
Also took care of a few other bits
Oil pump modified with radius'd edges for improved flow and fitted. I actually did this to the old one then decided to just replace it with new. So had to do it all again (only better - of course!). Naturally, I painted it orange! Also fitted water pump. I am as-yet undecided on the orange bolts - you'll not see these ones anyway but I have a whole engine bay kit - If they look gash I'll use normal stainless.
Test fitted Kinugawa Actuator to the turbo - I'm using this because the turbo didn't come with an actuator and this came with a handy adjustable bracket and various combinations of rod. It's from Japan and is a lovely piece of kit which certainly looks well made. They supplied it fitted with a 0.5 bar (7 psi) spring but I also have a 0.8 bar (11.6psi) spring if I need it. I'll be running an electronic boost controller so will decide later which spring I actually use.
Manifold is currently with Zircotec for ceramic coating. Whilst that's happening I shall crack on with the rest of the engine.
Ta ta for now.