Long time and no updates ;( Sorry for that.
The summer has been quite busy with work, holiday and other priorities, but sume things have happened to the oxy-ghia also, and I will attempt to wrap ut the status here.
I was not too happy about how the engine ran, and I had some issues with some injectors that died on me, and once that was handeled, it still seemed like I had some vacuum leaks. A little fiddling with gaskets and making sure the manifolds did not interfere with the cooling tin, and then that was also sorted.
Still I had popping and banging issues, and since I drive the car daily, I started also to moitor the fuel coinsumption. Not that I am overly concerned, but I figured that this may give me some hints as to whether there are some serious problems. The first couple of tanks showed consumption in the 13 mpg range, so something was clearly not right.
After verifying that there were no leaks, I adjusted the valves and I suddenly had a new car
Popping and banging disaapeared, and the engine ran very smooth. Also the mpg improved, and for the last couple of tanks I have been in the 26-27 mpg range. Which I find acceptable given my heavy right foot
Here's a plot of the consumption over time the last few weeks:
The little dip in early september is due to a long trip on a motorway at 70 mph and 8-10 pulls on a dyno; More on that in a minute
All in all the engine is beatuiful; pulls strongly at lower revs and also has a good bite at higher revs whenever I feel for it
I spent some evenings tuning, and I sstill run Alpha-N as I had scheduled a dyno session, and did not want to start from scratch on the tuning, but the plan is to try out speed density again as I think the driveability can be further inproved still.
In preparation for the dyno test, I also 3D-printed a set of quite long velocity stacks to see if there was a measurable difference between those and the filters I was using:
After some fine tuning of my MAPs it was time for dyno testing, and this was quite intimidating to watch (and hear):
It is quite loud at 6500 rpm inside a smallish garage