Well with some real progress being made in the exterior part of the project my attention turned to what was (or wasn't) happening under the bonnet! The 260z was released with the 2.6 Lt inline 6 cyl motor, which for all intents was a seriously strong motor. After enquiring with those who had done an engine rebuild it was decided to to find an L28 block from the
Later 280Zx couple that with an N42 head and use that as the basis for rebuild. We decided to go with the flat top pistons to up the compression, sports cam (which kicks in at around 3000rpm) blueprinted and balanced & new valves etc. I thought that this was probably the most opportune time to replace the tired but faithful 3 speed Auto with a 5 speed manual, which I think enhances the driving experience. My son's initial fervor to join the ranks of Zed ownership saw him purchase a 77 260Z 2+2 from North Qld to use as a donor vehicle for our projects, his generosity supplied the 5 speed box for the conversion. I was able to purchase a clutch and brake pedal from ebay and source the clutch slave and master cylinder from Autopro but had to bring in from the U.S the short flexible line that goes from the hard line of the master cylinder to the slave at the gearbox.
Just before everything was ready to go with the engine build I blew a head gasket in the original L26 which put the Zed off the road earlier than planned. It wasn't long before we got it the guys who generously helped me with the rebuild and began the process of out with the old and in with the new! While the old motor was out I did my best to get in and degrease and clean up most of what was left as well as paint around the engine bay which made the new motor look the part! It was about this time that I thought about fuel delivery. I already had a few sets of 240z SU carbs and a set of duel webbers that I bought from the U.s for this rebuild however after doing some research I narrowed it down to either EFI or triple carbs. Both of these systems are expensive and both have their unique benefits. As crunch time come to organise which direction I was taking I found a set of triple mikuni carbs in the States which after a little haggling I purchased landed in Australia for $1030.00 which is pretty good buying considering they were mikuni 44's.
It has taken quite a bit of time to get this setup right (which I haven't quite achieved yet!) with trial jetting of the carbs and having to redo some of the engine work which wasn't done correctly I feel that I am probably still only running the motor at about 80% of its capabilty. I have also had to purchase a new OEM manifold, new throttle linkages and BIG K&N filters to give the Miki's the best chance they have to breathe. One of the things I found was that after driving the vehicle for a while and then turning it off it was hard to start and when it did it was a little rough until the car was at normal operating speed and temp, I found that what was happening was that the heat from the extractors was percolating the fuel in the bowl casing all sorts of hiccups for the tuning. I then with the help of Mayhem from the Z club (who gave me a nice piece of Aluminum sheeting) made a heat shield for the extractors which I have found is sufficient to block the heat from the carbs.
