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OK! Yearly update, and boy has it been a big one.
After getting the car running well with the refreshed, I decided to make the run down from Melbourne to Phillip Island for the Phillip Island Classics in March. Feeling satisfied after a great day watching the racing (including seeing Mark's 260c coupe on track, and Heath's 260c wagon in the parking lot) I made to head home, started the car up and noticed the oil pressure warning lighting up. Thinking this was a case of a faulty sender (which I know is an issue on L6s), I continued the drive home and... disaster. About 15km into the journey, pulling out of a roundabout I heard a distinct and very loud knocking noise coming from the bottom end.
Knowing the issue was terminal, I pulled over to the side of the highway and did some damage assessment. My good friend agreed to make two separate return journeys back to Melbourne in his 1200 ute to get myself and my partner home so we could organise a tow the next day. And following an epic slog 12 hours the next day (made especially stressful by the fact the car is almost impossible to load onto a trailer due to the ride height), my partner and I managed to return the stricken car to my shed where it would sit for the next 8 months.
So begins the engine build that I had been wanting to do since I first purchased the car.
The engine came out after a few weeks of planning, and so begun the disassembly and new parts acquisition process. Removing the sump revealed a large amount of metal flakes from road bearings 3 & 4, as well as the front main bearing. There was also a number of chunks of a previous timing guide that had been left well beyond its’ service life and slowly disintegrated.
I took the crank and rods off to Dario at Engine Solutions in Essendon, who from a quick glance could tell they had suffered heat stress and were likely to need significant repairs. I decided then to cannibalise my spare L28, which despite having sat for 25+ years had only done about 120k kms.
The replacement crank and rods were taken off to Duggans in Resevoir, who balanced them with a set of brand new ITM 86.75mm flat top pistons as well as lightening my factory flywheel. The block was left at Engine Solutions, who hot tanked and bored it to match the pistons, decked the front cover and tapped the factory oil galleries.
While this work was being completed, I also acquired a number of additional parts with the view to make this a reliable but fun street engine. I sourced a new L28ET high volume oil pump, as well as factory L28ET head studs. I also had a brand new set of Weber DCOE45 jetted for an L6 sitting on a shelf (I had purchased these second hand but unused several months prior), and wanting to replace the poor quality Redline manifold I imported a period correct FET intake from Japan. This came with the added benefit of having a balance bar, allowing the use of the factory PCV system.
A big focus of this motor was sound, rather than performance - essential for a fun street car. After looking at the exhaust set ups run by some of my favourite sounding cars (such as Toyota 1GGE powered GX61/71 with FGK headers), it became apparent that a good portion of the inline 6 'howl' comes from similar length primaries, very long secondaries that merge to a single pipe near the end of a gearbox. Using my rudimentary welding skills (closer to terrible), I cut up my existing Hi-Tech headers to lengthen the secondaries from 42cm and 33cm to 134cm and 125cm respectively and merged them back into the existing 2.25" collector. I then took the grinder to my ANSA muffler which had proved too quiet for my liking, and removed all of the 40 year old fibreglass stuffing.
I also knew that I wanted to better to keep tabs on the engine with some additional gauges, as the factory 280c dash only features an 'idiot light' for oil pressure. Rather than installing a set of aftermarket gauges, I decided to have a go at making a custom loom to adapt my JDM 430 hardtop tacho dash (from one of my first posts several years back) to the AUDM rectangular dash loom. After a few days of fiddling I managed to hook this up, which drastically improved the interior ‘feeling’ of the car. I also added an innovate LC2 AFR gauge to aid future tuning.
Once the block and rotating assembly came back from their respective shops, I began the long reassembly process, which as a first timer was certainly nerve wracking. However seeing the engine all together on a stand was about as satisfying as it gets.
From here, again with my partner and my friend's help, the engine went back into the car and bolted up nicely. I then spent another long day cleaning up the remaining small tasks and by midnight was ready to turn the key over and... she started! No other feeling like it.
However, the journey wasn't over. Following the start, I noticed there was a decent amount of oil coming from between the rear of the block and the gearbox. With a trip to Japan coming up in a few weeks, and desperately wanting to get the car working prior to this, I made the call to drop the gearbox and replace the rear main seal.
Many days, hours and skinned knuckles passed, and turns out the rear oil gallery plug wasn't tightened enough... rookie mistake. However once the gearbox was back on and sealant had been applied, the leak stopped. Thanks again to my ever suffering partner who sacrificed her weekend to help.
With the leak fixed, the car made the maiden journey back to Melbourne – truly a great feeling. The combination of the Webers, 10.1:1 compression and lightened flywheel make the engine feel incredibly responsive, and the exhaust work makes it howl from 3500rpm and upwards. Better yet, the close gearing, small tyres and 30mm venturis mean the engine is always close to peak torque, so street driving is a real blast.
It’s great to have finally completed a project like this, and I now feel that the car is about as close to my ideal specification as it will get. Long live the L-series!