It has been far too long since I last updated this, apologies for that. I've been working on various sub-sections of the build - lots of wiring harness repair, getting the lights in order. I've also started painting various structural components (such axles) and am close to having a rolling chassis. Other small sub-assemblies have also been worked on. In real-time however, I am doing engine work, so I thought I'd bring the thread up to date on that as it has mostly been transmission and drivetrain stuff so far.
So, as a refresh, the vehicle has its original factory engine, a 3Bii. Sifting through the 3Bii threads on MUD, I see a lot of confusion and misinformation about them, probably because they were never sold in North America as far as I know, and were only used in BJ60s, 70s, 73s and 75s from 08/1988 to 12/1989 - 17 months. They did however go on to be used in Coaster buses for ten more years, so there are plenty of them out there. I have very limited experience driving 3Bs; but that, and the testimony I can find online from people who have drive both 3Bs suggest that the 3Bii has much more low end power and pick-up. It felt like I remember an HJ60 to drive, though without that slow straight 6 purr.
Regardless, it's an indirect injection diesel (so unsuited to turbocharging in my opinion) and has the inherent weakness of pre-combustion chambers, so I would prefer to replace it with something with direct injection and a turbocharger. I initially wanted to drop in a 15B-FT but legal constraints where I live mean I can only run with an engine which was originally sold in the model - so besides the 3B, a 2H, 12H-T, 2F or 3F - none of which I want.
So here it is, hosed down. 567,000 kms, original engine.
Obvious differences from a 3Bi - flat top 1HZ/1HD/1PZ style valve cover, no pushrod inspection window cover (the later B engines such as this use roller lifters and have pairs of bolts, visible in the picture to act as detents. Remove the bolts and the lifters drop out of the engine), and a 10 bolt exhaust manifold.
Obvious differences from a 3B - gear driven vacuum pump (below the injection pump). All 3Biis have rotary pumps, but some 3Bs also had the rotary pump, so that is not a distinguishing factor.
With intake manifold and injection pump removed, a very stout block casting is revealed. I believe the 3Bii block is significantly stronger than a 3B, though I have not had them side by side. You can see '3B' cast up behind the injection lines. Look to the right and you see a machined area - that's where they machine off '14B' from the block when they decide whether to make a block casting a 3B or a 14B. That gives me an idea... Now it could be that the subsequent machining of the 3B and 14B blocks makes them into truly different items, but I have a sneaking suspicion that it doesn't.
I bought a 3Bii engine gasket kit which comes with a head gasket, 11115-58081 (t=1.50 mm; the only size officially available for the 3B, though you can use thicker gaskets from the 4B). I then ordered a 14B* head gasket, 11115-58070.
Above is the 3Bii (and 4B) gasket, below is the 14B* gasket. Aside from the obvious contours (barely visible on this phone picture I'm afraid) on the 3Bii gasket to go around the pre-combustion chambers, they look functionally identical.
As an aside, the 14B* gasket has a softer finish and looks to be a better quality item. It is made from 5 stainless steel sheets, while the 3Bii gasket is made from only 3 (whilst being the same thickness of 1.50 mm). Also, the bulb-shaped opening on the right of the gasket where an oil orifice sits next to a head bolt gets a rubber O-ring on the 14B* gasket, while on the 3Bii it is a pressed ridge).
Stack the gaskets (here 14B* on top of 3Bii) and it's clear that the bolt hole, oil and coolant gallery pattern is identical.
Well, that is interesting...
EO