Me and bad habits!

[TijmenvdS]

I must say that after experiencing the 4.8 even though it is extremely comfortable, it just does not have the pulling power uphill that a turbo diesel has and I don't think I will trade my diesel for a petrol any time soon.
We have had the discussion in the past about the noise of the engine especially at idle but during our Botswana trip I had no difficulty getting really really close to animals. The V8 cruiser on the other hand upset the elephants quite a bit in Savuti but not my TD42. 1 wire engine for the win even though it is probably the most expensive of the bunch.

[davidvdm]

Always wondered what it would take to shoe horn a TD42T into the Sani Darn engine compartment is 6 inches too short, and you know what it's like when you don't have 6 inches

Nice one Pieter, I am totally jealous, I just love a whining big turbo diesel. Have you started looking to make space for nice 3" or 4" straight pipe under the Troll, you know you must

[hugejp]

I must say that after experiencing the 4.8 even though it is extremely comfortable, it just does not have the pulling power uphill that a turbo diesel has and I don't think I will trade my diesel for a petrol any time soon.
We have had the discussion in the past about the noise of the engine especially at idle but during our Botswana trip I had no difficulty getting really really close to animals. The V8 cruiser on the other hand upset the elephants quite a bit in Savuti but not my TD42. 1 wire engine for the win even though it is probably the most expensive of the bunch.

Daai 4.8 kort 'n hairdryer...

[ChristoSlang]

Peter, at least a 4.2 conversion means ripping out most of the electric bits, so no worries about ECU, dizzy, plugs, etc. any more! It seems that the adding of additional electrical bits tend to make many other engine changes a challenge. Will Michael be using the standard pistons instead of upping them to the stronger ones with oil squirters?

Any way - I'm sure you'll end up with much the same "vooma" for less fuel money. Michael sorted Chuck out late last year with a full rebuild, and my fuel consumption decreased by about 2 l/100kms. You're in good hands at SoJo

[Peter Connan]

Christo, the engine already has the strong Silvertop pistons. I have looksed at them, and they are still in beautiful condition. In fact, even the ring gaps are still within spec.

It has piston squirters fitted too.

The electric simplification was indeed one of the primary reasons I decided on the TD42, instead of fuel injecting the TB45 (which was the other option). Also the fording thing...

[Peter Connan]

Well, a fair amount of water has run under a fair number of bridges...

The current situation is that the car is currently running. But tomorrow poor Michael is sacrificing a holiday to help me replace the clutch, as the clutch is slipping. It felt fine on the engine before we stripped it out of the donor car, but the turbo just generates too much torque for it. There are only 3 other small issues: firstly, the Madman and the factory oil pressure sender doesn't seem to work well together. This will be fixed by fitting a second dedicated oil pressure sender for the madman. Secondly the heater hoses are second-hand and one is a make-do. These will be replaced. And lastly, there is a gap between the outlet of the turbo and the exhaust pipe that still needs to be filled...

Also, the interior is a bit stripped-out at the moment. As part of the process I replaced the gearbox, and to do that I had to take out the front seas, the center console and gear lever surround and the front carpet. Before I put the carpet back, I need to strip out some of the excess wiring added by previous owners and previous alarm installers. I also need to replace the hand brake cable, but this has actually been necessary for a while now. Just waiting for the new one, as there was no stock in SA.

Other than the madman's oil pressure, all the other instruments are working.

[Peter Connan]

The actual conversion process to convert from the TB42 to the TD42 is actually quite simple.

According to the manual, the TB42 and TD42 Y60's use the same gear and diff ratios. I replaced the gearbox on mine because, on a trip to Botswana in 2012, the gearbox got some water in, and I only discovered this about 25k km later. This resulted in the loss of synchromesh on 5th gear and a bearing rumble, and lately it has started slipping out of 3rd gear under compression when the gearbox is hot.

The bell-housing for the TD42 is slightly different to that of the TB42, in the area where the starter bolts on. The casting is the same, but the bolting pattern is different and the "nose" of the starter is larger, thus some new holes need to be drilled and tapped and some relieving needs to be done.

Other than that, a normally-aspirated TD42 would drop straight in mechanically. The engine mounts are interchangeable and in exactly the same place, the clutches appear to be the same. We did have to modify the bracket on the fuel pump that the accelerator cable attaches to, but the TB42's cable is just long enough to fit.

Conversion-10.jpg (317.23 KiB) Viewed 40326 times

The air conditioner is mounted in the same place, and it is not necessary to replace or modify the piping. However, the power steering pump and alternator need to reverse places.

Fortunately we had the alternator, power steering pump and power steering piping from the donor car, which all fits on the same chassis. So we just un-bolted the power steering piping from the steering box and bolted in the replacement. The vacuum piping is of course different and had to be replaced, as did the alternator wiring.

As for the rest of the engine wiring, this seemed quite simple (although an expert always makes things seem simple, and I left that part to Ant). The oil pressure sender is in the same place, and they are the same unit too, so it just plugged in. We cut the control wire from the TB's starter and fitted it to the "new" starter. The water temp sender is also the same, and we just needed to extend the wire a bit. The wire powering the solenoid on the carb was adapted to power the solenoid on the fuel pump, as they do the same job in the same way. Ant just needed to replace the plugs. The rev counter needed a special box of tricks to make it work, but I don't really know how much effort it was to install this.

Also, we had to install a glow plug circuit. We did this the easy way: a non-latching switch was mounted in the dash (where the choke cable used to be). This powers Cole Hersee solenoid mounted on the firewall. Both circuits are of course appropriately fused.

Oh, and if I had kept the engine normally aspirated, the exhaust manifolds are interchangeable...

The radiator is also different, with the piping reversed. However, my radiator was shot anyway, and needed to be replaced. The cowl and fan are the same though. We fitted a custom Aluminium radiator from Universal Coolers. The workmanship is beautiful, and time will tell how well it works. The water piping is generally much simpler. On the TB, there are water piping connections for the "oil cooler", the intake manifold and the heater. The TD only has the heater, and the piping is much more accessible.

[Peter Connan]

The hardest part was installing the turbo and intercooler. Tinus got me a great deal on an HT18 turbo and it's exhaust manifold (the standard Nissan units found on the last TD42 GU pickups). This was refurbished (all it needed was a new set of seals) and I polished the inlet and exhaust manifolds.

The intercooler is also from Universal Coolers. We took off the grill, removed the brace from the bonnet catch downward, fabricated new brackets and drilled two big holes through the body just above the body mount brackets. The intercooler brackets also brace the bonnet catch.

Conversion-3.jpg (210.64 KiB) Viewed 40550 times

Conversion-4.jpg (206.85 KiB) Viewed 40550 times

Conversion-5.jpg (205.67 KiB) Viewed 40550 times

Conversion-6.jpg (206.12 KiB) Viewed 40550 times

Conversion-7.jpg (246.18 KiB) Viewed 40550 times

I got lucky and got a set of intercooler pipes from Tommie for a good price, and I just needed to modify one of the pipes a little bit. I then also needed to find a new place to mount the hooters and ambient temp sender unit, but that was pretty easy.

Of course, a turbo diesel should have an EGT monitor, so we installed a Madman and Ant set it up to also monitor water level, oil temp, water temp and oil pressure (although as already mentioned, that is still a bit of work in progress). We also fitted a boost gauge, as I understand that getting the best economy on these motors depends on driving to minimize the boost and EGT.

[Peter Connan]

A little bit about the reasons and fiancial implications involved:

Some history to start off with:
The original TB42 suffered a cracked cylinder head at about 280k km. I firmly believe that was due to repeated over-heating, mostly before I owned the car. After buying it I soon realized that it had not seen anti-freeze for a long time, and the viscous was shot. I replaced the viscous fan with a dual electric setup, but that was not effective. I then returned to original with a new viscous and fan. That was better but the engine still got hot easily and by then the damage had been done.

However, on a forum dyno day my car produced an inspiring 60kW on the wheels, so there was obviously something else wrong as well.

At the time, it was cheaper to buy a running TB45 than to repair the TB42. The engine I got had belonged to Allan van Schoor, who had removed it for Frans to put in an LS V8. This engine had had a stage 2 conversion by Van der Linde, and who knows what else. I believe it had about 200-250k km on it when I got it. Because I am allergic to fancy electronics on overland vehicles, I retro-fitted the carb and distributor from the TB42. But because the fuel-injected TB45 does not have the infrastructure for the mechanical fuel pump I had to go for an electric pump. This proved to be quite tricky. The fuel pump set-up went through three or four iterations and I actually damaged the engine before I got it properly sorted. On Hennops trial the pump over-powered the needle and seat on a steep uphill (because of the angle the float closed with less pressure than normal) and flooded number 6 cylinder to the point where it bent the con-rod due to hydraulic lock.

On the forum trip to Botswana in 2018, the engine ran big-end bearings, and had to be re-built. We believe the reason was that an incorrect o-ring had been fitted between the block and the front cover, but I don't really know. However, the re-build did not fully cure the oil pressure issue. I am not sure why, as everything measured within spec, but on steep uphills or when hot, it would lose oil pressure. Also, the tuning was obviously not right and getting worse. Several visits to "experts" failed to diagnose the problem, but for the year between the re-build and the decision to replace, I averaged 3.8km/l.

So the decision was based on three options:
1) Repair the engine again, and live with the consumption (expected cost: R16k)
2) Repair the engine again and convert to fuel injection, living with the risk that brings (expected cost: R32k. Expected fuel consumption: 5km/l. Expected payback period: 2 years.)
3) Convert to diesel. The expected cost for this was between R50k (normally aspirated and with Murphy distracted) and R90k (turbo-charged and with Murphy paying attention). The trick is that despite the much higher cost and due to the better economy (at least 7km/l on the road), the payback period (especially when making use of BioDiesel) would be pretty similar to the fuel-injection option. But I knew I would never be satisfied with a normally aspirated TD42. I am not that patient.

So with a similar payback period, why did I still go for the diesel?
1) Have I mentioned that I hate retro-fitted computer management engines? I have personally done two in sports cars. Both let me down multiple times, and I have seen others failing as well. I believe a large part of the problem lies with the bad quality electrical connectors we get sold after-market, but on an overlander that sometimes has to wade deep water, this feels like a huge risk to me.
2) The fuel range. At 3.8km/l, I have a range of under 800km, and it's difficult to add enough jerry cans to get me to 1000. But at 7km/l, I can reach 1400!
3) Even my non-electronic TB45 would die in any ford deeper than about 500mm. The TD42 will keep going until I drown the snorkel. Don't get me wrong, I hate deep fords, but I feel one should be able to do at least 800mm.

The project has predictably run somewhat over budget, but not enough to make a huge difference to the payback period. Of course, only time will tell whether the decision was the correct one.

[mvcoller]

OK, so I now see why you went that route.

What would the financials have looked like if you sold your bus and bought an original Y61 TD42 and fitted a turbo to it instead? You would then also have had a later model vehicle....