Thread: The 85 Classic

So, it turned out this heavy breathing was a bad thing, but at the time there were other bad things which meant it wasn't really a problem.

The air intake into the turbo was particularly restrictive. Probably equivalent to a 1.5 inch tube squashed into an oval.
So I decided to try and fix it. I cut and gas-welded and smoothed it out a lot. Massive performance difference. I could actually pass trucks now. I was to learn later on just how much was wrong with my engine at this point.

So I blissfully drove the 500km to where I was studying at the time and noticed there were black oil splotches on the back tailgate and the oil was down a little. I drove it around a little and kept an eye on it. I figured it was power related, so I removed and blocked the boost compensator line to give it a little easier life. This didn't do much, turns out the boost compensator was also poked and the crowd who last rebuilt and reset the fuel pump didn't notice.

I had a weekend mountainbiking in an place around 400km away. We cruised down (80km/h was the towing speed back then) and when I got there I found my engine virtually dry. It had pumped 4 litres of oil out the breather in 400km.


Me and the other guys took a bus home, I arranged for someone to come with oil to pickup the rover and take it back to my parents place. Turned out the combination of hosing with rain and rear tyres being oiled by the breather wasn't a good one. On the way back the rover was spun into a bridge, peeling up around 16m of armco barrier. Surprisingly damage was minimal, some panel beating to 3 corners, vulcanise one tyre, replace the spotlights and realign a chassis bracket.
Or so we thought at the time. The rear axle casing was bent to give 4mm toe-in.

So rebuild #3.
This was done quickly and in-frame by me. No time or money to do anything else New rings, same cast iron sleeves and done in a weekend. While it was apart I went hunting for the source of the completely missing compression.
I found the air-cleaner used in the conversion didn't fit the elements inside.
Turbo compressor wheel was also awful from dust erosion. I cleaned up the blades with a file and sand-paper. It helped.

I bought a 100 series landcruiser air-cleaner element and built a cyclonic sheet-metal housing to suit. It was rough, but it worked. For the first time ever I knew it was getting clean air.
I also fitted a boost gauge, this showed I was getting 12psi max. I tested the wastegate on the IHI turbo later on and found it was not even thinking about opening until 20psi. That was never going to happen.

I ran it in by among other things, towing a dead daihatsu truck back from an alpine pass. Slow and boring trip. But I had a heater and stereo, the poor sod steering the truck was in the dark and it was -3C for hours.

For a year or so it was working okay. But fuel consumption wasn't good (8.5km/l) and it kept blowing oil out the back.

In the mean-time I found a replacement turbo compressor wheel and housing. I fitted this myself. Old on the left, new on the right.


Huge improvement. Boost jumpe from 12psi max to 18max and 15 was reachable fairly easy.
Unfortunately this rapid jump in boost was more than my engine with marginal compression could handle. The reused composite head-gasket was leaking oil down one side of the block and water down the other. I was losing even more oil out the breather and it became obvious that a proper rebuild was needed.

So I bit the bullet (kind of) and did another cheap rebuild. Aftermarket pistons, liners (chromard this time), rings and a genuine MLS head-gasket.

The cast-iron liners were left in place and bored to fit the chromard liners. At 5pm friday I had a block with liners back from the machine shop. 5pm saturday I had it started. But all did not go smoothly. A banjo bolt broke, the replacement had the wrong thread and stripped the hole in the front of the timing case. I lost a lot of oil from there. Not enough to cause damage, but the mess is still being cleaned up.

This rebuild lasted 3 years and 27,000km. I hadn't checked the rings. The aftermarket rings were chrome and of tension that was far too high. In 27,000km it had eaten the liners completely. Combined with some worn valve guides I had blue smoke and an engine that would run on it's own oil when under load.
On the final run on this rebuild it drank 2 litres of oil in 200km.
Somewhere around this time I noticed my new replacement compressor wheel (pictured above) was also getting eroded. It was slag from the gas-welded modifications to the intake piping coming loose. Oops. I was able to clean them all out with a flexi-hone.

Time for rebuild #4. This one I got mostly right.
I didn't know about graded liners at the time and the $1600 for a set of four genuine piston/liner/ring kits was beaten by the offer of an incomplete 6BD1T piston/liner kit for a few boxes of beer.

This rebuild was done in-situ over two weekends. In between I took the head to have new valve guides and seals installed and the valves tickled up. I got to everything but the crank main bearings. This time I used genuine Isuzu rings, they are cast iron and run oh-so-nicely in the chromard liners. The tension is greatly reduced.
On fire-up it burnt so clean within seconds that I could see up the exhaust. to the first bend at idle.

This was tested on a 2000km honeymoon adventure and worked perfectly. For the first time ever.
This was the first time I had ever hit 10km/l. The reduced friction of genuine Isuzu rings made that much difference.

I'm liking this even though most is unfortunate events that have happened no offense though...
So where you say cast iron sleeves are you referring to the chromard sleeves found in these motors or an actual cast sleeve that was fitted down in the block which then fitted the other sleeves into it ?
All I can say is wow these motors can stand up to alot of bad conditions...

Sorry you just answered my previous question about sleeves thanks

Fast forward a few years and with the engine mostly sorted, it was time to sort some upgrades. Particularly turbo, brakes and gearing.

I replaced the original solid discs up front with vented ones and fitted defender calipers with 25% bigger pistons at the same time. Having the braking power to throw passengers up against their seat-belts was a great novelty. I recommend this upgrade to everyone who can fit it.



After 6 months research on turbo sizes I picked up a T25 from a Nissan Bluebird CA18DET. I had access to a TIG at the time so I made a complete bolt-on kit in case it didn't work out. New downpipe, adjustable wastegate, the intake piping worked, slotting the holes let the turbo fit my existing turbo manifold and an outlet adapter fabrication let it work okay with the existing cross-over pipe.

Straight up it gave similar spool and more top-end power than the IHI did at the same boost level. I had an interesting time with a few different configurations, including hybridising the same turbo with a T2 exhaust wheel and housing (far too small, but good fun trying). Sadly this turbo died when the oil supply hose came apart on an uphill motorway at full boost. Well technically it didn't die then, it was mortally wounded and died in the same location almost exactly a week later. I refitted the IHI for a while.



The original setup of the MSA-5P box has a low 3rd gear, giving a really good 1-2-3 for offroad work but a stretch to 4th, which given the boost compensator issues I had was causing some big drivability issues. The gear-shift linkage was a work of art, but not of engineering. A shift rod and selector mechanism from another vehicle (rumoured to be austin allegro) was grafted into the top cover of the Isuzu box. It does work but the changing can be a bit sloppy.

I sourced a second hand MSA-5G box, the gear ratios on this match the 5P box except for a slightly higher 3rd gear. At the same time I managed to pickup the old TF727 3 speed auto from a 1983 classic rangie with the 1:1 LT230R still attached. After trying to find a buyer the TF727 went for scrap and the 230R was bolted in.
This dropped crusing rpm at 100km/h from 2,500 to 2000rpm. It saved some fuel but the biggest difference was a huge reduction in noise. I was now getting 10km/l or a shade above on most trips.

To fit the 5G box I had to get a new clutch plate and make a new adapter shaft from the back of the Isuzu box into the LT230. Both input and output splines on the 5G are different to the 5P box. While making this shaft it became obvious there was something missing from the old shaft. It was the oil seal. The adapter shaft made all those years ago from the Isuzu box to the LT230 had no provision for an oil seal at the LT230 input, so they threw it away. Which explained the continual oil dribble.

At this stage I also had the engine, gearbox and transfer out for about 5 months of cleaning, tidying and painting. Injectors were done (3 tips replaced) which made virtually no difference but most importantly I found the boost compensator diaphragm was work out. This prevented the injection pump from delivering more than a non turbos worth of fuel.


New diaphragm on the left, old on the right.

One clean and assembled MSA-5G with LT230R and new adapter shaft in between:


The cleanest this engine bay has ever been. Painted engine, freshly coated manifold with the same T25 as earlier, but with an ebay rebuild kit installed. All ready to go:

The combination of two of these changes turned out to be pretty eventful. Namely the changing of the boost compensator diaphragm (allowing the pump to deliver like it should for the first time in a long time) and installing the rebuilt T25.

The first test-drive was a wet and dark night, I went out my driveway in second gear, changed to third and accelerated around a corner in the way I used to.
It went sideways. I had to try this another 3 or so times just to make sure it was really happening.

Now I'm not sure what level the fuel was actually set at, it was dark and raining so I couldn't see any smoke. But I had to wind the fuel screw in a full 1.5 turns and wind the boost up to 20psi just to keep the EGT gauge below 750C for short bursts.

The progress reports on other parts are pretty good but sprinkled with the usual landrover surprises. The ratios in the 5G box are excellent, but I have a rumble inside which will need stripping for investigation. I got an excellent deal on some 97 discovery axles (rollover) which now reside underneath and greatly reduced the drive-line lash.

I have spent a lot of time generally fixing and repairing. Sorting out wiring (I had a fire at one stage), sorting out the suspension, fixing oil leaks and generally making the vehicle as quiet, smooth and comfortable as it can be.

Externally I want to keep it looking stock. It's staying on 29" wheels for general use which gives me the clearance needed for snow chains and full articulation. It also lets stock axles and diffs survive.

This is the cleanest it's ever been:


This is how far the stock size wheels disappear into the guards when your rear springs allow. Ignore the fronts, they are better now:


Side B


I have a few different sets of wheels, currently running disco 5 spokes for general use. I have a set of rostyle steels which had SAT treads but those tyres are now dead.

Chains:


Towing one of the nissans home when the going got too tough.

Engine bay pics?

Engine/GB CAD pics?

Snow pics?