Turbo upgrade / modification 200tdi

[landroversforever]

I wonder if Bowie69's question could be answered by determining what bottom end wear is like in most lumps at 200K miles of normal use?

I'd be interested to see what Ralph's 110 is like with the galactic mileage his has

[Nigelw]

I'd be interested to see what Ralph's 110 is like with the galactic mileage his has

I help out in a garage quite often on my middle of the week day off, few weeks back we had a Range Rover TDV8 in for a blown head gasket, three new pistons later along with new HG all back on the road, never expected to have one in bits personally but when we took the rods out to replace pistons they were over tollerance! This was on a dealer serviced car with 145,000 kilometers so 90,000 ish miles, in the book the owner had the 700euro bill for the remap @ 60,000 kms, Erik and I both think the remap hold direct resposibility for the early expiration of the engine, not even a full 100,000 kms on the remap! Direct comparisson to the 2.7 Range Rover Sport that had 410,000 kms on it and on std map, pistons still good, bottom end very much border line but within limits, that was also in for HG and owner asked to have crank checked after hearing a horror story of a snapped crank shaft.

Pays your money an takes your chances an all that

All said and done it's a hobby motor and not his daily so most likely it'll be minimal miles and road work will be easy going by the sounds of it?

I replaced my turbo in the summer an after much talking with different people, I followed the advice of folk who were not looking to sell me something and had mechanical sympathy and knowledge, put very simply to me "it's not a Range Rover Sport so stop expecting it to transform into one, and if you want vastly improved performance, start with a better engine and take everything from the filler neck to the tarmac into account", it is a given that I still don't fully comprehend the advice but I understood enough to buy a standard fully reconditioned turbo and be done with it. Perv(Ash) has a different vehicle and different expectations of it so, I look forward to seeing where this goes.

[TSD]

2.8 Powerstroke uses the same size mains and big ends as the 300tdi, despite being bored and stroked and having a VNT.

They are quite probably the same in the 3L common rail version too, but I have no direct evidence.

Would love to get my hands on one to find out...

[Bowie69]

Would you know if the bearings are the same spec? Could you fit them to the 300/200tdi?

Is the oil pump upgraded on the TGV compared to the 300tdi?

[TSD]

Don't know, sorry. They don't have LR part numbers, but I think that can be because parts were modified, or simply were locally sourced.

Maybe M&D could tell you, though for the shells, how would you know if the dimensions were all the same?

[Aragorn]

I know they're completely different engines, and every engine is different, but many car TDI (and turbo petrols tbh) engines are tuned with huge increases in torque over their design spec, and bearings very rarely appear on the "things to watch" list. Sure they might wear faster, but the whole engine will wear faster producing 200hp than it will producing 120.

On a 200/300TDI I'd be more worried about the cylinder head gasket and bolts, (and perhaps conrods, but the 200/300 is probably old enough that those are still way over-engineered). Modern engines typically use MLS head gaskets which are a lot more robust than the fibre type used on these older engines, especially when dealing with big cylinder pressures. Modern stuff also tend to have their rods designed down as small as possible, and as such they're usually the first part that needs upgraded when really cranking up the wick.

I suspect, without looking and confirming, that the bearings in a 200/300tdi are already larger than the bearings in something like a VAG PD130 or BMW M47, which both make way more power and torque as standard and can be tuned to in excess of 350lbft without touching the bottom end.

[Bowie69]

Yeah, my point is that at 1200rpm (just above idle), the oil pressure is likely to be significantly lower than at 1800rpm, so damage to shells could be possible if the oil pressure is low enough that the increase in torque (and relative increase down the conrod) would be enough to smash the bearings about (over time).

Add in potentially extra boost and the situation is made worse -more boost at lower RPM, with lower oil pressure?

Just a theory, from first principles.

[landroversforever]

Is there any way of changing the ratio of the oil pump? Get it spinning earlier?

[Bowie69]

I'd say not, given it is driven in the same way as the dizzy on a petrol 2.25.

[landroversforever]

Sorry to be a pain, but where is it driven from? I've not had a tdi in bits!

[Bowie69]

From the camshaft

[vulcan bomber]

200 oil pump is driven off the cam shaft via the skew gear under the Vac pump.

300 is off the nose of the crank and is an utterly carp design.

Both engines run with the same oil pressures.

Its ok worrying about oil into the main bearings but what about turbo oil pressure.

[GW8IZR]

Suppose if you wanted, dry sump and electric pump is an option?

[landroversforever]

Could you do it with just a dry sump pump? Electric clutch on it so it turns off, and have it sucking from the standard sump?

[GW8IZR]

I'm no expert but I think that would be chucking the baby out with the bath water, you'd lose the advantages of oil at all tilty angles etc.

[landroversforever]

That's a fair point, with the effort of getting a pump on there you might as well go the whole hog.

[miketomcat]

Not to point out the obvious but none of this is what ash wants to know believe me he's well aware of the needs of the engine.

Mike

[lo-fi]

Why on earth is this going off on a tangent with dry sumping?! And for the record, if set up correctly, dry sump is better for extreme angles.

Instead of wild, uninformed speculation, let's maybe look up the 200 and 300 engines oil pressure specs to compare. I'm sure the oil pressure spec for the turbo will be available too.

As for fussing about the big ends, I'll try and rake out my copy of Allen Allard's book on turbocharging. There's a good section on cylinder pressures, con rods and bearings. TL;DR: you're worrying about nothing.

[GW8IZR]

Well it was a question that was raised as part of a discussion, it's a pity if that's unacceptable

[lo-fi]

It's not that it's unacceptable, it's just ridiculous. In the same fashion that people jump in and throw a curve ball like dry sumping in, somebody needs to step up and say "hey, wait a minute, just look up some specs before making an issue out of a problem that doesn't exist".

Just trying to keep it sane, factual and on the straight and narrow, that's all.

Look at it this way: VNT conversion kits exist for the 200tdi. You'd expect that those producing the kits have done the research and engineering to ensure that it will work correctly within specifications and won't ruin the engine it's installed on. To make sure, and so as not to rely on taking someone else's word for it, do your own by looking up some figures and studying what's been done successfully before jumping in at the deep end elsewhere.

[Bowie69]

Sheesh I only asked a question.

A good one, I thought too.

[GW8IZR]

Sheesh I only asked a question.

A good one, I thought too.

Same here but I think its just easier to let it go ;-)

[Bowie69]

Yep, think you are probably right...

[Daan]

Ok, chaps, first of all a merry Christmas and prosperous new year.

I will give my 2p worth: For a start, I think your gearing is a bit tall, I would suggest 4.1 ratios. The fuel pin knowledge/bs discussion I completely thrown out of the window by replacing the adjuster for a longer bolt (m8 fine thread) and wind it in completely to jam it closed. This has simplified the fuel injection strategy so to speak; it now only depends on throttle position and RPM. This has improved the pick up enormously. I have done a bit of bottleneck removal in the inter cooler and intake manifold (see my build thread).

The turbo pressure i kept standard, and is 15 psi (it is a 300 tdi). This makes it discovery automatic standard, but still within manufacturers spec. Max fuel is kept standard, so the top end power is standard. I hate black smoke, and it doesn't have any with normal use. You can get a hint of smoke if you drop to 1000 rpm in fifth, but that is just pushing it for the sake of it.

I cant blow you over with big figures, but it really goes well. I dont think more power is desirable basically. Also, running the viscous fan with the correct cowling is important. A vnt is meant to work well, but I would start with getting the ratios right. But anyway, what do I know about diesel engines?

You think you can post a piccy of your intercooler?

Daan

[Aragorn]

The problem with "disabling" the adjuster as you've done, is the pump cant compensate for boost properly.

I'm not sure if your adjustments have left it in the "full boost" or "minimum boost" position, but when properly tuned for power (ie raised boost, lots of fuel etc), without that pin there doing its thing, it would be blowing massive clouds of black smoke everywhere when it was off boost. If you back the fuelling off to fix the off-boost smoke, you dont then have enough fuel to properly use all the air the turbos adding to the engine. Disabling the pin, can only have negatives in my mind. Some early VW TDI's came from the factory with a pin that was completely parallel. Swapping the pin out for a proper tapered one as is fitted to the 300tdi transforms how those VW TDI's drive, and is a common mod.

From your description, i suspect your change has left it in "full boost" position, but the stock tune (max fuel etc) is mild enough that your not getting much smoke when off boost, but have had a big increase to off boost fuelling (as the pump thinks its on boost) and as such much more power in the low part of the rev range. That change can be acheived with the pump working as it should however, via the various adjustments, while also increasing top end power. Unfortunately your approach wouldnt work if you wanted a decent hike in power.

I guess how much power you require is personal preference. As an example, my road car (a BMW 330d) is geared MUCH longer than a defender, it sits at about 1800rpm on the motorway at 70mph. But it manages that because it has lots of power, and makes over 350lbft at 1800rpm. The less power you have the longer the gearing needs to be to provide sufficient torque at the wheels to maintain acceptable performance. My brothers 320d runs at 2100rpm at 70mph. Smaller engine makes less power and torque, so they've shortened the gears to compensate. Your advocating shorter gearing and less power. To my mind, i'd FAR prefer lots of power and longer gearing. Driving the 330d and 320d back to back theres no question. The 3.0 is just better. Even just driving around town and not exploiting anywhere near maximum performance, the fact it can pull the gears easier makes it a much more relaxing drive, your not shifting around as much keeping the engine in the power band..

My isuzu was intolerably slow, so i wound things up and now its better. It sits at 3250rpm on the motorway at 70 though, which does my head in. You can barely hold a conversation. It'd be a FAR nicer place to be if it was running at 2000rpm and had the power to make that comfortable.