High altitude and diesel engine
 

In the Atlas and Hoggar I've experienced problems with black smoke and and less power when I got over 2500m altitude. Now I'm planning a trip to Pamir so I'm a little worried. The fuel-air mix are well set for moderate altitudes, should I change it when I get there? I'm in a TLC HJ-60 (Diesel 6).

Does anyone know about the problem?
Thanks for advices!

I wouldn't bother. This happens with all diesel engines at increasing altitudes. The problem is that you will never get the mixture exactly right. Injection pumps are impossible to set up correctly without specialist equipment and furthermore you may find you will run lean when you get down to "normal" altitudes. This can be potentially harmful for a diesel and is far worse than running rich.

Q

You could tighten down the spring on the turbo's dump gate.
There's a sort of bar between the exhaust side and the inlet side of the turbo, it regulates the turbo pressure by bypassing the exhaust turbine. Boosting turbo pressure at sea level will push hotter, but more air into the cylinder. At altitude, because the air is thinner, you'll simply bring the engine back to nominal.

Paint a mark where the nut is at the moment, so that you can reset it easily for the descent.
cheers
Luke

Hi Tripitaka
I took my Land Rover Discovery TDi300 across Tibet last year. Me and my mates were driving at over 15,000ft for ten days, and peaked out at an amazing 17,800ft.
The cars all made nasty smoke, and some were difficult to start from standstill under load, (ie up an embankment).
But once running I was barely aware of the reduced power. Just the other bloke’s smoke…
Use of gears obviously helped, keep the engine revs up above 2,000rpm and you should have no problem.
All best

------------------
Kitmax - Traveller
www.kitmax.com

There's no turbo on an H60

Andy

TLC H60
landy 101 ambie
1968 morris minor traveller
www.plymouth-dakar.com

Howzit

We vcurrently live at 1800m in Nairobi - bit of black smoke taking off and at low revs, but we were in the Aberdares last month (3100m) and although there was alot of black smoke there was only a loss in acceleration rather than overall power.

Howzit

We vcurrently live at 1800m in Nairobi - bit of black smoke taking off and at low revs, but we were in the Aberdares last month (3100m) and although there was alot of black smoke there was only a loss in acceleration rather than overall power.

[QUOTE]Originally posted by moggy 1968:
[B]There's no turbo on an H60

Oh Poo! :-(

You could always try installing a turbo; that would get more air into the cylinders.

In this day and age I find it difficult to imagine a diesel engine without a turbo, except on a dumper.

Thank you for the enlightenment
Happy trails
Luke

[quote]Originally posted by Luke:
[B]

I see we have a similar opinion of Solihull's Leyland years production.
(he says, carefully trying specifying in an attempt to avoid the flamings)

Good job someone invented synthetic oil, now they'll do two school runs http://www.horizonsunlimited.com/ubb/wink.gif

LOL

Some HJ60s have what is called an altitude compensator- its a round thing located on the rear of the pump. By turning that one way or another it is supposed to make a difference in how much fuel is given to the engine. Check out Ih8mud.com they have tons of info about LCs

John

Nice one, thanks for the tip

Andy

I have an 80 series Land Cruiser with the altitude compensator and it seemed to work well on a trip through N Africa last year, sept-nov. No really noticeable loss of power - No increase in black smoke which is usually a product of poor diesel quality, too much sulphur etc. Unusual addition to the car as it is a '93 car, Japanese import, with separate switch for centre diff lock, another for front and rear...excellent vehicle



------------------
pigapitcha

No HAC on landcrusier = Engine damage at altitude?
 

We are in Delhi and about to drive around Kashmir where passes reach 5475m high. Some last minute research has found my UK 1989 HJ60 Landcruiser does not have a high altitude compensator (HAC) on the 2H injection pump governer.

People have mentioned black smoke blowing at altitude, but not high exhaust gas temperatures (EGT) which i read can apparently damage and even melt the aluminium pistons!

I really want to drive the Manali-Leh highway, but really really don't want to wreck the engine. We are carrying a lot of weight and it is a long route. I dont have a pyrometer to measure EGT either.

- Is it enough to install a new airfilter, gear down and back off the accelerator?
- Should i try to manually adjust the fuel? but based on what, altitude / smoke?

Any information or experiences would be much appreciated,

Cheers, Andrew

P.S. for current Manali>Leh highway status:
Manali-Leh road « high road to..

Melted Pistons?
 

OK I maybe talking complete junk here but I would assume smoke equals un burnt fuel. Pouring diesel in to the cylinders and NOT burning it will actually have a cooling affect.

A non turbo diesel will be more robust / safe in this scenario when compared to a turbo engine.

We’ve been up to 3000m+, six adults, trailer and pretty heavily laden in our normally aspirated G Wagen (6 cylinder, 3litre). Lots of smoke (not as much as a turbo diesel) and no ill effects.

If you are concerned I would get an EGT fitted though. Or rig up something by using a multimeter with a thermocouple attachment to measure exhaust temp. by placing the probe on to the exhaust mainifold.

IMHO smoke in these conditions is of no consequence though.

Oh and I would definitely steer well clear of messing with the pump and fueling, definitely asking for trouble.

Moodoo - lucky you!

I think the 1990 80 series we did Manali-Leh in did have a HAC, although it seemed to smoke a bit and wasn't very fast at that altitude. But it's academic, for you wouldn't want to go fast anyway - both for safety and scenery reasons.

My advice - go slowly and enjoy the stupendous views.

Mark

overlandcruiser.net

I'm sorry, your advice is incorrect.
Diesels run leaner than stoichiometric; petrol motors always richer than stoichiometric. Stoichiometric is defined as just enough fuel for the air to burn completely.
A diesel, when overfueled, can develop very high EGTs. A petrol motor can develop high EGTs when underfueled.
So running at high altitude can cause high EGTs and damage an engine. This can be mitigated by installing a turbo to supply more air but not turning the fuel up..
All underfuelling a diesel causes is low power output.

Charlie

I'm sorry, you too are wrong. Extra unburned fuel tries to keep burning after the exhaust valve opens, leading to very high EGT and burned exhaust valves. Plus, overfueled diesels tend to melt pistons.
An unmodified naturally aspirated diesel at very high altitude might not burn valves and pistons, but on the other hand it might. Overfueled engines at sea level certainly do.
If a person were to take up residence at high altitude de-tuning the pump will lead to decreased fuel consumption and decreased EGTs, relative to leaving it alone.
Toyota's system on some of their diesels of an anaeroid ("DAC") and a throttle body to measure air flow should adequately compensate automatically for altitude.

Charlie

Not completely wrong:-)
 

Well I was absolutely correct in one of my statements, I was talking complete junk. Just goes to show you shouldn’t believe a thing you read on the internet.:stupid:

I subsequently did some research and you are correct. There you go you learn something ne everyday:clap:

I guess it’s less of an issue with electronically controlled pumps. Certainly our VW TDi measures atmospheric pressure and manifold pressure.


Cheers,
Russ

Interesting that rich = hotter EGT with aspirated diesels. So what advice are we giving our friend in the 60 heading for the high passes? Should he manually adjust his injection pump (can't recall if that is possible) or just take it easy?

Ch

My advice would be to leave the injection pump alone and just drop down a gear (and revs too). If you are comfortable playing with IP settings then maybe a different story. I am no pump fitter, but I can do some basics - but I would just take it easy and enjoy the scenery at a sedate pace than start messing around... especially on a vehicle with no EGT. At the end of the day as Charlie points out leaning the fuel will do no harm - but you have to be sure you are leaning! Toyotas (well the rotary Denso pumps AFAIK) generally for example you turn clockwise to increase fuel which is sort of against what you would expect! Even n/a stock vehicles can approach excessive EGT on long hills, but if you are aware and drive accordingly (or even better run a pyrometer) then you should be fine. If you boot it on long hills in 4th/5th with a trail of smoke then.... well alloy pistons will melt, heads will crack etc. If you are lucky you MIGHT see an increase in coolant temp - however (again for example) Toyos have a notorious dead spot in the factory gauge, and EGTs can rise very, very quickly.

Injection pumps can and are set up all the time with nothing more than a pyro gauge and watching for smoke... Black smoke indicates overfuelling - not sulpher. (my car runs on diesel with more than 100 times acceptable sulpher by EU standards and doesn't smoke at all). The overfuel can be due to worn injectors or the pump being worn - usually both together!

I run a boost gauge, a decent quality pyrometer as well as a digital coolant gauge - having played only a bit with my 1HZ, I like to have an idea what is going on down there! But on a stock vehicle I would just be careful and I am sure no problems will arise.

Hey guys just wanted to comment here as I have some experience overlanding and driving at altitude in an old diesel 60. My truck is a 1981 BJ60 (same truck but with a 4 cyl 3B engine instead of the 6 cyl 2H) with no HAC and I have taken it above 13,000 feet WITHOUT a turbo, and above 17,000 feet WITH one.

I will second the ih8mud.com link above. The diesel cruiser community on that site is what has kept my cruiser alive all this time, and where I've learned anything I know about them.

If you are thinking of driving above 10,000 feet for any length of time or for serious overlanding, I would definitely suggest getting a turbo installed. The 2H engine will take well to it, and there are plenty of resources available (ih8mud.com) for information on doing it. Make sure you do it right though... a crappy turbo install can leave you bleeding oil in the wrong places or worse, as happened to me eventually. A good turbo install set up for nothing more than altitude compensation should not adversely affect the reliability of the cruiser, and of course will increase longevity of the engine if you are driving at altitude a lot or with heavy loads.

***The black smoke is bad, yes it does mean high EGT's. The cruiser can handle a litle bit of it, but the advice I've always followed is "if you see the black smoke, let off the pedal until you don't see it anymore".***

Also not true IMO. A turbo forces more air mass into the engine block, which has a cooling effect. Adding a turbo will keep your engine's EGTs cooler in all conditions. However if you DO have a turbo and you are seeing black smoke, it is true that this is slightly more serious as you obviously have a problem with your turbo.


A poor man's safety net if you don't have the money for the turbo would simply be to install an EGT gauge so you can make sure you're not burning up and know exactly when to back off on the pedal. This should cost you about $120 US, and the install is as easy as drilling a hole. If you are planning on turbo'ing down the road, you will still want this gauge so its a win-win addition really.

I would suggest adding a turbo. Although mine blew up in the end due to a poor install and welding decision on my part, I would not have been able to enjoy the high altitude deserts in Bolivia without it, and that is something I would not have wanted to miss out on. Your engine will be more powerful and happier, and WAY more powerful and happier at altitude.

Oh, and be kind to your cruiser... don't do the 500,000km oil change thing. Cruisers are meant to be maintained forever, not driven into the ground for 500,000km's. :nono:

Manali > Leh > Srinigar, hopefuly no damage . . .
 

Thanks all for the advice, much appreciated. It was a great route to take and in my opinion well worth any risk.

We ended up driving very slowly for all of it, a lot of the time second gear / 1250rpm / 18kph, and never over 40kph the whole time. The scenery is so spectacular that it wasn't as frustrating as you would expect. Over 5000m the engine sounded so rough that I really didn't want to push it anyhow. The local drivers were amused though. Judging by the amount of black smoke they were kicking out they really don't care about high EGTs :)

A turbo would be nice, and what a great justification to get one! However cost-wise for now I'll probably go with fitting a pyrometer...

Cheers,

Andrew

We've done that stretch also with our BJ45. It has the 3B [4 cylinders] engine. Just keeping it slow and steady, we were able to drive that road without problems. Even the road to the Nubra valley. The so called "highest motorable road in the world" wasn't a problem. You can play with the accelerator a little bit and see where the car still feels ok and the black smoke is the least.

We are now on our way again to Bolivia. Same story; altitude. But other conditions make it worse here; head winds, washboard gravel and small dunes. You want to speed up to comfortably take on the washboards, but you can't. And slowing down gets you stuck in the small dunes In comparison this makes the Leh - Manali road easy...

Yeah you should probably get a turbo. The engine is designed to handle it... you are really pushing it and taking a risk even with your foot barely touching the pedal IMO. At the least you should do the pyrometer and I've found it also helps to widen/shorten the exhaust.

Then again you know what they say... go big or go home! Don't forget to air down on those washboards if you have a compressor to air back up again afterwards...:thumbup1:

These things are designed to run stock without any problems.. I don't see why you should install a turbo? We are not in a hurry, and the engine is not stressing at all... What's next; leather heated seats?

There's a reason they started shipping them with pretty much the exact same engines, only turbo'd just a few years later (3b=13bt, 2h=12ht). I don't think they were ever designed to run stock above 10,000 feet, let alone 15,000 feet. The HAC would have helped prevent damage, but only by limiting power...? Simply the naturally aspirated diesel engine just isn't meant to do that, and asking it to is asking for trouble... it's choking and starving... the fact that the components CAN handle the stress maybe is not the best guiding factor.

Sure, it can handle it... just like it can handle 500,000km oil changes, pulling far too much weight, being driven badly with almost no oil, being constantly overheated... etc., . I personally wouldn't do it if I had a choice though... My cruiser takes care of me because I take care of her.