Contacts needed (maybe)

Dennis by what you say over-fueling sounds about right but its not from having the pump tickled a tad its from bad fuel with too much octane mainly from ethanol mixed into bio diesel .

Same thing killed my old mans 1HD-FT in his 80 over-fueling caused too much pressure causing part of the piston to melt between the rings which caused the rings to break and cut a nice key way up and down the cylinder wall on no 2 .

I cant see how having the pump slightly advanced/tickled to ad a bit more fuel would cause this sort of problem as it would just make it blow black smoke more frequent if the extra fuel wasent burnt off in the combustion process just like keeping the boot in when climbing a hill in 2nd insted of just feeding it the right amount of boot .

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Originally Posted by lokka

Dennis by what you say over-fueling sounds about right but its not from having the pump tickled a tad its from bad fuel with too much octane mainly from ethanol mixed into bio diesel .

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And I am sure you base this on solid evidence and many hours of laboratory testing??? :angel:


EDIT:
(Adding ethanol (or methanol) to diesel LOWERS the adiabatic flame temperature). Biodiesel and bio blends will not have any significant quantity of unreacted ethanol or methanol, since it is expensive compared to oil feedstocks.

Fuel with high octane won't ignite in a compression-ignition diesel.

But a few litres of 91 octane got me through last winter on a tank of summer diesel.:angel:

I didn't think it was ethanol that was in bio diesel. And to nit-pick, isn't it cetane not octane for diesel?

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Originally Posted by isuzutoo-eh

I didn't think it was ethanol that was in bio diesel. And to nit-pick, isn't it cetane not octane for diesel?

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Ethanol or Methanol can be used during the transesterification process of biodiesel production. However it will react more or less completely with the oil feedstock.

Yes, high cetane rating is what you want for diesel fuel. High octane fuel won't burn well as Dougal said.


Anyway - back to Dinty's thread. Sounds feasible that there may have been an overfuelling or overheating issue either recently, or sometime in the past. This is a case where a turbo would have helped - as EGTs would have been lower with a turbo. Towing a heavy load up a hill with the foot flat to the floor will see high EGTs.

Even if you aren't fitting a turbo, it would be a very good idea to fit an EGT to the rebuilt engine, as it will allow you to see what is going on, and prevent this kind of thing in the future.

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Originally Posted by isuzurover

And I am sure you base this on solid evidence and many hours of laboratory testing??? :angel:


EDIT:
(Adding ethanol (or methanol) to diesel LOWERS the adiabatic flame temperature). Biodiesel and bio blends will not have any significant quantity of unreacted ethanol or methanol, since it is expensive compared to oil feedstocks.

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Ok so im Wrong looks like the info we were feed when asking why the one piston melted a bit and caused the greif to my old mans truck was all smoke and mirrors .

Tho we do know that after filling his 80 with diesel from a wollies servo up on the north cost of NSW the 80 ran rough and and had a few coughs and farts then ran with a miss that got worse till we pulled it out and found the probs

So the whole octane story we were told is incorect tho what ever was in that last batch of diesel killed the tojo and it sounds verry similar to denis's prob

The only way to melt a diesel piston is very high EGT. If it was just one cylinder then maybe a localised injector problem. But the injection pump will still only give the same fuel to each cylinder.

Did it lose boost?

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Originally Posted by Dougal

The only way to melt a diesel piston is very high EGT. If it was just one cylinder then maybe a localised injector problem. But the injection pump will still only give the same fuel to each cylinder.

Did it lose boost?

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Dougal im not sure if it lost boost at all but it still ran well enough with the miss to get it the near 700k trip home .

Were the pistom melted was in between the 2 ring lands and the rings had broken into a few bits and some had turned over on the lands and this is what caused the nice key way effect .

Sorry for the hijack dennis ;)

G'day All,
Well the news is, that the engine has been assembled and is in the engine bay.
What I need to know now, does anyone here have a part number for the throttle cable to suit Isuzu 4BD1 as fitted to a 1984 model??, also my Oil pressure switch has a minor leak, it is the type with the 2 wires coming out of it. I did see another thread re oil pres/switch, but not sure whether persons concerned got the parts they were after, I did a google search and found some suppliers but you had to order 500 switches LOL anyway cheers Dennis:angel:

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Originally Posted by Dinty

does anyone here have a part number for the throttle cable to suit Isuzu 4BD1 as fitted to a 1984 model

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It is the same as the V8 110 (and 3.5 disco?) throttle cable (NRC5494)

Here you go:
Land Rover County/Defender V8 Accelerator Cable 3.5 V8 | eBay