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[SA] oil differences

Brett_jjj

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Interesting conclusion. We use diesel oil in every new engine we build at work (even new crate engines) because diesel oils aren't friction modified and we have it on tap. Some people say you shouldn't do it, but it's served us well and we've never had a drama with any of the engines we've built. So, i fail to see how it could damage an already running engine...

I came to this conclusion because Ive seen a couple of engines now that have had diesel oil accidently put in them and then theyve all self destructed in a very similar way.. One engine was a ford 250 6. Old mate thought he'd take some diesel oil from work and use that in his ute. The next day the engine was buggered, just a big mess of broken parts inside the engine. The other engine I looked at afterwards was a buick V6 that this guys missus put 1 1/2 litres of diesel oil in it to top it up, it blew up not long after, and all these engines looked the same inside, everything pretty much smashed to pieces, and definitley not from overrevving either in any of these cases.All these engines were running perfectly before the diesel oil was put into them.
 
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383 hatch

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So, hold on a second, using your conclusion every diesel engine should end up with stuffed bearings and a smashed piston? I'm not sure if you're aware of this, but the internals of an engine all work the same basic way, regardless of the fuel used (you know, the crank turns around, the rod goes up and down as does the piston...). Explain to me the difference between a petrol and a diesel bottom end that makes a petrol engine self destruct if diesel oil is used.
 

greenacc

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Could be a case of cleaning too well! All those engines mentioned above were old dinosaurs that would have had years worth of scrap built up inside. Throw a dose of diesel oil in them and all that shirt is set free to block oil passages. Block an oil passage to a big end, little end, main bearing and bam you have a catastrophic failure as mentioned above,,,,,,,,,,?
 

yxyx64

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where does a joe average in Tamwortth get a diesel oil for engines that is not api c rated (or sae or milspec or whatever). They are all pretty much the same (....await imortality to say that is not an accurate statement....) within broad guidelines. I cannot even think of a diesel 4 stroke engine oil that could possibly cause a well running good 4 stroke petrol engine to fail.

Be willing to bet even the cylinder drain oils used in the big diesel 2-stroke engines (.....await others to tell me how 2 stroke diesels do not exist......). would not cause a catastrophic fail in a commodore.

Can only think of total loss diesel oil (diesel 2 stroke burn oil) as being an oil that may cause failure - but who knows as I doubt thgis as well (think of these as similar to 2 stroke motorbike oil). Not sure Tamworth would have any anyway.
 

Cava454

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Pretty sure u shouldn't convert to diesel oil if you have been already running normal oil. I was told the detergents break the carbon deposits and flush them through the motor which isn't a good thing.

Fresh motors its fine, but you have to get the correct type.

I may be wrong. But this is what I've read on another forum by a member who successfully uses it.
 

383 hatch

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Could be a case of cleaning too well! All those engines mentioned above were old dinosaurs that would have had years worth of scrap built up inside. Throw a dose of diesel oil in them and all that shirt is set free to block oil passages. Block an oil passage to a big end, little end, main bearing and bam you have a catastrophic failure as mentioned above,,,,,,,,,,?

Highly, highly unlikely. I mean, over a period of time in a really dirty engine, remotely possible, but still very unlikely. In a day? I don't think so. Diesel oils are designed with detergents that break down grime inside the engine and clean it out, they don't just break big chunks of gunk off and carry it through the oiling system...Think about it, how many diesel engines would be dead all the time if that was the case?
 

yxyx64

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tamworth.....used be plane fix up places there (still there ?)........maybe someone has lubricating oil from gas turbines and they think they can be used in cars. That type of oil would cause a pretty quick failure. They look pretty similar to a 10w engine oil at room temp (say a 10-40W when you pour it)
 

Brett_jjj

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I dont know why this happens, all I can say with 100% certainty is that these 3 perfectly running engines all had bad endings straight after someone put diesel oil in them, and all had similar extreme damage to the internals. None of them were getting the crap revved out of them or whatever or being driven by hoodlems, apparently they were just being driven nomally when they blew up.. 3 times Ive seen diesel oil used accidently in healthy petrol engines, and 3 blow ups straight after using it, coincidence? I highly doubt it.
 

K-BAGZ

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This discussion has just turned into an experience war... =/
 

383 hatch

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I dont know why this happens, all I can say with 100% certainty is that these 3 perfectly running engines all had bad endings straight after someone put diesel oil in them, and all had similar extreme damage to the internals. None of them were getting the crap revved out of them or whatever or being driven by hoodlems, apparently they were just being driven nomally when they blew up.. 3 times Ive seen diesel oil used accidently in healthy petrol engines, and 3 blow ups straight after using it, coincidence? I highly doubt it.

Honestly, i've seen engines that have run with no oil for a short period of time that don't look as bad as that engine in your VY thread...How can an engine that's had diesel oil in it, look so much worse for wear than an engine that's had no oil?
 
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