Does anyone run Diesel oil in their rotary? My brother and I run the OMP and have always used Diesel oil since its meant to keep the engine cleaner.

Recently though my engine came apart for a rebuild (coolant seal gone) and I found the rotors so caked up with carbon that its making me wonder if its such a good idea. Our engines have always run fine though.

Discuss

 

I don't know about keeping the engine cleaner but I do know that Rotella T has additives that have been removed from most other oils in the last couple years. It started to show up as cam problems on some friends high HP piston(Like 1000) drag cars. I have heard a lot of major engine builders have been seeing the same issues.
I run it in mine but I premix with Klotz.

 

Well Diesel oil has detergents in it that should in theory keep the engine carbon-free.

 

Depending on the age of engine and how its treated and driven will determine the amount of carbon on the rotors etc. Both my first gen engines ive torn about had ALOT of carbon on the rotors. The one i knew ran strong, the other no idea. Ive torn apart 2 FC 13B's and one had carbon the other did not.

My question is, do the detergents affect the lubricating quality of the oil? Do the detergents affect the burnability of the oil?

As we all know rotaries burn the internal oil, and that is a huge aspect in choosing oil. Diesel engines DO NOT burn oil, and therefore that is not a factor in the design of the oils right?

That's my objective observations. No opinion either way, i pre-mix with 2 stroke oil

 

I have to agree with that statement. What are the effects of the degergents when they are burned up?

It would be better to find out how oil will react to being burned up since that will be what determines the use of the oil.

 

Thanks for your input, this is the kind of discussion I was hoping for.

I did give my engine a good rev occasionally. I'd probably take it to 6500 or so once or twice at least every second time I drove it (its a daily driver). That wasn't necessarily to prevent carbon, of course But I was very surprised to see just how much carbon there was considering the way I drove it.

 

Is Diesel oil really better with additives? And How do you get carbon out of the engine once it is there? I have read that carbon is a huge problem with rotary's more than piston type engines.

 

not in N/A applications, and i highly doubt that it will be in boosted applications. Diesel oil is made to withstand massive shear stresses and pressures under the massive loads that are generated by diesel motors on their crank shafts. I'd say run a high quality gasoline motor oil, synthetic or not, in your motor. I currently run Royal Purple 20w50 in my 12a powered FB and love the stuff. I'm contemplating trying ELF/Total 20w50 next summer, but I don't know if I wanna change...

 

I too run premix with 2-stroke oil ... last time we tore down my engine didn't have much carbon deposit on there ... is carbon on the rotor really a bad thing ... the smaller combustion chamber should have slightly higher compression

 

diesel rotary would be pretty neat

 

The main issue with carbon buildup is the possibility that it will restrict the movement of the apex seals. If they do not move freely, they will not create a proper seal against the housings, resulting in lost compression and reduced power. If it gets bad enough, you can break a seal.

There are a lot of opinions on how to remove the carbon. Some like water, but my personal favorite is Seafoam. Just dump it in the tank every couple of months and you never have to worry about it. You can usually feel a pretty good increase in horsepower as soon as you start driving. It works that fast....



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We have them where I work. You can find them in the heavy duty mobile 60kw and above generators.

 

Thanks Whitey85 and kentetsu. For the sea foam I have used in a piston engine before, do you put it in and then change the oil or leave it in till it burns off? For piston engines I know you suppose to add it and then run it for 10 minutes than change it, so I was wanting to make sure for a rotary. And mazda 6 guy it would be awesome for a rotary diesel, I could be wrong but on how stuff works there is a flying car that uses a 2 or 4 rotary engines and it uses diesel fuel I believe I could be wrong I seen it a while ago. Try to check it out.

 

Just put it in a 1/4 tank of gas and go for a spirited drive. Thats all you need to do.

I would be skeptical about those diesel rotaries because judging from Yamamoto's book, it seems they are very inefficient because its more difficult to get the very high compression and then when you do reliability decreases. I will have to revisit that section though