Fiftyfifty

Sorry guys, another oil thread. But this one has a little twist. Haven't seen anything like this one aside from the one on reddit I recently created. So 90% say, go for the sohn and run the 2 stroke oil in the reservoir. But wouldn't the 4 stroke oil protect the Apex seals better? Not only does it lubricate better, but since it resists burning, it will stay in the combustion chamber a bit longer and lubricate longer.. 4 stroke oil, especially a quality synthetic is not dirty after 2 or 3k miles and still offers plenty of protection. The synthetic in my bmw straight 6 burns like butter. Check out this link where they say a quality Group V ester base stock "true" synthetic burns very clean and is the way to go in a rotary due to its superior protection. Even without the synthetic, I am not sure that the 2 stroke will offer the best protection necessary for the Apex seals. Of course I will be premixing with the 2 stroke in the gas for added protection on my new motor. Thoughts?

https://www.oldhallperformance.com/news/can-you-use-synthetic-oil-in-a-rotary-engines-debunking-the-synthetic-oil-rotary-debate

Loki

iTrader: (1)

While you're not wrong, you can just run Group 5 and some G4 synthetics, you have to know what you're doing. I don't know that engine oil is specifically better or worse than a good 2 stroke for the apex seal usecase, but 2 stroke is cheaper than most Group 5 oils. Group 5 is like RedLine or Amsoil. You can do it but it's going to cost a fortune to keep topping it off.

Also while they might not varnish/deposit like other base stocks, the additive packages in any oil still produce ash, which proper 2 strokes do not.

For me the advantage of the Sohn adapter isn't that you can run 2-stroke, it's that you can keep your engine oil in the pan and choose what you inject separately.

Fiftyfifty

So with the sohn, the same exact amount gets injected as without? There is no drop in delivery?

This is what I use in my bmw for years.

https://www.walmart.com/ip/Pentosin-...each/840788256

I was under the assumption it was a group V oil since it's a German oil and they are not allowed to say something is synthetic if it's not according to their standards, but from the reading I was just doing, it's probably not a group V.. so the RedLine high performance one is, and the price difference is not that big. A little over 10 bucks a quart. 1 quart for every 1k miles is what I have been doing for years and I did not feel it hurting my wallet and I will be doing the same with the RX8 I assume, except it won't be my DD.

Loki

iTrader: (1)

The sohn doesn't change anything about volume, only the source of the oil. You can tune the ECU oil injection tables to manage the volume.

1 quart per 1k miles sounds like regular around town driving. If you start racing and it's a quart per 20 minutes, the math might change.

At the end of the day, it's not like any of us have a lab to determine objectively what's better. Have to make decisions on incomplete information and go with what makes sense to you.

XDragon8

A good test is to check plugs periodically with whatever oil you go with. You can adjust premix in fuel accordingly also. Do what works for you.

I just stick with regular mineral oil without SOHN and change out the oil more regularly. 150ml of quality 2t in tank per full tank of fuel. Have found that more than this will leave oil spots on rear of car and more deposits on plugs.

Fiftyfifty

Cool. How much does that come out to per gallon?

Fiftyfifty

Yeah 1qt every 20 minutes is a bit more painful. Does it really get that bad on these cars when racing?

Loki

iTrader: (1)

I think I exaggerated it's more a quart per hour runtime, and I have increased injection rate programmed. But yes, it goes fast when you're having fun.

XDragon8

I think its about the 0.5 oz per gallon roughly. I did a fair bit of research and testing before settling on this amount. Works for me anyway. Trial and error really.

Fiftyfifty

When you premix, is it even safe for the 2 stroke and 4 stroke oil to be mixing together in the combustion chamber? No ill effects can come from this? Because as far as I know, you shouldn't be mixing them in the oil pan.

TeamRX8

iTrader: (25)

you don’t know what you don’t know

heads will begin asploding in 3, 2, 1 ….
.

Fiftyfifty

Thanks for the thread bump buddy