I was just wondering how many of you guys use synthetic oil, or have used it and what you think is better, the man made or the natural stuff?? I want the best for my rotary that will be run hard!

 

There is a debate of synthetic versus dino oil. Search for lots of info. The generally accepted advice is to use regular dino oil. Synthetic oil does not burn properly, and should thus not be used in the rotary as it has an oil injection system.

See http://www.aaroncake.net/rx-7/newowner.htm

 

synthetic oil will not burn as clean as mineral oil...since rotaries use oil injection their is alot of controversy about this. Regular motor oil burns shitty too though...ideally I believe that pre-mixing with oil injection blocked off and synthetic in the case is the way to go..but thats just my opinion.

 

No macrus is right, I use the premix w/ my injection system (not for long), and the car runs better overall. Since the stock injection system is not under pressure the oil just kinda droops outa the hole in the housing, so by putting premix oil in the gas tank the fuel injectors inject it in to the combustion chamber and spread the oil better.

 

If you have the OMP blocked off Id suggest synthetic. My first few oil changes are using mineral (bastards didnt have synthetic .. I thought that was wierd lol) but all the rest are going to be using synthetic, probably mobil1.

 

I have removed the OMP and I run Synthetic, with Bombadier Synthetic @-stroke as a pre-mix

 

How many people do this?? Does it work well over a long period of time? Anyone know if there is any negative effects of premixing? Just wondering..thanks.

 

The negative of it is you have to carry some premix around in your car and dump it in when getting gas and have stupid people ask you why you are putting oil in your gas tank.

 

what kind of moble1 do yall run 15w-50???

 

10-30 mobil 1 for me

 

do you see any HP gains with premixing? And what mixture do you run... and also again 2 stroke or 4 stroke oil? I own a TRX25R two stroke so I'm used to mixing oil just still not quite sure about these rotary motors... are they two or four strokes haha, but anyway, info would help, and wtf is the OMP And how/where do remove it.

 

HP gains????
Its a reliability(peace of mind) mod since MOP/OMP sometimes fail.

I am running synth and am not having any carbon issues.
It is wrong to say that synth burns improperly. It just burns at a higher temp and should burn cleanly when considering the high combustion temp. Anyone know what the exhaust gas temp is?

I've never seen a dead rotary that has run synth for its life. But, I have seen numerous toasted engines on a diet of dino.

 

Premix with 2 stroke oil. 4 stroke goes into the oil pan. I run 10w-30 for winter (maybe 5w-30 if it gets cold enough) and 20w-50 in the summer.

The OMP is found on the bottom passanger side of the front cover, just above the oil feed/return (dont know which it is) line for the turbo. And I dont suggest you just start ripping **** off because its what others are doing. I suggest you read and research then make your decision if its something you want to deal with.

 

wow is it rue that 87 ocyane is better for a N/A than High octane

 

I'm going back to syn. I think the benifits will outweigh the negatives in the long run. Also, I'm hearing more that the syn does indeed burn as well as the mineral. I don't think this debate will ever end.

 

Considering one of the strong benefits of 'synthetic' oil is its higher resistance to breakdown at high temperatures, I don't see how it could burn as cleanly as dino juice. But, when it does break down, it turns to ash- is this what it does in the engine? For the record, many(all?) 'synthetic' oils actually start with dino juice.

Maybe somebody here should do an experiment:
Take some synth and some regular oil-
put a small amount in two beakers-
place over flame (bunsen burner?) at a temp that appoximates the combustion cycle average temp-
see what happens-

now this may also need to be done with a mixture of gas- to more closely aprox what happens in the engine.

So who is going to volunteer to do this?

 

yea it is better to use low octane fuel in an N/A. It burns faster. The high octane is slower.

 

Whether it burns cleaner, faster or whatever, using syn is just a waste of money. I go through a quart of oil every 700 to 1500 miles. The only thing syn gives you is better protection against viscosity breakdown over a longer duration then dino oil.

If you are adding a quart of fresh dino oil every 700 to 1500 miles you are not going to have to worry about viscosity breakdown. Using Syn is a Waste of Money!

 

Guys I have done alot of research on this topic along with calling and talking to one of RacingBeats guys. I called RacingBeat because they have been racing rotarys longer than anyone. They use nothing but Amsoil synthetic oil in their race cars. I use Amsoil synthetic in my car, and trust me, I use nothing but the best on my car and wouldnt use anything that may give me prolbems. Synethetic all the way for me.

 

which oil should i use when i get my engine back from being rebuilt + ported? i think i read on here some time ago that said if i used synthetic, it would take longer to break in?

 

Meaning you're not premixing dino juice either? How long have you been running that motor on amsoil?

 

No premixing, I used Castrol 20-50 for breakin and from then on I have been using the Amsoil. The engine still doesnt have many miles on it yet, probally only 2500.

 

DO NOT USE SYNTHETIC!!!

 

That's absurd. Synthetic does a whole lot more than just hold up better under duress. Go to the AMS oil website, they've got a battery of comprehensive tests that will adjust your statement.

 

Ah man, I finally read this thread ( I had been avoiding it as the subject has been covered 100 times... to bad the search function must be broken)...

Okay here is the POOP AGAIN on synthetics:

Good quality Synthetics are perfectly fine to use in a normally operating (read still with factory OMP) rotary. The quality ones like Royal Purple, Neo, Redline and Mobil 1 all burn at under 500F with a low low ash (ash is what is left over after it burns) content (in fact lower than many cheaper conventional oils like Havoline, Kendal, Penzoil, etc).

Quality Synthetics as mentioned above are perfectly fine to use after the engine has passed its break in period and will not add or create deposits anymore than a good quart of Castrol.

Lets compare a couple 20W50s real quick:

AMSOIL 36 482 -38 <.5 ---
Castrol GTX 122 440 -15 .85 .12
Red Line 150 503 -49 --- ---
Kendall GT-1 129 390 -25 1.0 .16
Valvoline Syn 146 465 -40 <1.5 .12
Valvoline Tur 140 440 -10 .99 .13

The first number is Viscosity, how well it pours cold at it's temp range (lower the better)

2nd number is Flash, what temp the oils burn at (ideally between 400F to 500F, but not lower than 400F.

3rd number is Pour. Pour is tested 5 degrees F above the point at which a chilled oil shows no movement at the surface for 5 seconds when inclined. Again lower is better.

4th number is Ash. what is left after the oil is burned, again lower numbers are best as high numbers will lead to coking and build up in our engines.

and 5th is Zinc content. Zinc is used as an anti-wear additive, but in too high amounts it can cause build up. .11 is generally considered the highest you need for a 5000 mile drain interval and .13 the highest you need for a 7000 mile drain interval.

You can see just from those numbers that the Synthetics are every bit as good as conventional oil and in some cases better. But they all burn way under the combustion chamber temps found on our cars.

The scary thing is oils like the Kendal GT1 and Valvoline Synthetic, both of which have a high build up potential as well as the Kendal doesn't even meet the 400F min for flash meaning that the oil will break down radically fast in our cars and leave junk behind when it does.

But cheap synthetics (just like the Valvoline above) will leave ash just as bad if not worse than cheap conventional oils (again as mentioned above).

Avoid cheap mixes and cheap oils period!

Now the advantages, it is not unusual to gain about 1%(sometimes 2%) HP increase using a good synthetic (Royal Purple, Neo, Redline and Mobil 1).

Down side, cost! Typically the average Synthetic costs about $35 a half case (enough to change the oil in our cars), vs the $15-$20 a case that Castrol GTX is generally found for. So the quality synthetic is about 3 to 4 times more expensive.

IMO if you have money to burn or you are racing and need that extra 2-3 HP go with the quality Synthetic. Again it is perfectly safe. Just avoid the crappy/cheap ones (like Valvoline, Kendal, Havoline, Etc). But remember just because the bottle says you can go 10K miles on a synthetic you can't. They need to be changed just as often as conventional oils.

But if you are like the rest of us, and money is an issue, then use the Castrol or Penzoil and change your oil regually.