Can you run 10W-30 in a rex. I dont see what it would hurt, but I just wanna make sure!

 

my egine builder said to go buy what is says under the hood for oils for each temp. So if the tempiture is correctly yes you can run 10w 30 just make sure it is castrol gt

jr

 

And make absolutely sure...

THAT IT'S NOT SYNTHETIC!!!!

10w30 is what I run in Canadian Summer It's fine.

Jon

 

10w -30 will work fine but a heavier oil like 20w-50 is better if you plan on doing some spirited driving. also you can use synthetic but ONLY if you premix 2 stroke oil in your gas. not sure if you knew that or not already so i just figured id tell you just in case. right now i am running 20w-50 in mine. i like it alot better for the summer because it protects the engine better when you do some hard driving cause it heats up slower.

 

The 7 forgot something.

Use of synthetic: Only if you premix 2-stroke oil in your gas AND You block off the OMP with a block-off plate so that no synthetic gets into the chamber!

This second part's very important. Don't just premix and run synthetic, and assume everything's fine. You will have oil from both the gas AND the OMP, so you'l be running rich on oil, and the synthetic of that oil won't burn properly leaving horrible deposits in the motor.

But yeah, some of the guys run 20w-50, so whatever floats your boat I've yet to try it.

Jon

 

I run 20w-50 year round with no problems. Castrol GTX of course.

 

This crap about not being able to run synthetic in conjuction with the metering pump is a myth. Racing Beat themselves recommend using synthetic for all applications and they don't mention anything about deposits or blocking the OMP off etc. Many other experienced engine builders and racers say the same thing. I use Mobil 1 personally.

 

Well I bet it depends on the type of synthetic. Most companies nowadays (Castrol, Mobil, Redline)have cheaped out and are using type III base stock. Of course they didnt lower the price per Qt any.

 

Right on.
Racing Bleat has recommended Amsoil synthetic since at least 1985. Not a word about "horrible deposits", just glowing praise.

 

Yes Racing Beat now recommends Royal Purple synthetic...MAZDASPEED/Mazda Motorsports also recommends using a synthetic motor oil.
My first SE engine reached over 282,000 miles using Valvoline Durablend until I discarded it. I simply cannot justify the added cost of using a synthetic since my oil is changed before it hits the 3000 mile mark so Castrol GTX it is...20w-50 during the summer, 15w-40 during winter.
Interesting how Mazda says 5w-30 for the RENESIS.

 

Synthetic oil is DESIGNED to resist burning. people use it because it can withstand higher engine temps without burning off. so then if it doesnt burn off the OMP keeps injecting it onto the seals and it builds up. im not an expert but i am guessing that becuase it is synthetic you wont get quite the same deposits as normal oil but at some point, since it is on the rotors the synthetic will change state due to extreme heat. once again i am making eduated guesses but it seems to me that since its designed to NOT burn that it will change into something that stays in the engine. 2 stroke oil burns vitually clean and more is added by the OMP so no buildup. now maybe these deposits arent bad enough to do immediate damage but they should definatly build up enough eventually to seize the engine just like regular oil deposits.

 

Well I can say from my recent research that only Amsoil is made from %100 type IV base stock PAO oil. None of the others will say that. I am NOT an Amsoil dealer, nor have I ever used it, but after much research I think Im gonna start. They are honset about whats in their oil and no one else is. Do the research yourself, after all you DO have internet access right? Find out whats in motor oil, how its made/cracked/filtered etc.
As far as the whole debate on deposits and burning I dunno, but the flash point even for type IV oil is around 450 degrees F, IIRC. Post your findings please.

 

Actually, synthetic oil is designed to reduce friction and wear. It's high-temperature stability is almost pointless in a rotary as you will have cooked your engine long before even ordinary oil reaches it's thermal breakdown point.

I'm not an Amsoil dealer either, but I have used their products, mostly their 10-40 synthetic motor oil, their 75W-90 synthetic gear oil, and their "Power Foam" carb/engine cleaner. I can't say enough about their synthetic gear oil, it's great in non-LSD rearends, too.

 

but what about when its injected onto the seals by the OMP? wont it partially burn leaving some kind of substance that builds up over time?

 

lol, that's exactly what "Power Foam" is for.




...Amsoil should really be paying me...

 

the OMP doesnt actually inject it into the seal it just drips down the intake doesnt it?

 

power foam?

 

Yeah, and at the end of the intake manifold we find???

The rotor's seal passing by. Sure the intake mixture doesn't spray *directly* onto the apex seal (unless you have a peripheral port intake), but it gets there. Otherwise the whole OMP thing would never have even been concieved.

It just seems to make sense to me that to lubricate in the combustion chamber, you'd use an oil that's been designed to burn off and leave virtually nothing behind (except a bit of lube in the case of 2-stroke oil.. a bonus for us). Regular old motor oil isn't *designed* to burn, but it isn't designed *not* to either. Bottles of synthetic oil boast the ability to resist burning, not a good thing in our case.

And the final point in my mind:
Synthetic is almost double the price here. If I'm changing my oil every 4,000km, I don't need the "added protection" of synthetic. I don't need it's amazing lube ability and it's formula "specially designed to reduce oil burning".... All I need is 10w30 (or 20w50 for some of us) that was specially designed by a million years of crushed dinosaur and plant particulate! That's it! $15 for four litres, and my Rx7 loves it.

And if I get the chance, I'm putting that two-stroke resivoir in with the OMP adapter. There must be something about two-stroke that makes it good for our engine, or else premix guys would just run 10w30 in their gas tanks! (yeah, I know, it doesn't mix as well).

Jon

 

20w-50 mobil 1
and 2 cycle here

btw i can confirm that mobil 1 doesnt burn really clean
my omp is disconnected but still on, the fan blows the oil right onto the exuast manifold and there is build up there
its black and sticky

 

for what it's worth ...

the way i read it a while back is that this whole "no-synthetics-in rotaries"-stuff came about because Mazda and some oil company (I think it was Mobil, but don't quote me on that) had some friction between them over some issue or another and Mazda started putting that "no synthetic" recommendation on their rotary cars.

if i remember where i read it, i'll come back and post it.

BTW ... mineral oil leaves a sticky (brownish) residue when it burns, too.

 

Exactly how does that have anything to do with oil injected into the combustion chamber?

 

??
just a thought

 

EXACTLY! I'd go so far as to say that 4 oz. of MMO every other tankful will keep any so-called "deposits" from developing for at least 70,000 miles...every time I see this myth pop up, I ask the same question.....who has actually lost their own engine due to a stuck apex seal from synthetic oil use? No worthless thesis papers, theories, friends, or "I heard from someone" crapola. Just your engine. Each time the Forum goes dead silent. A sure sign that a lie has been perpetrated upon the rotary community.

 

Or that nobody who actually spends time on the forum bothers using synthetic.

The poll *does* put most of us in the 15-25 age range... and chances are people aren't shelling out the extra dough for synthetic if they don't have to. And if they're on here, they're getting enough "don't use synthetic" warnings and arguements to give them yet *another* reason not to use it.

Maybe you should look to people who aren't on the forum for that... people like my mum who ran my shadow for two weeks with the oil light on.... I'd say THOSE people are more likely to f-up an engine with syn than anyone else.

Jon

 

it proves that it doesnt burn clean, leaving gooey deposits, and that if his OMP was connected, thats what would be in the engine.

by saying that you would use 4oz of MMO every other tank you are agreeing that synthetic creates unwanted deposits. so maybe its not as horrible as its been made out to be but nevertheless, it still creates deposits which will eventually built up and seize the engine just like normal oil if you dont clean it up with MMO or whatever.

im not saying that synthetic is the worst thing to do to your engine, my arguement is that premix with 2stroke or running the omp adapter with another container is ideal becuase it burns clean. premixing without disconnecting the OMP defeats the purpose because then yea you get 2 stroke in there that burns clean but if the OMP is still connected, then you are still letting the regular/synthetic oil in there with the premix and after the 2stroke burns off the deposits from the other oil are left. therefore it is completely pointless to premix unless you disconnect the OMP. personally, when i get the money that is, i am buying and installing the OMP adapter and using another tank for 2 stroke.