Castor 927 vs Idemitsu Premix
Castor 927 vs Idemitsu Premix
I've searched for premix oils and have found some great success stories of both using Maxima Castor 927 and Idemitsu Premix Oils. Does anyone have DOCUMENTED differences these oils made after tearing down two separate motors with one using Castor and one with Idemitsu? In addition, has anyone tried Maxima SuperM 2 cycle oil?
Sorry for yet another premix thread but I was tired of all the opinions and i wanted factual information or at least pics.
Sorry for yet another premix thread but I was tired of all the opinions and i wanted factual information or at least pics.
I've searched for premix oils and have found some great success stories of both using Maxima Castor 927 and Idemitsu Premix Oils. Does anyone have DOCUMENTED differences these oils made after tearing down two separate motors with one using Castor and one with Idemitsu? In addition, has anyone tried Maxima SuperM 2 cycle oil?
Sorry for yet another premix thread but I was tired of all the opinions and i wanted factual information or at least pics.
Sorry for yet another premix thread but I was tired of all the opinions and i wanted factual information or at least pics.
Realistically, by the time someone would contribute time to drive two rebuilds thousands of miles with each oil brand and tear them down to show actual wear or carbon data is asking a bit much. Obviously you are just asking the question, and its fine. Just don't expect tons of informative responses. I personally use Idemitsu oil. I have a close friend that uses the cheapest premix at walmart.....
I think if you stick with a quality brand, you are good. Many people have used the OMP pumping grubby engine oil in there and making 3-400whp on the same engine for years.
Debating premix brands is like trying to find which "big brake kit" works best for my street car....
Idemitsu actually published detailed research on this topic years ago... unless something has changed, their premix uses a polybutene base stock. Their internal tests showed that this produces low carbon deposits in a rotary engine.

For the record, I won't hesitate to run Walmart oil + OMP in a rotary engine for most applications: not because it's good, but because people on the internet tell me not to, and I find this entertaining.

For the record, I won't hesitate to run Walmart oil + OMP in a rotary engine for most applications: not because it's good, but because people on the internet tell me not to, and I find this entertaining.
Joined: Mar 2001
Posts: 31,796
Likes: 3,210
From: https://www2.mazda.com/en/100th/
i read the study, and just to be simple, if deposits are lower with the polybuten base oil, and that is what Idemitsu sells, this is what you should use.
i'm sure you could find some other polybuten based oil, but the Idemitsu premix is available and not expensive....
i'm sure you could find some other polybuten based oil, but the Idemitsu premix is available and not expensive....
I used castor927 on my other FD with no issues but then again I never had to tear down the motor and didn't have the car for long. My new FD has been using Idemitsu for years. I've been reading castor 927 is the way to go for E85. Would going from idemitsu to castor be harmful in anyway?
Trending Topics
Joined: Sep 2003
Posts: 3,066
Likes: 7
From: Home of the Rolex 24
Another aspect in which I had delved is also what do these oils do to fuel related parts. Mainly to fuel injectors. Be interesting to see data on that. G
Idemitsu contains a special dispersant/detergent to help keep fuel injectors clean. That's straight from their website as well. They also have claims of helping with combustion sealing and what not. I personally run Idemitsu as I've been told it's pretty much the bee's ****. I've heard of many people also running Walmart 2 cycle. I guess it really comes down to preference and your own conscience. I feel better about myself knowing I'm pouring something designed for my engine into my gas tank. I premix as a failsafe to my OMP and its sensitive Oil injectors. I personally have not torn down my engine to inspect its internals or gone that deep into it. I can take pictures of it if it ends up poopin' the bed one day [knock on wood!].
Hope this helps
Matt
Hope this helps
Matt
Joined: Sep 2003
Posts: 3,066
Likes: 7
From: Home of the Rolex 24
Idemitsu contains a special dispersant/detergent to help keep fuel injectors clean. That's straight from their website as well. They also have claims of helping with combustion sealing and what not. I personally run Idemitsu as I've been told it's pretty much the bee's ****. I've heard of many people also running Walmart 2 cycle. I guess it really comes down to preference and your own conscience. I feel better about myself knowing I'm pouring something designed for my engine into my gas tank. I premix as a failsafe to my OMP and its sensitive Oil injectors. I personally have not torn down my engine to inspect its internals or gone that deep into it. I can take pictures of it if it ends up poopin' the bed one day [knock on wood!].
Hope this helps
Matt
Hope this helps
Matt
If you ever run E85 not all premix oils will work. Idemitsu separates out in E85 and would be worse than running nothing. Maxima Castor 927 will blend with E85.
Since I don't run E85, I've been using the Idemitsu and like it. Less smoke than the Pettit stuff or Redline.
-Andy M.
Since I don't run E85, I've been using the Idemitsu and like it. Less smoke than the Pettit stuff or Redline.
-Andy M.
i been using valvoline 2 cycle for my premix. im going to start giving the idemitsu premix stuff a try since i got nothin else to do with the FD.
its been running awesome with no issues and i finally have a chance to do other things than fix it
also running a 15psi methanol injected set up. now if only the website would work so i can place an order!
its been running awesome with no issues and i finally have a chance to do other things than fix it

also running a 15psi methanol injected set up. now if only the website would work so i can place an order!
http://www.dragonmotorsports.net/
I've bought over 8 cases from him. Maybe more.
Order mine from www.rx7.com
Order mine from www.rx7.com
I was using Maxima Castor 927, loved it (especially the aroma, MmmMmm!) I switched to Blendzall Racing Castor (also smells good, lol) which was cheaper....turns out the Blendzall was a BAD idea, cuz now my apex seals are stuck solid w/castor gum/varnish... HELP!! -I'll prolly do what the lil r/c engine guys do... throw rotors in a crock pot/slow cooker w/distilled water + anti-freeze/coolant and "cook" 'em for about 8hrs...(not boil)...they say it gets their engines clean as new...
Thread
Thread Starter
Forum
Replies
Last Post











