1985 Mazda Rx-7 gsl-se

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I have an interesting engine and am seeking an oil recommendation.

Its a 13b Rotary Engine, stock in a 1985 Mazda Rx-7 gsl-se I recently acquired. It has 68,000 original miles and is (to my knowledge) used to a steady diet of conventional 10w-30. The car runs great, doesn't smoke and has no leaks.

Opinions on Oil are welcome.
 
That's a pretty rare find. 13B's were only installed in the GSL-SE, and finding one with such low miles that hasn't been mechanically molested is great. Since that engine was built in the era of 1200+ Phosphorous levels, I think something like Valvoline VR1 10w30 conventional would be good. Apex seals are always the worry in Wankel durability, and zddp is for sliding wear resistance.
 
Mazda has (to the best of my knowledge) always recommended that rotary engines use conventional oil to prevent deposit formation in the engine ports. Not sure if this is warranted or not but lots of these lived their lives on conventional oil no reason that you couldn't continue running a conventional 10w30. I like Valvoline but that's a personal preference.
 
Pictures please!
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The car certainly is not perfect. But it runs great and is in very clean "driver" condition.
 
Nice car.

When u crank it make sure it starts. Otherwise u flood the engine.
It will be a miracle if it starts on the second crank attempt.
Nothing serious just have to pay a little attention while firing up.

Give pp 10w30 a try.

Heard a lot of rx7 owners also like castrol gtx.
 
You do not run synthetic in these engines. Well you can, but you wont like the results. Mazda does not want you to run synthetics in these engines. Plus the engine is 32 years old and has likely run conventional oil its entire life....

I'd run a stout non-synthetic 10W30 diesel oil. Rotella T or similar. Conventional VR1 would also be a good choice.
 
I know nothing of these engines. Always thought they were interesting, but never owned one ... OK, you know about my ignorance here, but what about a Grp III syn-blend like Maxlife? Wasn't around when this was new. So maybe it's OK - or not ...
 
Originally Posted By: bubbatime
You do not run synthetic in these engines. Well you can, but you wont like the results. Mazda does not want you to run synthetics in these engines. Plus the engine is 32 years old and has likely run conventional oil its entire life....

I'd run a stout non-synthetic 10W30 diesel oil. Rotella T or similar. Conventional VR1 would also be a good choice.

This is incorrect. Mazda doesn't want people running PAO or Ester synthetics, but Group III synthetics are A-Okay. Furthermore, there is no risk in switching from using conventional to synthetic - in fact, synthetic oil has more seal swellers than conventional and would reduce any current leakage or burning.

That being said, OP's Mazda could continue to use conventional without issue, or could switch to synthetic without issue, as long as he made sure it wasn't PAO or Ester based. Typically though, those Group IV (PAO) and Group V (Ester) oils cost a lot more than Group III synthetics, so it's probably safe to assume SuperTech synthetic 10w-30 would be alright in his Mazda.

All else aside, my personal recommendation to you, Clubber_Lang, would be to either continue using whatever conventional 10w-30 you like (PYB is my favorite conventional), or, you could step up to running a dual rated synthetic-blend Delo 400 XLE 10w-30:
https://www.amazon.com/Delo-400-10W-30-Synblend-Motor/dp/B00M1Y7JXY/
https://www.walmart.com/ip/Chevron-Synthetic-Blend-10W30-Heavy-Duty-Motor-Oil/35950292

Do know, however, that it's a 50:50 chance of getting either the old API CJ-4/SM version or the new API CK-4/SN version when ordering it online from Amazon or Walmart. Honestly either version would be great for your application, though, so whether you would get the blue or charcoal bottle wouldn't really matter too much.
 
OP, just so you know these rotary engines are designed to use/burn some of the motor oil. So be sure to keep an eye on the oil level.

RX-7s are fun, I had a 1988 and a 1995 (twin turbo).
 
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