1st Generation Rx-7 Oil Discussion (Rotary Engine)

[rearviewmirror]

I did a search for RX-7 and not much came up. I just picked up a 1985 Mazda Rx-7 GSL-SE. It's got a fuel injected 1.3 liter rotary engine. The car has 68k original miles, it's still using the oil metering pump and has not been premixed.

Here is the manufacturers recommended oil chart:

There has been a lot of debate about whether or not to run synthetic in rotary engines or not due to the fact that the oil metering pump injects oil into the engine to lubricate the internal surfaces and seals. This oil by design is burned. Based on the weight chart above and the climate in TX what do you lot recommend for a weight? Also, should I do the conversion to full synthetic? I don't want to start pre-mixing the car, the OMP is working as it should. Everything I read these days says that going with a 20W-X is bad because it's so much heavier at startup. Maybe a 10W-50 or 5W-40 perhaps?

 

[Dyoel182]

15w-40 maybe?

 

[Quest]

10W40 API-SM grade mineral oil.

 

[Quest]

Oh and besides: your engine is not "1st generation" for the REAL "1st generation" mazda rotary was in 1967(approx.) Mazda rotary Cosmo car; and the real 1st generation wenkel engine was back in the 40s back in Germany where Dr. Felix Wenkel developed it. NSU and even GM tried and failed over the decades....

 

[Shannow]

Mercedes and the U.S. military had active Wankel programmes as well.

NSU was a sad case...the Prinz (a single rotor sporty thing) lead them in, with quite a successful engine. Then they put it into the larger, luxury Ro80, and the driving style of the users caused the chatter mark issues.

Mazda put some engines in Holden Kingswoods for Japanese consumption. I oft wonder how they survived a large car and auto transmission.

20W-50 has been used in ring-dings for ages down here.

 

[rriddle3]

I had a 1979 RX-7 and used 10W40 dino in it here in Texas. FWIW, after 100,000 miles it developed oil leaks between the engine rotor sections, but never had an excessive consumption problem until then.

 

[simple_gifts]

Quote:

"1st generation" mazda rotary

I think he indicated 1st generation RX-7

 

[rearviewmirror]

Originally Posted By: Quest
Oh and besides: your engine is not "1st generation" for the REAL "1st generation" mazda rotary was in 1967(approx.) Mazda rotary Cosmo car; and the real 1st generation wenkel engine was back in the 40s back in Germany where Dr. Felix Wenkel developed it. NSU and even GM tried and failed over the decades....



It IS a 1st Generation Rx-7... Please re-read the thread title. I realize there were Wankel Rotary engines before Mazda, but I clearly stated this was in regards to the 1st generation Rx-7.

 

[levi]

If I'm reading the chart correctly, they're saying a 20wXX is ok at 15'F and above.

Think I'd go with a good 15w40 like Rotella/Delo/Delvac. Bet it would work good for you in that application.

:2cents:

 

[rearviewmirror]

Originally Posted By: levi
If I'm reading the chart correctly, they're saying a 20wXX is ok at 15'F and above.

Think I'd go with a good 15w40 like Rotella/Delo/Delvac. Bet it would work good for you in that application.

:2cents:


I was checking out the Rotella at VatoZone today. I might just give that a try as I think I'll stick with mineral oil for now. I've seen a recommendation for Castrol GTX 20W-50. That just seems so heavy!

 

[mechtech2]

I'd use a 10-40 dino.
I'd also mix 2-3 ounces of 2 stroke oil [per 10 gallons fuel] in the gasoline.

 

[Dick in Falls Church]

Neighbor used AMSOIL 10W-40 in his for a number of years, until he got new car fever and his kid got his RX-7. Now has about 300,000 miles on it--kid stopped using AMSOIL and used Mobil 1, which is probably not why the engine has been replaced once.

 

[Max_Wander]

I'd say a 30-40wt, straight if possible, with the least poly VIIs. poly VIIs dont burn too cleanly and a Rotary engine has no need for "fast flowing oil to the cams, lifters". the e-shaft bearings and trochoid gear are always seeing oil.

 

[rearviewmirror]

Revisiting this thread. I'm looking for a good 10W-50, does anyone know of any good ones? Otherwise I'll switch to a Castrol GTX 20W-50 or Havoline 20W-50.

 

[yannis]

elf Excellium 10W50 (PAO)
Liqui moly also makes one ,SYNTHOIL HIGH TECH 10W-50.
Since you live in Texas you could easily use a good mineral 15W40.

 

[rearviewmirror]

Originally Posted By: yannis
elf Excellium 10W50 (PAO)
Liqui moly also makes one ,SYNTHOIL HIGH TECH 10W-50.
Since you live in Texas you could easily use a good mineral 15W40.


The Rotella 15w40 comes in a gallon jug for $9.99 @ VatoZone.

Why is Rotella stated to be for diesel engines? I wonder if it will have any problems in a rotary, the oil used in the Rotary needs to be clean burning.

I better just stick with Havoline....... ?

 

[Drivebelt]

I'm also like HDEO 15w40 suggestion.

The Group II based HDEO 15w40's (CI-4+, CJ-4) are extremely good oils -- "synthetic-like" performance for half the cost of synthetics.

 

[Dick in Falls Church]

I'm also like HDEO 15w40 suggestion.

-- "synthetic-like" performance for half the cost of synthetics.


Sounds something like "partly pregnant"!

 

[REDDOG]

I would use a CJ-4 rated HDEO, since they are lower ash and some oil is burned by design.

 

[williar]

I'd use a quality 10w40. I used 10w30 in my 1st-gen & 2nd-gen
RX-7s, and it worked well with proper oil consumption. But in
Texas, 10w40 might be the better choice.