ACRx7-85

Hi,

Just bought a 1985 RX-7 with the 12A engine. This car is in mint condition with 37K original miles.

Wanted to know what oil I should be using and the weight?

Anything else I should know to maintain my car?

One thing I noticed is - when I start the car in the morning (pull the choke out) the car smokes somewhat and idles rough for a while. I know the smoke is normal but the rough idle?

Thanks

Bruceman

iTrader: (5)

The subject of engine oils is a huge can of worms. Do a search under "engine oil" on this forum and you will see what I mean.

Follow the recommendations in the owners manual for oil weight etc. Can not go wrong if you do this.

fatboy7

Factory service manual says:
5w-20 for below -4* F
5w-30 for below 32*F
10w-30 from -6*F to 86*F
10w-40, 10w-50 for above -6*F
20w-40, 20w-50 for above 20*F

Alot of people run 10w-30 in the winter, and 20w50 in the summer.

The actual brand of oil, or whether crude stock or synthetic stock, is the can of worms. Mazda, as well as a few well known rotary builders say no to synthetic. Other also reputable builders say yes to synthetic, but usually recommend only a certain type/brand.

The fact is, that because the rotary is designed to burn oil, you need to choose an oil that lucricates well around the bearings, cools the rotors, and yet burns well (while still providing lubrication). There are some brands of synthetic that have known to fail the latter, often leaving large amounts of carbon deposits, fouling plugs, and eventually killing motors. Castrol syntech comes to mind. Of course synthetics provide the first two properties far in excess of what standard dyno oil provides. That being said, if you can find a synthetic that also burns well, then bobs our uncle. Racing Beat suports royal purple, and I've heard several builders/ racers using AMSOIL with good success. Of course a race engine is not a street engine, and who knows, they could possibly disable the OMP and run premix avoiding the problem altogether.

BRealistic

While buying some MMO for the rex at Adtrance and bragging about its cleaning properties in rotary engines, since rotary engine burn oil and leave carbon deposits- the employee actually told me to use synthetic since since synthetics "burn completely clean- no deposits." He spouted off a few more things, so I left- no reason to tell a middle aged man working at Adtrance that he is a complete moron.