Poster6

Just got a 1980 12a. Motor has 15k but has been sitting. I farm and have copious amounts of 15w-40 oil for diesels.

My renesis took 5w-20 and this car calls for 20w-50 as of 1980. Is 20w-50 still recommended? Kentucky climate.

I'm a fan of synthetics and use them in all my piston gas vehicles along with lucas syn oil stabilizer. Usually use napa or valvoline syn oil.(valv makes napa oil)

So do I do synthetic or 15-40 or the 20-50. I'm leaning synthetic and a quart of syn lucas w a little bottle of 2 stroke oil in gas.

So confused. Lol

Ckforker

If your OMP is still working, historically, synthetic oil creates carbon buildup. If you're just premixing and no OMP (oil metering pump), synthetic should be fine. I've read on some articles that some synthetic oils have a different base and can be used, but carbon buildup is the death of a rotary and I wouldn't be willing to risk it.

I use 10/30, I'm mid Atlantic by the water, not too hot, not too cold.

Diesel oil has lots of additives, not sure how a rotary would like that.

j9fd3s

iTrader: (3)

the 15w-40 should work fine, the rotary doesn't care much about the oil you use.

mazdaverx713b

iTrader: (91)

I use only Castrol GTX 20w50. Just a personal choice there really. I run 10w40 if I'm driving my 7's into the cooler or colder months. 15w40 would likely be ok.

dguy

iTrader: (8)

I personally do not like or suggest using a 10w base on a rotary with a 60psi regulator setup (FB/FC) due to how many additives and polymers are needed to bridge the gap up to 40w. This is an old writeup but its still relevant:

FC3S Pro v2.0:&nbsp all_oilfaq_v1.2

I don't think its a problem to use a 10w base in a modified/higher pressure setup or FDs/8s etc.

Qingdao

iTrader: (3)

Rotella T4 is what I use.

Poster6

Hmmm I was leaning towards using dino oil of Napa(valvoline) 10w-40.? Going to put a dab of 2 stroke oild in the tank.

I'm assuming Luca additives are useless or not helpful in a rotary?

midnight mechanic

how about using what the manual recommends, and if you want to be proactive, make sure the motor oil is API sn rated or sn+. And turn that hyper active mind you got towards making sure that you change the oil and everything else at the right intervals and checking the OMP's.

I've only used Castrol GTX since I had to rebuild my VW bug motor in 1977. Once you choose a brand, it is better stick with that brand so you aren't mixing additives.

Poster6

Ok I bought 20w 50 valvoline. Wix oil filter. My omp works i assume. Any quick way to check?

Also, i have some a quart of 2 stroke oil to mix in tank as extra. How much do you all usuall put in a full tank? I'm assuming just a bare minimum.

j9fd3s

iTrader: (3)

you pull the OMP line off the carb and with a stop watch you run the engine at 2000rpm and see what comes out. the spec varies by year, but its 2-6cc (basically cc = drop). you do want to make sure its working.

with a working OMP, about 4oz for a tank is plenty. its really unimportant, you don't need any, and 1oz per gallon is probably too much, so somewhere in the middle

j9fd3s

iTrader: (3)

my work sent my team to a bunch of oil classes and you do not want to mix additives. its very simple, you do not know what is going to happen. they may mix, they may not mix...

Maxwedge

iTrader: (1)

OMP - as said above, if yours is working (and they usually are) you don't need to add anything to the gas. If yours was broken, or removed, it would be 1oz per gallon. But that's a PITA so hopefully yours is still pumping along.

Poster6

Thanks guys. I was basically just adding the 2 stroke oil mainly as a precaution for now as a backup lube until I can get everything lined out on the ol girl including my knowledge of the motor.

If this was a piston motor I'd put some sea foam in the tank but I was worried it might wash out what little lube there is in the rotor housing. Going to remove the carb and do a thorough clean out instead.

The good news is the gas reactor thingamajig and smog pump are gone and headers installed. Need to make sure the old vaccum lines are correctly removed to the carb and I'll be in business.

Banzai

iTrader: (13)

I regularly add a little Sea Foam to my gas. Helps break up the carbon deposits and fuel system clean.

7aull

iTrader: (2)

Likewise, I run a can of seafoam thru the gas tank 1x a yr to keep things tidy.
GTX 10-30 for oil the last 20yrs, 4oz of 2-stroke per tank as a precaution. OMP seems to be working fine. 110K mi on original 12A...

Stu A
80GS
AZ

Poster6

Lord shes a cranky ol Bxxxh. Had her running....poorly. fuel supply low. Gas tank was full of black goo. Changed fuel filter. And drained tank. Had out about 8 gallons in. Gas looked like oil. Got all bad gas out cleaned lines. Had good flow to fuel pump and when I went to turn on....the fuel pump quit working. Lol

Might be a fuse. I was over it. If it is a pump I may just relocate it to the engine bay to make changing filters easier. Takes a lot of work to get on my creeper. Need a car lift. Tomorrow I'm getting her purring.

mazdaverx713b

iTrader: (91)

Sounds like you're pretty close!! I could use a lift as well...and a bigger garage haha!

Maxwedge

iTrader: (1)

Ramps are a good start. I use plastic ramps which don't cut into the blacktop on hot days ( like metal ones do). Car is low enough I can use them in the garage too.

7aull

iTrader: (2)

Something to consider:
Tank itself might be compromised, as far as gunk just built up on the walls. Be it rust or whatever. Very common in cars that have sat! Been there. If your poor running persists after your work, you may want to drop the tank and have it pro-cleaned by a rad shop...

Stu A
80GS
AZ

midnight mechanic

I dropped the tank while just having a floor jack and car ramps under a 4x4 block of wood just infront of the the rear wheels. I needed liquid wrench for the two bolts holding the gas tank straps. Point is that dropping the tank isn't that hard.

If I were you, I'd try starting the engine using gas from a container to the carb, and eliminate the suspected gummed up gas tank and fuel lines. You just need to check that the carb bowls have fuel in them.

Also, it might be that your carb is gummed up. Old gasoline can precipitate out a resin that messes everything up.

Poster6

I have thr garage....my bldg is 60x80 with 30 foot sectioned off. The rest is a work in progress. Going to concrete it soon and then I'll put in a lift. 12kni think. That way i can lift farm trucks.

ray green

iTrader: (14)

And do an oil change.

10-30W will work, 10-40W if it's smoking, 20-50W is good for old engines.

You need to do some serious diagnostics on that bitch Poster, it sounds like she's just this side of firing.