2 Gallons of Mobile 1 5-40 Diesel Motor Oil was $52 at Walmart.

Lots of antiwear and not a bad price. It's kind of funny that Walmart has a better selection of oil than local auto stores.

 

So.... Let's talk numbers and how much extra ZDDP we need (if any)

What levels were zinc and phosphorous prior to being decreased?

Looking at the various racing oils, their levels are around the .18 - .20 levels - so 1800 - 2000 PPM. Does anyone know what the appropriate level is for a street driven RX7?


Howard's recommendation of Mobil1 5/30 or 10/30 have around 900 (.09) zinc and 800 (.08) phosphorous. See:
http://www.mobiloil.com/USA-English/...duct_Guide.pdf
The levels vary quite a bit depending on which flavor of Mobil1 you get in those weights to pay attention when you purchase your oil.

However, the 15/50 has 1300 (.13) zinc and 1200 (.12) phosphorous and has this comment in the column for Recommended Usage:

HT/HS applications. Racing and Flat tappet applications.


Reviewing the ZDDPlus web site, they state to add 4 oz to your oil but don't mention what base level of ZDDP they assume the oil you are adding it to has. Copy/paste:

A single 4-oz bottle is the correct concentration for a 4- to 5-quart oil change.

DDP is most effective if the concentration is between 0.18 and 0.2 % by weight. Tests have shown that concentrations above this amount, up to as much as several percent, have no effect except to prolong additive life. The current oils available today contain very little ZDDP.

http://www.zddplus.com/index.htm#AboutAdditives


so is 4 oz enough? What sort of level does 4 oz translate to?

 

Just found this but haven't fully digested it yet. I wonder if the answer is there...
http://www.zddplus.com/TechBrief7%20...20Dilution.pdf

 

Seems the article you posted answers that question by assuming the level of phosphorus to be lower than 800ppm due to the SM oil classification. However, It goes on to say that recent testing shows the levels to be closer to 600ppm when conducting tests of oil in that classification range.

It also says that most oils at that time (guessing when flat tappet cams were used) has concentrations of 1200-1600 ppm.

They also say that the 4oz. bottle of zddp plus generally increases the concentration of ZDDP in SM oil classification by 600ppm for a five quart oil change. So for us FD people it would increase it a bit higher due to the smaller oil pan.


This is why I decided to use a Diesel engine oil. It has the high concentrations of ZDDP and no addative.


John

 

John where do you get your Oil? What name brand and weight you use? How well does it burn when it mixed in the rotor chamber by the OMP?

 

ive been doing a LOT of searching and I was hoping to revisit this idea, since a lot of the information out there seems outdated now (2012).

Synthetic is better in every way period EXCEPT for it's burn off characteristics, which is more or less only an issue for Mazda's rotaries since they're designed to inject oil into the motor, correct? With the exception being that Idemitsu oil, which I'm assuming was designed particularly with that burn off characteristic in mind.

I guess my question is - has anything changed since most of these older threads <'05 were made? I guess what I'm more interested in is any changes in design to the 13b-rew since the car left the states, particularly 99+ specifically in regards to oiling?

 

I am currently running Idemitsu 20W-50 with an OMP, but I plan to eliminate the OMP soon and do premix only. Would it be wise to change brands or weights of oil when I do that, or is the Ide 20-50 still good for crankcase only oil?

 

I have searched around for the GM additive that Howard mentione but I can't seem to find it. Is it discontinued?

 

You have a few choices:
(1) Idemitsu oil
(2) racing oil
(3) Royal Purple HPS oil
(4) ZDDP, available in most auto parts stores, ask for it.

 

This Amsoil 20/50 is readily available locally, and I've been using for a while. Is this appropriate to use?

AMSOIL SAE 20W-50 Synthetic Premium Protection Motor Oil

 

ZDDPlus™ - ZDDP for Classic, Muscle Cars & More

according to the website Big Daddy Don Garlits uses it

so do i. (humor )

i bought a bunch of it thru Eastwood for a friendly price... i have used ZDDP+ since GM stopped offering the product in the 4 oz container.

howard

 

mmm revisiting this thread , i've been using Valvoline VR1 their racing oil as its the only readily available oil racing oil

I know the benefits of synthetic oil. But since I couldn't find the mentioned GM ZDDP addative I just went with the racing oil . I'd gladly switch to synthetic with the ZDDP .

If even you use it howard I'm guessing this is probably the way to go .. My

question though is what benefits to you get out of it . compared to racing oil .

synthetic works at a higher temp range then dino oil , so on a piston engine you can use a lighter weight synthetic oil and it would still lubricate as a thicker weight oil at higher temps . and because its inate thickness is less , there is less resistance and power is gained .

Also It can go longer then regular oil .

but since we use thick oil on our cars because blowback thins out the oil .

we'd still use 20-50 synthetic ? or am I missing something?

P.S. I over simplified things

 

"since we use thick oil on our cars"

i wouldn't use race oil because of its generally high viscosity. i have always used 5-30 oil. the FD generates high oil pressure which more than takes care of the lubrication. i seldom see bad bearings in the motors i disassemble. the stationary gears also look good.

you are correct in that high temps separate synthetic and non synthetic. the rotary generates high oil temps so synthetic should be the oil of choice.

hc

 

Thanks for clearing that up , as i've always been told 20-50 or to the gallows with me!

 

Such luminaries as Chris Ott and Ari Yallon swear by 20w50 for our rotary-engined steeds..... sorry Howard, but I wouldn't dream of running 5w30 in an FD going to the track. 20w50 all the way, especially in the heat of the summer

 

YEP

I think Howard is referring to drag racing where light weight oil equals higher HP.

For track use there are some BADASS oils available like mobil 1 0w 50 racing oil but no way am I paying over 10 bucks a quart for oil.

I like:
VR1 or mobil 1 15 or 20w 50 for the track car because both keep the temps down enough. My last 3 track car engines have died from tired springs both apex and corner. 1st 2 had around 7k miles and the 3rd around 5k. 3rd engine was still running though so I could of squeezed more out of it. If I ran water injection it might run forever (just kidding hehe)

For typical daily driving I recommend cheap oil (whatever is on sale) changed frequently.

PS There are very few turbo engines that will go 7k hard track miles so I'm not complaining. It's probably hard to get more miles out of spec miata before you're no longer on the podium and need a fresh engine to compete.

 

Mobil 1 20/50 is impossible to find anymore, I'm not sure they make it, which is why I switched to Amsoil. a 15/50 might be the ticket.

FWIW, I switched up to 20/50 from 10/30 around the time my turbos started making a little noise. I got a lot of time out of them after that, and the noise stopped (for years). Beyond the engine itself, wondering if the thick oil helps support the turbo bearings. 10/30 looks like water after a day on the track... you can barely see it on the dipstick.

 

Although, not appropriate for street use, I know of a few very respected race shops that recommend Schaeffer Oil for race use - even over Redline race Oil based on oil analysis. I've started using it on my Spec Miata after doing oil analysis using Redline race oil. Waiting on analysis results of the Schaeffers so I don't have data for comparison purposes myself on that motor.
Schaeffer Oil | Synthetic Motor Oils, Engine Oils, Diesel Fuel Additives, Industrial Lubricants Manufacturer

Schaeffer also has a street oil that I'll probably try on my FD once I run it through an oil analysis comparing it to the Mobil 1 15/50 that I'm running now. It is cheaper than Redline or Mobil. I think Neil in FL mentioned this oil a few pages back... I buy it here:
Oils, Lubes & Fluids : Advanced Autosports, Miata Race Parts, Spec Miata and TRANS AM Race Car Sales, Service, Build & Rentals Support in Midwest


Mobil 1 15/50 has good amounts of ZDDP as it is which makes it a great choice for rotaries. I don't think you need to add more ZDDP to it. There is such a thing as too much ZDDP...

Racing oils have greater amounts of ZDDP but not enough other additives for extended use in a street car from what I understand so consider that in your decision making criteria besides just the amount of ZDDP.

 

I run a diesel engine oil in my motor, high zddp at a fair price.

 

I've never seen 20w50. M1 does make 15w50 and I used to get it in gallon jugs. Now I can only seem to find it by the quart.

 

I'd Like to add a new wrench into the workings of The oil mechanism . Most of us have gone through this thread . and there are somethings that have come to mind , I had read this

FerrariChat.com - FAQ: Motor Oil Articles by Dr. Ali E. Haas (AEHaas) <-- which is in our FAQ , years ago when i worked at an auto parts store in fact . and everyone recommended oil weights depending on millage

But adding that knowledge according to what MR Ferrari says The thinner the cold weight the quicker it will get to operating temp , the better it will lubricate when cold , all + +

So I was at the auto parts store the other day . and I ran across some new oils with I believe it was 5-50 , and 0-40 weights .


Before I jumped the gun and bought these , I'm Interested in reading any cons to purchasing One of these new oils with thinner cold weights .

 

long time posting, but there are no real cons (at least for a "traditional" motor) for running a 0w oil. Exactly as you said, thinner cold weights lubricate better not only at cold temps, but all temps under operating temp. Obviously, cold temps are were 70-90% of engine wear happens (for traditional motors), so this is a good thing. The only negative I'm aware of is that the noack volatility is usually a little higher.

However, isn't the main concern for rotary engines the burn characteristics of engine oils, more than anything else?

 

The con is the friction modifiers used to create the warm viscosity number can breakdown faster as there is a lot more of it to create the wide ranging viscosity. You will probably notice those oils were synthetic or a synthetic blend. That is due to the fact that the base stock requires less friction modifier to achieve the same viscosity rating.

Personally I use 5w-40 rotella synthetic. It is a diesel engine oil and has high levels of zddp compared to gasoline oils.fpr the exact reason you mention, cold pumpability. 80% of engine wear comes from startup when you need the oil to be easily pumped.

You are in florida probably not as much of a concern as up in the north east.

 

What ends up happening is you can have a 0w-40 oil eventually breakdown to the basestock of a 0w oil at operating temp. This imo is not a concern for us as we change the oil often for other reasons.

I really dont understand why people us such heavy oils in these cars. If you keep the oil temps in check.

 

according to this little chart , its not as drastic as you guys up there with freezing temps , but it is still much thicker then operating temps

" Oils are divided into grades (not weights) such as a 20, 30 or 40 grade oils. This represents the viscosity range at operating temperature. But it is NOT the actual viscosity as we shall see. The issue is that viscosity is temperature dependent. Let’s look at a 30 grade oil and how the viscosity of this grade of oil varies with temperature:

30 grade oil (often referred to as a 30 “weight” oil):

Temperature ( F )....Thickness

302...........................3
212..........................10
104..........................100
32..........................250 (rough estimate) "

I don't believe that just because I live in a warmer climate I should neglect this LOL , and yes I have thought about using the diesel oil as you have mentioned before from Walmart . But since I ran into it this past weekend I just thought hey .. why not .

This right here is my only reservations for using the diesel Oils

http://speedtalk.com/forum/viewtopic.php?f=1&t=32279


These are the numbers for the Mobile 1 0-40 http://www.bobistheoilguy.com/forums...2590418&page=1