Mr.Snakey

Hello again,

First off, this topic has most likely come up many many times before but I'm reigniting it.

The discussion of oil, I want to learn a bit more about it and have you guys give your input on what oil you run and why. Ensuring the perfect lubrication of internal parts is of course critical.

I would also like to mention that in my FD the previous owner has installed a direct oil injection "rotary aviation" kit and is feeding my engine Amzoil interceptor 2 stroke oil. What would you think would be the best oil to pair up with this set up?

And of course, Synthetic VS Non-Synthetic?

Lastly, the Porsche guys have been running turbo diesel oil in they're engines, is this something we would also benefit from doing? Since from what I hear some oil companys such as Mobil1 has taken a certain chemical/ingredient out because of newer regulations, making not as good as it used to be. Turbo diesel oil does not have to meet this same standards and that (so far from what I know) is why they're running this oil. What are the pro's and cons?

This could be old news for all I know but it would still be worth it to know better for future oil choices.

Looking forward to hearing from you folks,

Thanks !

Alak

iTrader: (9)

If I didnt reinstall my oil metering system, I would be running Pennzoil Ultra Platnium. It was rated the best engine oil through independant testing over all other synthetics.

But im running castrol gtx 10w30 like anyone.

Alak

iTrader: (9)

540RAT - Tech Facts, NOT Myths

Quite the read but very interesting data.

Alak

iTrader: (9)

My mistake, that was pennzoil with an additive. If you look down at number 27 you will see castrol gtx 20w50 categorized in the outstanding wear protection. The first 30 or so oil are with additional additives. But you can see a few over the shelf choices.

He also goes on to say in the latter part of the document that a thinner oil should be considered for quicker heat transfer as opposed to a thicker oil. Which is likely why alot of cars these days run 0w20.

To be honest the only difference I notced between 10w30 and 20w50 in the rx7 was oil pressure. Temps never really changed, but I never really raced.

thewird

iTrader: (8)

I suggest 10w-30 for most low power street applications and 10w-40 for the rest. I stay away from the usual rotary 20w-50 unless its a high rpm (9k) motor with lots of bearing clearance. All the race guys use that oil and everyone thinks thats what rotaries need which is not true at all, its application dependent. The thinner oil will shoot through the engine and turbo faster on cold starts and cause less cold start wear on components. I personally use Royal Purple HPS 10W-40 in my car. I use the HPS because of the zinc additive. Though I plan to switch to 20W-50 now since I'm going to be revving to 9-9.5k RPM with the new porting and turbine housing.

thewird

Logitikes

What about on a completely stock engine? Ive been thinking about switching to synthetic, but from the service history, its been using 10w30 castrol gtx. Im planning to do some track days this year as well.

sctRota

iTrader: (2)

Royal purple 10W-40 and AMS oil for me. Why? To be honest, I just prefer the two. Or if I find that blasted Marvel oil again

thewird

iTrader: (8)

I'd say 10w40 if its going to see some track days just for the added protection. Stick to regular oil if its used mineral oil all its life and its original engine. There may be carbon deposits around the oil seals which the sythetic oil may clean out and turn it into a smoker over time. If its been rebuilt at some point, probably fine to switch. It's one of those its ok 99% of the time things, even on an original engine but if your that 1% then it kinda sucks hehe.

thewird

Mr.Snakey

I'm not sure what I'll go with just yet. As I've been discussing with many other performance car owners they say that the worst part of wear usually is from cold starts. With the thinner oil in the pan and direct injecting two-stroke oil, that may be the perfect balance from all aspects.

I think 10w-40 might be a good match for my application, I will also think about using that Royal purple. Does the zinc really help with wear? Some guys swear by it and others have no interest in the stuff at all.

23Racer

My opinion (and you can take it for what its worth) is that for the street a 5w50 synthetic works very well in 90% of applications. A 10w40 synthetic works very well also. Any of the major brand names does a good job, combined with a premium filter. The main concern on the street is fuel dilution of the oil strength and contamination build up in the oil based on your driving habits. You are basically trying to prevent wear with oil and a rotary has different needs than a piston engine.

In a piston engine the crankcase oil serves to lubricate the bearings, the valve stems, the piston to bore interface, the cam to lifter or rocker interface and also helps to provide a medium that helps to seal the rings to the bore.

In a rotary, especially if you have a separate way of adding oil to the fuel to lubricate the apex seals, all you are really worried about is lubricating the chain and the bearing surfaces. This is really easy work for most premium oils. That is why you can pretty much make your pick and it isn't going to matter a whole lot. The added zinc in Royal Purple or Brad Penn or Redline or Joe Gibbs or Rotella oils is considered to be a high pressure lubricant and a big help in cold start ups. It was removed from regular oils a number of years ago as any zinc out the exhaust port did quick work in killing the cats on your car. If you are still running cats and using a 2 stroke or regular injector oil in your fuel, then I would go with a high zinc content oil in your pan. If you are still using the standard oil injection system from Mazda that uses oil pan oil to lube the apex seals and you have to keep your cat alive, then use any regular premium oil that is available today without zinc.

For racing I have tried a bunch of different oils with different claims, been sponsored by Castrol and Quaker State and used their oils and I keep drifting back to Redline straight 40 weight or 20w50 Racing. All synthetics are not alike. The synthetic oils use a man made base stock that is rated regarding its quality, amongst other things, by the length of these things called esters. These are the strands in the liquid that provide the shear strength of the oil. Almost all of the synthetics out there today use standard length esters with other additives to provide the shear strength in the oil. This is also what provides the oil wedge that keeps your eccentric shaft from eating the bearings. They all work very well for a time, but after some abuse from heat, loadings or RPM, these additives break down and the efficacy of the oils starts to loose its capability. My Q racing synthetic 20w50 worked very well for about 90 minutes then I started to notice a drop off in pressures at idle. Its never bad, but it does drop showing that the additives are starting to break down and the oil looses its effectiveness.

Only two oils, that I am aware of, use the premium length esters which are almost double the length of the standard ones used in brands like Castrol, Mobil 1, Royal Purple, etc.... These two brands are the absolute premium race oil produced by Motul and the Redline race oils. I have run these oils a lot and never have seen a hot pressure drop at idle after racing for 90 minutes plus. In fact, these oils never change pressure limits for the time they are in the car. These are what I am going to use this year and a heck of a lot of other racers use them as well and not because they sponsor a lot of people, they don't. When you have to pay for your rebuilds yourself, guys use Motul and Redline.

So what do I use in me XJR (which is the only street car I have that I care about the rest are appliances) I use Royal Purple as its cheaper than Redline, a very high quality oil that is produced in very controlled conditions, a Wix or K&N Oil Filter as they are about the best and I change my oil frequently before it gets a chance to get fuel or contaminant fouled.

Your opinions may vary.

Eric

thewird

iTrader: (8)

^ I like this guy.

thewird

DaoNhatHai

iTrader: (38)

It's been a couple years since I will be back in an RX-7, but I've been using Royal purple 5w40 for the 4-5 years I've owned RX-7s

RE.Amemiya.FD3S

Guys, I live in a Hot weather area 35C~47C, Middle East, but it gets cold in the winter 27C~19C and I used Motul 15w50, the car smokes in cold start the rpm plays up n down for a bit then the smoke stops! I am think of getting RE Amemiya 10w40 SL, since I am an RE Amemiya freak

What do you guys think?
and how much of liters do I need to fill the engine up?

Thanks