Aeka GSR

iTrader: (4)

Doing some searching I found this:
http://www.joegibbsracingoil.com/tra...viscosity.html
I would imagine this is because you would need to feed oil at a quicker rate and a thicker oil won't move as fast as demand.
So yes, I worry about that first start when the bearings are WAITING for oil and it takes longer with thicker oil. The high RPM argument means nothing especially since our engines don't exactly torque on the bearings that hard anyway, it is all about temps as seen below:

So since I'm not racing and have dual oil coolers my oil temps should not be too out of control, hence a choice of 10w-30.

If you are seeing 300 deg oil temps while driving around, by all means use the 50 weight.

2007 ZX-10

you're not getting it: the apparent viscoity of any oil in an FD is going to drop off rapidly because of all the fuel dilution, that's why people run 20w-50...after 1,000 miles, it's probably equivalent to a 10w-30...look at the viscosity values in rx7rage's UOA report after 1,000 miles (p. 1)!

Aeka GSR

iTrader: (4)

Probably? Each percent of fuel dilution affects about 3 percent of the total viscosity. So that 50 weight will be sitting around 45. A 30 weight with that dilution would be about 27. I was told this percentage quite a while ago from some teachers when I was studying to become a mechanic (lol). Luckily I build sand rails instead. I'll bet that number still holds true.
I change my oil within 1000 miles.
It would be nice to see what kind of numbers my oil turns out and I am interested in taking my oil to the lab since I have read this thread, every engine is different, and I would imagine a newer engine of 4k miles will bleed a bit more fuel than my engine of 12k miles.

2007 ZX-10

http://www.performanceoiltechnology...._0702_2004.pdf

http://www.analaboratories.com/commo...e/oiltests.asp

http://www.machinerylubrication.com/...up=Lubrication

perhaps more of us should be running this
http://www.synthoils.com/sae60.htm

2007 ZX-10

the beauty of the rotary is that it's so dead simple, oil related failures are very rare, but excessive apex seal and bearing wear is a concern, of course

Aeka GSR

iTrader: (4)

holy crap! 60 weight? lol.
And yes fuel dilution can cut down a 50 weight to a 20, but 3% won't get anywhere near that as I've already explained, I would imagine some of these diesel guys have some huge problems.

2007 ZX-10

the question is, how bad does it get after say, 3,000 miles, which these days is considered a short drain oil change...I've heard reports of fuel dilution approaching 10% on this forum

2007 ZX-10

https://www.rx7club.com/showpost.php...7&postcount=11

with 10% dilution, the 60 weight Amsoil is looking more resonable

GoodfellaFD3S

iTrader: (213)

Don't forget about the teeth on the stationary gears and the rotors that mesh together, I seem to recall reading that because of this, we need superior shear strength, something piston engine guys don't have to worry about.....the meshing gears are very hard on the oil and cause it to break down more quickly.

^^**Take this with a grain of salt, going off memory.**

Aeka GSR

iTrader: (4)

This is why we must go with a race brand rather than an off the shelf oil. They recently removed many molly properties due to catalytic converter life. Specifically we should be using Idimitsu or equivalent.

AHURAMAZDA

With the Idemitsu. what type of oil filter do you all run, also i have an fc as well as an fd, i have had my fc for about 5 years now, and i run valvoline 10w30 and mix it with about 10oz of marvel mystery oil, i change the oil and filter religouslyevery 1500 miles, my oil comes out clean (almost looks new) every change, and i have no problems what so ever.

Aeka GSR

iTrader: (4)

I run the K&N. Lately I've just been running Chevron 10w-30 because my oil leak is out of control right now. I tried fixing it, and made it worse. That was the biggest waste of time ever. I end up dumping a quart in every 100 miles and am always cleaning my garage floor.

I have a second engine I'm building so I won't be dealing with leaks any more and hope to be running some Idemitsu soon.

2007 ZX-10

1. I wouldn't use use 10w-30 in these engines, I think this thread provides all the evidence you need

2. MMO is not needed unless you have good reason to believe there is significant carbon deposits in your engine, if anything, it probably degrades oil viscosity even faster

in the FD or FC? is your FC turbocharged? does the oil smell like gas?

Aeka GSR

iTrader: (4)

Not really, people need to take it upon themselves to see how much fuel dilution they have and how often they want to commit to changing their oil.

2007 ZX-10

true, but it seems all FDs have the problem, some are just worse than others

I run 10w-30 in my "sewing machine" S2000, I wouldn't even consider running it in the turbo rotary torture chamber with clearances that aren't going to touch a Honda motor, even for 1,000 miles

David0ff

iTrader: (6)

here is what i run in my FD after much research :
Shell Rotella T ( For Diesel ) [ 15W-40]

http://www.shell.ca/home/content/ca-...ella_data.html

Among other things :

Pour Point, ° C -40
Flash Point, COC, ° C 229
Phosphorous ppm : 1260
Zinc ppm : 1380
Calcium ppm : 3690 ( Good for the rotary bone )
Viscosity Index 139 ( >110 ==> VERY HIGH = not too much viscosity change with temp increase )
Sulphated Ash, %wt 1.0 max

GoodfellaFD3S

iTrader: (213)

Mark, I think the weight depends alot on outside temps. I run 10w30 here in the NJ/NYC winter months, but 20w50 all other times.

Also, Chris Ott over at RP/rx7.com has told me numerous times that MMO is not a lubricant, it's more of a cleaner. He recommended against using it on a regular basis, especially as a lubricative pre-mix, because it does not perform as such.

afterburn27

iTrader: (5)

+1 . 20w50 for the track as well.

IMO, changing the oil more often with a proper weight is a better solution than running a heavy weight oil. If you have a fuel dilution issue (most FD's do to some extent) and you want to stretch out your oil changes, then maybe a heavy weight oil is right for you. I don't know about you guys, but starting the car on a cold morning with 20w50 makes me nervous.

BTW, I think Howard Coleman runs 5w30 and he was very happy with his recent engine tear-down. Just another opinion from an experienced FD owner.

GoodfellaFD3S

iTrader: (213)

I remember Ari over at RP/rx7.com telling me years ago that he liked 20w50 for rotaries that see a lot of high rpm use and aggressive driving, which probably describes most of us here .

AHURAMAZDA

1. I wouldn't use use 10w-30 in these engines, I think this thread provides all the evidence you need

2. MMO is not needed unless you have good reason to believe there is significant carbon deposits in your engine, if anything, it probably degrades oil viscosity even faster


Quote:
my oil comes out clean (almost looks new) every change, and i have no problems what so ever.

in the FD or FC? is your FC turbocharged? does the oil smell like gas?

I run the 10w30 and mmo in my n/a 88, and it never smells like gas at all. also just a side note, back in the day when i had a 1st gen rx7 i used to run straight 2 cylce oil in it like for lawn mowers, it ran wonderfully, you could feel the difference as soon as i changed it to the 2 cycle, it ran smoother and it burned it off much more efficiently than with conventional oil (cleaner i guess), came out cleaner broke down slower and had no fuel smell at all, i wouldnt suggest this in any other model, but for the first gen it is awesome. i know that it sounds crazy, that is what i thought when i first heard about it, but it was awesome (and cheap).

skir2222

Hmm no one really answered my question but I have done plenty of research and learned some stuff at the same time about this.

According to the manufactures fuel dilution does result in lower viscosity rating, high rpm engines don't need as thick oil as a low rpm motor due to fluid transfer.

Everyone I have known that has a rotary motor personally, runs 10-30 even me, before I switched to royal purple and have never had a single oil problem and neither has anyone I know of. Maybe it's because they change they're oil at 3k miles or less and take good care of they're car.

Why is this all of a sudden being discussed, why is running 10-30w with the fuel diluation our engines produce bad now? We've known for years there is gas in the oil.

If this fuel dilution can break down a 50w oil to a 20w then it could break down a 30w to a 0w. I have read countless times people running 10-30 and have not read of any oil related problems that I can recall.

I don't know why anyone would say "we should be using racing oil" because countless people have been using 10-30 for years. I would believe as long as you follow the FSM for maintenance you should have no problems?

I am looking to switch oils so I am looking for something new to try.

2007 ZX-10

ok, but these engines warm up fast, and then you have the same pressure cooker torture test you have in the summer

2007 ZX-10

again, check out the viscosity values from the UOA on p. 1

GoodfellaFD3S

iTrader: (213)

My oil pressure gauge tells me to run 10w30 in the winter.....when I've run 20w50 in the winter the pressure was almost pegged when cruising, i'm talking 12- psi at ~3k rpms.

GoodfellaFD3S

iTrader: (213)

The FSM and mazda's recommendations are aimed at Joe Public, who makes a stock 215 rwhp and redlines his car once in a while. Mazda also gave us the AWS, precat, and plastic AST