Good technical discussion about Engine Oils
07-22-2009, 01:00 AM
#128
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For those of us non-metric people :350 kilopascals = 50.7632082 pounds per square inch
So, 50 psi @ 212 degrees F @ 3,000 RPM's. Even now I see about 70 psi @ 3000 RPM's around 180 to 190 degrees at 3,000 RPM's. I noticed at WOT I go as high as 80 PSI and that's with Mobile's 0w-40 in the car and about 3,500 miles on this oil change. That's pressure at the oil filter so it's hard to say how much higher it is outside the filter.
Last edited by Flashwing; 07-22-2009 at 01:25 AM.
07-22-2009, 01:20 AM
#129
Great information! That certainly helps to narrow down the focus of where you should be.
For those of us non-metric people :350 kilopascals = 50.7632082 pounds per square inch
So, 50 psi @ 212 degrees F @ 3,000 RPM's. Even now I see about 70 psi @ 3000 RPM's around 180 to 190 degrees at 3,000 RPM's. I noticed at WOT I go as high as 80 PSI and that's with Mobile's 0w-30 in the car and about 3,500 miles on this oil change. That's pressure at the oil filter so it's hard to say how much higher it is outside the filter.
For those of us non-metric people :350 kilopascals = 50.7632082 pounds per square inch
So, 50 psi @ 212 degrees F @ 3,000 RPM's. Even now I see about 70 psi @ 3000 RPM's around 180 to 190 degrees at 3,000 RPM's. I noticed at WOT I go as high as 80 PSI and that's with Mobile's 0w-30 in the car and about 3,500 miles on this oil change. That's pressure at the oil filter so it's hard to say how much higher it is outside the filter.
Time to switch to 0w20 and incur nycgps wrath LOL
07-22-2009, 01:22 AM
#130
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Lol, my motor is probably going to need a rebuild in another 20,000 miles anyway so what the hell!
At least that gives me a reference point. Clearly if I'm not producing 50psi at 3,000 RPM's then I'm not getting enough flow to lubricate the motor.
Worse case I switch to a 0w-30 which is fine with me.
At least that gives me a reference point. Clearly if I'm not producing 50psi at 3,000 RPM's then I'm not getting enough flow to lubricate the motor.
Worse case I switch to a 0w-30 which is fine with me.
07-22-2009, 02:11 AM
#133
Super Moderator
Oil pressure (reference value)
Oil temperature: 100C {212F} @ 3000 RPM
2004-08 RX-8 50.8 PSI...Oil Filter By Pass Pressure 11.4—17.1 PSI........Oil Pump Relief Valve Opening Pressure 64.0—71.0 PSI
.... 2009 RX-8 72.5 PSI...Oil Filter By Pass Pressure 20.3—26.1 PSI........Oil Pump Relief Valve Opening Pressure 156.6 PSI
Oil temperature: 100C {212F} @ 3000 RPM
2004-08 RX-8 50.8 PSI...Oil Filter By Pass Pressure 11.4—17.1 PSI........Oil Pump Relief Valve Opening Pressure 64.0—71.0 PSI
.... 2009 RX-8 72.5 PSI...Oil Filter By Pass Pressure 20.3—26.1 PSI........Oil Pump Relief Valve Opening Pressure 156.6 PSI
Last edited by ASH8; 07-22-2009 at 02:21 AM.
07-22-2009, 04:58 AM
#134
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Great information! That certainly helps to narrow down the focus of where you should be.
For those of us non-metric people :350 kilopascals = 50.7632082 pounds per square inch
So, 50 psi @ 212 degrees F @ 3,000 RPM's. Even now I see about 70 psi @ 3000 RPM's around 180 to 190 degrees at 3,000 RPM's. I noticed at WOT I go as high as 80 PSI and that's with Mobile's 0w-40 in the car and about 3,500 miles on this oil change. That's pressure at the oil filter so it's hard to say how much higher it is outside the filter.
For those of us non-metric people :350 kilopascals = 50.7632082 pounds per square inch
So, 50 psi @ 212 degrees F @ 3,000 RPM's. Even now I see about 70 psi @ 3000 RPM's around 180 to 190 degrees at 3,000 RPM's. I noticed at WOT I go as high as 80 PSI and that's with Mobile's 0w-40 in the car and about 3,500 miles on this oil change. That's pressure at the oil filter so it's hard to say how much higher it is outside the filter.
07-22-2009, 06:45 AM
#135
Cuz I read the FSM like 20 thousand times ...
oh what? where is that ? Its in "Enginedetails"
Sometimes when I go WOT I see as high as 630 kPa. only possible with 20w50 tho. with 5w30 (mobil1) or 0w30, highest I've seen is around 590 or something and only when it still fresh (less than 1000 miles)
Its ENGINE damn it ! not Motor !!!!
whats wrong with ur engine that u need a rebuild for ? too much 5w20 ?
oh what? where is that ? Its in "Enginedetails"
Great information! That certainly helps to narrow down the focus of where you should be.
For those of us non-metric people :350 kilopascals = 50.7632082 pounds per square inch
So, 50 psi @ 212 degrees F @ 3,000 RPM's. Even now I see about 70 psi @ 3000 RPM's around 180 to 190 degrees at 3,000 RPM's. I noticed at WOT I go as high as 80 PSI and that's with Mobile's 0w-40 in the car and about 3,500 miles on this oil change. That's pressure at the oil filter so it's hard to say how much higher it is outside the filter.
For those of us non-metric people :350 kilopascals = 50.7632082 pounds per square inch
So, 50 psi @ 212 degrees F @ 3,000 RPM's. Even now I see about 70 psi @ 3000 RPM's around 180 to 190 degrees at 3,000 RPM's. I noticed at WOT I go as high as 80 PSI and that's with Mobile's 0w-40 in the car and about 3,500 miles on this oil change. That's pressure at the oil filter so it's hard to say how much higher it is outside the filter.
Lol, my motor is probably going to need a rebuild in another 20,000 miles anyway so what the hell!
At least that gives me a reference point. Clearly if I'm not producing 50psi at 3,000 RPM's then I'm not getting enough flow to lubricate the motor.
Worse case I switch to a 0w-30 which is fine with me.
At least that gives me a reference point. Clearly if I'm not producing 50psi at 3,000 RPM's then I'm not getting enough flow to lubricate the motor.
Worse case I switch to a 0w-30 which is fine with me.
whats wrong with ur engine that u need a rebuild for ? too much 5w20 ?
07-22-2009, 06:57 AM
#136
Metatron
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when I go WOT I see as high as 630 kPa.
So there is no resistance to flow that you would consider 'too high'?
Just like a turbo, high pressure means little if there's no flow.
I have some ISO 680 weight oil you could try.....
S
So there is no resistance to flow that you would consider 'too high'?
Just like a turbo, high pressure means little if there's no flow.
I have some ISO 680 weight oil you could try.....
S
07-22-2009, 07:48 AM
#141
I know what is it for and how it works.
the point here is that, I can stay at proper pressure for longer with 20w50. but 0w30/5w30 (when I got the Reman I had 5w20 in there, its has less pressure than w30 or w50, dont remember the value right now) will loose its pressure after a few hundred/a thousand miles.
for the past 20 something years. The basics of 13B has not been changed. 20w50 work, so Im going to use it.
Time for me to break the other DTSS off the rear. be back in couple of hours.
Last edited by nycgps; 07-22-2009 at 07:53 AM.
07-22-2009, 08:04 AM
#142
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oh so you realize that above 80psi (~550kPa) your oil regulator aka pressure relief valve is open and bypassing a large amount of oil from the oil pump right back into the oil pan? Yea your getting flow... too bad 1/2 of it isn't even reaching your engine
07-22-2009, 09:09 AM
#143
I have been saying that for YEARS and it seems that Lexus and Hyundai also know this. Have you seen their American marketing campaigns for the Lexus IS and the Hyundai Genesis Coupe?
07-22-2009, 09:22 AM
#144
and that is the reason.
TOO BAD you're still getting that "bypass", as long as you are pushing your car. thats what it was designed for.
but its just sad that in about 1000-1500 miles your poor 5w20 will degrade so much and turn into crap,(its protection suck to begin with)
I would rather get 1/2 of "useful, still working, not crap" oil under certain condition. than having Full of crap at the same condition.
how about this, you can go ahead and have fun with your precious, I have fun with mine, I am going to open my engine up 50K miles later and check for wear.
I dont even have a new motor, mine is just a reman.
sounds fair to everyone ?
For reference :
Red Line :
0w-20
Lightest road car motor oil produced by Red Line. Offers increased fuel economy and is very popular in small engines and hybrids. Features a thicker oil film at operating temperature than a petro-based 5W-20.
Should we count our 13B into the "small engines" category ?
5w-20
Replacement for OE factory-fill oils in many new Ford and Honda passenger cars and light trucks. Excellent performance in weather where cold starting and short running duration are concerns.
0w-30
Better flow at extremely cold temperatures compared to 5W30 and 10W30. Features a thicker oil film at operating temperature than a petro-based 5W-30. Suitable for use where a 5W-30 is recommended.
5w-30
Provides the quickest starts and fastest oil pressure rise. Will reduce turbo lag and provides more power and best economy in an engine in good condition. Replacement for OE factory-fill oils in passenger cars and most light trucks, including most new GM cars and trucks. Thicker oil film at operating temperature than a petroleum 10W-40. Best choice for engines operated in extreme cold weather.
10w40
Best choice for engines that typically run high oil temperature or for engines in daily-driven vehicles regularly operated in hot weather. Great for medium and heavy duty gasoline engines in trucks. Best choice for high-performance engines that see street/strip or track activity. Features a thicker oil film at operating temperature than a petro-based 20W-50.
20w50
The ultimate high-temperature protection in Red Line engine oils recommended for street use. Good for engines that regularly run very high oil temperatures. Best for engines that run large clearances such as air-cooled engines or large-displacement, all-out racing engines that see occasional street use. Provides 25% more viscosity in bearings than petroleum 20W-50s. Not recommended for use in cold climates where temperatures are at or below 10°F or -12°C. Not recommended for street use in production engines that see sustained oil temperatures below 200°F (those engines should use Red Line 10W-30 or 10W-40).
Even when its dead cold out there. (16f)it did say all-out racing engines. but seriously speaking, redline is talking about a piston engine. and piston engine have much lower oil temperature than rotary engine. so yeah, I think I am better off with 20w50.
Im not sure about the upcoming 16x cuz it will be all different. but for 13Bs, its more or less the same thing, so yeah, 20w50 for me.
Dont get me wrong, I dont have any hate on 5w30, I use it on my Honda FIT, and Brother's FX-35(Mobil1), but for my father's CX-7, I use 0 or 10w40 (depends on stock in my basement, lol)
Last edited by nycgps; 07-22-2009 at 09:56 AM.
07-22-2009, 09:58 AM
#146
SARX Legend
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You have to take what the oil manufacturers say with a grain of salt. You would have to look at the specific specs of those oil individual oils to make an informed decision. It has been shown in many independent articles that the numbers on the bottles don't always mean a whole lot.
I get the feeling that some people didn't actually read and comprehend the entirety of the article DR. Haas wrote.
I get the feeling that some people didn't actually read and comprehend the entirety of the article DR. Haas wrote.
07-22-2009, 10:04 AM
#147
You have to take what the oil manufacturers say with a grain of salt. You would have to look at the specific specs of those oil individual oils to make an informed decision. It has been shown in many independent articles that the numbers on the bottles don't always mean a whole lot.
I get the feeling that some people didn't actually read and comprehend the entirety of the article DR. Haas wrote.
I get the feeling that some people didn't actually read and comprehend the entirety of the article DR. Haas wrote.
Hyundai saids they're better than BMW. (as much as I dont like BMWs, but Hyundai? hmm ...)
GM saids they have better hwy mpg than Toyota (Hello, your car is not selling well)
Toyota saids they're the most efficient mpg auto maker (hmm ... really ... so ? FWD FTL ?)
etc.
but we're talking about the manufacture itself talking about what their product is for. Just like Mazda's "holy bible" 5w20 "recommendation"(hint: not REQUIRED)
I dont see why I shouldn't put those(grade of oil is for X temp/engine types) recommendation into consideration
Redline is not the only oil manufacture who talks about what their product is for. You should know it. Castrol, and tons of others. they all talked about what their X weight oil is for X conditions.
Dr. Haas talked about a lot of stuff. but in the end I only see one conclusion : Use what you think its best for your application. Follow factory's recommendation.
so ... what does that mean ... nothing.
There are too many variables in those engines and there has been trouble with every oil used. I would stick with the factory suggestions as they have the largest data base to use for failure analysis.
13B-MSP got the biggest recall ever for rotary engine (well, maybe except the time that "old" synthetic oil ate mazda's cheap seals alive incident ...), first rotary to have that "5w20" recommendation. first massive recall not related to eating seals alive. first massive failure @ hot climates. thats a lot of first.
it COULD be that this engine has a defect to begin with, we just dont know it. Its kinda fishy that Mazda has told all dealers not to open them up. in the old days, they teach you how to check the engine internals in FSM. not anymore.
Last edited by nycgps; 07-22-2009 at 10:25 AM.
07-22-2009, 10:05 AM
#148
07-22-2009, 10:25 AM
#150
Registered
This topic is interesting as I've been dealing with oil viscosities here at work. Basically there has been a recommended oil rating for different climate uses (actually 2) but no one can say why it is that way or how it came to be. The answer is "we've always done it that way". I've been looking into it and what I found on our pumps was that the main engineer about 50 years ago had no idea what oil to use. He asked a friend who was an oil engineer and the guy basically replied, "just use X" and it stuck.
We build large mud pumps for oil drilling and the oil lubricates the bearings as well as the large bull and pinion gears. Our smallest pump has a 40 gallon capacity and is rated at 450 hp. Our largest holds over 80 gallons of oil and is rated over 2000 HP. We have the ability to build a 3000 HP unit. Our oil chart recommends 2 different weights and they are ambient temperature dependent. It recommends 75W90 for 0*F-100*F use and 85W140 for above 100* ambient temperature use. Sound strange? That's why I'm looking into it. We have to install oil heaters for colder climates and even then it's like thick molasses at startup.
What is really interesting is that our competitors recommend the same weights but there are some fundamental differences between different pump designs. Ours use roller bearings. Our oil temperatures hover around 30*F more than ambient which shows the mechanical efficiency of our pumps. On a 90* day we'll see oil temps at max power at about 120*F. One of our competitors uses babit style bronze sleeve bearings. On the same 90*F day their oil will reach 180*F. Both use the same oil and no one at any company can say why. The we have large chain cases that may have to transmit these loads. They recommend 10W30 motor oil. Why? The first person to build one used it! Don't think these things are necessarily thought out well. Sometimes a recommendation is nothing more complex than tradition. Then one day someone questions it, studies it, and finds that there is a better way and it's against tradition. Debate and mass panic ensue. We actually have self lubricating pumps but install external lube systems complete with their own oil pumps just because our customers can't accept the fact that you don't need them. Yes we charge them for it! Sound dishonest? It's not. They want it and we give it to them. They feel they know more than the engineers. We don't argue. They won't listen anyways. We just give them what they want.
I've been researching viscosites of various oils for this very reason. If they turn out to work fine, we'll keep using it. If I feel we need to change, we will. Keep in mind these pumps are upwards of $130,000 for the small ones and can easily top the million dollar mark. I don't want to get it wrong! After I learn all I can on it here at work, I'll start to look into Dr. Haas' reasoning as it applies to car oils. At the very least he's given me something to think about for our own uses.
One thing everyone should understand though is that just because you aren't using X weight oil doesn't mean your engine is going to suddenly blow up. This isn't the cartoons. Something doesn't work just because you don't know it can't. Many engines have gone 200K+ on thicker oils. Maybe thinner is better. I don't know. Maybe not. What if it turns out that running 20W50 will let your engine live to 200K miles but 0W20 will allow it to live to 225K miles? How long do you plan to own the car and will it ultimately effect you? Keep in mind that if you've been using an oil that has been working good, it's still going to work good after reading that thread. What if he's wrong in regards to rotaries? What if his theory only works on paper? How many miles do you think he really puts on a 550, and Enzo, a Lamborghini, or a Maybach? What are the longterm effects? What if it sounds good but your bearings fail after 40K miles? Then what?
I think it's a good read and worthy of more study but I caution anyone on just randomly jumping on the bandwagon out of faith. Understand the potential consequences if you are wrong. In my older RX-7's I've run anything from 5W20 to 20W50 and the engines always worked fine. I favored the heavier. My Honda has run 5W20 for it's 200,000 miles but Honda recommends 5W30. I am going to try a thinner oil in my '90 RX-7 just to see if I can feel a difference in smoothness. The car has 130K miles on it so it may not be a good idea. I'm actually not concerned of leaking. I want to see if I can feel a smoothness difference. If it doesn't feel as smooth, it's probably not doing my bearings any good. If it takes some life off of my engine so be it. I'll build a new one someday anyways. Don't just go do this in your newer cars until you are absolutely sure though. I'll test it in mine but I'm willing to accept any issues that may arise from the experiment. I don't recommend this for others. I may change it back later though.
We build large mud pumps for oil drilling and the oil lubricates the bearings as well as the large bull and pinion gears. Our smallest pump has a 40 gallon capacity and is rated at 450 hp. Our largest holds over 80 gallons of oil and is rated over 2000 HP. We have the ability to build a 3000 HP unit. Our oil chart recommends 2 different weights and they are ambient temperature dependent. It recommends 75W90 for 0*F-100*F use and 85W140 for above 100* ambient temperature use. Sound strange? That's why I'm looking into it. We have to install oil heaters for colder climates and even then it's like thick molasses at startup.
What is really interesting is that our competitors recommend the same weights but there are some fundamental differences between different pump designs. Ours use roller bearings. Our oil temperatures hover around 30*F more than ambient which shows the mechanical efficiency of our pumps. On a 90* day we'll see oil temps at max power at about 120*F. One of our competitors uses babit style bronze sleeve bearings. On the same 90*F day their oil will reach 180*F. Both use the same oil and no one at any company can say why. The we have large chain cases that may have to transmit these loads. They recommend 10W30 motor oil. Why? The first person to build one used it! Don't think these things are necessarily thought out well. Sometimes a recommendation is nothing more complex than tradition. Then one day someone questions it, studies it, and finds that there is a better way and it's against tradition. Debate and mass panic ensue. We actually have self lubricating pumps but install external lube systems complete with their own oil pumps just because our customers can't accept the fact that you don't need them. Yes we charge them for it! Sound dishonest? It's not. They want it and we give it to them. They feel they know more than the engineers. We don't argue. They won't listen anyways. We just give them what they want.
I've been researching viscosites of various oils for this very reason. If they turn out to work fine, we'll keep using it. If I feel we need to change, we will. Keep in mind these pumps are upwards of $130,000 for the small ones and can easily top the million dollar mark. I don't want to get it wrong! After I learn all I can on it here at work, I'll start to look into Dr. Haas' reasoning as it applies to car oils. At the very least he's given me something to think about for our own uses.
One thing everyone should understand though is that just because you aren't using X weight oil doesn't mean your engine is going to suddenly blow up. This isn't the cartoons. Something doesn't work just because you don't know it can't. Many engines have gone 200K+ on thicker oils. Maybe thinner is better. I don't know. Maybe not. What if it turns out that running 20W50 will let your engine live to 200K miles but 0W20 will allow it to live to 225K miles? How long do you plan to own the car and will it ultimately effect you? Keep in mind that if you've been using an oil that has been working good, it's still going to work good after reading that thread. What if he's wrong in regards to rotaries? What if his theory only works on paper? How many miles do you think he really puts on a 550, and Enzo, a Lamborghini, or a Maybach? What are the longterm effects? What if it sounds good but your bearings fail after 40K miles? Then what?
I think it's a good read and worthy of more study but I caution anyone on just randomly jumping on the bandwagon out of faith. Understand the potential consequences if you are wrong. In my older RX-7's I've run anything from 5W20 to 20W50 and the engines always worked fine. I favored the heavier. My Honda has run 5W20 for it's 200,000 miles but Honda recommends 5W30. I am going to try a thinner oil in my '90 RX-7 just to see if I can feel a difference in smoothness. The car has 130K miles on it so it may not be a good idea. I'm actually not concerned of leaking. I want to see if I can feel a smoothness difference. If it doesn't feel as smooth, it's probably not doing my bearings any good. If it takes some life off of my engine so be it. I'll build a new one someday anyways. Don't just go do this in your newer cars until you are absolutely sure though. I'll test it in mine but I'm willing to accept any issues that may arise from the experiment. I don't recommend this for others. I may change it back later though.