Gas/Oil Premix Thread
#3676
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Burning affects different chemicals differently, and even with a single chemical, they don't behave the same at widely diverging temperatures.
Aside from lab controlled testing inside a combustion engine that was torn down repeatedly to measure results (like bse did, though I'm sure it was his garage ), about the only way of actually testing this that I can think of is building a gasoline fueled blowtorch so you can set the burn to the actual AFR of the combustion, and add the premix oils into the fuel stream while the flame is torching onto each of aluminum, iron, and steel (all 3 metals are present in the engine). Examine the surface accumulation after each premix has been tested on each metal. Even that will be difficult to stay controlled between each premix.
Part of the problem is that gasoline is FILTHY by itself. Pour ~3-4oz of gasoline into a small jar, like a baby food jar, and light it (obviously be smart and safe about it). The gasoline burn will leave an encrustation of carbon around the inside of the jar, especially heavy just inside the top. I did this once with about 15oz in a larger apple sauce jar once, and there was about a quarter inch of carbon built up around the inside of the top edge by the time the gasoline finished burning out.
Granted, it's hardly a controlled burn in terms of air/fuel ratio, and that will make it worse, but still, it's pretty compelling to see how much carbon can be left behind by gasoline alone.
Now to compound this even further, pics from 9krpmrx8's last engine teardown shows that his clean 2-stroke oil was actually protecting the rotor from carbon buildup along the edges where the oil injectors sprayed. So clearly some oils will actually help to prevent buildup as well.
#3677
Zoomin'
iTrader: (8)
Haha, I get what you're saying and don't disagree.
But less residue after being burnt is less residue after being burnt, even if the test was incomplete since it lacked gasoline. If anything, the gas should only burn the oil more completely and therefore leave even less residue than without it, correct?
But less residue after being burnt is less residue after being burnt, even if the test was incomplete since it lacked gasoline. If anything, the gas should only burn the oil more completely and therefore leave even less residue than without it, correct?
You can have a clean burning premix oil, but the main question is... Is it doing it's job as a lubricant?
I'm not trying to put down Pettit's oil, but they're not approved by any of those ratings. It doesn't necessarily mean it isn't good, it could be for all I know and I'm sure it is.
#3678
SARX Legend
iTrader: (46)
Haha, I get what you're saying and don't disagree.
But less residue after being burnt is less residue after being burnt, even if the test was incomplete since it lacked gasoline. If anything, the gas should only burn the oil more completely and therefore leave even less residue than without it, correct?
But less residue after being burnt is less residue after being burnt, even if the test was incomplete since it lacked gasoline. If anything, the gas should only burn the oil more completely and therefore leave even less residue than without it, correct?
#3680
Haha, I get what you're saying and don't disagree.
But less residue after being burnt is less residue after being burnt, even if the test was incomplete since it lacked gasoline. If anything, the gas should only burn the oil more completely and therefore leave even less residue than without it, correct?
But less residue after being burnt is less residue after being burnt, even if the test was incomplete since it lacked gasoline. If anything, the gas should only burn the oil more completely and therefore leave even less residue than without it, correct?
Motul 710 is my premix of choice.
#3681
SARX Legend
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But there are many options. Academy Sports (local sporting goods store) has Mystic brand JASO FD brand synthetic 2 stroke for like $12.00 a gallon. That is what I use when I run out and forget to order a case of Idemitsu.
#3685
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The short answer is "yes".
The long answer is:
Yes, premixing does indeed help to protect against engine failure. However, premixing will in no way ensure your engine's survival, just like exercising regularly won't do anything to prevent getting run over by a bus. There are so many ways that this engine can fail, and premixing only addresses one of them (apex seal wear), possibly can help mitigate a 2nd (carbon buildup). Plenty of people opt to not premix because they figure it's just going to be wasted, believing that something else is going to kill the engine before apex seal wear will.
Like a heroine addict not bothering to consider lung cancer from smoking, because mainlining heroine is probably going to kill him before lung cancer shows up anyway.
This engine is all management of the risks, and knowing that there is no fail-safe, no perfect solution.
The long answer is:
Yes, premixing does indeed help to protect against engine failure. However, premixing will in no way ensure your engine's survival, just like exercising regularly won't do anything to prevent getting run over by a bus. There are so many ways that this engine can fail, and premixing only addresses one of them (apex seal wear), possibly can help mitigate a 2nd (carbon buildup). Plenty of people opt to not premix because they figure it's just going to be wasted, believing that something else is going to kill the engine before apex seal wear will.
Like a heroine addict not bothering to consider lung cancer from smoking, because mainlining heroine is probably going to kill him before lung cancer shows up anyway.
This engine is all management of the risks, and knowing that there is no fail-safe, no perfect solution.
#3687
GEAUX8
iTrader: (1)
The short answer is "yes".
The long answer is:
Yes, premixing does indeed help to protect against engine failure. However, premixing will in no way ensure your engine's survival, just like exercising regularly won't do anything to prevent getting run over by a bus. There are so many ways that this engine can fail, and premixing only addresses one of them (apex seal wear), possibly can help mitigate a 2nd (carbon buildup). Plenty of people opt to not premix because they figure it's just going to be wasted, believing that something else is going to kill the engine before apex seal wear will.
Like a heroine addict not bothering to consider lung cancer from smoking, because mainlining heroine is probably going to kill him before lung cancer shows up anyway.
This engine is all management of the risks, and knowing that there is no fail-safe, no perfect solution.
The long answer is:
Yes, premixing does indeed help to protect against engine failure. However, premixing will in no way ensure your engine's survival, just like exercising regularly won't do anything to prevent getting run over by a bus. There are so many ways that this engine can fail, and premixing only addresses one of them (apex seal wear), possibly can help mitigate a 2nd (carbon buildup). Plenty of people opt to not premix because they figure it's just going to be wasted, believing that something else is going to kill the engine before apex seal wear will.
Like a heroine addict not bothering to consider lung cancer from smoking, because mainlining heroine is probably going to kill him before lung cancer shows up anyway.
This engine is all management of the risks, and knowing that there is no fail-safe, no perfect solution.
Anthony
#3688
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Note that I advocate FOR premixing. I don't see the value in ignoring that risk. I also advocate addressing every single point of failure and managing the risk as much as possible. I don't see premixing as worthless.
#3690
GEAUX8
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Thanks yet again for your feedback. However, I never said that premixing was "worthless". All I was saying is that I think I'll be okay not premixing since I don't race or anything. Basically.....from everything I've read on here is that y'all are saying that the Mazda stock OMP is not sufficient for a stock 8 and I need to premix to extend the life of the rotors and housing alone? With that being said and say I decide to go ahead and premix, Idemitsu right? Thanks in advance.
Anthony
Anthony
#3691
GEAUX8
iTrader: (1)
Compression tested yesterday
R1: 7.9,7.9,7.7
R2: 7.8,7.8,7.7
So with that information.....I have no intention of getting rid of my 8 and I want to keep it as long as I can. Oh by the way, I bought this car used and it's on its second engine from previous owner who ran it until oil light came on.......moron. Anyway, thanks for chiming in. I appreciate any and all feedback.
Anthony
#3692
Flame On!
iTrader: (4)
We share similar stories.
Bought mine used, with 89k on the chassis, and 42k on the (3rd) engine. Had about 9 months left on the warranty.
Got a compression test from Mazda with almost the exact same numbers you have.
After the warranty expired, I started doing home compression test to monitor the health of the engine.
I sit right below Mazda min spec with almost 70k on the engine now. No engine issues yet, starts right up hot or cold, can get 22mpg hwy and between 14-17 all city with a/c. Been premixing since the first tank. I've also premixed my 3 rx7s and not a single engine failure yet. (knock on wood)
Bought mine used, with 89k on the chassis, and 42k on the (3rd) engine. Had about 9 months left on the warranty.
Got a compression test from Mazda with almost the exact same numbers you have.
After the warranty expired, I started doing home compression test to monitor the health of the engine.
I sit right below Mazda min spec with almost 70k on the engine now. No engine issues yet, starts right up hot or cold, can get 22mpg hwy and between 14-17 all city with a/c. Been premixing since the first tank. I've also premixed my 3 rx7s and not a single engine failure yet. (knock on wood)
#3694
Lubricious
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What exactly are the lubrication requirements of the seal/housing interface? It's a black art, afaik. Hence the endless debate. Note that the MMO is not behaving alone, there is already an OMP delivering lubrication. I view MMO as a supplement/additive. It doesn't have to carry the lubrication burden alone, whatever that even IS. And I'll note that MMO was originally intended both as a cleaner and for top-cylinder lubrication. A task that is somewhat similar to lubricating the seal/housing interface.
#3695
top cylinder lubrication has got nothing to do with apex seal lubrication.
Think about the 2 oil nozzles as an anti chatter device for the seals and premix as the all around lubricant.
The lubrication requirements of a seal\housing are the same of a 2 stroke engine. It's as simple as that. You have to reduce wear, friction and avoid deposits.
Think about the 2 oil nozzles as an anti chatter device for the seals and premix as the all around lubricant.
The lubrication requirements of a seal\housing are the same of a 2 stroke engine. It's as simple as that. You have to reduce wear, friction and avoid deposits.
#3696
top cylinder lubrication has got nothing to do with apex seal lubrication.
Think about the 2 oil nozzles as an anti chatter device for the seals and premix as the all around lubricant.
The lubrication requirements of a seal\housing are the same of a 2 stroke engine. It's as simple as that. You have to reduce wear, friction and avoid deposits.
Think about the 2 oil nozzles as an anti chatter device for the seals and premix as the all around lubricant.
The lubrication requirements of a seal\housing are the same of a 2 stroke engine. It's as simple as that. You have to reduce wear, friction and avoid deposits.
#3697
Flame On!
iTrader: (4)
Thanks for defending our country sir.
-Shawn
#3699
FULLY SEMI AUTOMATIC
iTrader: (9)
i use idmitsu premix. 8oz per tank. some use proteck. that **** you posted i would put in my weedwacker