My sneaky plan to extend engine life for Series I
10-18-2010, 10:20 AM
#76
The problem is seen mostly on engines that do very short trips like 3-5miles (pretty common here) without even reaching full temperature. Engines that did the e-shaft pellet bypass mod and lived a similar life showed less rear bearing wear. Still carbon build ups literally murders those units though.
10-18-2010, 10:59 AM
#77
Extraordinary Engineering
If you take our experience here as documental then yes
The problem is seen mostly on engines that do very short trips like 3-5miles (pretty common here) without even reaching full temperature. Engines that did the e-shaft pellet bypass mod and lived a similar life showed less rear bearing wear. Still carbon build ups literally murders those units though.
The problem is seen mostly on engines that do very short trips like 3-5miles (pretty common here) without even reaching full temperature. Engines that did the e-shaft pellet bypass mod and lived a similar life showed less rear bearing wear. Still carbon build ups literally murders those units though.
What are ambient temps?
How does the e-shaft pellet help with bearing wear in your opinion?
The reason I'm asking
The low ambient temps in fall and spring, My relatively short commutes lately, my low oil temps, 81K miles on my 2004 engine
Last edited by DarkBrew; 10-18-2010 at 11:02 AM.
10-18-2010, 11:09 AM
#78
You can find something on the bypass pellet here: http://www.racingbeat.com/Tech/Tech.Engine.3.htm
10-18-2010, 11:44 AM
#80
Extraordinary Engineering
They all ran 5w30 or 10w40 lubricants from several brands, synthetic and semis so i think that it is a good benchmark.
You can find something on the bypass pellet here: http://www.racingbeat.com/Tech/Tech.Engine.3.htm
You can find something on the bypass pellet here: http://www.racingbeat.com/Tech/Tech.Engine.3.htm
So can I sum up the learning as
placing load on the engine while the oil is cold can result in excessive bearing wear?
Have you seen any engines with the higher oil pressure bypass? It is supposed to allow higher flow of cold, thickened oil. Is there evidence of improvements?
Last edited by DarkBrew; 10-18-2010 at 11:51 AM.
10-18-2010, 12:40 PM
#81
Super Moderator
Anyone who uses ANY rotary for a daily or only occasional Under 10-15 Minute Drive needs their head read, they should not OWN a Rotary.
10-18-2010, 01:34 PM
#82
Extraordinary Engineering
My preference is always to see min 80C oil temps before shutdown
This wasn't a problem when I was 30km+ from work but now I'm 5.5km
Even that wasn't a problem till the temps started to drop.
Based on what bse50 is saying I have reason to be concerned.
So, a slightly longer drive each morning
Last edited by DarkBrew; 10-18-2010 at 01:39 PM.
10-18-2010, 05:08 PM
#83
So the e-shaft pellet modification would bring up oil temps more quickly since more oil would be spraying on the rotors?... It makes some sense to me that warmer oil flows better and lubricates the bearings better.
So can I sum up the learning as
placing load on the engine while the oil is cold can result in excessive bearing wear?
Have you seen any engines with the higher oil pressure bypass? It is supposed to allow higher flow of cold, thickened oil. Is there evidence of improvements?
So can I sum up the learning as
placing load on the engine while the oil is cold can result in excessive bearing wear?
Have you seen any engines with the higher oil pressure bypass? It is supposed to allow higher flow of cold, thickened oil. Is there evidence of improvements?
I like my oil pressure mod too but it's too early to draw conclusions. Well, it worked in other rotaries but that's all we know at the moment.
10-19-2010, 09:23 AM
#84
Registered
Installing the bypass mod doesn't affect lubrication at all. The stock system is there to reduce cooling oil flow to the inside of the rotors so the engine comes up to operating temps faster. This is all in the name of startup emissions. There is no performance benefit to installing the bypass mod. However, while the stock system is very reliable, IF it fails for any reason, it will fail in bypass mode meaning no oil to your rotors. Basically the bypass mod is an insurance against that possibility ever happening. I've never seen it happen though. Yes, I do use the bypass pellet. I also have my car insured although I never plan on needing it.
The worst wear on an engine takes place at startup and when cold. Most of this wear will be bearing wear. At higher rpms bearing wear isn't much of an issue but apex seal lubrication starts to become more of a concern. Different parts of the engine are more vulnerable to wear than others under different circumstances.
A good oil is a must to protect the engine and this is why I like synthetics. The additive packages in oils that are responsible for strengthening the protective qualities of oil don't even become active until around 160*F. Below that you are relying on 2 things. One is the viscosity of the oil but the second and most important characteristic is the film strength of the base oil itself which is independent of the additives. Synthetics win everytime in this area. I am directly saying that your oil NEEDS to be thicker when cold than when hot to do it's job. However thicker and thicker isn't better and better and even a low rated viscosity oil has plenty of cold temperature thickness to it.
Increasing oil pressure isn't always an advantage either. More pressure is not better and better. The key to anything automotive is that you need just enough to get the job done and no more. Keep in mind that a thicker oil will technically show more oil pressure but will have LESS oil flow. If you choked off the line so there was no oil flow at all, pressure would spike nice and high. Obviously this isn't a good thing. Once you get enough oil flow to where it needs to go, putting it under more pressure to hopefully increase the flow isn't going to do anything useful but rob usable horsepower from the engine.
The worst wear on an engine takes place at startup and when cold. Most of this wear will be bearing wear. At higher rpms bearing wear isn't much of an issue but apex seal lubrication starts to become more of a concern. Different parts of the engine are more vulnerable to wear than others under different circumstances.
A good oil is a must to protect the engine and this is why I like synthetics. The additive packages in oils that are responsible for strengthening the protective qualities of oil don't even become active until around 160*F. Below that you are relying on 2 things. One is the viscosity of the oil but the second and most important characteristic is the film strength of the base oil itself which is independent of the additives. Synthetics win everytime in this area. I am directly saying that your oil NEEDS to be thicker when cold than when hot to do it's job. However thicker and thicker isn't better and better and even a low rated viscosity oil has plenty of cold temperature thickness to it.
Increasing oil pressure isn't always an advantage either. More pressure is not better and better. The key to anything automotive is that you need just enough to get the job done and no more. Keep in mind that a thicker oil will technically show more oil pressure but will have LESS oil flow. If you choked off the line so there was no oil flow at all, pressure would spike nice and high. Obviously this isn't a good thing. Once you get enough oil flow to where it needs to go, putting it under more pressure to hopefully increase the flow isn't going to do anything useful but rob usable horsepower from the engine.
10-19-2010, 09:35 AM
#85
Extraordinary Engineering
Thanks RG. Detailed and interesting as usual!
The specific reference was
The simple reason I can see for the pellet mod making a difference here is that the oil should warm up faster if it is spraying on the rotors right from start-up vs. an engine where the flow is blocked off till warm. Warm oil flows better and reduces bearing wear...
The other thought is that the oil pressure bypass, which typically should do nothing under most operating conditions, should be matched to the thickness of the oil used at start-up. Bypassing your thickened oil back to the pan certainly won't help the engine.
My intent is to split the oil flows with a Sohn adapter and address the lubrication challenges separately. I believe in synthetics and I still have to research the two stroke oil market a bit more
The specific reference was
The other thought is that the oil pressure bypass, which typically should do nothing under most operating conditions, should be matched to the thickness of the oil used at start-up. Bypassing your thickened oil back to the pan certainly won't help the engine.
My intent is to split the oil flows with a Sohn adapter and address the lubrication challenges separately. I believe in synthetics and I still have to research the two stroke oil market a bit more
Last edited by DarkBrew; 10-19-2010 at 09:56 AM.
10-19-2010, 09:40 AM
#87
Installing the bypass mod doesn't affect lubrication at all. The stock system is there to reduce cooling oil flow to the inside of the rotors so the engine comes up to operating temps faster.
[CUT]
The worst wear on an engine takes place at startup and when cold. Most of this wear will be bearing wear. At higher rpms bearing wear isn't much of an issue but apex seal lubrication starts to become more of a concern. Different parts of the engine are more vulnerable to wear than others under different circumstances.
[CUT]
The worst wear on an engine takes place at startup and when cold. Most of this wear will be bearing wear. At higher rpms bearing wear isn't much of an issue but apex seal lubrication starts to become more of a concern. Different parts of the engine are more vulnerable to wear than others under different circumstances.
What I didn't mention btw is the use of weber carburettor jets in lieu of the stock e-shaft ones. In that case i'd take a higher pressure regulator over the stock one all day long.
Anyway, you're right as usual when stating that bearing wear occurs at start ups i would point out high loads\low speeds (traffic). A tad of extra pressure and the right oil may help to an extent, again in my opinion (which is highly contradictable usually
)
10-19-2010, 10:42 AM
#88
Registered
The weber jet mod is a good thing and I have done this in the past too. This is not technically effected by the bypass mod. Oil flow to this spot may decrease with the bypass open as there is less pressure to send oil through them but we consider this to be independent. While you can increase oil flow to the rotors with the weber jet mod, (even to the extent that you need to run a higher idle rpm if you use a large enough jet!) again I find that it's main benefit is to remove a ball and spring from the system that can fail by sticking which may reduce oil flow to the rotors.
Mazda uses the bypass to heat the rotors up faster which heats the combustion chamber up faster so the exhaust is hotter and the cat gets to operating temps faster. However by doing so this heat doesn't get sent to the oil as quickly which does mean that it takes longer to reach hotter oil temperatures. There is a compromse for everything. In this case it is engine protection for cat efficiency. I'd personally rather get my oil temperature up to where it does it's job the best which is where it protects the engine the best and then take the slight hit for cat efficiency and emissions when cold. The EPA wouldn't agree with me though but I would also argue that a more efficient engine that has less wear is a more efficient and cleaner burning engine.
Mazda uses the bypass to heat the rotors up faster which heats the combustion chamber up faster so the exhaust is hotter and the cat gets to operating temps faster. However by doing so this heat doesn't get sent to the oil as quickly which does mean that it takes longer to reach hotter oil temperatures. There is a compromse for everything. In this case it is engine protection for cat efficiency. I'd personally rather get my oil temperature up to where it does it's job the best which is where it protects the engine the best and then take the slight hit for cat efficiency and emissions when cold. The EPA wouldn't agree with me though but I would also argue that a more efficient engine that has less wear is a more efficient and cleaner burning engine.
10-19-2010, 11:28 AM
#89
I was referring to the pressure regulator, not the bypass pellet in this case. The reason is the one you described.
The only problem with the jets is finding the right size. anything between 2.10 and 2.30mm should work fine without said need of increasing the idle speed. Since i have many 2.10mm jets left from my 2 stroke days that's what I use :D
The only problem with the jets is finding the right size. anything between 2.10 and 2.30mm should work fine without said need of increasing the idle speed. Since i have many 2.10mm jets left from my 2 stroke days that's what I use :D
10-19-2010, 12:11 PM
#90
Registered
2.0 mm is what I used on mine. They do increase flow a little bit over stock. I also did an engine that had the 2.2mm jets and that engine required the 1000 rpm idle to build any significant pressure.
10-19-2010, 03:07 PM
#93
It's surprising how this kind of mod is so unpopular with the 13b msp community while it's been around for a long while!
10-19-2010, 03:15 PM
#94
Extraordinary Engineering
10-19-2010, 03:39 PM
#95
Super Moderator
I often wonder about guys modding these e-shaft rotor oil jets...you guys do it.
Mazda have left them alone in ALL rotaries from FC 1985...the Jet That is..unchanged...WHY?
The spring dates back to RX-2 (1970).
E-shaft Pellet originated in 1985 FC and is also unchanged.
Mazda have left them alone in ALL rotaries from FC 1985...the Jet That is..unchanged...WHY?
The spring dates back to RX-2 (1970).
E-shaft Pellet originated in 1985 FC and is also unchanged.
10-19-2010, 03:52 PM
#97
Super Moderator
OK..smart
10-19-2010, 10:25 PM
#98
So, is there a sound understanding of the bearing wear correlation with short-trip engines? I have a hard time believing it's cold oil, as cold oil should actually protect the bearing better at low engine speeds due to the higher actual viscosity (if I understand the relationships properly).
Of course, if the driver regularly revs the engine hard on cold oil, that would be something different.
But, it could also simply be start-up wear (that occurs in the first few revs immediately after startup, before oil is flowing) that happens regardless of oil temp & weight. Which is to say, we all experience it, it's just that for a short-trip car, there is is a much higher incedence of this type of damage per miles traveled.
My car is an '04 driven daily with about 55k on the odometer, so I would be a poster child for this kind of wear. I'm starting to have hot-start issues so a rebuild may be in my future. Should probably get a new starter first, LOL.
Of course, if the driver regularly revs the engine hard on cold oil, that would be something different.
But, it could also simply be start-up wear (that occurs in the first few revs immediately after startup, before oil is flowing) that happens regardless of oil temp & weight. Which is to say, we all experience it, it's just that for a short-trip car, there is is a much higher incedence of this type of damage per miles traveled.
My car is an '04 driven daily with about 55k on the odometer, so I would be a poster child for this kind of wear. I'm starting to have hot-start issues so a rebuild may be in my future. Should probably get a new starter first, LOL.
10-19-2010, 10:51 PM
#99
Extraordinary Engineering
So, is there a sound understanding of the bearing wear correlation with short-trip engines? I have a hard time believing it's cold oil, as cold oil should actually protect the bearing better at low engine speeds due to the higher actual viscosity (if I understand the relationships properly).
Of course, if the driver regularly revs the engine hard on cold oil, that would be something different.
But, it could also simply be start-up wear (that occurs in the first few revs immediately after startup, before oil is flowing) that happens regardless of oil temp & weight. Which is to say, we all experience it, it's just that for a short-trip car, there is is a much higher incedence of this type of damage per miles traveled.
My car is an '04 driven daily with about 55k on the odometer, so I would be a poster child for this kind of wear. I'm starting to have hot-start issues so a rebuild may be in my future. Should probably get a new starter first, LOL.
Of course, if the driver regularly revs the engine hard on cold oil, that would be something different.
But, it could also simply be start-up wear (that occurs in the first few revs immediately after startup, before oil is flowing) that happens regardless of oil temp & weight. Which is to say, we all experience it, it's just that for a short-trip car, there is is a much higher incedence of this type of damage per miles traveled.
My car is an '04 driven daily with about 55k on the odometer, so I would be a poster child for this kind of wear. I'm starting to have hot-start issues so a rebuild may be in my future. Should probably get a new starter first, LOL.
You're probably closer to the truth. Higher # of starts per 100 miles.
These engines take forever to warm the oil with the stock pellet and oil coolers in place. According to the oil guys, engine wear is minimized with oil operating at the right viscosity at the right temperature. Too hot and too cold are bad. Too thick and too thin is bad. So these engines run outside 'correct' conditions more often.
10-20-2010, 07:39 AM
#100
It's also no secret that any car driven primarily long distances on the highway can accumulate more trouble-free miles than one used in short-distance commuting.