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Will the x16 kill premix

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Old 04-17-2008 | 02:45 PM
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Will the x16 kill premix

I was just thinking that with the x16 going to direct injection will the advantages of premix be lost. With direct injection you are now just injecting fuel at the optimal location for combustion, this in all likelihood will not promote good lubrication. The success of the 3rd oil injector my be vital for the x16.

What do you think?
Old 04-17-2008 | 02:59 PM
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good point - I would think premixing would still help with lubrication just the same as it does now . The fuel is just coming in a little later with DI - it should still lubricate the combustion chamber .
Old 04-17-2008 | 03:01 PM
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I dont think so.

Cuz no matter how advance fuel injecting technology becomes, the basic attribute of the engine will not change. Which means the seal still needs to lube.

Its just that it might be better to change the OMP into using premix only.
Old 04-17-2008 | 03:08 PM
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depends on how much they inject.
Old 04-17-2008 | 03:20 PM
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Originally Posted by Jedi54
depends on how much they inject.
Lemmmme give you the Answer

Repeat after me

E
P
A

W
I
L
L

S
C
R
E
W

I
T

U
P

So yes it will need premix.
Old 04-17-2008 | 04:14 PM
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Originally Posted by nycgps
Lemmmme give you the Answer

Repeat after me

E
P
A

W
I
L
L

S
C
R
E
W

I
T

U
P

So yes it will need premix.
Correct - the 3rd injector will allow for a better distribution of the oil, but the reality is that to meet exhaust emission standards, very little oil can be used and still meet them.

Additional premix will still be helpful for those that care about longevity.
Old 04-17-2008 | 04:45 PM
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I think that with the 3rd oil injector the need for premix is pretty much over and I'd still think so even if the engine didn't have direct injection. Keep in mind at this time the engine is only semi direct and still contains 2 injectors in the current primary location. This could change of course.
Old 04-17-2008 | 04:46 PM
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I still dont think the premix will be as effective here. In the current Engine the fuel/air mixture is carried along part of the combustion chamber before it is ignited. It has time to contact the engine surface to lubricate. With direct injection the fuel can be injected right were combustion will happen allowing less fuel mixture to contact the engine surface. End result is less lubrication.

As to the EPA issue Mazda my have to use technology similar to those in diesels to trap particulates (unburnt oil). Not sure how or if this would work but it seems a good place to start.
Old 04-17-2008 | 04:49 PM
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Originally Posted by Raptor75
I still dont think the premix will be as effective here. In the current Engine the fuel/air mixture is carried along part of the combustion chamber before it is ignited. It has time to contact the engine surface to lubricate. With direct injection the fuel can be injected right were combustion will happen allowing less fuel mixture to contact the engine surface. End result is less lubrication.

As to the EPA issue Mazda my have to use technology similar to those in diesels to trap particulates (unburnt oil). Not sure how or if this would work but it seems a good place to start.
Lets just wait another 3-4 years then the answer will come !
Old 04-17-2008 | 05:19 PM
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WITF do you guys keep asking stupid questions like this. The d@mn engine isn't even out yet, so HITH would anybody be able to answer the (stupid) question.
Old 04-17-2008 | 05:27 PM
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Originally Posted by TeamRX8
WITF do you guys keep asking stupid questions like this. The d@mn engine isn't even out yet, so HITH would anybody be able to answer the (stupid) question.
It's still a very interesting discussion imho.
Old 04-17-2008 | 05:30 PM
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Originally Posted by Raptor75
I still dont think the premix will be as effective here. In the current Engine the fuel/air mixture is carried along part of the combustion chamber before it is ignited. It has time to contact the engine surface to lubricate. With direct injection the fuel can be injected right were combustion will happen allowing less fuel mixture to contact the engine surface. End result is less lubrication.
That is not how the oil is distributed in the chamber from premix.

The atomized oil and fuel is mostly in the air, with just a little hitting the combustion chamber (and other) surfaces until the explosion of combustion - at that time all the oil particles, because they are heavier and do not burn as fast a fuel, are literally thrown to all the edges and cover everything until they get hot enough to eventually burn (which takes much longer, relatively speaking, than the fuel)- think of it as a splatter effect like you put a firecracker in the middle of a water balloon.

Thus, premixing will always put usable oil in the combustion chamber, independent of if it is direct injection or port injection.

Last edited by Jax_RX8; 04-17-2008 at 05:34 PM.
Old 04-17-2008 | 06:11 PM
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people will still be paranoid... don't worry
Old 04-17-2008 | 06:25 PM
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The motor will not see the light of day so the discussion is moot.
Old 04-17-2008 | 06:29 PM
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Originally Posted by MazdaManiac
The motor will not see the light of day so the discussion is moot.
I'll remember this day.
Old 04-17-2008 | 06:33 PM
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we will see this engine in the future. Till then, interesting conversation nothing more
Old 04-17-2008 | 06:37 PM
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Originally Posted by Jax_RX8
That is not how the oil is distributed in the chamber from premix.

The atomized oil and fuel is mostly in the air, with just a little hitting the combustion chamber (and other) surfaces until the explosion of combustion - at that time all the oil particles, because they are heavier and do not burn as fast a fuel, are literally thrown to all the edges and cover everything until they get hot enough to eventually burn (which takes much longer, relatively speaking, than the fuel)- think of it as a splatter effect like you put a firecracker in the middle of a water balloon.

Thus, premixing will always put usable oil in the combustion chamber, independent of if it is direct injection or port injection.
That is fascinating. Would that mean that 4-stroke oil from the OMP would lubricate better than 2-stroke oil since the former doesn't burn as well?

However, I know everyone prefers 2-stroke premix or from a Sohn adaptor. Is that merely because the unburnt 4-stroke is bad for the cat and emissions. I'm guessing there must be more to it than that.
Old 04-17-2008 | 06:38 PM
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Originally Posted by MazdaManiac
The motor will not see the light of day so the discussion is moot.
Why do you say that? Improved but still poor fuel economy will kill it, perhaps?
Old 04-17-2008 | 06:40 PM
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Originally Posted by MazdaManiac
The motor will not see the light of day so the discussion is moot.
I totally agree with Jeff anyway i am more interested in working out a method to pre mix some of my lubricant amongst those lovely ladies on his avatar

Cheers
Michael
Old 04-17-2008 | 06:40 PM
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Originally Posted by Jedi54
we will see this engine in the future. Till then, interesting conversation nothing more
Originally Posted by Easy_E1
I'll remember this day.
Why would you think there is even the possibility of the rotary living on?

Each year, the sales of the RX-8 are halved.
They don't even advertise the car any more, it is excluded from all of the dealer incentive plans, it is excluded from the dealer satisfaction surveys and most dealers don't even keep them in stock anymore.

The current model is a warranty nightmare, it doesn't conform to the EPA standard from 5 years ago and, by design, it can't possibly conform to the 2010 standard - direct injection or not.
Unless Mazda invents a way for the engine to run completely without injected oil, its a dead end.
Old 04-17-2008 | 06:53 PM
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Originally Posted by MazdaManiac
Unless Mazda invents a way for the engine to run completely without injected oil, its a dead end.
unless they make it for the JDM market only - That way I'll still be able to get one . Hey maybe I'll be able to get them for you guys - good little side earner for me
Old 04-17-2008 | 06:53 PM
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the rotary engine is dead, leave it be

/end sarcasm
Old 04-17-2008 | 06:57 PM
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Originally Posted by MazdaManiac
it is excluded from all of the dealer incentive plans, it is excluded from the dealer satisfaction surveys and most dealers don't even keep them in stock anymore..
added to incentive / surveys again as of this last week.

Originally Posted by MazdaManiac
, it can't possibly conform to the 2010 standard - direct injection or not.
I'm taking the wait and see approach on that one. Who knows, maybe they'll come up with something.
Old 04-17-2008 | 07:27 PM
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Why would they have made it if they aren't going to use it? Seems like that would be a LARGE waste of money.
Old 04-17-2008 | 07:45 PM
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Originally Posted by Easy_E1
Why would they have made it if they aren't going to use it? Seems like that would be a LARGE waste of money.
They didn't "make it". They prototyped it.
Really, its just a casting change. Its not like its a big deal when you operate your own foundry.
The Renesis is just a differently machined REW with "advances" that were experimented with 20 years ago when it comes down to it.
Rotary engines were designed and advanced on a shoe-string budget compared to the expenditures for the big manufacturers. They exist mostly because of the efforts of dedicated, enthusiastic and motivated individuals at Mazda.
All of those Samurai are gone now.

With the high BSFC, the terrible emissions, the stringent CAT life requirements and, frankly, the lukewarm reception of the car buying public for an under-powered coupe that sits at the bottom of its market, there really isn't any reason to make the 16X.
The only reason that the RX-8 still exists now is to amortize the tooling investment cost. Even the "update" was just meant to help keep the collision dollars in-house.

I'd love to be wrong, but between Kyoto and gas prices, there will be no market for the RX-8 or anything similar in 2 years.


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