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-   -   Possible New Renesis Engine Failure Theory? (https://www.rx8club.com/series-i-tech-garage-22/possible-new-renesis-engine-failure-theory-210194/)

GeorgeH 01-18-2011 09:57 AM

Yes, thank you Eric for taking to time to post your findings in detail. I realize how expesive such undertakings are and I for one greatly appreciate your willingness to post here. It adds a great deal to this forum.

So, if indeed the OMP is critical to the lifespan of the side seals, particularly on a tuned motor, it seems that a discussion about the lifespan and potential failure modes of the OMP lines would be worth having. Does anybody have any more insights in this area?

9krpmrx8 01-18-2011 10:08 AM

Awesome Eric. Too bad we cannot run the SOHN adapter adjuster with the factory PCM.

MazdaManiac 01-18-2011 10:26 AM


Originally Posted by 9krpmrx8 (Post 3852013)
Awesome Eric. Too bad we cannot run the SOHN adapter adjuster with the factory PCM.

Why would you?
You can just tell the OMP to do what the adjuster has done through the PCM calibration.

Beodude 01-18-2011 10:29 AM


Originally Posted by 9krpmrx8 (Post 3852013)
Awesome Eric. Too bad we cannot run the SOHN adapter adjuster with the factory PCM.


What do you mean? I take it there is another part that can be used with a SOHN? What does the adjuster do?

9krpmrx8 01-18-2011 10:31 AM


Originally Posted by MazdaManiac (Post 3852042)
Why would you?
You can just tell the OMP to do what the adjuster has done through the PCM calibration.


Yes of course for those with the Cobb who utilize your services or can do it themselves, but with the adjuster you could set it and forget it. Not sure if that woudl be good on a daily driver or not though if you are adding a lot.

MazdaManiac 01-18-2011 10:42 AM


Originally Posted by 9krpmrx8 (Post 3852057)
Yes of course for those with the Cobb who utilize your services or can do it themselves, but with the adjuster you could set it and forget it.

Someone that is not running some sort of engine management should even be worrying about the OMP anyway.


Originally Posted by 9krpmrx8 (Post 3852057)
Not sure if that woudl be good on a daily driver or not though if you are adding a lot.

It would be bad on a daily driver. Look at Eric's posts above.
His cars spend most of their life at WOT.

On a street car, running at step 60 or something near it in stop-n-go traffic would just gum up your motor.

olddragger 01-18-2011 10:56 AM

do yall also remember the design change of the oil nozzles in the S2 model?
Those oil nozzles do not point straight down. If I remember correctly they have a pretty big angle toward the irons. Ash posted a picture somewhere on them. I wish they where transferable to the s1 engine as it appears they would better put the oil where it is needed?

Like I said before---I wish they would put oil injection for the sides and corners in the irons and not the housings?

Premix lubrication does not hang arround very long. You have to remember that the premix that is injected at the start of the combustion cycle is subjected directly to the combustion process. So a lot gets burned up pretty fast. I understand that the oil nozzles are right before the combustion phase too, but that oil is not atomized, it only wheeps down so it is not really in the "air" so to speak. That makes it last a lot longer and that is why, i am thinking, it does a better job of properly lubricating/cooling the corner/side seals.

Like I also mentioned earlier--- one person I know is running the lower cr rotors with the old side seal design and no oil cutoff ring? His build will be very interesting to watch.
OD

MazdaManiac 01-18-2011 11:00 AM


Originally Posted by olddragger (Post 3852097)
Like I also mentioned earlier--- one person I know is running the lower cr rotors with the old side seal design and no oil cutoff ring?

That will probably end badly (unless he is getting rid of the side exhaust ports),

9krpmrx8 01-18-2011 11:05 AM


Originally Posted by Beodude (Post 3852051)
What do you mean? I take it there is another part that can be used with a SOHN? What does the adjuster do?


The manual adjuster lets you set the amount of premix it pulls in to a a certain amount. However, this would not work as the factory PCM would sense a problem and put the car in limp mode.

9krpmrx8 01-18-2011 11:07 AM


Originally Posted by MazdaManiac (Post 3852069)
Someone that is not running some sort of engine management should even be worrying about the OMP anyway.



It would be bad on a daily driver. Look at Eric's posts above.
His cars spend most of their life at WOT.

On a street car, running at step 60 or something near it in stop-n-go traffic would just gum up your motor.

True.

shadycrew31 01-18-2011 11:29 AM


Originally Posted by nycgps (Post 3851780)
Sea foam not gonna remove the carbon completely, its mainly trying to "unstuck" a stucked springs



thats quite a lot of cleaning.

how much did the rebuild cost you? at least the rotor looks reusable (can't tell other parts)

We reused all major parts (Rotors, housings, eshaft)

The housings had a bit of chrome flake nothing major though.

I got the rebuild kit from Atkins, got cut to fit side seals from mazdatrix, got the injectors cleaned and flow tested from RC, tools cleaning supplies etc.

I'd say in total I spent 1800. But allot of that was random crap I was buying becuase I had lots of time to rebuild. coil packs, porting templates, etc.

Everything was coated in burnt up oil all through the intake the rotors everything. It took close to a week spread out over a month to clean every part.

Beodude 01-18-2011 11:48 AM


Originally Posted by olddragger (Post 3852097)
Premix lubrication does not hang arround very long. You have to remember that the premix that is injected at the start of the combustion cycle is subjected directly to the combustion process. So a lot gets burned up pretty fast.

I wonder how the 2 stroke does through the SOHN? I know it's meant to be burnt a lot more than 4 stroke is, but it's still on the sides also. Since it's meant to burn, would the engine get enough lubrication from it?

It would be interesting to see how the engine does with a constant fresh supply of fresh 4 stroke.



Also, since the hardest part of the entire combustion process on the side seals is the exhaust portion, would we want something that burns that easily? Could cooling be increased with (clean) 4 stroke that could potentially hang around until the exhaust phase?

9krpmrx8 01-18-2011 12:01 PM


Originally Posted by Beodude (Post 3852190)
I wonder how the 2 stroke does through the SOHN? I know it's meant to be burnt a lot more than 4 stroke is, but it's still on the sides also. Since it's meant to burn, would the engine get enough lubrication from it?

It would be interesting to see how the engine does with a constant fresh supply of fresh 4 stroke.



Also, since the hardest part of the entire combustion process on the side seals is the exhaust portion, would we want something that burns that easily? Could cooling be increased with (clean) 4 stroke that could potentially hang around until the exhaust phase?

Well, we will see when my motor fails. I have been premixing and running the SOHN with 2 stroke since break in on this motor. Although, my motor is not new, but a Mazda reman so some "old" parts were still used.

shadycrew31 01-18-2011 12:11 PM


Originally Posted by Beodude (Post 3852190)
I wonder how the 2 stroke does through the SOHN? I know it's meant to be burnt a lot more than 4 stroke is, but it's still on the sides also. Since it's meant to burn, would the engine get enough lubrication from it?

It would be interesting to see how the engine does with a constant fresh supply of fresh 4 stroke.



Also, since the hardest part of the entire combustion process on the side seals is the exhaust portion, would we want something that burns that easily? Could cooling be increased with (clean) 4 stroke that could potentially hang around until the exhaust phase?

The air/fuel mix would keep temps cool enough so there would be lubrication of the intake cycle to the beginning of the combustion cycle. This is true for all oils.

The only difference is the 2 cycle oil will burn clean off where as the dino or synthetic would leave a residue.

Ive seen exhaust temps as high as 1600 degrees. There is no oil that will withstand that so flash point goes out the window for combustion/exhaust cycle.

What we are really worried about is the residue/carbon buildup on the seals and springs. Which might be avoided with the use of 2 cycle oil on a sohn adaptor.

I'm sure someone else has a different opinion, Which I'm totally open to hearing. This is just the best I could work up in my head.

Beodude 01-18-2011 12:41 PM

From what I've been reading it's more likely the gas that hangs around, since there is so much more of it, and since it runs so rich from the factory there is a lot of it that gets unburnt.

Seems like it would be a difficult balance. You run closer to stoich, and you have side seal spring deterioration. You run a richer mixture, and you get carbon build up... Ugh.

9krpmrx8 01-18-2011 02:30 PM

It's a bit confusing to me (big surprise) that that gas is the main culprit of carbon build up since one of the key points of the Renesis is the lack of overlap that previous rotaries had which supposedly means that any left over fuel gets burned in the next combustion cycle. This is why the Renesis has such awesome gas mileage :lol:

The Reverend 01-18-2011 02:33 PM

i didnt think the elimination of the overlap had much to do with mpg?

rather meant better low rpm idling???

low rpm idling is redundant lol i meant idling and low rpm situations

9krpmrx8 01-18-2011 02:45 PM

I just watched an animation of it yesterday and it talked about the benefits of the overlap. Let me find it.


Edit:

Here it is at 1:37

http://www.youtube.com/watch?v=fM2yLbHD9vQ

DocBeech 01-18-2011 04:25 PM

The ethanol in the fuel is not only corrosive but its very drying on components as well. Its hard on thinner metals, and plastics as well.

shadycrew31 01-18-2011 04:44 PM

Im still not sold... I think that using dirty motor oil that is not meant to be burnt is the leading culprit to carbon build up and engine failure.

9krpmrx8 01-18-2011 04:46 PM


Originally Posted by shadycrew31 (Post 3852621)
Im still not sold... I think that using dirty motor oil that is not meant to be burnt is the leading culprit to carbon build up and engine failure.


I agree. But until we start pulling Renesis' part that have used the SOHN, synthetic, and premixed since day one then we won't know.

shadycrew31 01-18-2011 05:04 PM


Originally Posted by 9krpmrx8 (Post 3852625)
I agree. But until we start pulling Renesis' part that have used the SOHN, synthetic, and premixed since day one then we won't know.

Well I suggest you blow your engine good sir.

ASH8 01-18-2011 05:14 PM


Originally Posted by 9krpmrx8 (Post 3852625)
I agree. But until we start pulling Renesis' part that have used the SOHN, synthetic, and premixed since day one then we won't know.

What do your spark plugs look like 9K??, that will give you a pretty good indication.

I guess the top of Banger Pistons don't get carbon on them either?;)

Good vid..

9krpmrx8 01-18-2011 05:20 PM


Originally Posted by ASH8 (Post 3852650)
What do your spark plugs look like 9K??, that will give you a pretty good indication.

I guess the top of Banger Pistons don't get carbon on them either?;)

Good vid..


Check em' out at 12k on the "new" motor.
http://farm4.static.flickr.com/3136/...a21461b1_o.jpg
http://farm4.static.flickr.com/3227/...54c6048f_o.jpg
http://farm4.static.flickr.com/3343/...287be9ca_o.jpg
http://farm1.static.flickr.com/21/45...b216d182_b.jpg
http://farm5.static.flickr.com/4006/...6abe362e_b.jpg

nycgps 01-18-2011 05:23 PM


Originally Posted by shadycrew31 (Post 3852621)
Im still not sold... I think that using dirty motor oil that is not meant to be burnt is the leading culprit to carbon build up and engine failure.

is your gas.


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