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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/)

ayrton012 01-21-2011 10:32 AM


Originally Posted by olddragger (Post 3855672)
ok I am clear--part time dementia is a bitch.
I understand the omp design now--took some study, and it appears more complicated than it should be, but it is what it is.
OD

Great OD! Yes it is a simple system, the engine sucks air/oil mix from the nozzles. Without the air, it sucks only oil, much more oil from the MOP, because that can't hold the oil against that much engine vacuum. But the air from the nozzle's air pipe solves this problem.

MazdaManiac 01-21-2011 10:34 AM


Originally Posted by olddragger (Post 3855672)
Some ethanol testings locally are showing percentages up to 18-20%! You truelly do not know what you are putting in your tank. You know some water has to be in there also.

The water separates the alcohol out and it all goes to the bottom of the tank.

shadycrew31 01-21-2011 10:35 AM


Originally Posted by DocBeech (Post 3855615)
alright heres one for you I am pulling from another thread for your engine failure theory:




maybe our failure problem is much simpler than we think. The ethanol in the fuel is breaking down the Phthalates used in the making of the oil injection lines. Those deposits are then clogging our lines and causing the carbon build up we are seeing. It makes sense if you read the chemistry of exactly what ethanol does to plastic, rubber, and metal (with the exception of aluminum, for some reason aluminum seems to resist the corrosive affects of ethanol)

Even if that is the case which it appears to be unfortunately. Getting gasoline without ethanol in it is not feasible.

Also...

http://af.reuters.com/article/energy...NA934320110121

Dammit!!!

MazdaManiac 01-21-2011 10:46 AM


Originally Posted by shadycrew31 (Post 3855821)
Getting gasoline without ethanol in it is not feasible.

That's not true.
There are stations that don't have ethanol.
Ethanol is added after delivery of the gas.
It is up to the store owner to decide how much he wants to use.

MazdaManiac 01-21-2011 10:51 AM

BTW - A thread I started about this subject four years ago:

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/omp-boost-potential-problem-117352/

9krpmrx8 01-21-2011 10:53 AM


Originally Posted by olddragger (Post 3855672)
ok I am clear--part time dementia is a bitch.
I understand the omp design now--took some study, and it appears more complicated than it should be, but it is what it is.

Some ethanol testings locally are showing percentages up to 18-20%! You truelly do not know what you are putting in your tank. You know some water has to be in there also.
So if you are tuning on the edge, then I guess this has to be kept in mind?

Almost like a duel fuel car.
Even stations that use to be "pure gas" is feeling the pressure. Pure gas sure runs better in my car and it gets much better gas milage.

9K dang- if you are not motivating me to go ahead and test my nozzles before I fire this engine up. You can test them will they are in the engine cant you?
OD


Yeah you could test them while they are in the motor, but like Dan said, the UIM would have to be removed. But if the engine is out then it would be easier.

shadycrew31 01-21-2011 10:59 AM


Originally Posted by MazdaManiac (Post 3855833)
That's not true.
There are stations that don't have ethanol.
Ethanol is added after delivery of the gas.
It is up to the store owner to decide how much he wants to use.

Ahh I see well my experience in CA has been that every station has at least 10% to control emissions.

Also it is a federal law to have a biofuel mixed with gasoline. Selling straight pump gas with no biofuel additive would be illegal.

9krpmrx8 01-21-2011 11:06 AM

Check out Walmart, like I posted, not all Murphy USA stations have ethanol in the fuel. I am sure there are others. Let's not mix the ethanol debate in with this discussion.

MazdaManiac 01-21-2011 11:08 AM


Originally Posted by shadycrew31 (Post 3855851)
Also it is a federal law to have a biofuel mixed with gasoline. Selling straight pump gas with no biofuel additive would be illegal.

Not true.
There is just a mandate to sell a certain amount of biomass-based fuel in the course of doing business.
Station managers can choose to oxygenate their fuel however they like.

shadycrew31 01-21-2011 11:22 AM


Originally Posted by 9krpmrx8 (Post 3855859)
Check out Walmart, like I posted, not all Murphy USA stations have ethanol in the fuel. I am sure there are others. Let's not mix the ethanol debate in with this discussion.

I think the discussion has led us to the ethanol debate though.... New topic perhaps?

Side note: the Act increases the amount of biofuel (usually ethanol) that must be mixed with gasoline sold in the United States to 4 billion gallons by 2006, 6.1 billion gallons by 2009 and 7.5 billion gallons by 2012;[1]

Unless I'm reading that wrong which is possible.

olddragger 01-21-2011 11:27 AM

True the ethenol will settle out when it reacts with the water. Some drag racers in this area use E85, blend the gas out of it and use the remaining for there alki injection. They use the gas for their lawnmowers etc--taking the ethanol out takes away about 2 octane points by report.
Gasahol doesnt store well.

I can find pure gas in my hometown and it seems that the demand for it is increasing.
There is a line everytime I go to a pure gas station.

Guess the grassroot nechanics will see a lot more business.

Now back to the op's subject?

04Green 01-21-2011 11:37 AM


Originally Posted by dannobre (Post 3855735)
You would have to pull your upper intake to get at them....not sure how accessable they would be with your blower on there either :( You could pull a vacuum on the supply line...and if it works you can assume that all 4 are working. If it doesn't you can only guess as to how many are faulty.....but I guess at that point it wouldn't matter...you would have to pull them to figure out what was up

The test here, with the vacuum pump, is only to test the check valves, right? You could pass with all good check valves, also completely clogged oil line and good check valve, also completely clogged oil line, clogged injector, and bad check valve, right?

If we pull the injectors, we can see if the injector is clogged pretty easily, and test individually, but still cannot see if oil is flowing, right? With injector pulled, there is no way to run the motor and see if oil is making it through, right?

So, is there a way to tell the omp to "pump/meter like hell for a bit" so we can see if oil is flowing without taking it to a dealer? Maybe apply 12V to a specific pin? If that were the case, we could pull upper manifold, pull/clean/test injectors, flow oil, and then hope to get it all back together.

Or, is oil pressure / vacuum required to flow? If it is, maybe just try to suck some oil through with a little vacuum pump, if OMP will allow, maybe with 12V on a particular pin?

MazdaManiac 01-21-2011 11:57 AM


Originally Posted by shadycrew31 (Post 3855874)
I think the discussion has led us to the ethanol debate though.... New topic perhaps?

Already is one: https://www.rx8club.com/general-automotive-49/think-10%25-ethanol-sucks-try-15%25-206284/


Originally Posted by 04Green (Post 3855897)
So, is there a way to tell the omp to "pump/meter like hell for a bit" so we can see if oil is flowing without taking it to a dealer?

You can do it easily with flash programming. I have a calibration for the AccessPORT called "MAX OIL" that I use during Seafoam treatments. It turns the OMP up to its highest step.
It is also useful for starting/transporting a car with a blown motor.

DocBeech 01-21-2011 04:19 PM

My point was missed. So let me try again. Related to this topic of problems with MOP lines and injectors I believe that part of our problem could be degradation of the MOP lines from ethanol in the fuel. The same fuel which every oil analysis shows to be in the oil. Its known that ethanol breaks down plastic lines maybe our injectors are being clogged and our valves are not functioning properly because of damage from ethanol.

9krpmrx8 01-21-2011 04:26 PM

Yeah I mentioned that in the ethanol thread. Many UOA's show fuel in the oil, so you have a point.

MazdaManiac 01-21-2011 04:33 PM


Originally Posted by DocBeech (Post 3856260)
I believe that part of our problem could be degradation of the MOP lines from ethanol in the fuel.

I'm not sure how fuel could get to these lines unless the nozzles have already failed.

DocBeech 01-21-2011 05:21 PM

The MOP is using dirty oil. Oil that is already diluted with fuel.

dannobre 01-21-2011 05:58 PM

Ethanol would likely evaporate long before fuel and water....and below the normal operating oil temperatures....Not likely a huge component with E10 type fuels....it would be so slight that it would be negligible. That would be different with E85..but that isn't a issue for anyone.

I would imagine that heat would be the main contributing factor...The oil would also be post engine..pre-filter in the circulation....be that what it may :)

9krpmrx8 01-24-2011 05:25 PM

Yeah and my lines had 120,000 on them so I doubt the minuscule amount of fuel in the oil containing Ethanol was an issue in the deterioration of the lines. I just think if you are rebuilding a DD, replacing the OMP lines and injectors is probably a good idea if you have a good amount of miles on your car. getting my injectors cleaned and tested is next for me, I just wish I could have done it when i had all that crap apart :lol:

EricMeyer 01-25-2011 06:33 AM


Originally Posted by 9krpmrx8 (Post 3858926)
Yeah and my lines had 120,000 on them so I doubt the minuscule amount of fuel in the oil containing Ethanol was an issue in the deterioration of the lines. I just think if you are rebuilding a DD, replacing the OMP lines and injectors is probably a good idea if you have a good amount of miles on your car. getting my injectors cleaned and tested is next for me, I just wish I could have done it when i had all that crap apart :lol:

If I were a V8 guy looking at this thread from a distance I would say: "sure you replace your hoses and valves when they see a lot of use". Ethanol, oil or other there a lot of consumables that hang on the outside of the motor that perform some sort of mechanical function. If you were rebuilding a high mileage small block one could argue that you'd use: new fuel injectors, oil pump, lines, hoses, gaskets, anything with a valve.....basically anything on the exterior of the motor. We SHOULD be seeing decreased efficiency of many of these items because that's what your suppose to see. NOW, let's figure out if this decreased efficiency is leading to failure modes. THIS is the real question. Anyone can speculate. How do you get to the root cause?

RIWWP 01-25-2011 08:12 AM

Subscribed. Read every post.

It does make me wonder where the line between raced engines and street engines is. Almost certainly not a line at all, but rather a scaling grade. How hard do we have to thrash our engines on the street and how regularly to start seeing some of the same problems that Eric is vs common street problems?

olddragger 01-25-2011 08:14 AM

Eric,

Do you know of anyone that is running the S2 engine on the track? What are their experiences with engine life, tear down data etc? Wondering if the new design has really had an affect in the track enviroment. That would be invaluable data to have.
I dont know of any S2 teardowns really, I know Paul/ Rick had one that was a victim of a fluke accident--it inhaled something in a wreck? Nothing really found but the engine had low miles and easy use.
OD

EricMeyer 01-25-2011 11:01 AM


Originally Posted by olddragger (Post 3859454)
Eric,

Do you know of anyone that is running the S2 engine on the track? What are their experiences with engine life, tear down data etc? Wondering if the new design has really had an affect in the track enviroment. That would be invaluable data to have.
I dont know of any S2 teardowns really, I know Paul/ Rick had one that was a victim of a fluke accident--it inhaled something in a wreck? Nothing really found but the engine had low miles and easy use.
OD

The S2 is currently run in dry sump format in the Star Mazda series (formerly called the Pro Formula Mazda Series). In prior S1 and dry sump trim the Renesis ran a soft cut at 8,300 and hard at 8,600 rpm. Lambda at .91 to .95 and those cars had a fuel trim switch to add fuel only I believe.

I have heard the rpm ceiling has been raised for these cars and they make about 2 to 3 hp more on an engine dyno. 260 vs. 255-258. Motors we have had built by someone who has been very involved with this series turned 258 flywheel. These same S1 motors pulled approx 215 rwhp on a dynojet and 2004-2008 trans.

I am unaware if either of these two engines run an OMP.

olddragger 01-25-2011 11:12 AM

Ok, thats something.
09 injectors and intake manifold does seems to add a little power. I have heard others say the same.
I will see if anyone at the Mitty this year can give us any down and dirty info.
I have a gut feeling the S2 engine is giving more hours of use?
OD

9krpmrx8 01-25-2011 11:19 AM

Personally, I believe a few things contribute to the premature failure of the Renesis motor. I think you can look at the changes to the Series II and get a good idea of what the problem areas are with the Series I.

I think a malfunctioning OMP system will affect engine life eventually. Whether the affect is from the lack of cooling from the oil injectors or from a lack of lubrication is debatable but likely both are important. IMO, Injecting dirty engine oil is not ideal, Mazda only did this because the normal owner is not going to monitor and refill an oil reservoir. Premixing also helps but again, the average owner is not going to mess with premixing their fuel. I believe premixing and running the SOHN are necessary if you want your engine to live a long healthy life. We have seen bearing wear. I attribute that to insufficient 5W-20 oil in high load/high temp "extreme" situations and possibly due to low oil pressure. Running fully synthetic (if you have the SOHN) 40 weight or higher is a good idea and changing your oil regularly is a must due to the amount that remains in the engine and coolers. The Mazmart oil pressure mod is a no brainer.

Cooling is always a concern. Coolant temps and oil temps should be monitored and if you are seeing excessive temps then they should be addressed. There are several options to address these issues like proper ducting, freeing up area behind the fans, secondary radiators, Mazmart water pump, Mazmart Thermostat, better radiators (griffin, Ron Davis, etc.) better oil coolers, or simplified oil lines like the Racing Beat lines, and better coolers or a large single oil cooler.

Filtration is also important, and personally I don’t think there is any real benefit to running a hi flow filter on a street driven vehicle. The minuscule HP gains are far outweighed by the damage sand and other types of dirt can do to your engine. All I have to do is look at the built up dirt in the tray under my intake box to see what could possibly make it into my engine. I’ll stick with an OEM type WIX filter on this motor.

Habits are important too, if you are the type who just gets in your car in the morning and takes off, driving hard when the engine and oil are cold, then you are likely doing damage to your engine. The engine needs to be warmed up before revving hard and a stock 8 takes some time to get fully warmed up. I am in South Texas and even here when the factory temp gauge reads normal, the oil is still too cold to start redlining or putting a high load on the engine. However, to avoid moisture in the oil, and to help minimize carbon build up the RX8 needs to warmed up and driven hard from time to time.

Of course, if you only plan on owning the RX8 for a year or two and could care less if it makes it to 100-150,000 miles then just drive the damn thing and don’t worry about all this :)


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