Engine failure – Have you opened an engine up?
07-31-2007, 10:44 PM
#28
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Cut 'n Paste! Now I am insulted. I worked really hard on that for 4 or 5 minutes so you can call it Cut 'n Paste?!?
The answers are all there. If you would just stop posting duplicate threads for a minute and do a search, you will be rewarded with days of reading.
Really - DAYS.
The answers are all there. If you would just stop posting duplicate threads for a minute and do a search, you will be rewarded with days of reading.
Really - DAYS.
07-31-2007, 10:53 PM
#29
Much of the other issue is the lean OMP injection ratio that mazda programmed into the car, causing premature weardown of all compression seals, mainly apex seals and rotorhousings...which then leads to weak compression, slower starting, rougher idling, slight power loss, etc.
Kevin I don't think this is the issue. If it was a universal programming, then ALL the Rx8's would have a universal compression problem. Even if an improved ecu re flash was to supply more oil, how could you undo the damage that's already done to the engine? I mean there are people here on this forum that have over 100k on their original 2004 engines. I feel the excessive carbon build-up these engines are capable of producing is the biggest cause for these engines to loose compression. The side exhaust doesn't allow the carbon to escape the apex seal grooves like with the older engines with peripheral exhaust. So if the engine isn't run hard enough to generate the heat needed to burn the carbon, it just keeps building up and building up to the point the apex seals start sticking and the carbon just rotates continuously around in the combustion chamber for 100's and thousands of miles easily wearing it down. The recall has somewhat addressed the issue and now Mazda is doing a teflon coating on the rotor faces for the latest remans and new vehicles, however the coating on the rotors still does nothing for the build-up in the apex seal grooves. So if the upgraded engine is still run in low rpms a large percentage of the time, the engine can still experience potential failures in the future.
Last edited by T-von; 07-31-2007 at 10:59 PM.
07-31-2007, 10:58 PM
#30
Originally Posted by T-von
Even if an improved ecu re flash was to supply more oil, how could you undo the damage that's already done to the engine?
The second step (after verifying a loss of power in normal driving) is to run the OMP at maximum for 5 minutes and drive it again. If it passes, they slap in the new flash and off you go.
Originally Posted by T-von
I feel the excessive carbon build-up these engines are capable of producing is the biggest cause for these engines to loose compression. The side exhaust doesn't allow the carbon to escape the apex seal grooves like with the older engines with peripheral exhaust.
Originally Posted by T-von
The recall has somewhat addressed the issue and now Mazda is doing a teflon coating on the rotor faces for the latest remans and new vehicles, however the coating on the rotors still does nothing for the build-up in the apex seal grooves.
I've posted the pics. Let that one go.
Last edited by MazdaManiac; 07-31-2007 at 11:04 PM. Reason: added data
07-31-2007, 11:12 PM
#31
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Hey Icemark, where did you get your info on the burning of synthetic oil, I would like to read it. Also, I could imagine some chemicals in different oil products could effect the materials in the apex seals. One area the oil could effect would be the soft seals. I could imagine there could be an effect similar to the effect using non-girling brake fluid in old British cars. I am not a chemical engineer, that was reason I was asking these questions. I was hoping to find out from people who have actually opened up these engines and looked at the problems. It was looking for real data, because it seems so many folks seem to be speculating and sharing their best guess. I just want some data.
For example lets look at a few 5W30 oils Castrol GTX (the most popular oil used in Rotary engines), Valvoline Race, Quaker State, and a couple synthetics.
Castrol GTX....Flash point = 400/ ash (%) .80
Valvoline All Climate....Flash point 405/ Ash(%) 1.0
Quaker State.... Flash point = 410/ Ash (%) .9
Mobil 1.... Flash Point = 445/ Ash (%) .6
AMSOIL.... Flash Point = 480/ Ash (%) <.5
Red Line.... Flash Point = 455/ Ash (%) <.5
So looking at those 6, you can see they all burn at less than 500F (considerably less than the combustion temps in a rotary engine) and in the case of every synthetic they leave less behind than the conventional oil.
But not all synthetics are like that.. for example Valvoline Synthetic:
Valvoline Synthetic.... Flash point = 435/ Ash (%) 1.5
Wow, almost double the ash left over from the conventional Castrol and almost triple the ash of most of the other synthetics. Again as a reminder, the ash is what is left after the oil is burned. Sometimes it is high levels of zinc (used as an anti-wear additive in most conventional oils) or other additives-such as detergents all of which lead to build up or sludges.
And similar results for Castrol Syntec
Castrol Syntec.... Flash point = 437/ ash(%)1.2
Kinda surprising since Castrol Syntec is basically the same oil as BMW sells as their performance oil to be used in all their cars with only minor additive changes.
So see that is why I think that Mazda says no Synthetics... because the couldn't say don't use this brand or don't use that brand... So they just said across the board not to use them.
07-31-2007, 11:21 PM
#32
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Excellent, that was the kind of info I was looking for. I will go look at their reference sheets. Had I searched more I may have been able to find more info like this. Thank you for doing the research.
07-31-2007, 11:45 PM
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Personally, I plan to run my RENESIS hard, change the oil frequently, using whatever damn oil I buy or am given by a sponsor, and if I've somehow displeased the rotary gods (not to be confused with the beer gods, or RotaryGod, or even with God, Himself in general) then my motor will fail no matter what I've done. I do not plan to pre-mix. I shall fill it with the prescribed amout of oil at each oil change, keep my tires fully inflated and properly rotated, and absolutely flog this mother until the RPM needle and the redline have thoroughly consumated their relationship!
Now can we kill off this thread and go on to something productive? How about another RX-8 versus ??? thread? Perhaps a "Which should I buy, RX-8 or Skyline GT-R?" post?
Now can we kill off this thread and go on to something productive? How about another RX-8 versus ??? thread? Perhaps a "Which should I buy, RX-8 or Skyline GT-R?" post?
07-31-2007, 11:46 PM
#36
I've done that, so what is your point?
Hey Eric - I got your phone message. I'll call you tomorrow when I'm out of the shop, but can you do Thursday morning? I'd show up in Blythe around 5am I suppose (maybe a little earlier to give her a wipe-down first).
Last edited by MazdaManiac; 07-31-2007 at 11:49 PM.
07-31-2007, 11:56 PM
#37
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Your car has 4 seats... bring 3 women! LOL
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