ASH8

Sleepezy, the member here who works at the Mazda US reman plant said they are replacing sump pans to the later type with more baffles....his words.

ASH8

Possibly, I look at the Part Numbers and how the old # supersedes to the new part numbers or later ones used in say the RENESIS.

If the parts supersede forward it always means that they are safe and or compatible without any modifications, but it is extremely rare (almost never) that the old part will fit in the later car, or one uses the old part in the newer model.
It can happen but not "officially".

Many a time I have seen part numbers completely change and are "supposedly NOT Interchangeable", but when you look at them side by side there is No difference at all.?

Like oil pumps and By pass regulators (Piston plunger and spring) are the same part numbers, so the pump is pumping the same pressure, even the oil pump chains are the same from FC and FE (RX-8).

The 3648-14-250 By Pass Regulator used in the FC and FE S1 RX-8, by original parts model code (3648) originates from the 1976 13B RX-4., but the internals of this regulator (the plunger and spring) are originally from the Mazda 800 of the 60's. (0221 parts model code).

9krpmrx8

iTrader: (46)

Lots of info.

ayrton012

As RG stated in this thread, this kind of bearing can't damage if there are oil in it. It's not really depend on what is the warm side viscosity of the oil, 20-30 or 40.
So what is the situation when the bearing could be dry, without oil flow? At startup, and after starting, for a while, until the pressure does not build up in the eccentric shaft. Maybe in some situation this time is to long.

I have one thought. There is a thermo pellet in the eccentric shaft.

1. When is it opened (until the temp does not reach 60 C), the oil pressure can't build up so quickly inside the e-shaft, so it's is related to the bearings which gets oil from the e-shaft. They don't get enough oil flow.

2. If you stop the warm engine, the pellet will open when the e-shaft will cool down to 60C. When it's happen, the oil maybe will drain out from the e-shaft. So the next startup its time to fill it with oil again, and build up the pressure. And this period is dangerous for the bearings.

I know, this pellet was on the earlier 13B's too, but maybe there are some changes in the oil passages of the Renesis? I don't know.

ASH8

Interestingly the Eccentric Shaft Pellet and Spring are the same Mazda Part Number for ALL 13B and RENESIS Rotaries from the very first 1985 NA FC RX-7, FD RX-7 REW and RX-8 FE...from 1985-2010

# N326-11-D15 Pellet
# N326-11-D17 Spring

And Opens at 60C..
N326 is the Part Number model code for 1985 NA FC RX-7 parts.

So I guess if the Eccentric Shaft was starving for engine oil until 60C we would have seen the same bearing wear issues in all these 13B's over the past 25 years?

Many re-builders blank Pellet it off.

bse50

I always modify them, the lack of lubrication is what kills the engines here since many owners only do short trips (10-12mi or so). Lack of oil during the warm up, several short trips and you see the engines failing before 60.000mi.

ASH8

Yeah, I am not that keen on the idea, rotaries before 1985 never has this E Shaft heat pellet., But there is a reason for them

bse50

Same here, i think that a higher viscosity oil will also flow out of the eccentric shaft in a slower way, helping a bit during the next start-up.
It is frustrating to see engines that are in fairly good shape go bad for $10 parts.

bse50

This thread of yours actually put together some puzzle pieces i was missing while continuing a study that had as a subject some engine failures here.
I really have to thank you since now my picture is pretty much complete

ASH8

and your conclusions...if you have some...

bse50

The conclusions didn't change much
5w30 is not adequate to the task of lubricating the rear, hotter, rotor and the thermal pellet does the rest. Raising the system pressure is fine but i don't know how much it will help once you always have oil flowing there.
All in all your points are a good explanation to why our engines fail with a higher rate than the ones in the u.s. We do short trips and do way more cold start ups as a consequence
Any clue on why mazda did use the thermal pellet in such configurations?

ASH8

The Pellet is actually there to speed up engine temps from cold start up, rather than the full flow of Cold oil, the pellet does not actually stop the oil jets oil flow to the two rotors and their rotor bearings it restricts the flow...as soon as it reaches 60c it's then full flow to the rotors oil jets.

So the rotor bearings still gets engine oil just not as much until temps get to 60c +.

It probably is in all seriousness a good idea provided it does not fail, they are said to last the life of an engine, but if they fail you can have big troubles.
I guess this is why many rebuilders put a sold pellet or washers to stop E Shaft oil bypass...to be safe.

But I like the idea that it make the engine warm up far quicker, hotter rotors are better for emissions, gas burning and helps the prevention of carbon build up on rotors.

When you think of it without the pellet short trip drivers would never see a fully warmed engine or engine oil.

In the end it is probably the best compromise...

I am sorry guys but I still keep coming back to the same finding...Oil Viscosity..., particularly after oil is over a few thousand miles old..

****************************
BTW: Don't forget we have another form of Oil Heating and that is the Oil Cooler pellets or thermostat that opens at 65C.

So at 60c+ you get full flow of engine oil through the actual engine with NO oil cooling by Oil Coolers, then when oil reaches 65C you have complete Full flow from Oil Coolers through to Engine and back.

Then when Coolant Temperature Reaches 82c your Coolant thermostat opens for Full Flow and Engine Cooling.

bse50

I don't know what to think then, it is a give or take!
Oil flow vs oil temperature... I would pick oil flow since i believe that the problem with short trips is not the engine warm up (stop and go traffic is the law here...) but the lack of massive flow\huge number of start ups mixed with short trips.

As for the pellets lasting an engine's life i don't know, at times they fail

ASH8

Forgot to add, I guess also with the recent increase in Oil Pressure (doubled) on S2 RX-8's (two thirds of which is used for the EMOP set up) the other third for actual engine would also result in engine oil cooling quicker as it is moving faster through the oil network and hopefully removing excess engine heat more efficiently one would think.

*****************************

Frankly I am still jacked off as to why Mazda released the RX-8 in the first place with both Oil and Water cooling inadequacies, and the lubrication of Apex Seal issue....

YET AGAIN Mazda will pay a very expensive price for this engineering failure as there are many RX-8 owners who love the car but hate the engine failures, the Rotary Engines reputation takes yet another dive when it could have been prevented.

I totally blame Ford's ownership and influence at the time, it is obvious the RX-8 did not have enough Hot weather and longevity testing...before final production.

ayrton012

ASH. our oil coolers thermostat opens at 90C. You know it.

I think the e-shaft pellet is mainly for environmental reasons. It's work only means 1-2 minutes quicker warming.

I don't believe that Mazda doubled (!!!) the oil pressure in the S2 Renesis just for the e-mops. Maybe it was the step to avoid the e-shaft pellet's negativ effects on flow. They can't throw away the pellets, because of the environment factor.

We have to put together the pieces, because I think such a bearing wear is not a viscosity matter. It's a weak oil flow matter. There are not so much difference between a warm xxw-30 and xxw-40 oils, and for example almost every combustion engines working well in all over the world with 40 weight oils.

nycgps

iTrader: (1)

one day, I will take the stock e-shaft pellet out and swap it with the bypass pellet and to prevent further "possible" failure ... who cares about that extra what 1,2,3, even 5 minutes of extra start up emission

bse50

Talking about italian tune-ups, a guy recently swapped one without taking the engine down! He used a 6feet bar to remove it and nearly broke his fender

Anyway i've been running without airpump as well for a while and recently passed our emission test so...

I would like to know why this issue, per Ash, is more related to oil viscosity than oil flow because i put the second reason first, at least for the engines i have seen

arghx7

Mandated oil viscosity per SAE:



20W50 for me

nycgps

iTrader: (1)

- Have been using 20w50 after the first 400 miles on Reman Engine, will continue to do so

oh, I premix too. since day 1

treyoh5

having read all the posts in the more than 100 pages of oil discussions on this site ur 20w50 seems to be where im heading.

arghx7

post #21 said:

at 100 C

20 weight: 5.6 mm^2/s or 5,200,000 centistokes
50 weight: 16.3 mm^2/s or 16,300,000 centistokes

a difference of 11,100,000 centistokes . all calculations done here: http://www.cleavebooks.co.uk/scol/ccviskin.htm

the 50 weight has almost 3 times the nominal viscosity of the 20 weight. Now, we can debate how important that is, but the differences in viscosity are significant.

9krpmrx8

iTrader: (46)

Okay so wouldn't a 0W-50 be ideal for pumpability and protection?

olddragger

iTrader: (3)

dang good info
i identified that the engine will not even hold factory spec pressure at 3K with a 5/20w oil 2-3 yrs ago.
pressure versus flow versus volumne? Just remember a heavier oil will be pumped with the same volumne of a lighter oil--it just takes more power to do it. Its a mechanical pump so what it takes in--it IS going to get it out!
Flow? not as relavent in the rotary as a recip, but it is still something to consider.
Viscosity?--that is why i use deisel oil--look at the oil analysis reports I have posted. Deisel was the ONLY one to maintain its viscosity after 1K miles. It will NOT harm the engine--Good God.
Dont let the car set and fully warm up, drive it with a very light load.
I actually get more oil out with a vacuum pump than when i use the plug.
I dont use synthetic anymore. To damn expensive for a 3K oil change schecule
Magnets on my filter. The real kind.
My only concern at present is with the bypass.
olddragger

9krpmrx8

iTrader: (46)

That's true. You mean the oil cooler bypass?

olddragger

iTrader: (3)

yep and that most dont have oil temp gauges.
oh by the way can the pre 09's use the 09 filter?
OD