PhillipM

Not necessarily, in the same way that oil film strength only relates to film thickness when you consider them in an entirely theoretical ideal basis.
I'd take a good light-weight synthetic with immense film strength and shear resistance, over a mineral base-stock 20w50 with a thicker film but lower strength any day of the week.

Added to that more flow = more load capacity....

GeorgeH

iTrader: (2)

Goot points, Phillip. Yes, we need to consider film strength more so than thickness, and your points about the effect of the bypass valve are interesting too.

It's never as easy as it seems.

Sticking with RP for now.

olddragger

iTrader: (3)

what no talk about diesel oil superiority. it does have a higher level of phos and Zi but not enough to harm cats. Film strength far bypass's auto oil and dont even debate partial suspension properties,
SYnthetics are ok but you cant break an engine in with them and they are to dang expensive for 3K oil changes.
What would you rather have? 2-3k dino diesel oil change schedule @$15 a pop or 3-5K synthetic@ $32 a pop?
No brainer for me.
Besides like ASH has said--no internal changes for years and I have a tendency to believe the old rotary guys that have been building engines for years. Hands down.
olddragger

PhillipM

^^Over here diesel oils are pretty much the same as the petrol formulation just with slightly more detergents (indeed most are sold for both uses) they're no better for film strength/additive packages, etc.
Things may be different over the pond though.

ASH8

Actually the Temp Sender Unit behind Water Pump is very accurate in it's reading to the PCM, as for the Dash Temp Guage itself, Yep it is suspect, I guess you have seen one..it "guts", a cheap bi-metal strip with a ultra thin heat wire spun around it, that is it, not like the REAL guages of 30 years ago that had some "engineering" in them.

But yeah, the actual dash temp guage accuracy is questionable and cheap.
Fuel Guage is the same.

ASH8

Could not agree more OD..

Plus the guys that actually sell the genuine Mazda replacement parts to the guys who actually rebuild a naked Rotary.
The parts guys know what Quantity or Numbers of a particular engine part are sold/selling or stuffing up..

You see, most if not ALL Mazda Dealer Mechanics (techs) whatever you want to call then never get to see the inside of a RENESIS so how the Hell can they give ANY advice???

Plus most experience Parts Guys know a bloody side more than ANY mechanic does by sheer volume of what a Parts Guy Sells and Touches and Looks and See's.

Mazda's as a general rule are extremely reliable, throw a wobbly one to a dealer tech and they have NO Idea where to start or what to replace....in some cases it is hit and miss..."OH yes sir we have Ordered a new one "Under Warranty For you"...The Dealer mechanic is hoping he will never see that car again.

Having said that there are some very good guys like 'technics' who will give free advice and know what they are talking about from actual HANDS ON experience, Not Out of a Bloody Book...rant over..sorry OD.

olddragger

iTrader: (3)

diesel on this side of the pond must be a little different. It is designed mainly for trucking and heavy machinery here? I think diesel's are much more popular other there in cars? Here it is reportedly a better base stock and with additional phos and zi. It also has a much superior particle suspension because of the sulfur stuff diesels have to contend with. Oil analysis studies really look good.
Rick E gives it a thumbs up along with Paul.

lol Ash--I am with ya dude! Too many times a repair tech doesnt have to think--just push buttons --read a screen and then replace a part. Not saying there are not good tech/mechanics--there are, but it seems they are getting further and further apart.
My 1st job 43 yrs ago was with an Auto Parts store NAPA store. mechanic, machinist's and the parts guys used to trouble shoot all the time. Almost like one couldnt do without the other when really trouble shooting.
OD

PhillipM

Yes, it's quite common over here for car use - there's as many diesel cars sold as there are petrol over here.

ASH8

Sorry for the late reply (Senior Moment)

Yeah, I recall when I returned to Mazda this time as a Service Adviser after a holiday away from the car industry and Mazda Parts...I actually had a nervous breakdown...another story.

I was working at the same Mazda Dealer where I bought my RX-8 last year.

So... go back to 1992 this customer was complaining of a squeaky noise coming from the front wheels on her immaculate Mazda 323 only over light road bumps, cut a very long story short this tech had machine the disc's, replaced front brake pads, done wheel bearings over about a 2-3 month period and suspension bushes, drive shafts, etc, and yep the owner kept coming back time and time again...still the same symptom.

I just got back from leave, seen what this poor woman had been through, but still the squeaking front end.

I said to the mechanic who had the front wheels off again, put them back on, get some black tape.... see the Hub Caps, wrap some tape around the Hub Caps "Claws" Ring and put hubcap back on steel wheel rim, he did it and the noise was gone!!...customer happy....all it took was 3 feet of 1/2 inch black tape.

Why, I remembered the first Mazda 626 FWD of about 1985 that had those 'bottle top' looking chrome full plastic hub caps, this was the fix back then to stop the squeaking...

-=lil red=-

iTrader: (1)

So I'm guessing I will be using the same 20w50 and premix on my newly acquired 04 RX-8 as my other rotary powered cars. I will be rebuilding the engine in it. The car has 60k miles and it smokes like a train. Im guessing I will be finding burnt up side housings, oil control rings, and who knows what else once I tear it apart tomorrow.

ayrton012

That is why Mazda jumped to full syn 0w-30 in Japan, and increased the bypass pressure.

alnielsen

iTrader: (4)

It could just be carbon buildup. Try the SeaFoam treatment first to see if that helps.

olddragger

iTrader: (3)

very true--always decarbon first.
I was in the parts store in 1967--muscle car days in Ga and the only speed shop places in Ga were auto part stores--mainly.
I could tell stories MacGeyvor style. Remember cars squeaked a lot in those days. There were lots of paint stick "parts" (wedges) in them!
Remember the vars with the leaf spring suspenion in the rear? When you added a lot of hp to them sometimes the center bolt holding those leaf springs together would break under the torque load and the car would ride sideways. Lots of folks scratching their heads over that!
od

nycgps

iTrader: (1)

well he is going to take it apart anyway

make sure you post pics tho !

Flashwing

Wait, I'm confused here. Are you saying that Mazda allows Australian dealerships to rebuild RENESIS engines? I'm only curious because US dealerships cannot open any RENESIS engine, they have to send them out for rebuilds.

olddragger

iTrader: (3)

Flash I think he said "all" Mazda Techs never get to see the inside of the engine and the parts man sells parts to other mechanics that do rebuild the engines? That gives the parts man access to more problem solving info than the techs.
OD

nycgps

iTrader: (1)

Back then they let you rebuild them, they even tell you how in the shop manual.

Not anymore.

-=lil red=-

iTrader: (1)

haha carbon.

Took it out and apart today. Just as I expected. Rear rotor burnt up, rear side housing, the back of the intermediate housing burnt up, cracked apex seal, etc...

Never thought a newer engine would be this bad, I have taken apart 86+ 13B's in better condition.

nycgps

iTrader: (1)

Mazda screwed themselves up a lot on the 13B-MSP.

Got any pictures ?

ASH8

Flash, you have to take this in context from me and OD talk...

Don't know where I said Mazda Dealers Service Guys re-build RENESIS's.

I said..
I think it is very self explanitary...

Mazda Dealer Parts Guys Sell Genuine parts to Businesses outside of the Dealers Workshop/Service centre. Parts For all kinds of Mazda's.

Therefore what I am also saying is these very Parts Guys (like I was) get to know what engine parts are selling and being replaced, the ratio of what parts in rotary rebuilds.

Everything is sold separately apart from say an engine gasket and seal set.
If they asked for Rotor Bearings (unusual) or Stationary gear bearing or whatever I get to know what parts are being used in what model of engine, my stock records also tell me the quantities sold in say a year.

A Mazda Dealer Tech just swaps out with another engine already re-built, they rarely get to see the insides of a rotary.

In the 1970's we as a Dealer did all the R100,2,3 and 4 warranty re-builds..
The RX-7 were very reliable...daylight actually between the earlier ones.

Today dealers don't do them because of cost and lack of technical know how to do them, they just do swap outs.

As far as I know in Australia they still put in a brand new Factory engine in the RX-8, but my dealer were starting to send old ones back rather than binning/trashing the engines.

There was talk a dealer was going to do the warranty re-builds for all Mazda Australia replacements rather than all brand new ones, I don't know if this will still happen...I will find out.

ASH8

Hi Mate...

Yeah Picks would be great, and some details on the car, mileage, service history, Auto or manual, type and condition of engine oil.
I guess this is a RENESIS engine?...DOH if you already said so..

DO you think the owner cared for the car??, how was it treated...

ASH8

Jeez, if I read this I would not have ranted on just then...Bloody Hell I am going senile!!..

Yes OD, this is what I meant mate...I thought I was pretty clear...am I that bad aye??? ....

Flashwing

Ok, so the parts people are selling parts to other shops or service centers. Let's take journal bearings or stationary gear bearings for example. When these parts are sold do you know why they are being replaced?

ASH8

Yes, sure sometimes the person may bring part of the engine or part in for advice, one of my Customers who I would sell thousands $$'s of rotary parts a month was next door to my warehouse and I would call in and look, talk, pick up and supply parts for rotaries...in most cases like bearings you would know why they were being replaced.

Generally the customer would say I have a 13B REW RX-7, I need this , this and this.,,you get to know what they want and why...and you suggest what they have not asked for they should have or replace and the reasons why..

I think I said this here before, stationary gear bearings were hardly ever replaced, in the hundred we did on 10A,12A for coolant entry under warranty at around 30 to 40,000 miles, the bearings including rotor looked like new...No wear marks at all...yep the same 0820-10-502B Stat Gear Bearings used today from a 10A R100.

I was always the enthusiastic Guy, always wanting to know why, how and when, this is how I learned, by asking techs questions, looking at engines that are naked, looking at gearboxes, crashed cars for panels, etc etc.

Sure, some parts guys just have no interest into what they do, I was never one of those... I loved my work..I was a workaholic, and I paid for it in the end...not in a good way.

neXib

Since there's so much talk about oil strength, specs and so on. What should you look at if you want to premix, like which product do you pick.