DamonB

Nah, he's just got a 40 gallon tank

bajaman

whoa folks....I LOVE the rotary, don't get me wrong. I just feel it is totally unrealistic to expect it to survive in today's marketplace. There simply is no compelling reason to buy a vehicle equipped with one, in this case an RX-8, over another sports car unless you just dig the styling of course. And I like the RX-8 a LOT. People like to brag about a vehicle they just dropped 30+ large on, and not expect the conversation to be something like, (you) "Yeah, this is my new RX-8." (friend) Cool looking car man....isn't that the one with the engine that has been recalled? I heard those things get lousy mileage....is that true?"
The competition has all sorts of whiz-bang neat-o frito technology and boasts state of the art engine, transmission, and suspension components.
I still think that in order to make the rotary a viable, signature engine they need to make a 3 or 4 rotor, 400+ hp engine, put in some exotic chassis and body that makes people say "WOW!" as in the FD debut days, and bring this puppy in at 2100 pounds or so....and who gives a **** if it cost $100K? Mazda NEEDS this, in my opinion. They NEED people saying, "Oh man....have you seen that new ******' RX-7? Son of a bitch does 3.2 sec 0 - 60 and will run a 11 second 1/4....and tops out at 209 mph....******' A! It just SMOKES the Ford GT and new 'Vette, you can't touch this thing unless you bring a $300K Ferrari to the party!"
Yep....that is what Mazda needs.

t-von

iTrader: (8)

Newer synthetics may be safe to burn inside the engine compared to the past but know one ever said anything about the synthetics effect on the rotor oil seals. Think about it, piston engines don't have oil seals moving around near the combustion chamber like rotarys do. Knowing that the engine was originally never designed to run a synthetic, Mazda probably never designed the rotor oil seals for synthetic oil. To me it makes no since for this NA rotary engine to be having this particular problem when the second gen didn't. Maybe Mazda was right all along.

bajaman

How the HELL do you get better than 32 mpg in an FD?????? Best I've ever got is 22 (old stock engine), average is 10 - 12 mpg with the new engine. Do you turn it off and COAST a lot or something?

t-von

iTrader: (8)

He's burning the fuel more efficiantly with his ceramic coated rotors. The more fuel you burn, the more efficient your engine becomes. It is however one hell of an increase if it's true.

KMAR

https://www.rx7club.com/attachment.p...hmentid=192126

In this picture and explanation, the Mazda Technical Service information says that the carbon deposites cause misfire and/or knocking. The picture is pointing to a port, not the combustion chamber. Shouldn't they have taken a picture of the plugs carbon deposits? I'm just a little confused why they would point out the port which isn't the combustion chamber, is it to fool us into believing that this is the problem. I have seen engines with deposites like this running off regular oil and not giving the symptoms these people are suffering from.

I agree, Mazda has to do something like what bajaman said. Most people who buy Corvettes don't care about fuel economy I'm guessing, I don't. I pay about $1.30 plus a litre right now for gas. It hurts but, I just don't care, I'll just have to stop eating out or drinking beer to afford the gas, no big deal. Well, it is a big deal, I like beer, just not mixed with car. Later guys, K.

krishant

to be honest...these cars with rotary engines were not designed for fuel economy...simply not the point of the whole vehicle....it was to build smooth performing and excellent handling sports car that can wind down the twisties at speeds faster cars can't maintain in the curves....the rotary was primarily used for performance but most of all its light weight and small size....the combustion area is smaller than a gallon of water but yields 8500rpms...and once again is one of a kind engine...people just gawk when they realize there aren't any pistons, cams, etc under the hood of a rotary powered vehicle.

krishant

the rule is simply never use synthetic oils if the manufacter doesn't use it from the factory or the engine is designed for it....you really dont reap any true benefits other than longer OCIs....but even then the balance in cost etc is the same...plus the oils don't flow the same and peform the same...if its not tested its probably a bunch of hype from the oil companies...stick to castrol GTX it gets the job done...

GoodfellaFD3S

iTrader: (213)

I don't know what car you're driving, but it's definitely not a modded turbocharged rotary. Synthetic oil has many benefits for this application, and I have been using it consistently since 2001.

DamonB

No way in hell ceramic coated rotors can produce such an increase in gas mileage. No way in hell.

DamonB

I've got a model airplane engine with a combustion are the size of the nail on my pinkie finger and it turns over 10,000 rpm. So my model engine is better?

Improved FD

same thread in the lounge
https://www.rx7club.com/showpost.php...8&postcount=40

iceman4357

iTrader: (2)

To your point as well, if there is a little carbon build up you can do the gallon of water trick to "clean" your engine out.

KMAR

GoodfellaFD3S, your running synthetic, I thought with the BNRs that is bad, at least that is what the website says? I'm going to get the BNRs some day and I run Royal Purple right now with the stockers but, will switch back when I get the BNRs. Royal Purple says this:

Rotary Engines

Can Royal Purple Motor Oil be used in a rotary engine?

Yes. A rotary engine is a modified four cycle engine that recommends the use of an API licensed motor oil for street applications.

More information and FAQs on lubrication of Rotary Engines:

In a rotary engine, the oil lubricates the eccentric shaft bearings, thrust needle bearings and rotor bearings similar to a crank and rod bearing of a piston engine as well as being injected into the combustion chambers to lubricate the apex seals, corner seals, and side seals helping to create the sealing mechanism doing the equivalent job of the piston rings.

Royal Purple provides outstanding protection for the e-shaft, rotor bearings, thrust bearings and is suitable for the oil injection system as it has proven to run cleaner than other oils and is an excellent choice for rotary apex seals, corner seals, and side seals.

Mazda makes a statement in the Owner’s Manual not to use synthetic oils in a rotary engine, why do you say that it is OK?

Royal Purple has performed seal compatibility testing on the components used in a rotary with excellent results, including older rotary engine seals dating back to the Cosmo. Royal Purple’s Technical Services Manager David Canitz has been an owner and racer of rotary engine cars and has used synthetic motor oils in rotaries since 1985 with excellent results. He has been trying to find an answer to this Mazda statement for the last 18 years.

In the early development of synthetic oils decades ago, there were purportedly some seal compatibility issues. Today’s synthetic oils do not have the compatibility issues of the old oils. There is no substantiated evidence of seal compatibility issues with Royal Purple.

Here are some facts:


The Mazda Factory racing departments recommend and use ‘synthetic’ oils including the winning 1991 Leman’s 20-G 4 rotor Mazda 787B.


MazdaComp USA printed manual (now Mazdaspeed) recommends the use of synthetic oils for racing conditions.


Royal Purple Motor Oils have been used in rotary engines (both race and street) for ten plus years with excellent results.


Royal Purple Motor Oil is compatible with the bearing material, sealing elastomers, and combustion seals used in a rotary engine.

I heard that synthetic oil doesn't burn like mineral based oils and will coat the inside of the engine with deposits.

If this was a problem with synthetic motor oils in general, then all internal combustion engines using a ‘synthetic’ would experience increased deposits on internal surfaces. The opposite is actually the norm.

Conventional four cycle motor oils will typically leave deposits of carbon and ash when injected into the rotary apex seal, corner seal, and side seal areas. Royal Purple’s motor oil actually burns cleaner due to the synthetic base stock being free of contamination and many of the additives being ‘ashless’. This may not be true for all synthetics but Royal Purple has been proven to work extremely well in rotary engines.

Royal Purple’s formulation of synthetic hydrocarbon motor oil does burn at the nominal combustion temperatures experienced in both street and racing applications, whether normally aspirated, turbocharged, or supercharged. (500 – 1700° F idle to race rpms typical combustion temps)

Will the synthetic oil effect the oil seals?

No. Royal Purple’s Motor Oil is fully compatible with the elastomers found in rotary engines as well as more conventional piston engines. The oil seals, housing seals and other elastomers used in rotary engines typically consist of Buna N, Nitriles, Neoprene, or Viton materials which are also commonly found in piston engine cars.

I hear that synthetic is ‘thinner or lighter’ oil, is there a greater possibility that the oil will leak between the seals?

No. If an engine’s sealing surfaces are in good condition, synthetic oil should not cause any leakage. However, if an engine has marginal seals, there is a 50/50 chance the seals will leak less or more. A synthetic motor oil is going to have similar viscosity to that of a conventional motor oil – except at extreme temperatures. Due to a flatter viscosity curve, at low temperatures it will not thicken as much (easier winter cranking) and it does not thin out as quickly at higher operating temperatures (better oil film at higher rpm).

Should I go longer or shorter between oil changes?

Royal Purple recommends that the maximum oil drain / filter change interval listed in the Owner’s Manual be followed while under warranty (new RX8). For FA, FB, FC, FC Turbos, and FD rotaries, extending drain intervals from two to five fold is possible if desired. Since the rotary engine injects oil through the use of a metered oil pump, either adding oil into the carb base plate air / fuel mixture or directly injecting oil into the rotor housing, rotary engines will consume oil of one quart per 1000 – 3000 miles. It is important to maintain the proper crankcase oil level in your rotary engine if you decide to extend oil drain intervals.

If I pre-mix my fuel for the rotary engine, do I use the same ratio as with mineral based oils? Does it burn at the same rate?

In an ideal world, the rotary engine metered oil pump should inject an ashless oil designed to burn in the combustion chamber and use a four cycle oil in the crankcase for the eccentric shaft, rotor bearings, and thrust bearings. For the street, Mazda simplified the OE system to use just one oil, that being a typical four cycle oil for both the e-shaft as well as the combustion chamber. Royal Purple recommends using our standard TCW III 2 Cycle Oil if the metered oil pump is still enabled. The two cycle oil being added to the fuel tank is in addition to what Mazda designed to inject and acts as a supplement or insurance. Depending on which engine, the level of modifications (street port, Bridgeport, peripheral port, nitrous, turbocharged) and application, the typical mix ratio could vary from 200:1 to 800:1.

For a pure racing application where the metered oil pump has been disabled or removed, again based on the actual engine and modification level, the ratio could vary from 150:1 to 600:1. For this application, we recommend our Racing 2 Cycle TCW III product or the standard 2 Cycle TCW III can also be used.

A stock FD twin turbo 13B with the MOP oil injection system can typically use about one quart per 1500 miles under hard street driving. If this vehicle is getting 15 mpg, the gasoline to oil ratio is 400:1. If the oil consumption on this vehicle reduces to 1 quart per 2500 miles and fuel efficiency increases to 20 mpg, the gasoline to oil ratio increases to 600:1. The stock metering oil pump is a great system as it varies with throttle position (load on the engine). Pre-mixing has to be calculated for the ‘worst case’ that will be seen by the engine for that fuel load. Under racing conditions, that’s wide open throttle at racing rpms. This means that at idle, the ratio may be slightly fat (rich).

I guess I still don't understand why some manufacturers say no to synthetics or why they don't tell you what synthetic is safe to use if a company like RP is saying its ok.
K.

Nuvolari

iTrader: (4)

For all the cocky Rx8 owners that have come up to me and dissed on the reliability of FD's. Welcome to our nightmare ! These cars are doomed like the 7 due to poor dealer support and lack of seasoned rotary techs.

Montego

iTrader: (1)

^^ lol

yuichiror

iTrader: (1)

Normally, yes, synthetic oil is bad for BNR's. There was a thread a while back about BNR's and the maker stated that you can request syn oil friendly seals when you order your turbos.

KMAR

I'll have to check out that thread. Thanks.
How much you guys pay for a Litre of Royal Purple, up in Vancouver B.C. its like 12 bucks. Quite a bit of money. An oil change is like 55 bucks if I do it myself.

yuichiror

iTrader: (1)

I think I pay like $5 or $6 a quart (0.95L) for RP. Yeah, I like it too.

Here's the thread about the BNR's: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/what-turbos-get-553594/

KMAR

Hmm, maybe I should purchase some on line in bulk and get it sent North to me then. You guys get it a little cheaper. I do most my shopping out of the US. Stuff in Canada is too expensive.

Thanks for the link, I hadn't looked yet, so this saves me a little time. Ya, searching Forums at work, bad! Ha Ha. But, I'm going to read it anyways!

GoodfellaFD3S

iTrader: (213)

I am running dynamic seals instead of the standard carbon seals so there is no problem with running synthetic.

adrock3217

Uh..ok. Issuing a recall to replace all damaged engines..that sure sounds like poor dealer support to me! Yep! I remember back in 1995, Mazda did the SAME thing for the FD. They replaced all damaged engines, via recall. Oh wait..nevermind.

The FD and the SE are TOTALLY different cars. Don't compare an NA rotary to a turbo rotary.ever.again.