Wankelguy

You know, it just occurred to me that a LOT of the people who are premixing are using SYNTHETIC two-stroke oil to premix, like Bel-Ray for example. And, ALL oil will leave a residue when burned, even oil dripping on an exhaust manifold, lol. This isn't the first time the anti-synthetic myth has been questioned on this forum, and I'm sure it won't be the last.

Now if I could just convince people to stop putting ATF in their motors...

The_7

synthetic 2 stoke is supposed to burn. synthetic 4 stroke is not

Metallic_rock

I just put 2 oz of MMO in my fuel every time I fuel up, and I run Castrol 20 W50. That's what Mazdatrix recommends for our engines, and on top of that, the MMO will keep stuff clean AND lubricate, so...

I like the way I do things, it seems to have smoothed out the idle with the MMO in there, too. If someone wants to try something new (synthetic) I'm going to warn them that it has the potential for being really bad, and I wouldn't use it, but I'm not going to say straight up "Don't use it"

Use what you want... be the guinea pig. Tell us in a few thousand miles if it makes your apex stick. No one else here will mind... engine builders will be happy. We will be happy to have seen someone get good/bad results just for our own knowledge.

Do I have any volunteers for synthetic???

vipernicus42

iTrader: (4)

What we need is someone who's experienced in tearing down and rebuilding rotaries..

Get this person to rebuild an engine (taking note of what it looks like before the rebuild)... run it for a few thousand km, and break it down again.

Same thing with "regular" oil.

more work than most people would be willing to do, but if someone wants to... I'd love to see it

Jon

Metallic_rock

as would I.

fatboy7

REVHED said he's running mobil 1, and I know that there are others on this forum who do the same.

Remeber that synthetics have changed alot over the last 20 years. IIRC Mazdatrix still makes mention of synthetic oil shrinking water seals. The fact is that sythetics had a problem with rubber seals, but that the incompatibility has been resolved a long time ago. So I consider Mazdatrix's opinion on this dated.

The name that I've heard several times in conjuntion with synthetic oil deposits is the old formulation of Castrol Syntec. I'm sure that even that is probably safe in a rotary now, because they were the ones that ushered in the bastardization of the term "synthetic", by the use of cracked oils instead of PAO base stocks a couple years ago.


[tangent]
Rx7carl, where did you hear that redline and mobil have started using cracked base stocks? While Mobil could easily have switched, being a very large oil company, I'm not sure if I believe that Redline would make the switch, being a much smaller company who has soley made synthetics from day one . It would be a stupid switch especially if you consider that they would lack the expensive equipment that hydrocracking requires.

Mobil calls their oil tri-syn. It would be misreprentation to make reference to the three standard synthetic basestocks then throw them out the window and used a cracked stock - but I can't rule out the possiblity.
[/tangent]

Wankelguy

You know, the answer to this whole synthetic oil build-up question is to simply use "Power Foam" or even Techron concentrate to clean the engine's internals every few months. I've torn down engines where the ONLY thing wrong with them (a stuck apex seal) could probably have been cured without having to tear the motor down simply by using one of the aforementioned products.

One more thing: if you use ANY carbon-dissolving chemical to loosen and clean out deposits, make sure that you blow it all out at full throttle then take the car out for at least a 30 minute drive at highway speeds afterwards, to avoid having the loosened carbon and crap redepositing itself.

Rx7carl

LOL, and pray tell whats the difference in the base stock?

Rx7carl

Mobil has switched after their unsucsseful attempt to bring the truth out about Castrols switch to Type III base stock (1997). They lobbied the NAD of the council of the BBB and got nowhere, so I guess they figured "if ya cant beat em....." Cant say for sure about redline (I should have been clearer on that). BUT nowhere in any of their literature do they state what base oil they use. Of all the research Ive done ONLY Amsoil will put in writing that they use %100 PAO (Type IV) only base stock. The others use careful wordsmithing to make it sound like they do, but they will NOT come out and say it.......wonder why? I dont know if Redline EVER used Type IV, and they dont need to reprocess Type II (regular dino oil) into type III themselves, Chevron opened a huge facility for this in Lousiana and Ill bet most small "performance oil" companies buy from them. BTW Royal Purple wont specify exactly what type base stock they use either.

Bottom line for me is this. If they cant put in writing that they use ONLY Type IV PAO base stock, then you dont know what theyre using (is it 0.01% PAO?). Saying they USE highest quality synthetic base stock is meaningless, wordsmithing, legaleese, bullshit, chickenshit, cheating, no good, dirt eating, boot licking, nonsense in my book.

wwilliam54

well at any rate 2-cycle premix and a good synthetic is the absolute best
so thats what i stick with

The_7

i said that becuase he was talking about premixing with synthetic 2 stroke, sounded to me like he was suggesting because of this 4 stroke synthetic wouldnt leave deposits.

i wouldnt mind doing it if i had the extra money lying around but.....i dont

Rx7carl

Ok, but both oils are made from the same oil, just different additives make them different. SO if its the base oil (syn vs dino) that causes the deposits, then any syn oil made from the same base oil whether 2 or 4 stroke will do the same thing no?

vipernicus42

iTrader: (4)

So what you're telling me then is that it's the *additives* which are synthetically made, and not the base stock itself?

I always thought "synthetic" oil was made in a manufacturing process which (although it may have required regular oil stock) added so much artificially produced chemical to it that the oil became more artificially "synthetically produced" than natural. Which lead me to the generalization "synthetic is made 'in a lab' as a manufacturing process, non-synthetic is dug out of the ground and filtered (refined) a bit"

IF the only difference is the additives, then it will be those additives which are left behind after burning. Synthetic additives in two-stroke oil then would be the part that (quote) 'leaves a lubricant behind when it burns' and the additives in the regular 10w30 synthetic oil would be the part that (quote) 'is designed not to burn off, making it so that your car can go longer between oil changes...' yadda yadda....

You're still left with something being left behind after burning, but this time instead of us thinking that it's the bulk of the oil left behind, now it's whatever's added to the oil.

So regularly refined dino oil doesn't really have a huge amount of "synthetic" additives, might as well stick with the clean stuff. :P

I'm no oil expert, maybe I'm WAY off... but hey, at least I'm willing to admit that I don't know ****, try to make some educated guesses, and not be afraid to change my stance a bit.

<--- still thinks syn is a hassle if nothing else

Jon

vipernicus42

iTrader: (4)

And until I see that engine breakdown, I'm gonna play it safe and cheap with the "Don't use synthetic" routine.

It's better to warn people, in case it *does* have some meaning to it, than to tell people "go ahead and use synthetic" and possibly lead to some sorts of problems.

Doubtful that this means anything, since it's source...sucks... but the drunken monkeys at the local Rx7Heaven are hardcore against synthetic, and say that they have seen what it can do to a motor... as I said, the source in itself is almost enough to make me jump to the other side of the fence.

Jon

mar3

iTrader: (8)

But why?? Except for expense, there is no danger. No one has yet to come out and say it's cost them an engine. Therefore, it has never cost anyone an engine until I'm proven wrong, so thereis no synthetic oil danger. You're not playing it safe, you're believing a lie. Much like everyone supporting the Invasion is falling for the lies....but that's another corner of the Forum altogether....

Spinner-D(eluxe)

The whole problem people have with synthetic oil is they equate it to being plastic like. I am serious here!

Imagine burning plastic molecules in your engine. What a sticky gunk of a mess that would be. For some reason it's just human nature to think synthetic is unnatural, and plastic like and doesn't burn etc... Maybe because fire, or combustion is a natural thing, we feel a need to use completely natural inconsistent oil. Synthetic oil molecules are the same as dyno oil; they are just all the same size and consistency (very smooth and slick). I use Amsoil, so when my engine dies I'll break it down and let you know what I see; probably a bunch of sticky plastic like gook. heh.

Rx7carl

Jon Im sorry for confusing you. it IS the additives that different. What I meant that syn 2 stroke and syn 4 stroke oil have the same base oil.

Ok, Im gonna give a simple clarification since some of you guys seem too damn lazy to look this **** up.

Type III oil is the "new synthetic". It made by reprocessing regular motor oil. Dino oil is a mixture of many different size and weight molecules. After filtering and cracking we get our typical base stock for motor oil. This still has a mixture of different size and weight molecules. What they do is to chemically "crush" it and break up the molecules to make them more uniform. However, they still vary in size and length and weight. And the lighter components boil off in your crankcase.

Type IV (PAO) is a true synthetic, and BTW the only oil used in jet engines (Im a 20yr airline mech). It is totally different. This oil is chemically constructed from short chain (2 molecule) oils IIRC rapeseed oil, safflower oil. Its built into long chain (10 molecule) molecules. This oil has all its molecules the exact same length, so it is of perfectly uniform quality and consistant. It is a pure oil, not a hodgepodge like dyno oil, or type III.

Rx7carl

They get to call Type III "synthetic" cause the reprocessing is considered "synthesizing". So "technically" its synthesized oil. what a ****** joke huh?

mar3

iTrader: (8)

I'm a lazy a$$, Carl, thanks for the breakdown...you need to become the Official RX-7 Club.com Forum Amsoil sales rep....

Rx7carl

LOL Mario, Im gonna try the amsoil, and if it works as well as they say Ill become a dealer myself.

Wankelguy

Amsoil used to have a deal where you could become a dealer for six months for a ten dollar fee. That way, you could buy a bunch of Amsoil products at dealer cost. I did that a few years back and bought a case of Power Foam, a few gallons of 75W-90 gear oil, etc. The lower cost more than makes up for the $10 fee.
The guy who started Amsoil was a jet fighter pilot, BTW.

Rx7carl

Good info thanks!

fatboy7

Ok, I want to take a moment to explain in what way sythetic oils are not designed to burn.

Like Rx7carl noted quite well in his above post, the only major difference bewteen refined stocks and PAO stock, is the uniformity of the molecules. This obviously has an impact on its lubrication qualities, but what does it do to its ablity to burn? Where did the marketing slogan that says sythetics are designed to not burn come from?

Oil, like any liquid, at any given temperature will have a percentage of molecules that have enough speed to break the surface of the liquid and become vapor - much like water and humidity. When you start your engine, the combined mixture of oil, water, and fuel vapors in the the crankcase will be drawn into the engine and burned. As the oil heats up it will continue to evaporate, but at an increased rate. These vapors too are drawn into the engine and burned. So basically as you drive your car, the engines oil is slowly "boiled" off much like water from a hot bowl of soup. On a typical piston engine this "boiling" of of the oil constitutes around 90-95% of the oil burn-off. The rate at which it evaporates is highly dependant on temperature. The boiling point of synthetics are higher than typical refined oil. Thus less of it will evaporate off at any given temp, almost half as much in most cases. So the switch to synthetic magically lowers oil burn-off by almost half.

Viola, sythetic is designed to not burn off... but what does it really mean for us. Nothing. Because the burn-off talked about has more to do with evaporation than quality of its burn.

Rx7carl

Very true. Thats one of syn oils advantages. Since their are no light molecules they dont have any evaporation. IIRC the flash point for PAO is 425*F. So it WILL burn.

Wankelguy

Good point.
I've noticed reduced oil consumption in my Fiesta after switching to Amsoil, maybe that has something to do with it. Also, it seems like the oil is staying really clean, not turning dark as fast as regular oil.

edit: Whoops, I was replying to Fatboy7's post, didn't know you were gonna sneak one in there, Carl!