Which weight synthetic oil?

[ctjstr]

I give up, beating head on table.

ctjstr - Well that don't look good. What happened? To thin a oil viscosity in high temps?

Actually, I was just funnin with ya. That piston came out of one of our nitro methane fueled Harley drag bikes. Had a wee bit of detonation that broke the outside of the valve pocket off and allowed nitro down the cylinder wall where it lit and caused the damage. Unfortunately, I've probably got a dozen more like it. About the only thing they're good for after that is making a clock out of them....
The only thing oil related is that we try and find decent oil at the best price we can. Our oil only has to make it through about 30 seconds of use and 1500 engine revolutions between changes, so I'm probably less concerned then most about which brand. About the only thing I won't use is Amsoil, just because I'm tired of the sales pitch. Its probably great oil but holy cow..the verbal advertising gets old real quick. (But I'll even use that if its donated and the donor promises not to talk about it )

 

[dutchman56]

I did some reseach today and have the following numbers

Conventional 15W40 | Synthetic 15W40
vis at 40 c 107 cst | 91.9 cst
vis at 100c 15.1 cst | 15.3 cst
vis at 100f 551 sus | 467 sus
vis at 210 79 sus | 80 sus
viscocity index 148 | 177
pour point -36c/-33f | -48c/-55f

also have attcahed viscosity table for oils which show the ranges a oil can have for each weight of oil.
Hope this is of some help. What you use is a decition based on load, temp and cost for each application.

 

[kenmac]

All I know is that if you DON'T use the right oil, you'll end up with pistons like this.....

conventional
I'LL bet you didn't use castrol

 

[kenmac]

About the only thing I won't use is Amsoil, just because I'm tired of the sales pitch. Its probably great oil but holy cow..the verbal advertising gets old real quick. (But I'll even use that if its donated and the donor promises not to talk about it )[/quote]


You are missing out on a very good oil. I don't know about sales pitches .I buy on line

 

[ctjstr]

well maybe...but like someone posted, there are a ton of good oils out there. If I'm buying it, I happen to prefer Royal Purple, in part because it has some qualities unique to use with nitro methane, in part because I get a good deal on it, but also because its good oil. I have no clue whether its API rated, and don't really care. Works great for me. But so does castrol, penzoil, redline, quaker state etc etc. Oil's like religion..pray at the quart bottle of your choice. Want to use amsoil? Way cool. Someone wants to give me a case or two, that would be even cooler. I sure wouldn't turn it down. (I'd prefer 20-50 or strait 70 wt if that happens.) I'd just prefer not to hear the sales pitch. For me, its like not going to K-Mart..they probably have good prices on stuff I might use, I just hate the smell of pop corn when I shop, so I won't go in. I might feel different if I'd EVER had an oil related failure, but I've thrashed a bunch of engines in all sorts of vehicles and oil has just never been a problem for me. I'm way more concerned about stuff like whether my windshield is clean then what kind of oil I'm using. Its fun talking about it though.

 

[saparks10]

well maybe...but like someone posted, there are a ton of good oils out there. If I'm buying it, I happen to prefer Royal Purple, in part because it has some qualities unique to use with nitro methane, in part because I get a good deal on it, but also because its good oil. I have no clue whether its API rated, and don't really care. Works great for me. But so does castrol, penzoil, redline, quaker state etc etc. Oil's like religion..pray at the quart bottle of your choice. Want to use amsoil? Way cool. Someone wants to give me a case or two, that would be even cooler. I sure wouldn't turn it down. (I'd prefer 20-50 or strait 70 wt if that happens.) I'd just prefer not to hear the sales pitch. For me, its like not going to K-Mart..they probably have good prices on stuff I might use, I just hate the smell of pop corn when I shop, so I won't go in. I might feel different if I'd EVER had an oil related failure, but I've thrashed a bunch of engines in all sorts of vehicles and oil has just never been a problem for me. I'm way more concerned about stuff like whether my windshield is clean then what kind of oil I'm using. Its fun talking about it though.

I guess i'm exaclty opposite. I care more about whats in my engine that whats on the outside. The best analogy i ever heard was comparing engine oil to blood. If you were going to have surgery and needed a blood transfusion would you try to make a deal with the doc and get not quite the best blood but not the worst for a good price. Or would you want the best possible blood, regardless of price. I know i'd want the best they have, not some slightly hep c positive blood. LOL. I guess i think the same way about engines, the oil is the life blood of the engine.

 

[MikePA]

The best analogy i ever heard was comparing engine oil to blood.

Poor analogy. There are no 'grades' of blood. It either meets a standard or it doesn't. If it doesn't, you don't receive it. And the implication about oil is that some oils will damage (hep c) your engine which is false.

As ctjster said he's never had an oil related failure and his environment is as extreme as it gets. Unless you have specific circumstances that require an advanced oil, such as Royal Purple for use with nitro fuel, or extreme temperatures where synthetics are better, you're throwing you're money away, but, it's your money. Absent unique circumstances, the vast majority of people would be better off using a dino oil and changing it according to the operators manual.

A search of this forum would reveal these same discussions arise every so often, just like locusts. Same arguments by new people, but that's what forums are for.

 

[saparks10]

Poor analogy. There are no 'grades' of blood. It either meets a standard or it doesn't. If it doesn't, you don't receive it. And the implication about oil is that some oils will damage (hep c) your engine which is false.

As ctjster said he's never had an oil related failure and his environment is as extreme as it gets. Unless you have specific circumstances that require an advanced oil, such as Royal Purple for use with nitro fuel, or extreme temperatures where synthetics are better, you're throwing you're money away, but, it's your money. Absent unique circumstances, the vast majority of people would be better off using a dino oil and changing it according to the operators manual.

A search of this forum would reveal these same discussions arise every so often, just like locusts. Same arguments by new people, but that's what forums are for.

There are different grades of blood, they are referred to as type O, b, ab, etc. Just as there are different grades of oil, 0w-30, 15w-40 etc. And yes some oils will damage your engine, i.e. using 0w-30 when 15w-40 is needed.

 

[DieselPower]

There are different grades of blood, they are referred to as type O, b, ab, etc. Just as there are different grades of oil, 0w-30, 15w-40 etc. And yes some oils will damage your engine, i.e. using 0w-30 when 15w-40 is needed.

No that would be different types of blood. Different types of oil would be API CJ/4 or SM.

 

[MikePA]

There are different grades of blood, they are referred to as type O, b, ab, etc. Just as there are different grades of oil, 0w-30, 15w-40 etc. And yes some oils will damage your engine, i.e. using 0w-30 when 15w-40 is needed.

Ditto what DieselPower said. They're types of blood. Type O isn't a better blood than Type B.