I've been surprised to see that many engine builders still say on their websites not to use synthetic oil while breaking in an engine, they say that it will not allow the piston rings to seat in for some reason, post more oil myths you know
Oil myths
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It is not a myth.
It is fact IF you have rebuilt the engine. The factories have much better torquing of parts, absolutely clean and perfect surfaces, etc.
When you rebuild it, your torque wrench probably isn't perfect, you are probably reusing bolts, your machine shop probably isn't as well qualified and equipped as the factory.
You WILL have more oil consumption until breakin is complete, and it will take longer with synthetics when you rebuild. The length of time (miles) will also depend on you choice of materials, both in quality and metal type.
It is fact IF you have rebuilt the engine. The factories have much better torquing of parts, absolutely clean and perfect surfaces, etc.
When you rebuild it, your torque wrench probably isn't perfect, you are probably reusing bolts, your machine shop probably isn't as well qualified and equipped as the factory.
You WILL have more oil consumption until breakin is complete, and it will take longer with synthetics when you rebuild. The length of time (miles) will also depend on you choice of materials, both in quality and metal type.
Originally Posted By: widman
It is not a myth.
It is fact IF you have rebuilt the engine. The factories have much better torquing of parts, absolutely clean and perfect surfaces, etc.
When you rebuild it, your torque wrench probably isn't perfect, you are probably reusing bolts, your machine shop probably isn't as well qualified and equipped as the factory.
I disagree with almost everything you say here, unless you're using the cheapest machine shop in town and are doing a true 'shade tree' rebuild.
People doing rebuilds these days fall in two camps: trying to eke a few more miles out for the fewest possible dollars (the shade-tree rebuild), or those who are either restoring a vintage engine for a collectible car or are building a racing engine.
The latter camp uses good machine shops that take more time and execute to FAR higher precision than any mass-production assembly line can. The assembly lines have gotten far, far better since the 60s, but they're still mass production, automated, parts are grouped by crude "binning" to similar dimension/weight rather than hand-fitting with careful measurement, individual component balancing, etc.
All that said, whether to break in with synthetic or conventional oil really doesn't matter, IMO. No oil is "too slick" to let parts break in if the proper break-in procedures are followed. The additive package for break-in is more important than the base oil (especially for certain kinds of engine, like non-roller cam engines), and there are lots of very good break-in oils out there. Since break-in oil is not there for extended use, extremely cold starts, extremely hot operation for extended times, etc., it simply doesn't NEED to be synthetic, so most break-in oils are not.
It is not a myth.
It is fact IF you have rebuilt the engine. The factories have much better torquing of parts, absolutely clean and perfect surfaces, etc.
When you rebuild it, your torque wrench probably isn't perfect, you are probably reusing bolts, your machine shop probably isn't as well qualified and equipped as the factory.
I disagree with almost everything you say here, unless you're using the cheapest machine shop in town and are doing a true 'shade tree' rebuild.
People doing rebuilds these days fall in two camps: trying to eke a few more miles out for the fewest possible dollars (the shade-tree rebuild), or those who are either restoring a vintage engine for a collectible car or are building a racing engine.
The latter camp uses good machine shops that take more time and execute to FAR higher precision than any mass-production assembly line can. The assembly lines have gotten far, far better since the 60s, but they're still mass production, automated, parts are grouped by crude "binning" to similar dimension/weight rather than hand-fitting with careful measurement, individual component balancing, etc.
All that said, whether to break in with synthetic or conventional oil really doesn't matter, IMO. No oil is "too slick" to let parts break in if the proper break-in procedures are followed. The additive package for break-in is more important than the base oil (especially for certain kinds of engine, like non-roller cam engines), and there are lots of very good break-in oils out there. Since break-in oil is not there for extended use, extremely cold starts, extremely hot operation for extended times, etc., it simply doesn't NEED to be synthetic, so most break-in oils are not.
Yeah that is the excuse apparently they say synthetic is too "slippery" to let the rings bed in which sounds like utter B-S to me
The few engines I rebuilt or helped rebuild got conventional oil for the first run. The oil wasn't staying in the engine long enough during the first run to warrant the additional cost of a synthetic oil.
Originally Posted By: 440Magnum
Originally Posted By: widman
It is not a myth.
It is fact IF you have rebuilt the engine. The factories have much better torquing of parts, absolutely clean and perfect surfaces, etc.
When you rebuild it, your torque wrench probably isn't perfect, you are probably reusing bolts, your machine shop probably isn't as well qualified and equipped as the factory.
I disagree with almost everything you say here, unless you're using the cheapest machine shop in town and are doing a true 'shade tree' rebuild.
People doing rebuilds these days fall in two camps: trying to eke a few more miles out for the fewest possible dollars (the shade-tree rebuild), or those who are either restoring a vintage engine for a collectible car or are building a racing engine.
The latter camp uses good machine shops that take more time and execute to FAR higher precision than any mass-production assembly line can. The assembly lines have gotten far, far better since the 60s, but they're still mass production, automated, parts are grouped by crude "binning" to similar dimension/weight rather than hand-fitting with careful measurement, individual component balancing, etc.
All that said, whether to break in with synthetic or conventional oil really doesn't matter, IMO. No oil is "too slick" to let parts break in if the proper break-in procedures are followed. The additive package for break-in is more important than the base oil (especially for certain kinds of engine, like non-roller cam engines), and there are lots of very good break-in oils out there. Since break-in oil is not there for extended use, extremely cold starts, extremely hot operation for extended times, etc., it simply doesn't NEED to be synthetic, so most break-in oils are not.
widman is from Bolivia. In his part of the world, a lot of what he says is true.
Originally Posted By: widman
It is not a myth.
It is fact IF you have rebuilt the engine. The factories have much better torquing of parts, absolutely clean and perfect surfaces, etc.
When you rebuild it, your torque wrench probably isn't perfect, you are probably reusing bolts, your machine shop probably isn't as well qualified and equipped as the factory.
I disagree with almost everything you say here, unless you're using the cheapest machine shop in town and are doing a true 'shade tree' rebuild.
People doing rebuilds these days fall in two camps: trying to eke a few more miles out for the fewest possible dollars (the shade-tree rebuild), or those who are either restoring a vintage engine for a collectible car or are building a racing engine.
The latter camp uses good machine shops that take more time and execute to FAR higher precision than any mass-production assembly line can. The assembly lines have gotten far, far better since the 60s, but they're still mass production, automated, parts are grouped by crude "binning" to similar dimension/weight rather than hand-fitting with careful measurement, individual component balancing, etc.
All that said, whether to break in with synthetic or conventional oil really doesn't matter, IMO. No oil is "too slick" to let parts break in if the proper break-in procedures are followed. The additive package for break-in is more important than the base oil (especially for certain kinds of engine, like non-roller cam engines), and there are lots of very good break-in oils out there. Since break-in oil is not there for extended use, extremely cold starts, extremely hot operation for extended times, etc., it simply doesn't NEED to be synthetic, so most break-in oils are not.
widman is from Bolivia. In his part of the world, a lot of what he says is true.
I own 3 speed shops and we assemble and disassemble a lot of engines. I can tell you without and iota of doubt that conventional oils do a MUCH better job at seating rings. Conventional oils do produce a little more heat and friction and goes a long way in honing cylinders and seating rings.
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The term synthetic should be replaced with ' good oils with friction modifiers'
Any basic oil is good for running in as it lets the parts wear in before they work harden (rings especially) if you have an oil with FM then this can impact this critical stage.
Any basic oil is good for running in as it lets the parts wear in before they work harden (rings especially) if you have an oil with FM then this can impact this critical stage.
a few people have told me that 20w50 will harm my engine and some that it will even blow up, 300k miles later it hasn't blown up, isn't it strange?
Myth: I know better than the car manufacturer what spec. oil to put in my car because my butt tells me so! All of those engineers just waste their time all day and throw out some numbers off the top of their heads.
I was told Mobil 1 0w40 would blow up my 280ZXT. Even though the owners manual recommended 10w30, I was supposed to run 20w50 because "reasons."
Originally Posted By: AuthorEditor
Myth: I know better than the car manufacturer what spec. oil to put in my car because my butt tells me so! All of those engineers just waste their time all day and throw out some numbers off the top of their heads.
I trust Ford and M1 more than the thick oil guys for my engines lubrication needs.
Myth: I know better than the car manufacturer what spec. oil to put in my car because my butt tells me so! All of those engineers just waste their time all day and throw out some numbers off the top of their heads.
I trust Ford and M1 more than the thick oil guys for my engines lubrication needs.
Originally Posted By: FordCapriDriver
Yeah that is the excuse apparently they say synthetic is too "slippery" to let the rings bed in which sounds like utter B-S to me
Well, what they're "right" about is something that also applies to most conventionals. From what formulators here have posted, and what even Royal Purple states (and markets) is that you want an oil with high AW compounds and low quantities of friction modifiers. The average SN/GF-5 oil (synthetic or conventional) isn't going to fit that exactly. Most synthetics won't, even a high zinc race oil, since such an example will have a lot of friction modifiers.
RP, for example, offers a high zinc break in lube, and it's conventional, because the other aspect of the reasoning is that an expensive synthetic is a waste for a short break in interval.
Yeah that is the excuse apparently they say synthetic is too "slippery" to let the rings bed in which sounds like utter B-S to me
Well, what they're "right" about is something that also applies to most conventionals. From what formulators here have posted, and what even Royal Purple states (and markets) is that you want an oil with high AW compounds and low quantities of friction modifiers. The average SN/GF-5 oil (synthetic or conventional) isn't going to fit that exactly. Most synthetics won't, even a high zinc race oil, since such an example will have a lot of friction modifiers.
RP, for example, offers a high zinc break in lube, and it's conventional, because the other aspect of the reasoning is that an expensive synthetic is a waste for a short break in interval.
I didn't know that , i guess you learn something new everyday
Originally Posted By: Garak
Originally Posted By: FordCapriDriver
Yeah that is the excuse apparently they say synthetic is too "slippery" to let the rings bed in which sounds like utter B-S to me
Well, what they're "right" about is something that also applies to most conventionals. From what formulators here have posted, and what even Royal Purple states (and markets) is that you want an oil with high AW compounds and low quantities of friction modifiers. The average SN/GF-5 oil (synthetic or conventional) isn't going to fit that exactly. Most synthetics won't, even a high zinc race oil, since such an example will have a lot of friction modifiers.
RP, for example, offers a high zinc break in lube, and it's conventional, because the other aspect of the reasoning is that an expensive synthetic is a waste for a short break in interval.
Most of what you said is true. To add to your comment about friction modifiers, yes you do want less except having a decent amount of MOS2 is not a bad thing because MOS2 has micro polishing abilities that can help during the break in process.
Originally Posted By: FordCapriDriver
Yeah that is the excuse apparently they say synthetic is too "slippery" to let the rings bed in which sounds like utter B-S to me
Well, what they're "right" about is something that also applies to most conventionals. From what formulators here have posted, and what even Royal Purple states (and markets) is that you want an oil with high AW compounds and low quantities of friction modifiers. The average SN/GF-5 oil (synthetic or conventional) isn't going to fit that exactly. Most synthetics won't, even a high zinc race oil, since such an example will have a lot of friction modifiers.
RP, for example, offers a high zinc break in lube, and it's conventional, because the other aspect of the reasoning is that an expensive synthetic is a waste for a short break in interval.
Most of what you said is true. To add to your comment about friction modifiers, yes you do want less except having a decent amount of MOS2 is not a bad thing because MOS2 has micro polishing abilities that can help during the break in process.
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Originally Posted By: Garak
Well, what they're "right" about is something that also applies to most conventionals. From what formulators here have posted, and what even Royal Purple states (and markets) is that you want an oil with high AW compounds and low quantities of friction modifiers. The average SN/GF-5 oil (synthetic or conventional) isn't going to fit that exactly. Most synthetics won't, even a high zinc race oil, since such an example will have a lot of friction modifiers. RP, for example, offers a high zinc break in lube, and it's conventional, because the other aspect of the reasoning is that an expensive synthetic is a waste for a short break in interval.
I agree that a short OCI with a synthetic for break-in would be a waste, but what about the factory cars that come filled with synthetic? They all seem to break-in with no issues, right?
Well, what they're "right" about is something that also applies to most conventionals. From what formulators here have posted, and what even Royal Purple states (and markets) is that you want an oil with high AW compounds and low quantities of friction modifiers. The average SN/GF-5 oil (synthetic or conventional) isn't going to fit that exactly. Most synthetics won't, even a high zinc race oil, since such an example will have a lot of friction modifiers. RP, for example, offers a high zinc break in lube, and it's conventional, because the other aspect of the reasoning is that an expensive synthetic is a waste for a short break in interval.
I agree that a short OCI with a synthetic for break-in would be a waste, but what about the factory cars that come filled with synthetic? They all seem to break-in with no issues, right?
Aren't most new cars already broken in before being sold?
no, they aren't.
the manufacturing process is different so there's less tolerance on the dimensions of various parts (and the clearance in between) and measures are often taken to make the cilinders more uniformly round but every car still needs to have the piston rings run-in and seated.
Sometimes new cars use a substantial amount of oil until they're run in. It lasts up to 50.000 miles if the owner operator is lightfooted, in my experience. Maybe it's because of modern FM oil, who knows...
the manufacturing process is different so there's less tolerance on the dimensions of various parts (and the clearance in between) and measures are often taken to make the cilinders more uniformly round but every car still needs to have the piston rings run-in and seated.
Sometimes new cars use a substantial amount of oil until they're run in. It lasts up to 50.000 miles if the owner operator is lightfooted, in my experience. Maybe it's because of modern FM oil, who knows...
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