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Dino oil VS. synthetic- motor break in???

Can Can

Can Can

Pusher Man
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I've read countless times that dino oil should be used to break in a new motor, and synthetic should be avoided until around 10K. Can someone please explain the reasoning behind this to me? And if this is indeed true, why the heck are lots of manufacturers using synthetic oils in their vehicles(some with VERY expensive motors) right from the factory?

I would prefer to see some evidence backing up your replies or FIRSTHAND EXPERIENCE, if possible. The old "my sister's best friend's brother's uncle's mechanic said so" kind of reply isn't what I'm looking for here.
 
I'll see if I can find the article, I saw it way back when I was building my motor, but it was either Hot Rod, Car Craft, Super Chevy, one of those, had an article and the jist was that synthetic was too 'slick' and would keep the rings from seating. The newer straight from the factory cars with synthetic have a different ring/bearing material that allows them to break in with synthetic.

*begins googling*



Well, after searching, I found this http://www.mobiloil.com/USA-English/MotorOil/Synthetics/Myths.aspx mobil1 says its fine to break it in on synthetic, then I found an FAQ from royal purple and they said they recommend waiting 2000 miles before switching to synthetic...... Im still looking for that article from oh so long ago....
 
one of those, had an article and the jist was that synthetic was too 'slick' and would keep the rings from seating.
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I recall plenty of people saying the same thing. However, how can a synthetic oil of a given weight(ie. 10w30) be "slicker" than a dino version???? I mean, is it 10w30 or not????

:confused:
 
10W30 referrs to the viscosity, not the "slickness". I don't see why it would be a problem to engineer a "slicker" oil.
 
What motor are you working on? Roller cam or flat tappet?
 
CanmoreK5 said:
I recall plenty of people saying the same thing. However, how can a synthetic oil of a given weight(ie. 10w30) be "slicker" than a dino version???? I mean, is it 10w30 or not????

:confused:
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It doesn't neccesserally mean viscosity as far as "slickness." Synthetic provides a better cushen between metal parts, it manages to stay between two objects and keep them lubed longer, thats why it stays "slicker." Try an experiment one day, get a little dino on your fingers and rub them together. For a few rubs your fingers will feel extremely slick, but after a couple of rubs the oil pushes out and runs down your finger. Do it with synthetic next, it will feel to stay between your fingers longer.

From what I have gathered from Amsoil literater (I'm a dealer). The slickness and greater overall lubricity of synthetic makes it harder for bearings and rings to wear into eachother. You want your engine to have a fair amount of wear to incure during the first few thousand, thats how everything gets seated and "broken in" obviously. Dino simply lets this happen faster so you can get your fuel mileage up where a good engine would be and your oil consumption down to where a good engine would burn. Why prolong this period?:wink1:

I think the main reason why newer engines are getting synthetic these days from the factory is because their tolerance is much better than old engines. Why does my '98 Vortec 454 require 5/30W oil and both my '81 and '76 454 like 10/40 or even 20/50? Better tolerance between bearings and other wear parts!

Better, tighter fitting parts from the factory yield less breaking in to occur which leads to being able to use more types of oils out of the gate.
 
Well, Chad, viscosity and slickness are kind of related. On that note, what kind of lab test determines "slickness", and what parameters are used to grade it?

I still don't understand how a dino oil can be less slick than a synthetic oil. :dunno:
 
CanmoreK5 said:
I recall plenty of people saying the same thing. However, how can a synthetic oil of a given weight(ie. 10w30) be "slicker" than a dino version???? I mean, is it 10w30 or not????

:confused:
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friction modifiers... teflon, moly, etc. rings, camshafts, and lifters specifically come to mind when thinking of parts adversely effected. addatives which actually coat the surfaces in the engine, without the proper friction, they wont break in properly.
 
I the last 5 years, I've personally had 2 engines which I've rebuilt. Both started up on valvoline 5w-30, run for 300-500 miles, and changed. The sbc was put on full synthetic Valvoline and has continued to run it. It has moly rings, and seemed to be "normal" in every way that a rebuilt engine should. The engine machinist (regular drag engine builder) said the moly rings should seat within 100 miles. It has about 2000 miles on it now, and seems to take no oil, or show any signs of usage. This is a street engine, that gets run to 6500 with regularity. The V-6 was changed at 500 miles, and was kept on the regular Valvoline, although 10w-40 for summer use, and 5-30 for winter. It has cast iron rings, and now has about 2500 miles on it. It also acts normal, as far as oil consumption goes, using 1/2 qt. in about 12-1500 miles between changes. I will probably go to full syn, or syn blend next oil change.
I have seen new Corvettes put together, and started on the assembly line, taken to the emissions test station, run through the 12 minute (?) cycle, and taken right to the truck for delivery, with Mobil 1.

my 2cents :rolleyes: :rolleyes: ..................





















































and I did stay at a Holiday Inn Express last night.;) ;)
 
Yes and no. IIRC, viscosity refers to the thickness or resistance to flow of a liquid. What I'm saying is what beater said, you can take two liquids with equal viscosity and make one less resistant to friction by engineering it differently.
 
CanmoreK5 said:
Well, Chad, viscosity and slickness are kind of related. On that note, what kind of lab test determines "slickness", and what parameters are used to grade it?

I still don't understand how a dino oil can be less slick than a synthetic oil. :dunno:
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I think that oil is rated on its viscosity (i.e. flowrate at a given temp.) So even though 2 non similar oils are rated the same viscosity the additive package each has determines what type of conditions it will excel in. Have you ever seen the ball bearing test of AMS oil, and regular Dino oil. That gives a good example of the slickness of the additives, and base.

And with the exception of piston rings, I believe you can't make a bad choice by using synthetic immediately. Even with the rings, it would just take a little longer for them to seat, than with a less protective oil (Dino)
 
CanmoreK5 said:
Well, Chad, viscosity and slickness are kind of related. On that note, what kind of lab test determines "slickness", and what parameters are used to grade it?

I still don't understand how a dino oil can be less slick than a synthetic oil. :dunno:
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Viscosity and slickness are two seperate things, but do indeed cross paths.

As beaterK20 said very well, additives and the oil stocks used will determine slickness.

What I think you are thinking of....

A 20/50 dino will seem to have the same slickness to the touch as a 5/20 good synthetic, but not because the dino is just as slick from additives as the synthetic, it's because it's thicker and takes longer to thin out.

A thicker viscosity can disguise itself as a slicker oil simply because it is harder to push out of the way. Thats how viscosity and slickness cross paths.

This doesn't mean you can just dump in 20/50 dino and have more protection. it's then harder to shove in between bearings and lifters on a tight clearanced engine, and that is hard on said engine when you fire it up. A thinner "slicker" oil would be a better choice on a tight clearance engine.
 
What I'm saying is what beater said, you can take two liquids with equal viscosity and make one less resistant to friction by engineering it differently.
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Okay, that makes sense. Now, where can I see some studies that "prove" this???? Don't send me to the Mobil1 or Amsoil site, please. I would prefer to see something independant.
 
It's a bad idea to use synthetic oil to fire up a flat tappet motor. Using an oil like Shell Rotella T (for deisel engines) is a good oil to use. Most engines older than the late 80's are flat tappet. I use the Shell oil in all of my older engines because it still has the correct anti-wear package to reduce wear to the camshaft. The EPA mandated that all cat converters be warrantied for 120,000 miles, but the anti-wear additives in the oil would destroy the cat converters. So the manufacturers use roller cams to be able to use the "new" oils without the anti-wear package.

Here's some stuff to read...

http://www.hughesengines.com/general/techArticleDetail.asp?articleID=1000039

http://www.cranecams.com/pdf/548e.pdf


You still need to go check out my "Baby Santa" pics and tell me how cute my kids are... :D :haha: :doah: :wink1: ;)






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CanmoreK5 said:
Okay, that makes sense. Now, where can I see some studies that "prove" this???? Don't send me to the Mobil1 or Amsoil site, please. I would prefer to see something independant.
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think of the additives as something like Astro Glide. dont know why that's some slick ****, but it just is. deal with it. :haha:
 
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