Synthetic Oil, Pros and Cons of using it in babbitt bearing engines

[Dave Chiotti]

Synthetic Oil, Pros and Cons of using it in babbitt bearing engines

[Rusty_OToole]

Since cars still use babbitt bearings (in a different form) it should be ok. I think the main lookouts would be for the seals (leaks) and washing caked on  dirt back into the oil.

[lump]

I think that better oil is better oil, and usually a very good idea. I run synthetic oil in all my cars, EXCEPT my 1923 Hupmobile. I inherited this car from my Dad, and he had always warned me to use non-detergent oil in the old engine, to avoid dissolving old caked-on oil/dirt deposits, and dumping them into the oil pan. (As Rusty mentioned above). But if I could find non-detergent synthetic oil, I would use it in a heartbeat. 

[Spinneyhill]

If you change from a non-detergent to "detergent" oil, you will gradually dissolve the crud. Just change the oil at short intervals a couple of times. Your engine will benefit very greatly. Just remove and clean the sump and oil intake before changing. The whole purpose of oil additive packages is that those fine particles (those deposited everywhere in the engine by non-additive oil) do not settle out and drain out with the oil.

 

It seems to me that non-detergent synthetic oil is an oxymoron!

 

In general, wear tests show a good number of synthetic oils perform better than pretty much all multi-grade mineral oils.

[nickelroadster]

Synthetic oil is made to last a long time.  Most of our older cars do not have an oil filter and thus we change oil much more frequently.  Synthetic oil will get dirty just as quick as regular oil and you would need to change it for that reason just as often as regular oil.  This means you are spending much more and not getting any benefit from it.

[Jubblies]

+1 nickelroadster

I stay away from synthetic oils preferring mineral oils rich in zinc (ZDDP).

I've heard a few stories of detergent oils being used in older cars and clogging filter pickups then starving the engine of oil as nothing could get to the pump.

I have a few classic cars that I only use mineral oil in and with regular oil changes all is ok.

 

I know the mineral oil was the only oil used in the era of my cars and with oil technologies better now than they were back then I trust sticking with OEM or close to it.

[mercer09]

This means you are spending much more and not getting any benefit from it.

 

 

 

 

Have you priced synthetic lately? not much different then regular oil and so I use it in everything.............................even my lawn tractor.

 

In the crazy chance that an engine run dry-the synthetic will save the engine. Not so with reg oil.

[captndan]

If you use mineral oil you also must ware a white silk scarf.   That's what the early pilots had to do because of the exhaust contains mineral oil.

[DonMicheletti]

Captdan.

That was because they ran castor oil and it was a total loss oil system

[Spinneyhill]

15 hours ago, nickelroadster said:

Synthetic oil is made to last a long time.  Most of our older cars do not have an oil filter and thus we change oil much more frequently.  Synthetic oil will get dirty just as quick as regular oil and you would need to change it for that reason just as often as regular oil.  This means you are spending much more and not getting any benefit from it.

 

The longevity of synthetic oil is because it doesn't break down as quickly as many mineral oils. It is a strong reason to use it: temperature, shear and viscosity stability.

 

It will get dirty just as quickly. That is the whole point of additive packages. They scavenge the combustion products and any other residues from the engine and they drain out with the oil. 

 

As for not getting any benefit, see my comment above. They is less wear with synthetic oil, in general. Wear tests show some synthetic oils are better for flat tappets (less wear) than any mineral oil with full zinc (ZDDP).

[edinmass]

You can't use synthetic for engine break in, the rings won't seat. I run my pre war motors 5000 miles on regular oil, then switch over. When I worked at our dealership we would do a swap over to synthetic and you could actually see the idle increase about 100 rpm from reduced friction. Word of caution, if you use it in an engine with a wet clutch, the clutch could slip so severely the vehicle won't move..........don't ask how I learned this! Ed

[C Carl]

Dave , you would be well served by looking up a topic started by Windsor Ron headed "Detergent oil". Go back in General Discussion  5 or 6 pages , find by last posting November 27 by JFranklin. You will be a bit of an oil expert by reading it , and then studying the referenced Richard Widman paper. And yeah , synthetic oil and grease do help preserve mechanical components with better friction reduction. As mentioned above , synthetics can give you a greater margin of protection in some failure modes. I was driving my '76 Eldo quite hard and fast in very hot conditions with what proved to be a marginal radiator. Overheated before the lead-foot maniac behind the wheel could stop and nose into the wind at idle to cool off. So hot both exhaust manifolds cracked and had to be replaced along with the radiator. But no damage to engine internals due to the high flashpoint of synthetic oil. Also fortunately , I happened to be using a too high viscosity 20W/50 for the hot Summer So. Cal. temps. I have put many tens of thousands of miles on the car since , and I still tend not to hang about. I believe that Cad to be the world's fastest 500 cu. in. Eldo road car due to the suspension mods I have made. I am 72 , and doubt I will ever grow up. No , it doesn't smoke or rattle or clatter , just thanks me for being a synthetic addict. I do have more modern much faster cars , they run synthetic too. My much older , much slower cars also enjoy the superior qualities of synthetic lubricants. I have switched a great many engines to synthetic, some with over 100 thou' on 'em , with no negative impact whatsoever. Happy motoring , Dave. I hope you enjoy the read. BTW , this topic comes up so very often , I wonder if there is some way to immediately link to what has been already been answered so many times ? But I have limited primitive computer abilities so I sure don't know.

[Curti]

My Corvette C6  says use Mobil 1 right on the tappet cover, from the factory.

[Spinneyhill]

On 12/11/2016 at 11:04 PM, mercer09 said:

In the crazy chance that an engine run dry-the synthetic will save the engine. Not so with reg oil.

 

I have seen a "test" carried out as part of a fund raising raffle. Punters put their money on the number of minutes and seconds an engine would run after the oil was drained out. From memory it was a 6 cylinder Holden engine, so probably about 3.5 L engine. It was a well worn engine obtained from a wrecker's yard. This was perhaps 20 years ago so it was probably a 60s or 70s engine. It ran at full throttle, with radiator connected, for something like 25 minutes before slowing and seizing.

[JACK M]

23 hours ago, Spinneyhill said:

 

I have seen a "test" carried out as part of a fund raising raffle. Punters put their money on the number of minutes and seconds an engine would run after the oil was drained out. From memory it was a 6 cylinder Holden engine, so probably about 3.5 L engine. It was a well worn engine obtained from a wrecker's yard. This was perhaps 20 years ago so it was probably a 60s or 70s engine. It ran at full throttle, with radiator connected, for something like 25 minutes before slowing and seizing.

 

They do that kind of thing at some of the local car shows around here. they drain the oil and coolant.

I am always surprised at how long some of them will run while 'bricked'.

[Rusty_OToole]

If anyone does want to change a really old motor to synthetic oil  you can take off the oil pan and valve cover and clean out most of the sludge manually (this is a good idea in any case). You can also add a Frantz oil filter to any engine with an oil pump. Then you could use synthetic with no problem and probably increase engine life by 100% or more.