Lets talk Oil.... 120W vs 25w-60 in radials & V-12's

[Speeddemon651]

So what oil do you run in your radial or v-12 and why. I currently run 120W in my P&W 1340 and are about to try multi weight 25W-60. My plane stays in the Mid-Atlantic all year round. The overhaul shop says either or will work just fine. I don't have pre-oiler but I do cank with the mags off till I see good oil pressure before every start. I've been told some people say 25w-60 leaks more but I think it depends on the engine.

[Matt Gunsch]

Depending on where you are located could help you decide. We ran 100w all year with no problems. I had another owner who ran 120 in the summer and 100 in the winter along with a oil heater.

If you are on the road, you will be able to find 100w everywhere, where 120 and 25/60 will be harder to find unless you carry your own.

[Speeddemon651]

I usually always stay local to the region and don't do much winter flying. I'm mainly looking for the best metal to metal wear protection. Seems like most of the people I talk to these days are all running 25w-60.

[51fixer]

120W on 1340s, Merlins and Griffon.

Used XC in the past but the Merlins had much more rust accumulate on the valve train. The XC doesn't seem to stick on surfaces after shutdown.

XC is green at oil change, 120W is black. IMO 120 keeps more junk in suspension when you drain the oil.
120W seems to generate more varnish on surfaces keeping them protected.

Roush recommends 120W.

Mixing some 100W on the road is no big deal.

Has R-2800 fail after 15 hrs of using XC after years of using W120. Might have been a coincidence.

[Fleet16b]

We always run 100 mineral in both our inlines and radials.
I have always been led to believe that detergent will clean the engine better by not sticking to the internals.., thus falling off the internals and removing particles etc. But at a loss of maximun protection
Mineral sticks to the internals and leaves a varnished finish which protects the internals better.
With that said , if your aircraft flies frequently all year round, then detergent will work just fine.
If the aircraft flies infrequently or seasonal , then you may want to use mineral so that the internals are coated and protected during long periods of not running
Many people believe that mineral oil is for engine break-in periods only but that is not the case.
Remember most of these engines were designed before detergent oils even existed

Last edited by Fleet16b on Tue Jul 08, 2014 9:16 am, edited 1 time in total.

[Stoney]

Used Aero 100 for years and swicthed to 25W60, oil leaks went down. I liked it, PNW based R-1340.

[AG pilot]

I used Phillips 25W-60 for years in my Air Tractor's R1340 at the overhauler's recommendation. I liked it just fine.

I did not notice any worse oil consumption, or dripping than when using Aeroshell 120., and took peace in knowing the oil was getting around better in the engine on cool morning starts (blower bearing).

Ag planes sit dormant here in Colorado for months in the winter without start-ups. Of course we are a much drier climate than the PNW!

[51fixer]

We always run 100 mineral in both our inlines and radials.
I have always been led to believe that detergent will clean the engine better by not sticking to the internals.., thus falling off the internals and removing particles etc. But at a loss of maximun protection
Mineral sticks to the internals and leaves a varnished finish which protects the internals better.
With that said , if your aircraft flies frequently all year round, then detergent will work just fine.
If the aircraft flies infrequently or seasonal , then you may want to use mineral so that the internals are coated and protected during long periods of not running
Many people believe that mineral oil is for engine break-in periods only but that is not the case.
Remember most of these engines were designed before detergent oils even existed

The 120W isn't detergent oil. No such animal exists in aircraft oils anymore.
It is an Ashless Dispersant additive in the oil. Basically they keep very small particles of chemicals and byproducts of combustion and other foriegn material in suspension in the oil so those undesirable items drain out with the oil.
I've noticed the parts from UK operators I've seen that used straight 50 wt are incredibly built up with gunk. People I know at engine O/H shops have told me the same. Even with the W120 there is some varnish layer that builds up on the interior. Much more in the Merlin than I ever noticed with the XC oil.

http://www.aviationtoday.com/am/repairs ... 7xO_6VBoyA
The ashless dispersant package consists of molecules with polar heads and nonpolar tails, according to a Phillips 66 lubrication specialist. These molecules surround dirty carbon and soot byproducts of combustion and suspend them in the oil. Without the ashless dispersant, these particles tend to group together and precipitate onto the guts of the engine. With the ashless dispersant, fresh oil quickly turns black after running for a few hours because the nasty combustion byproducts are suspended in the oil. This chemical has nothing to do with wear characteristics or capability (or, as the Phillips 66 specialist explained, lubricity and film strength). The presence or absence of the ashless dispersant package does not in any way affect the oil’s ability to retard or promote the seating of the piston rings to the cylinder walls. Another component of the chemical package, which makes up 5 to 10 percent of a typical quart of AD, oil is an antioxidant.
All that the ashless dispersant package does is pull undesireable combustion byproducts into suspension in the oil so that they get drained out when the oil is drained.


http://www.swaviator.com/html/issueja02/Hangar7802.html
10. No detergents are ever added to aviation oils.
There is no such thing as an aviation oil that contains detergents. Aviation oils have not contained detergent packages since the mid-1950s. Single and multiviscosity grade mineral-based oils instead contain ashless dispersant (AD) additive packages. ADs are very different than detergents:
• ASHLESS refers to non-metallic additives. Detergents, on the other hand, are metallic by nature. Detergents may scrub existing ash deposits from an engine’s interior surfaces, which will contribute to the ash content, and possible clogging, of the oil.
• DISPERSANT refers to the oil’s ability to suspend combustion by-products, keeping them dispersed until the oil is drained.
Because they suspend engine by-products, AD oils darken faster than non-AD oils. This is a sign that the oil is preventing by-products from solidifying on interior engine surfaces. All AD aviation oils contain oxidation inhibitors as part of their standard additive chemistry. AD oils will not dislodge quantities of sludge from interior engine surfaces that lead to restricted oil screens. AD oils do not add deposit build-up. Instead, they help dissipate existing by-products over time. For example, if an operator uses a non-AD oil for 500 hours, then switches to an oil with an AD package for 500 hours, the AD oil will not "clean out" the first 500 hours worth of engine deposits.

11. Engines using a straight mineral oil can easily be switched to an ashless dispersant (AD) oil.
If the changeover is completed properly, there are no negative effects to switching from a straight mineral to an AD oil, regardless of the number of operating hours accumulated. All AD aviation oils use the same base stock and additives. For instance, Phillips 66 Type A 100 Single Grade AD Oil uses the same base oil and additives as Phillips 66 multiviscosity 20W-50 X/C AD oil. AD oils will not remove past accumulations of lacquer and varnish or hardened sludge. Therefore, AD oils will not cause sludge to move, blocking oil galleys. When switching from mineral to AD oils, a darkening of the oil as the dispersant suspends surface deposits can be expected at the first two oil changes. This poses no danger to the engine and means the oil is properly suspending engine-wear particles.

[Speeddemon651]

How many of you guys run pre-oilers ? I consistently hear about 50/50 say get one and that its just extra weight and more things to go bad, isn't needed.

Also does anyone use oil additives ?
The previous owner of my 1340 was a retired Air force Capt. , he started training pilots to fly the t-6 at age 19 in Malden Air Base and had years and years of airshow formation aerobatics as well as 50 years of experience behind the 1340. He swore by STP, yup you read that right STP..... He would run about 10% + or - of it with 120W and whenever oil was needed to top off the tank he added just STP. I know what your thinking, I imagine the percentage of STP over 120w would grow with consumption over time between changes. Long story short, right before I bought the plane the engine was pulled with 1800 hrs on the clock and sent to Covington for an overhaul. Few days later they called him in amazement and specifically wanted to know what exactly was being ran in the engine. They couldn't believe how slick everything was when they tore it down and how good the internals looked....

I have yet to run a drop of anything but 120W in the 1340 since overhaul but I'm curious if anyting else has experience with running additives?

[RobC]

I went to one of these NWOC meetings after I got the T-6 and asked the man from Shell about multi-visc vs straight w120. He said that if you are not running at temperature extremes, 120 is fine. Nothing wrong with multi-visc - just spending extra money for no benefit.

Interesting about the STP. Some of the old-time A&P's swore by Marvel Mystery Oil. Especially if the engine has been sitting a long time.

[Dave Hadfield]

I like Phillips 25W60, and it's been in the Warner in the Fairchild forever. Engine life has been great, much longer than anyone would have expected probably, back when it was last overhauled, in the 70s.

It seems sticky. I know when cold it drops to a 25 viscosity, and you'd expect it to run off vertical surfaces, but I don't think it happens. A film seems to remain. And we don't get corrosion in the cylinder heads, even after cool running spring and fall, and long-ish layups.

Also, my father has run it in the Gipsy in the Stampe since the 70s, or whenever the stuff first came out. Swears by it.

This is anecdotal evidence of course, but I like it, and don't plan to change.

As for the others, Merlins pretty much always have pre-oilers now, because the camshaft followers are fingers, not bearings, and you want an oil film up there before start if you can arrange it. Plus the crankshaft of course. Allisons are not so critical. I have no direct experience with big radials -- there is only one R-2800 in the VWoC collection.

My 2 cents.

Dave

[51fixer]

This must be a WIX version of-

TASTES GREAT


LESS FILLING

[51fixer]

We have pre oilers on the Merlin and Griffon and used before each start.

[Rod Schneider]

This must be a WIX version of-

TASTES GREAT


LESS FILLING

Yeah, oil threads can get a bit lengthy with more opinions than there are brands and type of oil!

One thread on a Porsche forum is up to 102 pages with over 330,000 views and over 2,000 replies!!!! http://forums.pelicanparts.com/porsche- ... -oils.html
Lots of opinions!

[Fleet16b]

Interesting about the STP. Some of the old-time A&P's swore by Marvel Mystery Oil. Especially if the engine has been sitting a long time.

As stated above I strictly use mineral oil in vintage engines
I have also used MMO in my vintage engines for years
Learned this from my father who used it on aircraft way back in the 1930s
I was told that at one time it was banned in Canada but was successfully lobbied by many vintage aircraft, car, motorbike, tractor, boats owner etc back into Canada ( anyone esle hear this)
Most vintage aircraft people I have dealt with swear by it .
I add a bit to both my fuel and oil
At 5 hr periods I also squirt it down around my valve stems and guides on my Kinner R55