P&W 1340 Oil

[T-6G Pilot]

I was hoping to solicit some opinions from the expertise of some of the members of this board.

I am currently running a multi-weight viscosity oil in my airplane. For reasons I won't go into here, I am considering switching to a "straight" weight. Anyone have an opinion if this is a good or bad thing to do? If good, which weight of oil should I put in.

Thanks for the help.

Mike

[oscardeuce]

In my O2-A with Continental IO 360 D I run 100 weight straight mineral in the Summer and 40 weight mineral in the winter.

[John Lane]

I my opnion, these engines were designed & built around straight weight oils and are liquid cooled as well as air! Why change something that has worked for 70 years. Oil companies have developed new oils they claim will do a better job, but over the years all I've seen are problems. Good Luck!

[skymstr02]

When I had my T-6G, I ran 60 wt Aeroshell year round, but then I was in southeast Texas at the time. No problems at all. Multigrade wasn't made in a 60wt at that time, and I was too cheap to change to 15W50 for the winter months. Two fifty a quart for 10 gallons wasn't in the cards for me. Winter where I was lasted about 2 months, and with no heat in the cockpit, I wasn't too thrilled about flying anyway. I usually did my annual during the winter anyways.

There's nothing wrong with a 15W60 mutigrade. I know of two T-6 operators running it. I also know of a DC-3 operator running the 15W60 with not oil related problems. The multigrade meets or exceeds the P&W oil specs.

Are you running an Airwolf oil filter also?

[spookyboss]

We use the P66 25X60 in our AC-47 and it has worked very well for us and we are happy using it.

[Matt Gunsch]

I'll Echo what John Lane said, I stick with what works. I overhauled a 1340 with 1200hrs on it that ran nothing but A/S 100w. It was very clean, and was easy to clean up for inspection and reassembly. As a addition, if you don't have it, install a external oil filter like those from Air Tractor. We were able to go 50hrs between oil changes and only checked the screen at annual.

[Robbie Stuart]

If you have any time at all running what you are using, & you have good results, unless you are going to a different climate, or higher usage, or some major change in your ops-----stick with what you are using. Round motors do not like to change their blood in mid stream. If I were starting out with a fresh engine I would take John Lane's advise go with a good straight weight. (I have known John for a long time & he has forgot more about this stuff, than I know).
Best Regards
Robbie

[EDowning]

Well....This could raise more ire than the previous paint scheme debate, but here goes. I operate a R-3350, a wright 975-E3 and an M14P, all on Phillips 25w60. I also have tremendous respect for John Lane's opinion, but I have done a lot of research on this issue and I kind of come at this from a different angle. I think the 25w60 handles heat very well and doesn't suffer viscosity degradation as readily.

First, I firmly believe that all major brands of oil sold today are far superior to any of their original (old) counterparts. I have a North American Yale (Wright 975-e3) and it, as with all Yales, tends to run with a very high oil temp normally. Rebuilt the oil cooler, rebuilt all baffling and still had high temps. I was running Aeroshell 120 and had several conversations with Shell and one of the Shell factory experts actually reccomended that I try a multi viscosity oil. Phillips 25w60 runs almost 10 degrees cooler in my particular application.

By far the most important consideration is operating at proper temperatues, correct capacities and regular and timely oil changes.

In many ways I think this is a "ford" or "chevy" sort of debate.

I am a very strong believer in the need for aftermarket filteration. I use the Aviation Development Corporation filters on my engines (www.aviationdevelopment.com). I particularly like the fact that they don't have any signifigant addditional capacity and they give a bypass indication very quickly when the micro screen is contaminated with anything. The heat sink design also provides some additional heat dissipation.

[Stoney]

12 years of Philips 25W60 and I always had at least no lower then 72 over 80 on all cyls, most were 78 over 80 on a 1550 hour engine.

[Glenn Wegman]

Work on one 825 hour trouble free merlin using Phillips 25W60 and another 900+ hour Merlin using Aeroshell W-120. Can't really say I have a legitimate preference.......but I like Aeroshell in the South and Phillips anywhere it snows.

Glenn

[T-6G Pilot]

Thanks so far for everyone's input. This is exactly why I posted here. I new I would get some good "intel" from a variety of sources.

I did install the Airwolf system at the last annual so I am looking forward to the 50 hour oil change intervals and not having to pull the screen at each oil change. (As an aside, she is sporting a nice new paint job as well !)

The other side of this issue is that our unit(National Capitol Squadron of the CAF) got donated over 600 cases of oil from Exxon. The reason I am considering the change is to help the unit out and buy some of this oil. Since most of it is "straight" I thought I would switch if there were no serious issues with engine reliability/performance/safety. Based on some of the comments here, I have not see Exxon mentioned when it comes to oil. Anyone have any comments on Exxon oil in general?

Thanks again for the discussion.

Mike

[Ollie]

We use the same oil in all our Beavers and the Harvard, and that is Aeroshell Mineral 100. We never had problems with the engines (well, they are Pratts to begin with ), and since we don't fly them in the winter, we don't bother with switching the oil.

Oscar, O-360s in the O-2? I thought they had O-470s... Interesting!

[John Lane]

One should never acknowledge such questions in fear of starting a major debate and people may have the impression one is acting as an authority in a given field! In this case, I too don't feel there is a right or wrong answer, I just have my own opinion, however I do agree with Glenn on using multi-viscosity oil's liquid cooled engines! Mike, I'm sure your more confused than ever with all the imput you've received! Remember if it works for you stick with it, then you too will have your own opinion. Great discussion, Happy Holiday to all

[skymstr02]

Oscar, O-360s in the O-2? I thought they had O-470s... Interesting!

Yep, the IO-360-D to be exact, 210 mighty horsepower, each. But also have 8 gallons per hour fuel flow at cruise.

[Ollie]

Excellent, thanks for the confirmation.

That's a lower consumption than my Focke-Wulf for 145 more available horses!