Oil for C-145

[blueldr]

Rapid starting and a hasty departure ofttimes may be required because of an irate father, but even more so by an incensed husband. I sure wouldn't want a crankcase full of fat oil under those circumstances.
Can't you just immagine waiting for 40 degrees centigrade with "Dad" on the prowl with the old double barreled convincer, or, worse yet, the fuming spouse with the scalpel.

[T. C. Downey]

In Switzerland.

In the lower 48, it's good for lubricating the outside of the engine case seams, gasket parting-lines, etc..

One of the oddities I've experienced with the use of 15W50 was a decided reduction in oil-consumption immediately after an oil-change....then about 10 hours later, a considerable increase in oil consumption. By the 25 hour mark, it would be at/near the maximum I'd allow. Another oil change,...and it'd drop back down to near zero again....and then repeat, repeat, etc..

When I used straight-wt oil.... the oil consumption remained the same throughout the period.

I could only imagine the additives in that multi-grade/semi-synthetic stuff depleted as time was accrued and the consumption increased accordingly. (This experiment was conducted on one side of my Baron, with the other side using only straight wt 100W. And the multigrade side definitely stayed wetter with leaks. I even switched sides once and confirmed it was the oil...not the individual engine. It was a dramatic demonstration.)

That's another reason I use straight-wt oils. Clearly, this is a subjective experience.

The syndrome you describe was discussed by real oil industry experts with no product to sell, on a different web page, and all of them agreed that the additive package in the multi weight oils of the major labels is totally gone in 20 hours.
The 0-300 was designed to run on 40 and 50 weight oils that comply with the " AD" requirements of all aviation oils.

I overhauled Ken Bixlers C-145 on his 170-A a couple years ago, it had been torn down and inspected by his Dad in 1960 due to a prop strike, by they found nothing wrong so it went back together with the same parts and a new gasket set, that was the only maintenance done on this engine until I tore it down in 2010, it had been run from day 1 on W 80 and W100 no filter. This aircraft has very good records as Ken's Dad was an A&P-IA and the aircraft has been in the family since 1957

In all my days working on aircraft engines I had never saw any engine that varnished and slugged up. but guess what, the crank measured new standard all the lifters were re-grindable and the cam was too. we replaced both of the major gears in the accessory section 2 new mags 6 new ECI cylinders a light weight starter, and converted the start circuit to a key start in compliance with the STC for the starter, and added a new oil filter.

I whole heartedly agree with you, there is no need to over dose this engine with an additive package it does not need.

[KS170A]

It's in the C145/O300 TCDS E-253 page 2.

NOTE 1. Maximum permissible cylinder head, barrel and oil inlet temperatures, 525°F, 290°F, and 225°F,
respectively.
Maximum oil inlet temperature limit is 240°F, when using Spec. MHS-24 oil SAE No. 50 above 40°F
ambient and SAE No. 30 or 10W30 below 40°F ambient.

While flying recently with ambient air temps in the mid-90's, I noticed my oil temp getting uncomfortably high (I know, typical in O-300's). Reading through this thread, the engine TCDS, and Continental's SIL99-2B, I conclude that using Phillips X/C 20W50 allows us to operate with an oil temp up to 240°F (TCDS Note 1 states SAE J1899-qualified oils as equivalent to CMI Spec MHS-24 oil, which seems to allow the 240°F limit. The Continental SIL lists the oils approved under J1899).

I may just be late to this party but for some reason I had the impression that you had to run the straight-weight oils to use the 240° limit. Thoughts?

[lowNslow]

Either way it may be a moot point since you can only use the multi-grade oil at 240 degrees when ambient temp is 40F degrees and below. The O300s I've flown did not have an oil temp problem at those cooler ambient temps.

[edbooth]

I have used them both being based in both hot and cold areas over the years. George's observations appear to mirror what I experienced relative to oil consumption, leaks, etc. The multi-grade did seem to help during the cold northern Illinios winters, but other than that IMHO, for these engines, I think the multi- grades are just a place for folks to needlessly throw their extra money at.

[Bruce Fenstermacher]

Seems pretty clear to me.

TCDS.png

If you want to use temperatures above 225 and the OAT is above 40F you must use a SAE 50. Not at multi weight.

If you want to use temperatures above 225 and the OAT is below 40F you can use a or SAE 30 or multi weight 10W30.

No matter what oil it must meet Spec MHs-24. Oils that meet SAE-J1899 or J1966 meet Spec MHS-24

[GAHorn]

J1966 and MHS-24 are quality and additive specifications....not viscosity specs.

The Continental note allowing increased Oil temp to 240-F is predicated on a straight weight SAE 50 oil... which also happens to meet the J1966 and/or MHS-24 specs. (multi-wt oil does not qualify at OAT temps above 40-F)

Either way it may be a moot point since you can only use the multi-grade oil at 240 degrees when ambient temp is 40F degrees and below. The O300s I've flown did not have an oil temp problem at those cooler ambient temps.

+1

[MoonlightVFR]

This type post could go on for a while

In just a quick read I am picking up innuendo, irony, strong personal opinion, not subject to change.

Can you envision a week long seminar, perhaps billed as MEN & THEIR AVIATION MOTOR OIL

Would a week be long enough? There would be booths, forums , stand up personal testimonials from the audience, product displays showing that lovely word viscosity.

I sometimes mix terminology. It should properly be Aviation Engine oil NOT Aviation Motor Oil.

Am I right?


regards

[KS170A]

In just a quick read I am picking up innuendo, irony, strong personal opinion, not subject to change.

Certainly not on this forum!!

[edbooth]

This has been an ongoing area of discussion for eons..or at least during the last 36 years I've been associated with the club. I think it finally comes down to personal preference.

[cessna170bdriver]

This type post could go on for a while

In just a quick read I am picking up innuendo, irony, strong personal opinion, not subject to change.

Can you envision a week long seminar, perhaps billed as MEN & THEIR AVIATION MOTOR OIL

Would a week be long enough? There would be booths, forums , stand up personal testimonials from the audience, product displays showing that lovely word viscosity.

I sometimes mix terminology. It should properly be Aviation Engine oil NOT Aviation Motor Oil.

Am I right?


regards

So you HAVE been to a convention maintenance forum, eh Grady?

[GAHorn]

The first convention I attended was Las Vegas and I found out that my predecessor Tom Hall had plans to fire himself and nominate me as his successor. The next convention was Wilmington and I found out with about ten minutes notice from Cleo Bickford that I was supposed to conduct a maintenance seminar.
It just so-happened that I had brought some materials with me to simply share with others and gather opinions anyway on oil temperature issues and on tailwheel rigging....so guess what the topcs were?

Anyway... later on I got a great many compliments on the "wonderful maintenance seminar" I'd conducted, and when I asked each complimenter what part they enjoyed the MOST... they universally answered, "Not a single motor oil argument...Thank you for not bringing up the subject!"

...In just a quick read I am picking up innuendo, irony, strong personal opinion, not subject to change.....

As for the viscosity argument... I read the TCDS not as an opinion of the mfr'r...but as a specification requirement in order to comply with approved data.