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I have read that most of the wear on an engine is in the first minute after startup, the oil having drained away from the moving parts. Having once stored a car for several months, I believe it. Synthetic oil is slicker than non-synthetic, and It would seem to me that it would drain off faster. Most of our planes often go more than a week between flights. My conclusion is that non-synthetic oil offers more wear protection than synthetic. What do you think?
Bill

Absolutely not. Many studies have shown that the synthetic oil 'cling factor' is far superior to dino oil. Once had an 0-320 that sat idle with 15/50 Aeroshell semi-synthetic for 12 years and it STILL had oil residue on the parts. Turned over half a blade and started perfectly. That engine (with an original 700 hrs since new) now has 1500 hours and runs like a Swiss watch. Pre-oiling or heating in temps under 40 degrees will help an engine last much longer.

Pre-oiling...do you mean pressurizing the oil galleys before engine start? If so, what kind of accessories are required?...an extra electric oil pump or something similar that you would turn on to get the pressure up before starting?

A long time ago in Popular Mechanics there was a column called "Say Smokey". Smokey answered questions from readers about their car problems. He was a staunch advocate of that idea although to my recollection, never offered a solution. (DISCLAIMER-This was about 35 years ago so my memories are a bit foggy).

Just a few years ago I helped an A&P mechanic do this to a C-85 engine that had been sitting idle for a year, by removing an oil galley plug and attaching a hand pump. After a few "pumps" the oil pressure went up. He put the plug back in and then started the engine.

Sounds like a good idea if you are unsure of the condition of your engine.

I have a 5 year old 3300 Jab, that hasn't been turned over yet. Its still pickled from the factory.
I'm ready to start it now. I asked an old A&P what I should do before first start. He suggested
pressurizing the oil system, filling the oil filter and oil cooler with oil and taking out half the
plugs so there is no compression. Then spinning it over watching the oil pressure gauge for
a reading within say, 10 seconds.

To pressurize the oil system, I'm thinking of using a rubber squeeze bulb,
and feeding the oil into the spare oil pressure sender location.

Rick
Sonex 524

Synthetic oils are a disaster where 100LL is used. Read Mike Bush's articles as he describes the issues in detail.

Ercoupechris wrote:Synthetic oils are a disaster where 100LL is used. Read Mike Bush's articles as he describes the issues in detail.

I don't agree. In his more recent articles (Savvy Aviator #52, for example) he doesn't claim they're a disaster; just that the synthetics' ability to resist breaking down is not the problem in Aviation engines. The problem is the contaminants and moisture that get trapped in the oil, thus necessitating frequent oil changes regardless of whether its natural or synthetic.

FWIW, Aeroconversions/Sonex Aircraft recommends several non-synthetic and synthetic oils for the Aerovee and Aerovee Turbo (after break-in). See the Aerovee Manual for details (its freely available on the Aeroconversions website).

EDIT: I did some more digging and I stand corrected. In the "All About Oil" EAA Webinar in 2013, Mike Busch claims that _fully_ synthetic aircraft oils were phased out a few years ago because they couldn't deal with the lead sludge and related contaminants in aircraft engines (comments around minute 34-35 of the webinar). I believe his claim is that the remaining "synthetic" oils are all blends.


--Noel

I was at a seminar where Mike B. was speaking a couple of years ago and he said he would not recommend using semi-synthetic oils if given the choice. You are right Noel, his belief is that synthetic oils don't handle lead contaminants very well. He is also not a particular fan of multi viscosity oils either. I hate to say it but I do drink the Mike Bush Kool Aid. He has saved me tens of thousands of dollars in compulsory maintenance and I like his common sense approach to everything airplanes.

That being sad, I do use synthetic oils in everything else that In have with an engine ;-)

For pre-oiling, I'm planning to install one of these

https://m.summitracing.com/parts/ctr-24-046

I'm not sure you could use it for the very first start,nbut once it's installed it's an accumulator that allows you to have oil pressure PRIOR to starting the engine. As a bonus, it will provide some seconds of oil pressure in zero-neg g conditions. I have done some research on it that indicates positive results, including there have been a few write-ups on the vaf board.

Gordon

I've never run anything in my VWs but 20-50 for almost two decades. The main reason was always cost. Since my cars didn't have oil filters, I usually changed my oil at quicker intervals. The secondary reason was some discussions that the synthetic and blends would cause a weepy engine as the loose tolerances in the old design were not well suited to the smaller molecules in synthetics. I always figured my VWs "marked their territory" enough without making it worse and paying more to do so.

I have yet to have a VW engine grenade on me (knock on wood). I still advocate that a well driven and well maintained VW is extremely dependable. One of the best things you can do to maintain your vehicle is to actually drive or, in this case, fly it regularly.

GordonTurner wrote:For pre-oiling, I'm planning to install one of these

https://m.summitracing.com/parts/ctr-24-046

I'm not sure you could use it for the very first start,nbut once it's installed it's an accumulator that allows you to have oil pressure PRIOR to starting the engine. As a bonus, it will provide some seconds of oil pressure in zero-neg g conditions. I have done some research on it that indicates positive results, including there have been a few write-ups on the vaf board.

Gordon

Gordon - Just remember that you're adding extra weight, extra parts, and extra leak-points for the oil. You have to make a very personal calculation as to whether all those things are worth slightly reduced engine wear over the long-haul**.

Like Chris, I'm a big fan of Mike Busch and he's pretty adamant that most engines have problems and failures because of infrequent use ("they don't wear out; they rust out"). His chief claim is that its not the lack of oil at startup that causes damage (or running lean, or any number of supposedly-abusive practices), its small amounts of moisture (and perhaps other contaminants, such as in the oil) sitting around in the engine for weeks or months between starts that allow corrosion to get a foothold.

--Noel

**I say this as someone who has used accumulators in race cars, so I've nothing against them specifically. I just am not sure that the tradeoff is worth it in a small, light, easy-to-maintain aircraft like the Sonex. An RV is a different beast with a much higher empty & gross weight, bigger engine, etc.