Engine break-in / first flight

[erich weaver]

I have a new IO-360B1b from AeroSport Power that was built up using ECI components. I still have a few questions regarding engine break-in after reading the ECI break-in instruction manual, a few past VAF posts from Mahlon Russell, and a Lycoming Service Instruction on Pre-oiling.

Dumb stuff first: It is advised to use mineral oil for break-in. Why? How does it differ from a standard aviation grade petroleum based oil? I note that the ECI break-in instructions recommend Phillips SAE20W-50 oil for break-in AND ALL SUBSEQUENT OPERATION and state that it is "100% mineral" - see http://www.eci2fly.com/pages/tech.aspx#breakin. The picture of the product is small (pg 13), but I dont see anything screaming out "Mineral Oil" on the label. How do I identify mineral oil?

I would like to have the thrill of doing the first flight on my RV-7A. It makes sense to me to do some taxi-testing with the plane prior to the first flight, but I am concerned by the numerous engine break-in admonitions to keep the ground runs to a minimum, working up to a maximum of only several minutes of running at any one time. That doesnt give one much opportunity for taxi testing! How did you smart folks balance these conflicting needs out?

Lastly, I was shocked to see the following in the ECI instructions: "...we do not recommend cycling the propeller untiil approximately 10 minutes of flight time have been accumulated." Huh? Are they serious? Im just supposed to take off on my first flight without verifying I have pitch control on my propeller?

Thanks for any insights you may have to offer regarding these issues

erich weaver

[Ironflight]

Erich,

I agree that there is a lot of info out there to read! I basically used Mahlon's instructions to a tee (Hey, Mattituck built my ECI component engine...), and had no problems. You can run the engine until CHT's get to about 350, which does give you time to test brakes and learn how to steer the airplane around on the ground.

As far as taxi tests, many experienced folks have come down on the side of NOT doing high speed taxi tests with an aircraft such as an RV, where the basic design is well understood. Flight testing an RV is more of a production test than it is an experimental test. A lot can go wrong on a high speed taxi, and a lot of airplanes have been damaged or destroyed that way - very sad. If you're looking to familiarize yourself with the airplane, I'd suggest getting some transition training. If you have built the airplane anywhere near to plans, it's going to fly fine without the taxi testing!

Break-in oil - I used Exxon mineral oil, because I got a free case from Mattituck. Worked fine, and yes, you do want mineral oil - the detergent in regular oil is counterproductive to the breakin process, but I'm not enough of a chemist/metallurgist to tell you why.

Prop cycling? I cycled mine before first flight....hope it doesn't fall off sometime soon! I never deep cycle the prop - just long enough to hear a reaction, then back to full forward.

Paul

[Mike S]

Straight mineral oil is another term for the old school vernacular "non detergent"
--------more or less. Modern oil has lots more in it than just "detergent".

What they are going for is no additives that sometimes hinder the break-in process.

Mike

[plehrke]

I recently flew my RV-6A with a new IO-360 B1B from Aerosport Power. I ran the engine for less than an hour before first flight. I spent about 15 minutes of ground run with out the cowl on starting for the first time, checking for leaks, and adjusting the idle and mixture. I then only did two taxi runs down the run way. Not sure what I would do with any more as anything above 40 kts you have the potential for lift off or you are over heating the breaks.
I worried over the engine break-in (running high power for the first 5-10 hours) but decided getting the rings to seat was more inportant than getting good full envelope flight data. My first flight I circled the airport for 45 minutes at 80% power (checking temps and flight controls) before throttling back to to do a stall or two just before landing. The next 10 hours I just flew the engine break-in and then continued with normal flight test envelope expansion test require lower power settings. Engine broke in fine and does not burn any oil between oil changes.
As far as the mineral oil goes I used AeroShell W100 straight for the first 30 hours (one oil change at 5 hours) until my second oil change and then went to an ashless dipersant 15W-50. In the straight mineral oil I added the Lycoming anti-scuff additive LW-16702 per service bulletins 446 and 471 and service instruction 1409 and page 79 of the Key Reprint articles (page 79). Mineral oil has no additives.

Philip

[pierre smith]

Good to see you still on the forums Philip. Any chance of you going to LAL?

Regards,

[plehrke]

No not this year. To much work and not enough flying. I did make it to the Mid-West RV flying last week end in Marion IL. See the VAF Headline News Roundup from yesterday or go directly to the link of the pictures
<http://picasaweb.google.com/VansAirForce/Chuck>

Philip

[tommylewis]

I flew my RV7a a week ago. I did a 3 min ground run of the engine, no cowling on, a couple weeks ago to verify no leaks. Then as I taxied for the first flight, I did slow taxi to one end of runway to break in brakes, and then a high speed taxi to just get nose wheel off, 40-50 mph, to the departure in of the runway to verify there were no issues. Then runup check and departed on first flight. But, I had test flown this procedure and plan in a neighbors RV7a so I knew how easily the nose wheel comes off.

I did work with our EAA chapter first flight guy to develop a plan for the first flight, and was glad I did. In the excitement of the event, I needed a plan to follow to ensure I did not miss any important details.

Good luck with your first flight,

Tom Lewis

[erich weaver]

Philip wrote: " In the straight mineral oil I added the Lycoming anti-scuff additive LW-16702 per service bulletins 446 and 471 and service instruction 1409 and page 79 of the Key Reprint articles (page 79). Mineral oil has no additives."

I have not read those service instructions, but are you sure this is recommended for break-in? This directly contradicts what is recommended by ECI. They say at least three times "CAUTION: Do not use any oil containing anti-scuffing additives during break-in." Based on previous posts, I was thinking the idea with mineral oil was to avoid additives.

erich

[gasman]

The oil ring must break in first...... Re-read ECI instructions, or call them.

[Aden Rich]

Mineral oil has no additives in it. This is to help "seat" the piston rings to the cylinders walls during the break in process. The lack of additives makes more friction which help hone the rings the sides of the cylinder walls. If you use oil with additives it will "slick" over the rings and you won't get a good seat. This will lead to less horsepower and oil usage for the remainder of the engine life. My father and and I have built almost 10 RV's with rebuilt engines. We follow mineral oil break in for 50hrs with running the engine at 75% power or above for at least 10 hrs. Try and use 75% during most of the breakin process. First run your engine for 5 hrs then change the oil, again using mineral oil. Inspect filter for any particles and send an oil sample for baseline data to a test lab. Run engine for another 15 hrs then change again. I ran oil for about 15 hrs again until 50 hrs. Changing oil often allows you to inspect for wear/particles. It also will allow for inspection for leaks and engine area problems. After 50hrs then use normal oil. A good multi weight oil is for great for starts and colders climates. Hot weather can use straight 50 weight. Engines are expensive and oil is still cheap. Changing oil often and checking the filter is not a bad practice. I change oil every 50 hrs after that. I also purchased an AEROMAG magnet for my oil filter and it works. This keeps any metal particles from going back into the engine along with the filter. All of our engines ran strong and burned little to no oil. My friend who works at a oil test lab tested all of the aviation oils and said Exxon was the best. He also said the Rotella-T 15-40W which you can buy at Walmart was superior to Exxon. Diesel engine oil can be ran in a aircraft motor because of the low RPMS that they run. They also have a lot of detergents in them to help keep the engine clean. Hope this helps. Aden Rich