Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Old 12-23-2017, 08:24 AM
rvdave rvdave is offline
Join Date: Jun 2005
Posts: 398
Default Engine break in again

Iím planning on first flight and engine breakin in the next couple of weeks in the frigid northern mich temps. Wondering if there is other than normal breakin procedures for this time of year? Nothing mentioned in what Iíve read from lycoming, aopa or otherwise. Iím expecting better cooling overall but maybe too cool for cylinders 1,2 donít know. Should that be a concern?

Much confusing write ups about power and mixture settings for first few hours, is that all related to cylinder head temps (other than high pressures for ring seating) which once again may not be a factor for this time of year?

Can someone give me a guideline for hp/mp settings for breakin? Is 70-75% achieved by any recommended combinations of throttle/prop controls? Is it all based on chts?

Other readings say donít worry just high power first few hours, watch out for shock cooling.
Dave Ford
Cadillac, Mi
Reply With Quote
Old 12-23-2017, 09:13 AM
737Guy 737Guy is offline
Join Date: Nov 2017
Location: Meridian, TX
Posts: 8

Hey Dave, I’m by no means an expert but I’m a huge fan of Mike Busch (Savvy Aviation). He has a wealth of knowledge.
I have broken in cylinders on IO540s and here is what I’ve done.
1. Use a single viscosity oil
2. Pre heat your engine. Oil sump element, electric blanket, radiant light etc.
3. High power settings at low altitudes so power is >70%. If possible, (WOT) wide open throttle.
4. Break in is complete when oil consumption stops

Once again Mike Busch has written several articles on this subject. Give them a once over and have fun!

Shane Adair
Still looking for a 7/7A
Reply With Quote
Old 12-23-2017, 10:36 AM
jedimike007 jedimike007 is offline
Join Date: Jan 2005
Posts: 29

Run it hard, keep the temps inline but don't baby it. WOT if possible, and I've had great success with Phillips X/C oil for break in and after. In the previous shop I worked at we used this on procedure on all 30+ new engines and never had issues.

Mike S
Glasair III under construction
Rv-8 flying
Reply With Quote
Old 12-23-2017, 11:21 AM
Canadian_JOY Canadian_JOY is offline
Join Date: Aug 2007
Location: Ontario, Canada
Posts: 2,013

Just completed our first flight a week ago. Engine is a brand new certified Lycoming O-360-A1F6 turning a Hartzell C/S prop. Pre-heated using Reiff Turbo XP cylinder bands and sump and oil cooler heating pads. Oil temp was in the top end of the yellow when we started the engine. OAT on the ground was -15C and -20C at altitude. Ran it for an hour at 75%, full rich with 100LL, kept power well up in the pattern and landed. Oil consumption was minimal, perhaps 3/16" on the dipstick.

Flew it again on Thursday for 2.1 hours in similar OAT, again at 75%. Mixture full rich (ouch she's thirsty!). Oil consumption was less than in the first hour, so between a quarter and a half quart total in 3 hours. EGTs and CHTs are flattening out, getting closer together as time goes on. As expected, #3 CHT is the warmest of the gang at about 325F Oil is Philips XC 20W50.

I don't know if we're doing it right but the engine certainly doesn't seem to mind the way it's being run. Oil consumption so far would indicate we're not glazing cylinders. Oil temp isn't as warm as I'd like it to be despite having a butterfly valve closing off the 3" SCAT tube to the remote-mounted oil cooler.
Reply With Quote
Old 12-25-2017, 10:31 AM
jeffw@sc47's Avatar
jeffw@sc47 jeffw@sc47 is offline
Join Date: Aug 2014
Location: Simpsonville, SC (SC47)
Posts: 259
Default more comprehensive engine break-in procedure

Searched Mike Busch Savvy Aviator for engine break-in advice, nothing comes up in the savvy Aviator list, AOPA and EAA articles.

I would like to find a comprehensive new engine break-in procedure. Starting with first engine run, generally a short time run to check out everything under the cowl, to take a look at fittings and such. Then, something comprehensive about the first few hours of flight time to seat the rings, and then to the first 40 to 50 hours.

So far I have only found a few short procedure lists for different segments of break in time slots.
Jeff Warren
Simpsonville, SC (@SC47 > 10nm NW Triple Tree)
1946 Bellanca Cruisair 14-13-2 (72 YRS OLD 8/15/18)
RV14A (N14ZT), Ser#140195
Start 10/11/14
Dues paid 12/2/18 (USArmy 2/67-2/70)

Reply With Quote
Old 12-25-2017, 01:53 PM
vlittle's Avatar
vlittle vlittle is offline
Join Date: Jan 2005
Location: Victoria, Canada
Posts: 2,078

From the manufacturer:
V e r n. ====
RV-9A complete
Harmon Rocket complete
S-21 under construction
Reply With Quote
Old 12-25-2017, 02:18 PM
YellowJacket RV9 YellowJacket RV9 is online now
Join Date: Oct 2012
Location: Clearwater, FL / KZPH
Posts: 1,192

Two excellent guides. I followed the advice from Mahlon and had no problems, even in 80ish degree Florida weather, breaking in 4 new cylinders.

Chris Johnson
RV-9A - Done(ish) 4/5/16! Flying 4/7/16
Reply With Quote
Old 12-25-2017, 02:21 PM
rv8ch rv8ch is offline
Join Date: Feb 2005
Location: LSGG
Posts: 2,502
Exclamation Test club

Originally Posted by vlittle View Post
Good document - it did have one funny comment however:


Mickey Coggins

Last edited by rv8ch : 12-25-2017 at 02:24 PM.
Reply With Quote
Old 12-25-2017, 09:29 PM
737Guy 737Guy is offline
Join Date: Nov 2017
Location: Meridian, TX
Posts: 8

Hard Facts About Engine Break-In
Most people seem to operate on the philosophy that they can best get their moneyís worth from any mechanical device by treating it with great care. This is probably true, but in many cases, it is necessary to interpret what great care really means. This is particularly applicable when considering the break-in of a modern, reciprocating aircraft engine. Aircraft owners frequently ask about the proper procedures for run-in of a new or rebuilt engine so they can carefully complete the required steps. Many of these recommended break-in procedures also apply to engines which have been overhauled or had a cylinder replaced.

The first careful consideration for engine run-in is the oil to be used. The latest revision of Lycoming Service Instruction 1014 should be consulted for this information. The basic rule which applies to most normally aspirated Lycoming piston engines is simple: use straight mineral oil of the proper viscosity for the first fifty hours or until oil consumption stabilizes. Then switch to ashless dispersant (AD) oil.

The exceptions to the basic rule above are the O-320-H and the O/LO-360-E series. These engines may be operated using either straight mineral oil or ashless dispersant oil; however, if the engine is delivered with ashless dispersant oil installed, it must remain on ashless dispersant oil. The Lycoming oil additive P/N LW-16702 must be added to the O-320-H and O/LO-360-E engines at airframe installation, and every 50 hours thereafter or at every oil change. An FAA-approved lubricating oil that contains, in the proper amount, an oil additive equivalent to LW-16702 will meet the requirements for the additive as stated in Lycoming Service Instruction No. 1014M.

All Lycoming turbocharged engines must be broken in with ashless dispersant oil only

When taking delivery of a new aircraft, there is another point which must be emphasized. Some aircraft manufacturers add approved preservative lubricating oil to protect new engines from rust and corrosion at the time the aircraft leaves the factory. This preservative oil must be removed by the end of the first 25 hours of operation.

Each new or rebuilt engine is given a production test run at the factory before the engine is delivered to an aircraft manufacturer or customer. After installation in the aircraft, the engine is run again during the test flights. These test runs will ensure that the engine is operating normally and will provide an opportunity to locate small oil leaks or other minor discrepancies. In addition, these test runs do the initial seating of the piston rings. The rest of the break-in is the responsibility of the pilot who flies the aircraft during the next 50 hours.

A new, rebuilt or overhauled engine should receive the same start, warm-up and preflight checks as any other engine. There are some aircraft owners and pilots who would prefer to use low power settings for cruise during the break-in period. This is not recommended. A good break-in requires that the piston rings expand sufficiently to seat with the cylinder walls. This seating of the ring with the cylinder wall will only occur when pressures inside the cylinder are great enough to cause expansion of the piston rings. Pressures in the cylinder only become great enough for a good break-in when power settings above 65% are used.

Full power for takeoff and climb during the break-in period is not harmful; it is beneficial, although engine temperatures should be monitored closely to ensure that overheating does not occur. Cruise power settings above 65%, and preferably in the 70% to 75% of rated power range, should be used to achieve a good engine break-in.

Remember that if the new or rebuilt engine is normally aspirated (non-turbocharged), it will be necessary to cruise at lower altitudes to obtain the required cruise power levels. Density altitudes in excess of 8000 feet (5000 feet is recommended) will not allow the engine to develop sufficient cruise power for a good break-in.

For those who still think that running the engine hard during break-in falls into the category of cruel and unusual punishment, there is one more argument for high power settings during engine break-in. The use of low power settings does not expand the piston rings enough, and a film of oil is left on the cylinder walls. The high temperatures in the combustion chamber will oxidize this oil film so that it creates a condition commonly known as glazing of the cylinder walls. When this happens, the ring break-in process stops, and excessive oil consumption frequently occurs. The bad news is that extensive glazing can only be corrected by removing the cylinders and rehoning the walls. This is expensive, and it is an expense that can be avoided by proper break-in procedures.

To summarize, there are just a few items to remember about engine break-in:

If a preservative oil has been added by the aircraft manufacturer, drain it no later than the first 25 hours of operation;
Follow the engine manufacturerís recommendation regarding the oil to be used for break-in and the period between changes;
Run the engine at high cruise power levels for best piston ring/ cylinder wall mating;
Continue break-in operation for 50 hours or until oil consumption stabilizes. These simple procedures should eliminate the possibility of cylinder wall glazing and should prepare the engine for a long and satisfactory service life.

Copied from a Lycoming bulletin.
Sorry I couldnít find the Mike B. Info. Iíll keep looking....
Shane Adair
Reply With Quote
Old 12-26-2017, 11:24 AM
Aluminum Aluminum is offline
Join Date: Jul 2017
Location: San Jose, CA
Posts: 201

Originally Posted by Canadian_JOY View Post
Oil consumption so far would indicate we're not glazing cylinders.
What are the conditions to watch out for where glazing would occur?
Dan V
'91 Zodiac flying since 2013
RV-14A in progress
2019 dues worth every penny
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 06:29 PM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.