Re: Cylinder break-in tips needed
Posted: Wed Sep 11, 2013 2:38 pm
OK, Sandy..it's your choice... but just to be sure you understood what was suggested.. that slow and easy can lead to an oil-burner due to rings that don't seal well....
Formed to preserve and promote a truly classic airplane
https://forum.cessna170.org/forums/
I don't think Sandy is/was doing a "run-in" nor do most cylinder change-out operations in the field. Most of those operations involve a short run to check for leaks, then as quickly as possible, get airborne for the break-in flights.T. C. Downey wrote:Two points that I would like to clarify, when you read ECI's breaking instructions their major concern is over heating the new cylinders. They recommend a special cowling for first run on the ground, etc. ....
It is not an "old wives tale"....it is a personal choice based upon many decades of industry practice providing reliable results.T. C. Downey wrote:....... The requirement for a single weight oil is an old wives tale, and has been proven to nor be true many many times....
These comments are certainly valid, in my opinon. The only point I'd make is they are not chronologically documented. Let me do so (and I speak from the experience of assembling many of those engines at a CRS that allowed the customer to choose between new-process cyls and "overhauled" surplus ones when the NOS stocks dried up.):T. C. Downey wrote:...Now my personal observations and recommendations.
1. The methods of manufacturing of todays cylinders is much different than what TCM used in 1940s when your 0-300 was developed. The cylinder barrel is a different alloy, the honing method is different, The cylinders we see coming to us today are honed with a very fine stone and we don't see the deep cross hatching scratches of yesterday. Thusly we do not require the long break in period we did prior to the change in design. The last several sets of cylinders I have installed have shown no high oil consumption during breaking or after, they will go to the first 25 hours on less than a qt. of oil. We no longer see the oil usage drop off that we used to.
2. BMEP.. AKA (internal cylinder pressures) Break Mean Effective Pressures is what causes the ring to expand against the cylinder wall at high power settings. In days of old we needed high pressures to seat the rings due to the use of cast iron rings and deep scratches in the cylinder walls. we no longer use either of these two items. (breaking in chrome cylinders is a different subject) We now use chrome rings, and a very smooth cylinder wall, and this set up breaks in almost immediately....
T. C. Downey wrote:...IMHO flying around at high power setting is a waste of gas. and presents a possibility of over heating the cylinders and removing the temper of the new rings. ....
Tom, I beg to differ. If that were true....then please explain why so many owners are still experiencing high temps and high oil consumption 2, 3, or 5 and more hours later? It's a simple answer...those cylinders have not yet been properly broken in.T. C. Downey wrote:...When the new cylinders are ground run properly, and you fly to pattern altitude your new cylinders are broke in and ready for normal usage....
[/quote]T. C. Downey wrote:...I tell my customers to limit their power setting to no less than 2450 RPM in cruise, and lean to vibration then richen to smooth operation, and run it that way all the way to TBO.
Nope GA, nothing but standard prop settings, I have one customer who tows banners with a 172 / 0-300-D climb prop and runs it WOT and leaned to best power, he is coming up on 2600 TTSN on his cylinders and none have been off for re-work.gahorn wrote:(It is possible, and even likely, that Tom has more customers in the Pacific NW that use props of lower pitch and capable of higher RPMS than the "stock" ones used elsewhere in the lower-48.
Are you insinuating that every one else are dummies?T. C. Downey wrote:[...GA,
explain the difference between W100 and 20W50 oils.
Every one else read "oil talk for dummies" on the ECI web page
Sorry,, some times you point gets lost in the long oratory.gahorn wrote: Are you insinuating that every one else are dummies?or are you simply trying to bait me into a game of "stump the chump"?
I'd never do that with you George.
I ain't goin' there. If you have something specific to say..then say it please.
I asked to see if you really do believe there is a lubrication difference between the two oils.
The ECI website article to which you refer already says the same thingwhat I've already said:
Oil Viscosity
Points made are well taken on both sides of the issue of whether to use single or
multi‐grade oils. In the final analysis, you know that your aircraft is subjected to
extreme temperature variations and starting conditions. Many aircraft fly
frequently. Many aircraft don't fly enough. Successes (and lack of) suggest there is
simply not one viscosity that is always the best for all flight environments. RAM sees
the following:
• Multi‐Viscosity Mineral Based (AD) oil is working well in higher usage airplanes.
• Single Viscosity Mineral Based (AD) oil is working well in lesser‐flown aircraft
I choose the 100W for the reason I already stated...I don't fly that often.
W H A T !! ?? !! You don't read and hang onto my EVERY WORD !! ?? !! I'm smushed! Absolutely smushed!T. C. Downey wrote:....Sorry,, some times you point gets lost in the long oratory. .
T. C. Downey wrote:....OBTW if you are using the W100 for corrosion protection, you are using the wrong oil.
Seriously,, w100 and Phillips 20W50 aren't the best for corrosion protection. If that is why you are using it. In the quote above that is what I read less used engine use W-100 to me that corrosion protection, but if you use it because of better start up lubrication, it ain't the best at that either.gahorn wrote:T. C. Downey wrote:....OBTW if you are using the W100 for corrosion protection, you are using the wrong oil.
Seriously, tho'....there you go again, Tom....throwing out a kernel....with no clue what you really mean by it..
My preference ???? Exon Elite for engine that do not run for long periods. I used a C-150/0-200 for the maintenance of it for well over ten years, that 0-200 got less than 10 hours per year placed on it, we ran Exon Elite with no problems.gahorn wrote:So, Tom...what is your preference for corrosion protection? (Mine is to fly the airplane as often as I can using AS100W with no additives ...admittedly only about once a month....and to plug the exhaust, intake, and keep it stored in a dry hangar... no indication of rust when I "boroscoped" them after 12 years of that.)
I don't like the "plus" oils because I don't want EP additives in with my "yellow" metals.