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  #1  
Old 04-09-2012, 08:35 PM
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Ironflight Ironflight is offline
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Default All Broken In?..

It was almost a month ago that we decided to replace all four cylinders on the Valkyrie?s 1500-hour engine due to excessive oil consumption and low compression. It really didn?t take very long to get the new jugs in hand (a couple of days from A.E.R.O.), the old jugs removed, the engine compartment cleaned up, and the engine re-assembled. All-in-all, about a week for the mechanic work while doing my normal job. Unfortunately, I also had a week-long business trip and another week spent at Sun ?n Fun thrown in there, so it wasn?t until last week that we were really able to fly the airplane and break in the new Nitrided Lycoming cylinders.

The break-in philosophy was as documented by Lycoming, ECI, and Mattituck (all three have handy reference guides). 65-75% power to provide adequate but not excessive BMEP to seat the rings, shallow climbs to keep lots of cooling air going through the cowl, careful monitoring of CHT?s to make sure that things didn?t get out of hand, and richer-than normal mixtures to help with temperatures (and probably to buy another yacht for the CEO of Exxon?). As expected, the first few hours exhibited CHT?s in the low 400?s, peaking about 430, and oil temps (reflecting the heat that had to be removed ) up around 220. I tried to keep the flights confined to the early morning hours to provide for lower ambient temps, since summer seems to have arrived on the Texas Gulf Coast.

It was about hour number seven, cruising over to Louisiana for lunch at 3,500?, when I noticed a fairly rapid drop n CHT?s and a corresponding fall in Oil temps. The CHT?s went down from 425 to about 370 in a ten minute span, with nothing else being touched, and the oil dropped down to about 195. There was much rejoicing ? the break-in seemed to have occurred! We enjoyed a nice lunch and departed for Houston about 1330 local, but alas, the airplane had been sitting in the sun, little cooling had occurred, and we had to climb for altitude in the heat of the day ? CHT?s were back in the 400?s again. Oh well?patience is a virtue, we were still in the early hours of these cylinder?s lives. The next flight was later that evening, and once again I saw the break-in signature after leveling off at cruise- ten minutes of higher than normal temps, followed by a drop all around.

The next morning I launched again, and this time, there were no high temps at all ? everything appeared to be much closer to ?normal? for this airplane, and I took that as a sign that the Val waned to shake things out a bit, so we commenced to yankin? and bankin?. I had avoided aerobatics completely because the slower speed associated with a couple of G?s is not conducive to good cooling. Sure enough, through ten minutes of lops and rolls, the temps all behaved normally ? slightly elevated, but within the ?good? band.

When I landed, I noted the time on the EFIS showed just shy of ten hours since the jugs were installed ? about normal for a good break-in period. It?s too early to get an oil usage trend of course, and we?ll keep the break-in oil in the sump until it?s time for a change, but overall, it looks like the transplant has been a success and I expect the Val to go a long way on these new jugs. A great side-benefit, of course, was the thorough going-over of the entire FWF installation, with lots of little tweaks, fixes, and clean-ups ? well worth the time after six and a half years of constant flight.

Paul
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Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
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  #2  
Old 04-09-2012, 09:04 PM
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Default good to hear

That the breakin is going well. Sounds like a textbook lycoming breakin. I am confident those lycoming cyl's will serve you well.

bird
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rv8 entire airframe at airport now, painting done, intersection and gear upper and lower fairings done, maybe order engine around first of year or before the next rate increase.
"to fly is a privilege that I am so thankful to God for"
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  #3  
Old 04-09-2012, 10:15 PM
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RV10inOz RV10inOz is offline
 
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Default

Paul,

Quote:
(and probably to buy another yacht for the CEO of Exxon?).
Nothing wrong with your break in procedure, but there is a cleaner and more cost effective way

DB
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  #4  
Old 04-09-2012, 10:38 PM
johnny stick johnny stick is offline
 
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Default And that would be....

Do tell, RV10inOz
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  #5  
Old 04-10-2012, 12:54 AM
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RV10inOz RV10inOz is offline
 
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Default

It drags out all the flat earthers....Doom and Gloom.....The manual says this and anything else is BAD/Wrong.

The way I will break in all future engines is ........... (sshhhhh just quietly while nobody else is listening) at a power setting of say 27.5" and 2500RPM and around 50Litres/13.2USG per hour which happens to be 75% power and around 45-55F LOP. (see table below *)

The CHT's will be lower, the break in just as effective, less deposits and a whole heap less fuel used. In fact I used this power setting yesterday to demonstrate what happens.....funny enough the data backed, fact based science works!

But heck.....who wants to listen to that when the OWT's are so much more believable?

Of course if you can't get your engine to operate like that, best to either get it to quickly or leave the red knob full bore until such time as you can.

By the way, the practise of leaving spats and fairings off during break in is NOT a good idea.

It drives me nuts after seeing our first flight or two without them compared to with them. CHT's much better with. I will never do that again, if I want to check for brake leaks and problems I will unscrew them.

Here on VAF we should take an oath to stop engine cruelty, and part of that is never break in with spats/fairings off.

Mates don't let mates abuse their engines!





*Table of fuel flows for different engines in the RV fleet. This is done beyond 40deg F LOP and around 75% power.

150HP 7.55GPH
160HP 8.05GPH
180HP 9.06GPH

Last edited by RV10inOz : 04-10-2012 at 01:06 AM.
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  #6  
Old 04-10-2012, 07:52 AM
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Ironflight Ironflight is offline
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Default

Well, geez, if you're going top give away ALL my secrets Oz...... Yes, the last couple of hours were done LOP because that's where cooler CHT's can be found at close to a reasonable fuel flow. I like to use full rich initially because you get the coolest overall temps (although cooling the cylinders with fuel is not that efficient and terribly costly) - then when I think everything is on the way, I went to the lean side. Conservative mechanically, wasteful of resources - but it makes me comfortable.

(Of course, this assumes that you have an engine/fuel system that will run smoothly LOP - some don't)

Paul
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Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com

Last edited by Ironflight : 04-10-2012 at 08:04 AM.
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  #7  
Old 04-10-2012, 08:44 AM
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hydroguy2 hydroguy2 is offline
 
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Location: Townsend, Montana
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Default

Quote:
Originally Posted by RV10inOz View Post
.......The way I will break in all future engines is ...........

(sshhhhh just quietly while nobody else is listening) at a power setting of say 27.5" and 2500RPM and around 50Litres/13.2USG per hour .......

By the way, the practise of leaving spats and fairings off during break in is NOT a good idea.
Except at those power settings, some of us are smoking right along (I'd be over 180kts). Not a good combo around here the mountain waves and turbulence was killing me and I was unable to run those settings for very long. I'll be sans pants next time.

New motor, new airframe, rookie pilot might not be a good engine breakin policy anyway.
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  #8  
Old 04-10-2012, 08:52 AM
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Low Pass Low Pass is offline
 
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Default

Quote:
Originally Posted by Ironflight View Post
...and probably to buy another yacht for the CEO of Exxon?...
Paul
Careful, Paul. Sounds awfully political!
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  #9  
Old 04-10-2012, 09:04 AM
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Ironflight Ironflight is offline
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Default

Quote:
Originally Posted by Low Pass View Post
Careful, Paul. Sounds awfully political!
Just a lame attempt at humor, actually....
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Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
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  #10  
Old 04-10-2012, 07:08 PM
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RV10inOz RV10inOz is offline
 
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PD

I was surprised that you hadn't, but you sneeky critter you were just trying to dodge the flat earthers And stir up the oil execs They deserve it, its not political....its fact!

Hydro guy, if your CHT's are well under control, fine, if you want the extra drag, but running around for any period of time over 400 is not optimal so why do it. I assume you were doing something like 75% power with extra drag?

Cheers
David
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