NOtes on a new a3B6 engine

[jetdriven]

this is a continuation of these two threads

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=3&threadid=5197

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=1&threadid=5268

 

New engine has 8 hours on it. Pretty much everything forward of the firewall was replaced. Well, the starter was reused, thats about it.

Some observations:

-the new engine runs quite a bit hotter than the old one. The dearly departed engine would run 360 CHT at 15 or 20  LOP at cruise. At 1500' leaned to a straight 10 GPH it would run 330 CHT.  WOT full rich sea level 330 CHT. This new one is 360 full rich full throttle, 330 in cruise with cowl flaps open, and with cowl flaps closed goes up to 380 and keeps climbing.  They tell me it is because the rigs are still seting. it better be.

The airplane is slower now. I expected that going to 20 degrees timing.  But not this much. The airplane would indicate 183 MPH on a 80 degree day at 1000'.  Bumping the timing up to 25 degrees gave us about 188-190 MPH IAS.  One cold day (32 degrees) it indicated 195.

The new engine does not like LOP as well. The GAMI spread was 0.8 GPH...far too great to be useful. When #2 was peaking, #3 was already 40 LOP. Removing the injectors, cleaning in acetone and then Hoppes #9 cleaner, and rearranging #2 and #3 for each other, brings it down to a 0.2 GAMI spread.  The old one had a zero spread.

Right now, the fastest IAS I have seen during the break in is 173 MPH.  This is substantially slower.  This is a pretty big disappointment, but I have been told to expect a few MPH back after the rings are fully seated.

The new engine is light years smoother than the old one. Being a factory engine the flywheel is drilled to balance it. That and the prop getting refinished and static balanced makes for a smooth running engine.

I am still optimistic after the engine is fully broken in we can get our speed back with the 25 degrees timing, but requires some serious cash to do it. That electroair is nearly three grand. But a 5-knot slower airplane with a 1/2 GPH fuel flow higher than before, and Slick mags,  costs an extra 500-1,000$ a year to operate 200 hours, so there is an economical reason to do it still.

[KSMooniac]

How are you breaking it in?  What kind of oil?  Did you check for induction leaks prior to flying?

[M016576]

I'm now waiting on a new tailpipe (found some holes in the old one at the bend while reinstalling it... Thought about a patch, but after the coin for the OH, what's another 300.00). before I get my shop overhauled "new" motor up in the air.  Will be interesting to compare and contrast experiences through the new motor process.  You're already beating me by about 3 months of time!  I'm hoping that the new motor runs smoother and that my gami spread is the same (should be, same injectors).  Will post once I get some hours on her....

[jetdriven]

Quote: KSMooniac

How are you breaking it in?  What kind of oil?  Did you check for induction leaks prior to flying?

[KSMooniac]

FWIW, I ran regular Aeroshell 80 for my break-in and did one local flight about 45 minutes at ~80% power LOP, and then a 4-hr XC at 80% LOP with the cowl flaps open the whole way and mine was done breaking-in after that XC.

[Bolter]

Quote: KSMooniac

FWIW, I ran regular Aeroshell 80 for my break-in and did one local flight about 45 minutes at ~80% power LOP, and then a 4-hr XC at 80% LOP with the cowl flaps open the whole way and mine was done breaking-in after that XC.

[jetdriven]

Ours never used oil.   Perhaps 1/4 quart in the first 5 hours

[garytex]

Sometimes break in can be seen as a reduction in CHT's, and it can be noticable if the rings break in within the first 2 or 3 hours during a continuous flight under the same conditions.  It is pretty interesting to watch.

[KSMooniac]

Yes, reduction in CHTs and lack of oil consumption.  Temps came down on my XC flight, and on the return flight I didn't need any oil after an additional 4 hours of flying.

[201er]

Byron, do you regret switching to A3B6?

[jetdriven]

Nope, not yet. The single mag enigne ran very well but going forward that mag is going to be hard to service.  I am surprised at how low the climb rate is and how much slower it is. I think 25 degrees timing will restore that.

[201er]

What if it's something other than the timing??

[jetdriven]

Then I'm going to be really pissed.

[smccray]

Quote: jetdriven

The airplane is slower now. I expected that going to 20 degrees timing.  But not this much. The airplane would indicate 183 MPH on a 80 degree day at 1000'.  Bumping the timing up to 25 degrees gave us about 188-190 MPH IAS.  One cold day (32 degrees) it indicated 195.

[snip]

Right now, the fastest IAS I have seen during the break in is 173 MPH.  This is substantially slower.  This is a pretty big disappointment, but I have been told to expect a few MPH back after the rings are fully seated.

[FlyDave]

I have a 1982 201 with an A3B6 with 1300 hours on it. I've put 450 hours on it in the last 2.5 years since I bought it.

I just installed a JPI 830 so I finally have accurate numbers.

In this hot summer weather, taking off from KEMT (300' msl) on climb out, WOT, max RPM & full rich & cowl flaps full open burning 19.2 gph @ 90 KIAS & CHT's 325-350. At 1,000' AGL I go to 25/25, 105 KIAS and begin leaning when I get to 3000' DA burning ~15.5 gph and lean to keep the CHT's around 325-350.

At 7,500 - 8,500 DA I'm burning 10.6 gph and get 157 KTAS. Today @ 7,500' IA, DA was 10,300, trailing 1/2 cowl flaps and CHT's 325-350. I'm trailing cowl flaps in the summer to keep temps down. I loose ~ 1 kt. for 1/2 cowl flaps. I loose ~ 3 kts. for full cowl flaps.

Byron - I'm not sure if I am referring to something different than you are about mixture but my mechanic actually leaned my engine out a bit and it runs a little hotter than it did last year in the summer. This mixture control is at the bottom front of the engine but I'm not sure what it's called. I can ask my mechanic  - let me know.

[201er]

So did the rings seat yet? Did you get Lycoming's blessing?

[jetdriven]

Per Lycoming, 25 degrees timing will not void your warranty. I have it now, in writing.  Expect a new thread and a full writeup on the position of Lycoming, the magneto change required to run 25 degrees timing, and the performance changes as a a result.

[HopePilot]

Awesome!

 

[HopePilot]

Duplicate.

[BigTex]

Byron - Just out of curiosity, will you be going back with the same Aeroshell 100/Camguard combo for your new engine?

[jetdriven]

Nope I think the plan is Philips 20w50 X/C and camguard.  Also dropping regular oil analysis.  We knew from the filter before it alerted us.  

[201er]

Quote: jetdriven

Nope I think the plan is Philips 20w50 X/C and camguard.  Also dropping regular oil analysis.  We knew from the filter before it alerted us.  

[Becca]

Quote: jetdriven

Nope I think the plan is Philips 20w50 X/C and camguard.  Also dropping regular oil analysis.  We knew from the filter before it alerted us.  

[Cruiser]

I would recommend you do the oil analysis on the first few oil changes to establish a baseline for this new engine. If all looks good they you can decide

[FlyDave]

Quote: Becca

I hadn't heard this.  I think we should continue to do the oil analysis.