Engine overhaul - flow balancing?

[jeckford]

Our 1982 M20J with about a 1100 hrs on IO360 A3B6 engine  needs overhaul due to internal corrosion.

 

We are taking to Mena Aircraft Engines in Mena, AR for overhaul.

 

They offer an upgrade package and have a STC for flow balancing cylinders and also installing Gamijectors.

 

Anyone have any experience or thoughts on these upgrades?

 

Thanks,

 

John

 

[Steve Dawson]

I think I'd ask them what work do they do to the engine and what do they claim for performance for this improvement? Do they have proof? How much do they want for the upgrade

[Alan Fox]

Flow balancing usually involves removing material from inside the ports.....I would not do this on my engine , because it will probably increase the likelihood of cracks in the ports....(over time)

[Bob - S50]

And, if you get the cylinders flow balanced and later have to replace one, can they and will they flow balance the new one to match?  If so, how much will that cost?

 

Bob

[MooneyBob]

Just curious, what is corroded on the engine, how did you find out? Any performance issues?

Thanks.

[jeckford]

Just curious, what is corroded on the engine, how did you find out? Any performance issues?

Thanks.

 

 

Purchased plane 3 years ago.  It has zero time factory reman engine installed in 2004 and then only flew 300 hours until time of purchase.  We had pre buy at well known MSC in Texas and everything checked out fine.  Compessions all in upper 70's.  We have put almost 800 hours on engine without problems.  Compressions still in upper 70's.  No issues on oil testing. 

Over last year we were seeing increased oil consumption from 8 hrs/qt to 6 then 4.  Last month it was 2 and we had #4 cylinder pulled and it showed some corrosion.  This is usually our hottest cylinder.  I recently did a flight and averaged 1 hr/qt.  We had all cylinders pulled and there was corrosion and pitting.  We were expecting to do a top overhaul however when engine was inspected further there was corrosion involving the cam and cam followers so our mechanic recommended a major overhaul.

[Raptor05121]

I have heard nothing but good things from GAMInjectors. They claim reduced fuel flow and high power, and I have read several reviews that confirm this. Nothing firsthand, however.

[The-sky-captain]

John,

Mena OH'd my engine back in 11 and offered the same upgrade. I did not go the flow balancing or GAMI route and am still able to run LOP smoothly. They do a great job, I think you will happy with the standard OH if you go that route.

[aaronk25]

I'd recommend the powerflow exhaust before any other mods. This pic was today at 4000ft 9c, and the indicated airspeed was squarely cornering the 160kts peg. (Actually got it to 161kts IAS). This equals 170kts true.

The power flow has put an honest 8-9kt gain on my J.

It's not legal to do, but if the mags were timed to 25 degrees instead of 20d your mooney would feel like a rocket ship. The dual mag, single shaft are spaced at 25d where all the newer split mag systems are 20d.

[carusoam]

IO360 with years of low hours has an increased chance of rusty cam.

Rusty cams turn into MOH...

In this case, a good PPI would include a look at the cam.

Note for anyone looking to buy an IO360 that has been sitting for a long time....

Follow up question,

Is there a better cam material that can be chosen to avoid this on the OH?

Best regards,

-a-

[aaronk25]

....buy a cam from anyone other than lycoming. My factory new cam came apart in 2.5 years and 400 hours. 2 year warranty....wouldn't stand behind it.

Interesting for the money they get a guy would think you could get some super hard impervious to rust camshaft.

[rbridges]

....buy a cam from anyone other than lycoming. My factory new cam came apart in 2.5 years and 400 hours. 2 year warranty....wouldn't stand behind it.

Interesting for the money they get a guy would think you could get some super hard impervious to rust camshaft.

 

that sucks.  how many hours you have on your new engine?

[Alan Fox]

Actually Lycoming makes a roller cam now....might be worth the addl cost at upgrade...

[Steve65E-NC]

I had a now defunct engine shop in Mena do flow balance on an overhaul back in 1992.  Only problem, the cylinders were Cermichrome.  Within 600 hours I had to replace the first one.  Within 800 I had to replace all.  The cylinder plater helped some with cost on Cerminil replacements.  So the effect of my flow balance was lost early.  The Cerminils have held compression well but with higher oil usage.

 

I understand that most IO360s need a top overhaul around  1000 hrs.  So in doing your economics figure to cover the cost of that mod in around 1000 hours.  I also wonder what this process does to the value of the removed cylinder as a core.  Not saying it is bad, these are just some of the complexities.  

[Jeev]

 

I understand that most IO360s need a top overhaul around  1000 hrs. 

No disrespect Steve but I definitely do not agree with that. TIO-360 sure but the non turbo Lycomings especially the smaller displacements will go much longer than 1000 before a top if flown properly. By properly I mean flying regularly and keeping the CHT's below the low 400's and preferably 350-370 in cruise. I flew my last IO-360 to 2200hrs and over 10 years it only needed 2 cylinders. :-)

As for flow balancing I looked into it about a year ago when I did my engine and in the end decided there was no concrete data supporting a significant power increase. The io-360 usually runs great LOP with the factory injectors but if it doesn't you can always add the GAMI's later. Good luck

[Ron McBride]

I did a top overhaul on my IO360 about a hundred hours ago.  I purchased from Lycon used cylinders that were first run.  they polished the intakes and exhausts for me.  They run great, I can feel a little power increase, but my weights and temps change a lot every time I fly, so it is hard to tell.  they also coated the outside of the cylinders with a coating to aid in cooling.

 

With a new oil cooler, better baffles, cowl closer, oil cooler relocation,   all temps are cooler.

 

Ron

[orionflt]

I have heard nothing but good things from GAMInjectors. They claim reduced fuel flow and high power, and I have read several reviews that confirm this. Nothing firsthand, however.

The Gami injectors seem to make a bigger difference on the continental engines, the Lycoming injectors seem to perform better so it is not much of an upgrade.

 

Actually Lycoming makes a roller cam now....might be worth the addl cost at upgrade...

the only way to upgrade to a roller cam is to send your engine back to Lycoming. I guess you could buy a new case and all the other associated parts you would need to do an upgrade, but at that point it would probably be cheaper to just go to Lycoming.

 

Brian

[Alan Fox]

Because the 4 cyl Lycoming feeds equal length intake runners , tuned injectors have no value to a 4 cyl Lycoming ,  I would bet the cooler running in the previous post could be attributed to the baffles and cowl closure.....

[aaronk25]

I had a now defunct engine shop in Mena do flow balance on an overhaul back in 1992. Only problem, the cylinders were Cermichrome. Within 600 hours I had to replace the first one. Within 800 I had to replace all. The cylinder plater helped some with cost on Cerminil replacements. So the effect of my flow balance was lost early. The Cerminils have held compression well but with higher oil usage.

I understand that most IO360s need a top overhaul around 1000 hrs. So in doing your economics figure to cover the cost of that mod in around 1000 hours. I also wonder what this process does to the value of the removed cylinder as a core. Not saying it is bad, these are just some of the complexities.

On my Io360 we re-used the same cylinders at 1,700 hours for the overhaul as they still met factory new barrel specs....not service limits but New limits! I also run hard power settings such as 2700rpm at 4,000ft at peak egt or even slightly ROP like at 20rop. I've put at least 1,000hours on these cylinders running it this hard. Still within new limits. The trick I believe is keeping everything cool. I never operate over 380 degrees and CHTs are at 330-350f most of the time.

When I got the plane we fixed a bunch of baffle issues and CHTS dropped by 60 degrees. The previous owner was bitching about doing top overhauls at 800-1,000 hours by its easy to see why he was running at 400-440d!

I don't believe there is a damn thing wrong you can do to cylinders besides get them hot. But I only have 1,000 hours of testing....but there still new. In fact Sam said they looked in great shape and it would be a shame to throw away such s great set of cylinders.

He also has used wide deck cylinders on hand he could rebuild for cheap....not many wide deck used around. He said people just want them changed after 2000 hours and three still in great shape! Remember our wide deck angular valve 200hp cylinders are $2350 best buy vs the Parnell valve at $1200 so there is darn near $10k worth of cylinders.

Besides I hate new parts.

[BobAustin]

Had the port & polish/ flow balance BS done when I had the IO360 in my 85 M20J.  For the reasons stated above skip the port job since any speed increase is too small to detect.

 

Lycoming very difficult to deal with re warranty.  Local pilot had new roller cam engine installed, had serious problems, Lycoming outlasted her with delaying tactics...she had to finally buy another non roller engine as needed the plane..

 

Try without GAMI on that engine for reasons stated,  Power Flow on the other hand is very desirable.

 

The 1000 hour ohaul story applies to 231 not 201.  It is all about the pilot and whether he has JPI, Ei or similar for all cylinders.

[jetdriven]

I often run mine at 83% power LOP, thats 29", 2500 RPM and 11 GPH.  Its got 400 hours on it now.  We pulled a jug off looking for the source of high iron in the factory engine since we installed it. Didnt find anything wrong but the cylinder, piston, etc all measure to new limits.

[RobertGary1]

A couple years back I needed to overhaul my fuel injection system unexpectedly. This included a proper cleaning of the injectors. I was amazed at how balanced they were afterwards. No vibration at LOP, etc. Balancing may be far less important than a good overhaul of the injector system.

 

-Robert