Cylinder overhaul recommendations

Hello VAF...

Looking for recommendations on cylinder shops.

In my recent thread I was having an issue with run away CHT on number 2. I thought it was resolved, but was sadly mistaken. After checking everything else the last thing to do was to remove the cylinder. What we found was that the cylinder is pushing oil. The face is valve is blackened with burnt oil and so is the top of the piston. We expected to find an obvious reason for why this was happening, ie...a broken ring, but did not.

The heat is coming from the burnt oil deposits which are turning red hot. On my last flight everything was fine until again the number 2 CHT rapidly started increasing....and continued increasing to 450 after I pulled power to near idle.

So now I will be calling around to some cylinder shops and check out my options for overhauling this cylinder. Figuring on at least a new piston and rings. I have chrome cylinders...not sure how the new rings would seat without honing. Can the chrome cylinders be rechromed?... what about NuChrome...?

OH Cost vs new..these are angle valve cylinders too..

I have used Don George in Orlando may times. His shop does good work and the cost is very reasonable. The turn times and communication during the repair evolution is great as well.

An angle valve cylinder will almost always be cheaper to overhaul than to replace with new. A parallel valve cylinder usually costs 60%-80% of the new cost to overhaul.

+1 For Don George

Has done many for the folks in this neighborhood --- did an engine for me, way back. Good reputation.

AES

Tina, the Cylinder Lady, at AES in Chandler, AZ has done good work for local experimental builders.

http://www.aircraftenginespecialists.com/cylinder.html

AES recently assembled my O-360-A1A from my yellow tagged parts and will test run it as soon as I have the cowling finished.

Cyl ovhl

Brown cylinder, Tulsa Oklahoma Larry brown owner, I would cross the pacific on his cylinder work

Just a thought, read up on this. Particularly Mike Busch on cylinders.
www.avweb.com/news/maint/182902-1.html
They seem to have a lifespan. Why not go new for a little more and, hopefully, not have to go through this again in your lifespan? Aluminum isn't like steel and only had so many cycles in them before they croak. Kinda like ski bumps, you only have so many in your knees then poweee!
I bought a plane with first run overhauls, they lasted 700 hours - whoopee. Had they been new and gone 2000 hrs or more I'd never have overhauled my engine for $17,000 and been down for 9 months.
But I have several friends building engines for their under construction RVs with used cylinders and wonder what the heck they are thinking. Just my 2 cents...
ps: ask these "good results" pozters about longetivity...note they don't include that in their posts....

I have to agree with new over overhaul. The overhauled cylinder I put on my O-320 lasted only 200 hours before it was replaced by new. Anecdotal, but after that experience I will go new the next time I need to replace a cylinder.

I had a very good result with Poplar Grove Airmotive.

Dan

flyingriki said:

Just a thought, read up on this. Particularly Mike Busch on cylinders.
www.avweb.com/news/maint/182902-1.html
They seem to have a lifespan. Why not go new for a little more and, hopefully, not have to go through this again in your lifespan? Aluminum isn't like steel and only had so many cycles in them before they croak. Kinda like ski bumps, you only have so many in your knees then poweee!
I bought a plane with first run overhauls, they lasted 700 hours - whoopee. Had they been new and gone 2000 hrs or more I'd never have overhauled my engine for $17,000 and been down for 9 months.
But I have several friends building engines for their under construction RVs with used cylinders and wonder what the heck they are thinking. Just my 2 cents...
ps: ask these "good results" pozters about longetivity...note they don't include that in their posts....

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here is a longevity report for you, I have run overhauls in a rental fleet for years and had very long life from them. infrequent use kills engines.

yes they have a life, its a whole lot longer than two or three rebuild cycles. most failures are do to parts that are replace in a overhaul. the biggest problem i have seen in bad valve seats which all get replaced. also a lot of guide problems, which also get replaced.

A good overhaul shop does a lot better job of setting up a cyl than the factory.

I don't buy into the new is better idea, quality work is better.

bob burns
RV-4 N82RB

A good overhaul shop does a lot better job of setting up a cyl than the factory.

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That there is truth. A cylinder isn't good because its new. Its good because its good. The best Bell47 operator I know sends all his NEW cylinders out for rework. He's been living in front of an O435 since vietnam and does NOT crash.

n82rb said:

here is a longevity report for you, I have run overhauls in a rental fleet for years and had very long life from them. infrequent use kills engines.

yes they have a life, its a whole lot longer than two or three rebuild cycles. most failures are do to parts that are replace in a overhaul. the biggest problem i have seen in bad valve seats which all get replaced. also a lot of guide problems, which also get replaced.

A good overhaul shop does a lot better job of setting up a cyl than the factory.

I don't buy into the new is better idea, quality work is better.

bob burns
RV-4 N82RB

Click to expand...

Not hearing any numbers here? Maybe you get paid to replace them?

aerhed said:

That there is truth. A cylinder isn't good because its new. Its good because its good. The best Bell47 operator I know sends all his NEW cylinders out for rework. He's been living in front of an O435 since vietnam and does NOT crash.

Click to expand...

The operative word here is NEW.......

Thanks all. I have phone calls to make tomorrow. I do not know yet what the cost is to overhaul, but I do know factory new angle valve cylinder is 2500.00. Eci has been making angle valve cylinders for several years now as far as I can tell. Does anyone have direct info in them?..

Keep in mind that a cylinder does not always need an overhaul, often times it just needs to be repaired. Obviously the time on the cylinder and the condition will dictate what need to be accomplished.

An overhaul requires the following parts to be replaced irregardless of condition: exhaust valve replacement, intake valve guide replacement, exhaust valve guide replacement, exhaust valve retainer replacement and piston ring replacement. These are in addition to stripping, cleaning, zyglo inspection of the heads, visual and dimensional inspection, replacement of worn parts that are not a mandatory replacement items, etcetera. If a cylinder passes inspection and can be overhauled, it usually costs between $800.00-$1000.00 A new parallel valve cylinder costs between $1000.00-$1300.00

Sometimes a cylinder will have exhaust valve/guide, or piston ring issues that will not require a complete cylinder overhaul. A cylinder repair can range from $350.00 all the way up to the cost of an overhaul. For me, the determining factors as to whether to repair or replace a cylinder come down to the condition of the cylinder bore and the cylinder head.

I almost always opt for new vs overhaul on parallel valve cylinders. I would personally never pay to have a bore chromed on a parallel valve cylinder. If you have enough bore wear to warrant chroming the bore, then you will spend as much, if not more, to properly overhaul the cylinder then it will cost to replace it with new.

Angle valve cylinders are so expensive that it starts to be economically feasible to send them out for a good overhaul if the heads are not cracked and the exhaust ports are not erroded badly.

Of course a new cylinder hasn't been fatigued like a used one, and the aluminum does have a life. Of course I've also read right here about dozens of guys with bad ECI cylinders etc. that have had to pull almost new cylinders. In Ryans case you can see from a mile away that the channel chrome is so shiny you can see the valves and stuff in the reflection. Theres also a wear step showing. That tells me this is at least a 3rd run jug that has already had a cycle on that chrome. Were it me I'd buy a replacement stud assembly in nitride, touch up the old valves and drop them into the new one. New rings, keepers, and gaskets. For five hundred bucks I'd have a cylinder that will outlast the other three almost for sure. Sounds better than three grand.

Barrett Precision Engines
Bpaengines.com

Jerry Esquenazi
RV-8 N84JE

flyingriki said:

Not hearing any numbers here? Maybe you get paid to replace them?

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and maybe you are just set on having everything brand new. at one time i had 3 planes on rental that averaged 150hrs a month, not only was I paying for them I did the work replacing them.

this man is asking for real info on new vs overhaul.

ive seen overhauled jugs that I would not put on an airboat and ive seen new that were barely in tolerance. I have no problem using a good overhaul its all in who set the jug up. I used one guy for all my jugs.

I did not give numbers because i have sold all my rental aircraft and do not have the books in front of me. to throw out general numbers my PA28 had about 4300 hrs on the lower end when I overhauled it and the last jugs that were on it had close to 2000 hrs on them and when right back on after overhaul and now have close to 600hrs on them with no problems. my o-200 went about 1500hrs on a set of chrome overhaul jugs. ive seen ECI jugs pulled with less than 100hrs on them. Ive seen them go 2000hrs. do I want to overhaul a 10th run jug? no, but I will go a couple of runs and thats probably more then most people will put on an engine in a lifetime.

bob burns

aerhed said:

Of course a new cylinder hasn't been fatigued like a used one, and the aluminum does have a life. Of course I've also read right here about dozens of guys with bad ECI cylinders etc. that have had to pull almost new cylinders. In Ryans case you can see from a mile away that the channel chrome is so shiny you can see the valves and stuff in the reflection. Theres also a wear step showing. That tells me this is at least a 3rd run jug that has already had a cycle on that chrome. Were it me I'd buy a replacement stud assembly in nitride, touch up the old valves and drop them into the new one. New rings, keepers, and gaskets. For five hundred bucks I'd have a cylinder that will outlast the other three almost for sure. Sounds better than three grand.

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Wher do you get these new $500 angle valve stud assemblies?