Cylinder overhaul recommendations

[flyingriki]

Originally Posted by n82rb

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

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

[flyingriki]

Originally Posted by aerhed

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.

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

[miyu1975]

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?..

[Mike H]

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.

[aerhed]

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.

[RV8Squaz]

Barrett Precision Engines
Bpaengines.com

Jerry Esquenazi
RV-8 N84JE

[n82rb]

Originally Posted by flyingriki

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

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

[Mike H]

Originally Posted by aerhed

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.

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