Hey guys,

So I need some input from the 520 gurus on here. Here is the scenario:

Factory new engine in 2001.
Current time is 1451.
TBO is 1700.
All cylinders replaced 450 hours ago with ECI cylinders. I'm hearing from some 520 owners that cylinder work around 1200 hours is common.
Flown 37 hours in the last 6 months, so it has been regularly flown.
9/2014 compressions all in the high 70s.
9/2015 compressions all in the 70s except two at 66. I know compressions can be finicky and it would be prudent to check for air passing by the exhaust valve.
No recent oil analysis taken. One will be taken today and sent in.

So the questions at hand are:

How much would one reasonably expect to get out of this engine?
Anything about 520s that one would need to know? Any concerns regarding the case or anything else?
Regarding valuation on the aircraft, how should this be looked at? As a timed out engine or something more like a mid time engine?

Thanks!

Not a guru but I've had one and been around a few.

Nothing wrong with 66/80 on those. I think they can be run something like 50/80 and still be OK.

It's worth what someone will pay for it. Market is soft on everything I've ever tried to sell that's airplane related. [emoji1]

If it was new in '01 it's got the VAR crank, and phase three case. Not sure when the 7th stud came out but you probably have that too. Those are the most desirable features.

If I were buying, it would be timed out. Selling...I'd try to capitalize on the remaining 250 hours.

Are you buying another plane? What's going on with the 206/210 (I forgot which) you already have?

Sorry I know squat about 520s.

soyAnarchisto wrote:Are you buying another plane? What's going on with the 206/210 (I forgot which) you already have?

I've got the same question. I've been hoping to make a run west and see several folks including you and that 205 family hauler.

Brett

Well it's obviously not timed out, but it's like 70ish percent there, of course for pt91 ops this doesn't matter, I've seen skydive and tow 520s and 550s and 470s go well past TBO.

Tips, just standard engine management, good engine analyzer and prudent use of the mixture, cowl flaps and power settings.

I've always leaned and configured for target CHTs, 350max cruise, 380 max climb,

remember the oil analysis isn't a indicator off that bat, it's just a trend and it worthless without prior analysis to back it up,

be sure to cut your filters and look for signs your engine is getting ready to say adios

Keep a eye on your engine pressures and temps for different stages of flight, as well as fuel and oil burn, watch for trends, engines don't often just check out, they normally give you plenty of heads up.

Remember even after a overhaul, engine time isn't a good guarantee of reliability, most engines that I've seen have catastrophic failures were very low time.

Change your oil often, I'll typically go 30hrs with my filter, it's the cheapest mx on a aircraft.

Use the right oil for your conditions and preheat when needed (sub 40f regions), read your FAA approved POH as well as engine manufactor operators manuals.



Mostly all common sense stuff.

gbflyer wrote:Not a guru but I've had one and been around a few.

Nothing wrong with 66/80 on those. I think they can be run something like 50/80 and still be OK.

It's worth what someone will pay for it. Market is soft on everything I've ever tried to sell that's airplane related. [emoji1]

If it was new in '01 it's got the VAR crank, and phase three case. Not sure when the 7th stud came out but you probably have that too. Those are the most desirable features.

If I were buying, it would be timed out. Selling...I'd try to capitalize on the remaining 250 hours.

Thanks gb. I'll look into it. I think some of that was covered by an AD, or so I've been told.

93K. Yeah all good points I've followed with my 470 with regards to how to operate engines.

I've just don't know anything about 520s and if they have any particular concerns or things to look out for or avoid. Whee said he was advised to not run them at low power settings for cruise, something I routinely do on the 470. Stuff like that. Also just looking to see how common cylinder work is around the 1200 hour mark is.

Thanks!

As far as the cylinder swap game on big continentals I would say a lot of that comes from the guy sitting in the seat and using the knobs and levers in front of him. I just ran the 520 in my 206 with millennium's on it to 1900ish hours without ever changing anything but the oil and the lowest jug was 76 this December. I used that engine on floats (heavy, long water runs, hot) as well as winter wheel flying in cold temps. Proper power settings (high) and slow thought out cooling/heating cycles as well as thorough preheat in winter conditions all contributed to the reliability. Honestly I would have continued on with that engine in a part 91 scenario but commercial use dictates the overhaul. My only recommendations are run that engine hard and know how to use the cowl flaps. Another thing I will add is I don't have any form of engine monitor other than what Cessna installed so I probably dump more fuel through the cylinders than most with monitors.

Don't give a second thought to the one "low" cylinder....well within reasonable range. Differential compressions are often a function of the mechanic doing them. If he'd fiddled with it more, he might have got it up to match the others, but because it is okay.....why bother.

Something I learned a long time ago from Lycoming was that there are a LOT of old, multi run cylinder assemblies out there, especially on Continentals. An engine comes in for overhaul, and the shop pulls the cylinders, and "refurbishes" them. They now meet standards, so they slap them on that engine or another being overhauled. "

But, since all those cylinders get is a yellow tag, nobody really knows how many hours those cylinders have on them. Some have three or more runs on them.....and those cylinder heads become work hardened. So, these get installed on your engine, and at between 1000 and 1200 hours, they start giving up the ghost.....and those cylinders are replaced with some other "overhauled" cylinders, and the "bad" cyllinders go back to the shop and are once again worked over, and installed on yet another engine.

Eventually, the heads crack or the cylinder is stepped, or ???? and the cylinder gets chucked.

For years, our outfit went this route with cylinders, and many of our 520s would have four, five or six cylinders replaced by the time they hit TBO. Then, maintenance got smart, and tried running NEW cylinders on overhauled engines......and voila! Now, they'd replace maybe one or at most two cylinders before TBO.

Your engine has new cylinders at 1000 hours. I'd be surprised if they don't go to TBO just fine, assuming you're not abusing the engine, and it sounds like you're paying attention.

I've run a number of 520s to TBO, and a couple some beyond. As noted earlier, pay attention to operating it, don't try to skimp on fuel through it, and it'll likely take you to 2000.

Some folks limit takeoff rpm to 2700 as well. running those things at 2850 imparts a lot of stresses. If you're on wheels, and not super heavy, and you have a good prop, 2700 for takeoff should work in many situations. Or just roll it back a llittle bit.

Make absolutely certain your fuel flows are set up a little on the high side as well. As noted, fuel is these engines best friend.

MTV

Hi Corey...hey ive had both, and at least in cessna's ive really had superb luck and enjoy the quiet and no oil use of the o-540 lycoming...fwiw....JO

This plane has an IO-520 on it already, so I'm just trying to get a feel for its longevity and how they run. Thanks for all the input.

Quick question on the fuel comments. We all know cylinder temps = cylinder health. I'm assuming the advice to not skimp on fuel is in large part related to maintaining cylinder temps. Anyone have personal experience running them LOP? In talking to Western Skyways, they say no problem. Just make sure your Gami spread is less than 0.5 gph and keep the temps where they should be...which is no different than how I ran my 470 LOP. I'd like to hear from someone with the Gami setup running LOP to see what their experience has been.

So what are you buying? 206 or 185?

Posted a video yesterday by Bill Ross in another thread, he talks at length about running these engines LOP/best economy. He works for Continental, straight from the horse's mouth so to speak.

You might give him a call, or any of the other Continental tech reps.

I have GAMIs in my IO-520D in the 185 and drive it around all the time LOP except during takeoff and climb. During cruise I see a speed loss of about 4 mph, however I'm burning 5 GPH less fuel to do it.

Let's say that you run LOP 90% of the time and save 5 GPH over the life of an engine. For a 1700 hr TBO, you would run approximately 1530 hours LOP. That turns into a fuel savings of 7,650 gal of fuel. In Alaska, avgas is around $5 per gal so your lifetime savings running LOP is $38,250. It's like getting a free engine.

My current engine is still young and healthy and I figure that I have saved around $10,000 so far.

Thanks guys. Good info.

Skalywag, I'd like to see that video. What thread was it in?

Squash, what kind of fuel flow are you seeing LOP? What's your Gami spread and how many degrees LOP are you able to obtain?

Grassstrippilot wrote:Thanks guys. Good info.

Skalywag, I'd like to see that video. What thread was it in?

Squash, what kind of fuel flow are you seeing LOP? What's your Gami spread and how many degrees LOP are you able to obtain?

Cory,

Here you go:
https://www.backcountrypilot.org/community/forum/latest/continental-motors-webinar-on-leaning-18809

Awesome! Thanks!

My typical cruise settings below about 4000' are:
25" MP. 2300 RPM. Fuel flow 11 gph. Running somewhere around 30-40 deg LOP on the richest cylinder. CHTs are all less than 360.

Once above 4000', I just maintain WOT and let the MP be determined primarily by altitude (normally aspirated engine). 2300 RPM. Fuel flow will be pulled back slightly depending on altitude. 10-11 GPH. Once up high, sometimes I run 0-25 degrees LOP on the richest cylinder.

Thanks! That's ballpark what I was expecting. What's the bottom of the rpm normal operating range? Since I'm based at 4500', all my flying has been WOT minus 1/2" MAP to assist in LOP ops (a trick Gami told me to do and it helped).

Don't go below 2,300RPM.

Words like "engine stoppage" were used.

http://www.tcmlink.com/pdf2/CSB09-11A.pdf

Interesting. It also says "The reported population of aircraft (equipped with the affected engine models that operate using an RPM less than 2300 RPM for extended cruise operation) is limited."

It looks like only 4 variants of the 520 engine were included. I wish it had some more info regarding the cause, what was failing, and how these models of engines differ in design from the other unaffected engines.