The International Cessna^® 170 Association

From looking at ads of 170'f for sale, it appears to me that these engines are being overhauled well before TBO. Are they not good engines? Is there a secret to getting them to run for 1800 hrs? Thanks, Greg

There is nothing particularly wrong with the engine design as aircraft engines go. Most of the early rebuilds are probably due to the engine sitting idle for to long a period of time and rust building up and causing problems.

It has been my observation that the weak link in most aircraft engines is the cylinders and more specifically the valves. Depending on what the condition of the cylinder is at rebuild ie new or rebuilt I would expect between 800 and 1200 hours of trouble free operation assuming constant operation without long idle periods.

Many owners when faced with the decision of a full rebuild or just a top overhaul when the cylinders start to give problems will go with the full overhaul for peace of mind.

This engine, the Continental O-300 holds the WORLD'S RECORD for longest flight on record is 64 days 22 hrs 19 min. Set by Robert Timm and John Cook in a Cessna 172 . They took off from McCarran Airfield, Las In 1958 this engine took off in a 172 and flew until the following year, landing in Feb. 1959. The airplane and engine are still hanging above the baggage claim area in the Las Vegas airport.

Many of these engines have been "overhauled" (repaired actually) and flown with used cylinders, cranks, etc. and this has resulted in a record of premature rebuilds. When Superior, ECI, and TCM began making new parts again, the engines have recovered their formerly enviable record for durability.

Hey I just saw they used some snake oil in those record setting planes for the flight. Wonder if it is anything like MMO.

From Wynn's web site wrote: new records for light plane endurance flights are set. The first at 1200 hours and the second at 1650 hours, were set consecutively in aircraft protected by Wynn's Friction Proofing. "Old Scotchman", a Cessna based in Dallas, Texas, set the 50-day, 1200 hour mark. The "Hacienda" of Las Vegas, Nevada, set a new record of 64 days, 22 hours, and 19 minutes. Federal aviation authorities certified Wynn's products for use in light aircraft.

Another fact just hit me. I don't recall seeing MMO mentioned on the forum for several months. Another record.

Bruce,
You'r a sick, sick person wacking that MMO Hornet's nest with your verbal stick Another way to get to TBO before needed, is misuse of other wise exclent addons. Such as a Tannis Heater system. Several years ago I had to pull a jug off an engine, for the reason, I can't rember, but found rust flakes hanging off the cam and crank! After questioning the owner, I found he kept his Tannis on a timer, and haden't flown the A/C all winter. The heating and cooling had allowed moisture in and out of the engine all winter, which had, in less than four months, ruined the engine!
brad

N9149A wrote: Another fact just hit me. I don't recall seeing MMO mentioned on the forum for several months. Another record.

Way to go Bruce... I expect another MMO or mo-gas controversy any day now

Hello i have a cessna 172 with a 0300a with 2020 hours on it only one cylinder replaced and it still runs fine. rob loomis

Rob,
The TBO is only recomended by the manifacturer! If I'm not mistaken I think Pat Bartone run an engine to 2500 HRS. with as far as I know no ill effects! on the flip side, I had an engine in an ercoupe with 600 hrs (I know It depends on who overhauls an engine) but had flown this A/C with the owner to get his private liceance, and noticed a light viberation all the time we flew. He got his liceance then came time for annual. The comperions were good, but we had a major oil leak at the #3 cyl. base so elected to pull the cyl. When I pulled the cyl I also gave the rod a pull and found it to move excesivly, went into it further and found the journals on all cyl's to look like rat-tailed files! So IMO The reason to look at an engine in a spicifacted time is to make sure the bottom end is as good as the top. As I said, just my opinion!
brad

Per the old Cessna SNL's (7-27-54) the C-145 had an 800 hour TBO. Per the current TCM SIL98-9, the TBO on the C-145 is 1800 hours or 12 years whichever occurs first. It also states the same as George alluded to about the engine being only as good as the parts/labor put into it. If an engine were "ran hard" all the time, I would stick to the TBO. The TCM SIL states ag planes is 1200 hrs, and that skydivers, towers, etc. may require more frequent overhauls. I doubt many operators pay much attention to (or even know about) the calendar requirement for the overhaul. At AOPA's 35 hr/yr for the average pilot, that's only 420 hours between overhauls. That would get expensive on an hourly rate.
Steve

Notwithstanding the good-natured jesting regarding snake-oil...
I'll go on record as still opposed to the use of such "miracles" in aircraft use. "Certifying" the use of a product in an airplane is not the same as "approving" it's use in aircraft. A certification of use merely means that the product was verified as having been used. It provides no proof of benefit or detriment. The Wynns Friction Proofing product does not carry any FAA approval indicators and is not approved for use in any aircraft with standard airworthiness certificates, as far as I know. The aircraft in question was not disassembled and inspected after their record flights, as would be required for products seeking approval.

(This msg was posted because I believe the originator of the thread was seeking a serious response to his question and I wanted to insure that no humorous responses to our visitor were lent undue credibility.)

I'll go on record as still opposed to the use of such "miracles" in aircraft use.

George, you just can't help yourself can you.
BTW will using MMO and MOgas save me enough to pay my annual dues?

Before I overhauled my engine [C-145], it had over 2200 hrs on with just regular good Shell oil. Former owner said as long as it runs good, keep running. When I bought the plane, I overhauled it. If you know me, I run it, but don't abuse it.

John

On the subject of engine times, I pulled the O-300A out of 2326D at a shade under 2500 hrs SOH. I chose to do this for safety and piece of mind but it was smooth and running great. Maybe I just had too much money.

Bill Hart wrote:

I'll go on record as still opposed to the use of such "miracles" in aircraft use.

George, you just can't help yourself can you.
BTW will using MMO and MOgas save me enough to pay my annual dues?

Only if you purchase it from my aftermarket/add-on store located in Spicewood. (TIC170A members get it at a special price.... one year's membership included! Free shipping. Lifetime warranty.)

Bill Hart,

If you fly that airplane enough on Mogas, it will not only save you enough to pay your club dues but will also pay for the next overhaul!