Question from a 337 shopper (hot rear engine)

[hewilson]

I'm new to aviation. Just began my IFR training but I'm anticipating getting a 337 when all my training is complete. I've heard mostly good things about the plane but two sources have said that the rear engine tends to run hot and this leads to increased maintenance and/or it does not make the full overhaul time. Is this correct and if so, have any after market solutions been worked out? Thanks in advance for any input.

[Jerry De Santis]

I am on my second Skymaster. The rear engine does run a bit warmer on the ground than the front engine, but, when flying, I have found it no different than the front engine.

From my experience, and I heard the same things you have, I have not found the rear engine to have any shorter life than the
the front engine. I am now 400 hours over TBO on both engines with my P337G. When I had my 337F, It likewise went several hundred hours over TBO. It depends how you treat and operate the engines that will determine the life of it.

I bet the people that told you that the rear engine does not make TBO have never owned or even been in a Skymaster.

Jerry

[kevin]

I too have owned two Skymasters, and second what Jerry has said.

Kevin

[skymaster]

in the summertime do not park downwind and perform single rear engine extended full power run up. common sense but probably happens. J

[hewilson]

Thanks for the info. guys. Its very helpful. What a great site!

[Ernie Martin]

An entire web page for prospective 337 buyers exists in the "other" website at www.skymaster.org.uk/purchase.asp which deals with many of these issues. The "hot rear engine" story is just that, a story. As others have said above, the rear engine runs marginally hotter than the front but well within normal bounds and has no impact on TBO. And, yes, if you are in Miami (as I am) and have a long delay in taxiing (which typically faces downwind) the rear engine can overheat. This happens, like, never, so it's not an issue, but if it were, that's what the temp guages are for, and you take corrective measures (like shutting off the rear engine while you wait).

Ernie

[RRossner]

Rear engine over heating is not really an issue as long as proper (and normal) cooling precautions are taken on real hot days. It may cost a bit more, but running a bit more fuel through those engines can really make a huge difference. You will find it ¡s even less of an issue if your engines are inter-cooled which I highly recommend.

Having flown several hours in a Super Skyrocket, with the entire new engine compartment baffling and the additional rear engine cooling duct, that engine actually now runs cooler then the front engine! Go figure!

Rick

[bede1@msn.com]

I have to agree with everyone else. My bird P337G has all new baffle seals in both engine compartments and I have found that I usually have to take off with the rear cowl flaps about an inch or two open. Any more than that and I have a hard time keeping the cyl head temp over 290. Hottest head temp runs on #5 cyl. This time of year I know is different than during the hot summer, quess I will see then. If engine seals are all good then you should get more than ample cooling.

[SkyKing]

Hey Bede1 "Bob",

Did I really read what I thought I read? ... you only have the rear cowl flaps open an inch or two on takeoff? You're a candidate for fried cylinders. The only APPROVED procedure I know of for start-up, warm-up, taxi and takeoff is for the cowl flaps to be FULLY OPEN. Better re-read your Cessna POH and Continental TSIO-360C Operator's Manual.

Once you're into cruise or enroute climb, then you can adjust the cowl flasp as needed in order to maintain constant cylinder head temps, but on takeoff with what you're doing, you could easily incur hotspots, and with the cost of new cyclinders at about $1,000 a whack plus labor & miscellaneous, not a good idea.

SkyKing

[RRossner]

I agree, those cowl flaps need to be opened all the way for all ground operations and especially through your TOC.

On real cold days you can close them to help speed up your initial warm-up but that's about it.

Sufficient cooling at high MP settings is a must for extended engine life.

Rick

[SkyKing]

You'd better read the Ops manual again... YOU NEVER, NEVER CLOSE THE COWL FLAPS TO WARM-UP THE ENGINE! Here, instead of me saying it, here's the verbatim text from the people who made the engine, Teledyne Continental Motors. This text is found on page 43 of the TSIO-360C/CB "Operator's Manual" under the section entitled "Abnormal Enviornmental Conditions".

"DO NOT CLOSE THE COWL FLAPS TO FACILITATE WARM-UP AS HOT SPOTS MAY DEVELOP AND DAMAGE IGNITION WIRING AND OTHER COMPONENTS."

Enough said.

SkyKing

[RRossner]

You learn somthing new everyday, especially in aviation! I did not know that!

I have never actually done this as here in CA, the weather is not that cold but someone once told me to give it a try until the engine oil temp gauge came off the bottom peg, an then at that point open them (the cowl flaps) back up.

I'm glad I never really tried it! Everyone disregard my last post on this subject and thanks for the info Skyking.

Rick

[hewilson]

Thanks to all who replied to my query. This thread has been remarkably helpful.