HELP - Looking at a 337

[Ernie Martin]

GMAS and others, I'm looking at a '73 337G which has had a recurring oil leak on front engine cyl 6 where pushrod tube goes into case. At last repair, the mechanic (who's a good one and 337 savvy) noticed that the case hole was bigger than it should be, with the tube going into the case with little friction; which explains why every 2 years or so it leaks again. So he not only replaced the seal but added a sealant. Engine is 1200 hrs SMOH.

Questions. Is that likely to fix the problem. If the leak fails in flight, what's the worst-case leak rate (1 qt per hr? 5 qts per hr?). Would appreciate earliest possible answer.

Ernie

[rick bell]

whem my engines had 1200 hrs they leaked and used oil around
1qt every 4 hrs.my suggestion is that it does not matter much except for the belly mess (which becomes a real pain cleaning).
the engines are on thier last leg as far as time is concerned. you will burn up 200 hrs real fast anyway and it will be time for overhauls. high time engines are a negative for pricing, look at the whole picture airframe, avonics, interior, paint and the accessories (controllers turbos, wastegates, hoses, props
ect as these can add up to the ammmmount of an engine oh).
oil leaks and hight time engines doesn't mean you arn't looking at a sound a/c

[Bob Cook]

Ernie

Is this normally aspirated? or is this a "P" model?

what are the TOTAL hours on this engine? Has it been thru the shop once already ? "H" Casing? Crank been updated?

All makes a difference. You should be able to stop the leak around this area as it is not under that much pressure.

Bob

[GMAs]

well ernie...

the part that goes into the case is not the problem..actually the push rod tube should go in..about 1/8 to 1/4 inch..past the seal and the two washers... the way it is made up ... is...

the first washer.. naturly its cont engine part... and it goes against the case recess... then you have this big squishie rubber donut kinda thing.. then another washer and then a spring which pushes aganst the push rod tube and the top washer...

The way it works.... is that the push rod tube bead presses against the spring.. which then presses against the first washer...which then causes the rubber donut to expand which pushes against the first washer... now while the donut expands.. it seals against the inside recess of the case lip... sealing the oil from coming out...

the other end of the push rod tube then goes against the cyc head and a rubber O ring and seals the head oil which comes from the rocker arms and goes back down the push rod tube... inside and dumps into the crankcase...

So when he says the hole is bigger ... does he mean the washer or the case itself...????

1200 hrs on a turbo is getting on in time.. about 1400 is all they will go... GMAs

[skymaster]

howdy ernie: i wish i had been a part of the bahama trip. It sounds as though your leak problem will have a simple resolution. My opinion regarding overhauls is throw away the recommended mfg. TBO and run till they stop producing. With a competent operator and same pilot this is significant because its so damn expensive. Someday i'll make the journey and meet all you guys who I have respect for getting off their bottoms and making it happen. Next week we are installing Owen's tip tanks on the 73p . My promise is to write up a brief synopsis and share with the site. GMAS can give me hell for my poor grammar and non sequitir writing ability. The aircraft will be down 7 days. It goes up to BNA 6/10. It takes the wing from 38'?to a little over 44". It adds 40 gallons . Currently 73p has 123 useable. This gurantees me non stop on most frequent trips T00-GLD. Anhuac, tx. -Goodland Kansas. 670nm. Mostly headwinds both ways. It should save me 1-1.5 hours per trip plus haul some less expensive fuel. T00 fuel is 1.86/gallon vs 2,36? It doesn't matter if i cant cost justify, I like the idea non stop. Hopefully, Maybe someone else will when they pry my hands off the airplane. J

[rick bell]

are you getting the wing ext or are the winglets part of the tank. i'm interested if this part of the gross wt. increase. whats the approx. cost. i have the stol,winglets and boom fairing which has helped in my type of flying. also would be interested how much reduction in actual stall at gross. thanks rick

[skymaster]

howdy rick: actually do not know much about performance enhancement. however its not drgraded. I can go back and get the paperwork. But stc weight bump is extra because it has the the fuel jettison installation. normal loads on the 73 p337 with robertson stol normally exceed landing weight 4700. even if i had the jettison kit and had a emergency landing i would probably exceed mfg's landing weight 4465 ? lbs. My friend with a p-210 will swear his tips outperform a non tip. The winglets are not part of the deal and i need to look up the cost. Its expensive . I do not like fuel starts and stops . The previous owner of this 73p had wired and plumbed for tips. He had a stroke before he could get them installed. The 77 and up models carry ?140 gallons. Usually people operating p models travel distance requires more fuel. cessna probably realized this with those models. 73 has 123 gallons. Currently Its easier to put on the tanks than move to 77 or up model. the downside is most rental hangers are 40' . Fortunately mine is 60'. There is always a trade off. Not buying the increase weight stc could have some insurance exposure. It better be a bonafide emergency . JCH

[Ernie Martin]

Thanks to all of you for your replies. I bought it that evening and flew it from OSU (Columbus, OH) to TMB (Miami, FL) yesterday. It's a '73 337G normally aspirated (with the clam-shell doors) and long-range tanks. Beautifully maintained at OSU FBO last 4 years. Rear engine essentially 0 SMOH. Front engine (as you read) 1200 SMOH but with 2 new cylinders over the last couple of years; good compression on all cyls and no leaks; no VAR crank. Good suite of electronics, including WX900 stormscope and GX50 IFR approach certified GPS (the former quite useful down here!). New paint and interior in '98 (hangared since then) and a burl wood electro luminescense custom panel installed recently -- quite an upgrade over my beat-up '69 which I was using principally to carry building materials (like bathtubs!) to the Bahamas.

Thanks again. Ernie

[kevin]

Congratulations Ernie! Post a picture for us sometime...

Kevin

[Bob Cook]

Does it come with floats ?

bob

[Keven]

Ernie,

Congrats! I fly in and out of OSU frequently, and I'm pretty sure I know the 337 you bought. Looks like a pretty sweet ride!!!

Don't let Bob bother you too much. You don't need floats on that thing, just make sure your home base airport extends that damn runway an extra 1000' or so:)

Seriously, congrats. Let me know what it's like to have one of them fancy Skymasters;) Can't wait to see it.

Keven
________
Gamo ts 22 22 caliber pellets (http://airsoft-shop.info/p/gamo-ts-22-22-caliber-pellets/)

[Ernie Martin]

Thanks, Kev. Bob's still welcome to come see me at Great Harbour.

Ernie

[Eustacio-Chachi]

Congratulations Ernie! So far no news fron Argentina. Next time I go to Miami will drop by to take a look at the new family menber.

[WebMaster]

Sounds like a nice plane, Ernie.
Good luck with it.
Did you have any issues on the flight home? How was oil consumption?

[Bob Cook]

Ernie

Didn't want you to get your feet wet ;>)
I was just joking......
Let me know when the runway is back to normal and I will take you up on it in two weeks.
Glad to see you back in the air with a good aircraft.
Get out the camera.
Oshkosh in style ??

Bob

[Ernie Martin]

Thanks to all of you. Oil consumption seemed negligible in the 6.5 hours, and there was essentially no oil on the belly or aft of the rear engine, but I can't tell for certain until I check it next (at re-fueling and upon landing at home it seemed OK but I need to wait until my next flight, when the oil in the heads and case will have settled to the bottom, to make an accurate determination).

Ernie