336 Vs. 337?

Hello, I am looking for a Nice 337 or even considering a 336, I have been trying to get some info on both planes, the 337 is easy, I have read a lot of info on it and are mostly confortable with all the details, however apart from some basic differences, the info on the 336 from actual owners is really scarse. Maybe you can help me decide, I need some specifics as whats the real difference in speed from a normally aspirated 337 and a 336, what about flying? Is there much difference in “feel” and about the rear engine cooling, I supose the original fan works, since this planes have been flying for almost 40 years, but is it a maintenance problem? Is it too delicate? Does it do a good job in cooling the engine? (I have no doubts that the sccop is better, but how much?)

I am selling a 1965 Cherokee 235 (VERY good condition), once I sell it I will be ready to get either a Skymaster or a 336 if it sounds good. So far all the owners of 337s seem to drive me away from the 336, but no convincing reasons so far. If the speed difference is less than 10 Kt. Or so (which is what I have been able to get so far) then it would seem like a 336 is a very good economical twin. It seems that real world 337 only fly at about 155 Kt. True and not the optimistic 167 that the specs say

Many thanks in advance for you thoughts.

regards,

Ignacio Romero

[Bob Cook]

Iromero.

There is a good history lesson on the 337. Check out the Riley website.

The reason for the 337 successor was the speed on the 336 did not compete with other light twins hitting the market. The 310 was getting very good miles/gallon compared to the 336.

Advantages are;
1) insurance / hard to do a gear up on this one
2) maintenance, something to consider.
3) your mission. typical profice of distance. short hops?
4) cost of annuals. / lower
5) you can forget the "3 green" over threshold..
6) cheaper to buy (my opinion)

Down side
1) its a drag....
2) slower.
3) harder to sell. (personal opinion)
4) picks up more ice.
5) little more sluggish on the climb.
6) cooling ? heard mixed reports, however, do not think it is an issue.
7) I think there is a difference in Gross Weight (less). But you also have less weight due not having all the hydraulics.
8) less macho ......... <G>

Think the big consideration is your leg length and typical mission. The range (amount of fuel) is less than in post 74 337s. You can add aux tanks on the 336 along with horton or other stall kits.

Unless you are doing a lot of X country or long range flying, the 336 will give you the second engine safety and certainly will cut the cost/hr for insurance and maintenance. You offset this will a little more time in the cockpit and a little more time on the engines...

I think GMAS can give you some numbers on the maintenance side of things.

Always pick an aircraft based on what your needs are, not your emotions ............

my 2 cents.

bob

Thanks for the info Bob, I think it woulb probably fit my profile, funny you mention about the climb, the book numbers say that the 336 actually climbs a little bit better than the 337, but then that's exactly what I'm trying to verify, also as far as have been able to confirm, it seems like the 336 would cruise at about 145-150 Kt. while the 337 would do something like 152-155 in real life flying, so the speed difference alone wouldnt seem enough to justify the extra expense. There also seems to be a difference in forward visibility in both planes, but I guess I would need a real life experience in this. Is this a real difference?

Regards,

Ignacio

[kevin]

In answer to your question: Is it real? Yes.

The "forward visibility difference" in a 336 is because of the (I think it is called) angle of incidence for the wings being different, and a bit unusual for the 336. I have flown as a passenger in a 336 once, and own a 337, and can vouch for the difference. Whether you would find it objectionable or not, you must decide. I suggest you find a 336 owner who will give you a ride, and a 337 owner as well, that will help you decide better than any written description. Where are you located?

Kevin

I'm located at ktmb Tamiami in southern florida, I also fly a lot to esatern PA, to MPO.

Yes, I guess I have to take a look at it first hand.

[SkyKing]

Ignacio,

I'd forego even considering the 336 because you'll definitely be rewarded with faster cruise speeds with the 337. Also, you'll find refinements in the airframe and engines throughout the model years as the product went to its close in 1980. In my personal estimation, based on those refinements, I'd go for the latest model year your pocketbook can afford. And buy one with as nearest the compliment of radios and options as possible, because if you start adding stuff afterwards, it gets expensive very quickly. Typically the older 337's, if they haven't been updated, will have an assortment of gyros and radios that will have to be replaced, plus some early models had AD's that the later ones don't... an important consideration.

Since you're down in Florida, you might check on a 1977 normally aspirated 337 I've seen advertised on The Controller website...

http://www.aircraft.com/listings/for...D=1042088&nh=0

Here's the basic info:

S/N: 337-01790, N-53696, 8263 TT, 1384 SMOH / 926 SMOH, IFR, Aircraft ready to go. Great Interior and Exterior. RG International (305)871-3471 (305)876-9540

Seems I recall seeing a $60K price tag, and considering model year and the equipment, later Narco avionics, not a bad airplane to possibly consider. Maybe ask for some help from folks who live near your area and who frequent this board that could assist you with looking at this one, as you don't want to buy a pig-in-a-poke. I know Ernie Martin and Bob Cook don't live too far from you and could possibly drop in for an eyeball.

SkyKing

[Bob Cook]

Must agree with you Skyking.

Seen a few normally aspirated 337's at a good price. Probably 60-90k depending on radios and condition.

Due to difference in technology and all the resale issues I would try and find a later model 337. Tamami to PA is a good non stop haul. You do not want to sit in the AC more than 4 hrs. I do it all the time but I must be realistic and stay with LL100 rather than JP4 <G>.

Bob

Thanks to all for the valuable insight, I looked at the ad for the 77 337, it seems like the good price is because the plane has 8000+ hrs on the airframe. So another question has arised, is this something really to consider? I have always thought that I would not like an airplane with more than 5k or so on the airframe, but I am not sure if this is a good way of thinking. Would this be a problem?


Regards,

Ignacio

[Alan Williams]

I've just spent a ton of loot bringing a low time p model airframe with good engines up to good condition.
It cost significantly more than I had hoped but I now have what I wanted and learned a few things along the way about refurbishing.
Here are a few thoughts.
1. Have a clear idea what your expectations of an aircraft are. Excellent condition good for all weather and new for everything or good enough for summer nice day short journeys.
2. The idea is you only get what you pay for.
3. Best dollars spent by far, are in having a knowedgeble well -reputed AME and an avionics chap do a thorough assesment and cost estimate to bring the aircraft to your acceptable level of condition and avionics. Then ask for a contract to do the work. The prices should be the same. If not - RUN.
4. Carefull and knowedgeable shopping with good research can yield bargains as airplane owners are notoious for spending money they know can never -ever be recovered. Thier pain is the new buyers gain. Shop carefully and look for the best condition you can possibly afford as it will be much cheaper than fixing a bargain beauty.

[Bob Cook]

Alan, Imero

Alan, could not agree with you more. There are a lot of pitfalls when looking at 337's. High time engines needing new cranks can cost a bundle.

A low time aircraft can be a nightmare, moreso than one with 8k hrs. You get what you pay for.

Don't skimp on a good pre-inspection and go into it planning it is a dud and be happy if it is better! Better yet find one there are good constant service records that reflect a conciensious owner that values his (her) derrier.

If you find one consult the board as many here may know the AC or can do a prelim eval.

A normally aspirated 70 up 337 should do the trick with king radios and good times. A new Garmin 530 is probably a mask for deeper problems.

Then find a good lawyer to protect your investment <G>. I think you need to be prepared to spend 80-100k. We have a boardmember that lives in Miami that has just been thru this and found a nice one this summer. Maybe he can make some recommendations.

Bob

[SkyKing]

Bob,

GMAs had discussed the pros and cons of the new VAR cranks on the old board... when all is said and done, it would appear from all of the empiral evidence available in the field that the original cranks in the TCM 360's are probaby pretty much fail-safe, and I'll just bet they're more reliable than the new... as there was a lot of hornswaggling going on between the Guffaws at FAA and TCM. I haven't heard of one failure yet, have you?

So, even with TBO or beyond, without splitting the case, I'd feel comfortable with a good top overhaul or new cyls, and maybe a good going over of the accessory case (oil pump, etc.) and doing what's required as far as other components. When you think about it, 1400 hours isn't much on these engines, and it's the cylinders that take the brunt of the abuse (HEAT). And besides, if you're only doing Part 91 operations, there's no need to get excited about the other kinds. <G>

My nickel.

SkyKing

[Bob Cook]

Skyking

You still need to factor it in when you buy new engines along with,perhaps, changing from a lightweight case (C) to a (CB). There is a core charge.

I am not arguing politics; it is a fact TCM will charge you when you anti up to the bar.

My prepurchase appraisal had the VAR cost in it.

Bob

[Guy Paris]

Iromero,

There is a lot to take into account. log book inspection would tell a lot and I would have to say everything isn't always put in the logs. Engine times and prop and govenor times plus age since o/h on props, when I had my props o/h one of my blades had a crack in the flange, I will use it some day should make a nice mail box post.... The hydraulic power pac, has it ever been o/h. Time and age on engine hoses and hydraulic hoses, mag inspections, alternator inspections, actuator inspections for leaks there are a bunch of them, corrosion, glass condition, instruments (when o/h), and so on. Get someone (A mech) who knows Skymasters to really look it over with you, a good pre purchace inspection would be worth its weight in GOLD, one bordering on being a annual, maybe even an annual at that time and if things don't look good along the way and you can't come to some sort of a compromise, close it up and move on. Over the years I have done all of the above and then some. Last annual I had the nose gear removed and gone thru, suprised what one will find. Looks real good all spiffied up too. Took out the main gear actuators and changed all the O rings etc. I have boots on mine and some of the valves needed to be addressed too. Good luck! Guy Paris N1312L....