What's a ballpark weight difference between an O-320 and an O-360?
What's a ballpark weight difference between an O-320 and an O-360?
40 sq/inches = about 55 lbs
Last edited by 8GCBC; 05-06-2012 at 11:45 AM.
The 0-360 series engines are equipped with either a float type or pressure type ... range in weight from 296lbs to 332 lbs., while the TI)-360 weights 386 lbs
The 0-320-A sump and intake pipes. .... Stroke: 3.875 in (98.43 mm); Displacement: 319.8 cu in (5.24 l); Dry weight: 244 lb
Thanks. So unless you have a light O-360, the O-320 could almost been seen to put out more horsepower to weight...if I'm figuring that correctly.Originally Posted by 8GCBC
If I had a choice it would be (T)(I)O-360. Airframe people (CC, ACA, Aviat, Cessna, Etc.), will choose a (I)O-360 for a four cylinder first. The public demands it in modern aircraft manufacturing.
A light 0-360, with leading exhaust. There will be one in Valdez....if you are able to attend.Plenty of horse and can it be light enough? We shall see!
PS.- there is also an 0-390 available that is STC'd. Can be up to around 230 HP!!! Heavy, but.....................................yeah!A light 0-360, with leading exhaust. There will be one in Valdez....if you are able to attend.
This wasn't necessarily for a cub, rather a HP/weight comparison in general.
I think the book lists a Lycoming O-320 at a minimum of 287 pounds. I think the O-235 is 244 pounds.
This is a very difficult question to answer because not only do the models vary in weight but also because the accessories included in the weights vary. So, to get an accurate answer you need to know exactly what was weighed. Was a starter and generator attached to the engine when it was weighed? etc. I have struggled with this question and have yet to come up with a good answer, but.... with all that said, if you are comparing carbureted, commonly used cub engines, the difference will be a min of 15 pounds for the engine itself; however, that is not the whole story. The prop will add considerable weight as the common borer prop used on the 0-320 is a LOT lighter than the appropriate 0-360 prop. Other accessories, to include the often used dynafocal mount on the 0-360 also add weight.
The best answer to your question that I have been able to come up with is that an 0-360 package will be about 40 pounds heavier than a comparable 0-320 package. Unfortunately, I do not have any hard numbers to back this figure up so please take it with a large salt lick.
Other thoughts
Angled valve engines are much heaver than straight valves
Injection is heaver than carbs
The dynafocal mount adds about 10 pounds
Pawnee props are heavy
Newer engines are heavier than the older ones (up to 15+ pounds)
Experimental Superior or ECI engines are heavier than older Lycomings
Exhaust systems vary wildly in weight and can add close to 10 pounds if not selected with weight consideration
Hope this helps a little. It is not an easy question to answer and if folks have "Hard Data" I would certainly welcome it.
Bill
Very Blessed.
The weight difference is very model specific, but in many cases it is very small. Here is an example: O-320-D1A weighs 285 pounds with starter and alternator. The O-360-A1A weighs 290 pounds similarly equipped. Lightweight starters and alternators can reduce these weights by 10 pounds or so. An O-360-A1F6 with counterweighted crank will go 298 pounds.
You can get the exact weight from Lycoming for any model engine in their Detail Specifications publications. They break down the weight of the base engine and each accessory -- mags, carburetor, starter, alternator, etc. Unfortunately each publication costs $15 and it only covers a limited number of engines, such as O-360-A series.
Dave Prizio
Dave Prizio
TX Sport Cub N114DE
If you take a O-320 wide deck with the stock generator and stock starter and replace that with a O-360 narrow deck with a lightweight starter and alternator you are looking at minimal weight difference.
Took a trip with my friend to Montana last weekend. He has the stock Cub with 82/42 borer, 8.50 wheels. I had to pull my throttle back to 2300 so he could stay with me at his 2450. I was burning 5.8 gph, he was burning around 8 gph.
It is my experience that the narrow deck is NOT lighter than an early 1960's wide deck. That is a myth.
This is from a previous thread.
I have heard all kinds of claims regarding the weight difference between narrow deck, wide deck, tapered fin cyls, narrow deck cyls Vs wide deck cyls, New ECI Vs older engines.
I went to the engine shop today and did a little mythbusters testing,...........
Narrow Deck case, Mid 60's vintage, with banana plates, = 52.3 pounds
Wide Deck case, Mid 60's vintage, A2B = 49.0 pds
Wide Deck case, Mid 60's vintage, B1A = 48.5 pds
Wide Deck case, Mid 70's vintage, E2D = 49.85 pds
Wide Deck case 2010 vintage =53.95 pds
So the narrow deck is not necessarily the lightest case and it is certainly not 8 pounds lighter as one person said. The max difference here is 5.5 pounds. Mostly between the older case and the newest case. Several folks did say that the case has gotten progressively heavier over the years and that does seem to be true.
Narrow deck Cyl, with valves and springs only, 19.3 pounds
Wide deck cyl, " ", 19.45
Wide deck cyl, " ", 19.0
Wide deck cyl, " ", 19.60
So if we average the wide deck cyls we get 19.35. That is not a significant difference. So wide deckcyls Vs narrow deck cyls are a wash.
The new ECI tappered fin cyls are 4 ounces lighter than the std cyls according to Monty Barrett. Thus 1 pound total for the engine.
Banana plates for the narrow deck case (included on the case weight above) are 1.6 pounds
Through studs for the cases above (included in the above weights) are 1.8 pounds
I thought I would throw this out there for folks to consider, and also to tie up this thread.
Bill
Last edited by Bill Rusk; 05-16-2012 at 05:49 PM.
Very Blessed.
As others have said, it all depends on the model designation and the accessories.
I have a friend who, at overhaul time, switched from an O-320 to an O-360, and at the same time he converted to lightweight alternator and starter. His net weight change was negligible.
I've also seen (and flown) some O-360 equipped Cubs that were real porkers, and much of that is engine.
As Bill says, consider that big club up there for a prop alone.....
The primary reason the angle valve engines are all heavier is, I believe, because they all have counterweighted cranks. I think....
MTV
Although it was 12 yrs. ago, i remember gaining 48 lbs. on the nose with an 0-360A4M replacing the original 0-235 on our PA12. More weight was gained with the 82-41 borer pulling it. We compensated for this by placing the battery behind the extended baggage. Flys very sweet!!
Mike
On ebay right now theres some dipstick tubes for lycomings all the way down to 3 inches long and some up to 15 inches, some are plastic and the others cast or steel whatever they are. Wouldnt the plastic ones that are the shortest be the way to go? most i see have the 6 inch housing. There is quite a difference in weight between the 2. What is the right length one for a 0-320?
Last edited by tempdoug; 05-17-2012 at 07:13 AM.
Most angle valve engines have counterweighted cranks, which adds about 8 pounds by itself, but there are many other differences. (also note there are parallel valve O-360s with moveable counterweights such as the O-360-A1F6) Angle valve cylinder heads are larger with more fin area. Other things are beefed up inside, too. On average the typical angle valve IO-360 engine is about 35 pounds heavier than a parallel valve O-360 engine. The angle valve engines are also about an inch wider.
Dave Prizio
TX Sport Cub N114DE
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