Here is an engine weight comparison: Rotax, Continental + others

[rogerh12]

FYI:
Here is an engine weight comparison. I found this on the internet, so I don't know how accurate it is, but all weights are in lbs. I see the A-65 is 173 lbs, whereas the electric start C-85 is 207 lbs, which sounds about right.


Rotax 503 85
Great Plains VW 1600CC 160
Hirth F23-EP2 70
Jabira 119
PZL 2A-120 129
Rotax 582 95 Includes 20 lbs radiator, etc.
Continental A-65 173
Limbach L 1800 154
Limbach L 1700 161
Rotax 618 136 Includes 20 lbs radiator, etc.
Great Plains VW 2180CC 165
Franklin 225 230
Limbach L 2000 155
Rotax 912 165 Includes 20 lbs radiator, et
Continental C-85 207
Limbach L 2400 181
Continental C-90 207
Great Plains VW 2600CC 190
Stratus Subaru EA-81 205
Continental O-200 220
CAM-100 225 Includes 20 lbs radiator, etc
Formula Power C100 210
Rotax 914 155
Lycoming O-235 215
PZL 4A-235 226
Hirth F30-FP24 101
Continental IO-240 250
Continental O-300 277
Lycoming O-320-A 243
Lycoming O-320-D 253
Franklin 335 320

[HighWing]

Major Skeptic here. Example - granted not a Stratus, but some of the NSI Subaru guys, back in the day, were putting a 25 lb battery in the tail cone for W/B. Do the math - 25 lbs at ten feet aft of the datum is 250 ft/lbs. To balance that two and a half feet forward of the datum would require an engine weight 100 lbs. heavier than the Rotax 912.

If your VW is only five pounds heavier than the Rotax then a no brainer W/B wise. The weights of the 912 vs the 914? If it was your typo, fine, but is the 914 lighter than the 912 with all that turbo stuff on the same engine castings?

If I were checking alternative engines, there is no way I would rely on lists or manufacurers claims. Re-read John McBeans note on the UL engine they are testing. Not a lot of discrepancy factory vs. certified scales weighing, but if the factory numbers were nine pounds heavier than John's weighing It would carry much more credibility for the industry, at least in this hangar. What I would do is determine empty weights of airplanes using the various engines I was interested in. This would then include all accessories - everything necessary for flight Plus ballast. Pay particular attention to the W/B required ballast and do the math. When you have a Model IV with an empty weight of 780 lbs. you can't attribute it to an engine that weighs only 5 or 30 lbs. more than the 912. What else did he put in there - 100 lb. upholstery? - no brainer.
Lowell

[rogerh12]

The wieght figures are off the internet, so who knows how accurate they really are, but someone put a lot of work into finding these figures, so they are probably correct or close to it.

The 912 turbo weight, I guess, is without accessories, thus it show lighter that the standard 912.

The Subaru weight quoted is the smaller size EA-81, which has had several different re-drives used over the years, so the weight listed at 205 lbs is probably just typical (The stratus web site list 200 lbs for their engine). The re-drive can suck the HP down though, I would guess 80 HP at the prop would be typical.

The larger and more popular (now days anyway) Subaru engine is the 2.2 Liter, which weights a whopping 315 lbs !!!!! (but really produces the power - that weight is also from the Stratus web site)

The direct drive electric start VW installed weight is about 180 LBS from my experience, but you can shift some of the weight closer to the firewall by choosing alternate accessories (like dual magnetos driven off the back of the motor), which reduce the impact on the airframes CG (you can also use a light weight wood prop). The VW’s do not require a large battery to start, the ULTRASTART RED BATTERY weighs 4.4 lbs and will start the engine just fine (but not much power is left in reserve if you loose the generator).

I heard some really wonderful things about the Jabira, and I bet they would make a good light and fuel efficient engine choice for the model 3 and 4’s, but have not heard of anyone using one with the fox or avid

[t j]

They are way low on the rotax 503 and 582. I think the weights listed are for a short block.

[Mnflyer]

The list is pretty much worthless most of the weights are way off.

[rogerh12]

This is off the Sonerai builder site. It has specific engine weight details on a stripped down C85:


My C85-8 Continental engine has 85 “Clysdale” HP at 2575RPM at, 2750RPM about 90HP (if I want to run it that hard). The engine has NO electrics & must be hand propped. It weighs about 180 LBS on the plane…close to what a 2180VW weighs with starter & alternator.

[akflyer]

The "about" part could mean 20 + or - (probably more) When dealing with planes, about just dont cut it.

[rogerh12]

I think it's also important to note that the C-85's are often fitted with a metal prop. That's a lot of extra weight out in front of the noise, which affects both the total engine installation weight and the CG of the aircraft. I would think it also puts more stress on the engine mount, so your engine mount would need to be more hefty).
I Other engines can use a light weight (and cheapish) wood prop, which gives a lighter total installed weight and affects the aircraft CG less (but it's hard to beat metal for durability)
Roger