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Big Displacement Lite Weight 0-375/ I0-375 Engines

Bart Lalonde

Registered User
The 375 is a large displacement lite weight engine. It is available in carburetted and fuel injected models. With dynafocal or conical mounts. It is also available in fixed pitch and constant speed versions. The low compression version make 195 HP and is happy with mogas. The high compression version needs 100LL and makes 205 plus HP. We have put nitrous oxide on some and pushed them up close to 300 HP. This is not recommended but does prove they are durable. They weigh the same as the equivalent model 360 and only 10 pounds more than the new style 0-320s with the 3/8 thick prop flange crankshafts. If anyone has any questions, I would happy to answer them.
 
375

Mike the 375 is 30 pounds lighter, makes within 5 HP, and is a much easier fit in a Cub type plane. Because it uses primarily parallel valve 360 parts it is much less expensive to build as well. The high compression version has a BMEP of 162 PSI. The 390 has a BMEP of 158 PSI so they are very close in the cylinder pressure department.
 
Are they certified or experimental? Are the HP numbers listed IO or O?

I have an O-360 with a C/S prop, that I would be interested in exchanging at O/H.
 
375

The 375 is only available in a non certified version. All the parts used to build it are certified except the crankshaft. The crank is made off the same raw forging that the 320 and 360 cranks are made from and all the process are the same. The HP numbers don't vary much weather carbed or fuel injected. We have a cold air induction that adds a few HP but it is for injection only due to the horizontal layout of the servo. On trade ins we would need to talk.
 
Bart: Thanks. I am in the process of building a Glastar, and am always thinking about which engine. It will be on floats, and originally I was thinking O360 and IO390. With any luck I may need an engine in a year or so.

Mike
 
Bart

what kind of power can you build out of a 0320 that would be in a certified Super Cub?
 
0-320

I can usually 170 full size horses out of a certified 0-320 without to much trouble. This is equivalent to the 200 ponies some other talk about.
 
We are installing Barts 0-375 in an experimental cub right now, my opinion so far is that it is high quality for a good price. We have installed a dynon Flightdek180. The aircraft will be flying next month, I will post some numbers . A Pawnee 43 pitch prop on the nose.
 
Re:036? engine

Bart, I am a new viewer. I have a Wagareo 2+2 with a sort of morfadite 0360 in it. It left the factory as a 0360-3b3 (I think that's what Lycoming called it), but somewhere it acquired slant valves or wedge head, I've heard them called both, cylinders. I will be pulling this engine down in the spring and am interested in what can be done with this other than taking it back to stock. Any information will be appreciated.
Jim L
 
The following is H. O. Aircraft's data. So, with the possible exception of cost, why not use the O-390 or IO-390? The weight is about the same.
Darrel
0-390_specs.jpg
 
Most people use 285lbs as the dry weight spec for O-360. Not sure how the 301lbs figures in. Also you forgot to compare price. I bought an O-360 core from Wentworth for $8K (200TTSN on engine, had minor prop strike). After I was done overhauling it with the help from my A&P friend, I only had $12K into it.

I am not saying the IO-390 isn't a very appealing choice for an experimental Cub, just want to make sure all things are considered.
 
IO-390 Engine vs O-360

The fuel flow numbers and weights cited above for the IO-30 vs. the O-360 are just not right. These are the creation of some marketing guy. Although some owners have reported better fuel flows with the IO-390 vs. the O-360 at the same cruise speeds in the Glasair Sportsman, for instance, the numbers here are way off base.

Any way you cut it the FWF weight of he IO-390 is significantly higher than the O-360-- around 30 pounds. This makes the larger engine a poor choice for planes that are already a bit nose heavy, such as the GlaStar mentioned in an earlier post. It may also not be a very good choice for a Cub, especially one that is to be flown solo a lot.

These are both great engines, and they each have their place. There is no need to make stuff up to try and make one look better at the expense of the other.
 
I was just quoting the H.O. Aircraft web site. I have no particular knowledge of the pros and cons.
I do have a friend with a SC on amphibs. He recently bought the MT prop to replace a Hartzell because the W&B was a little IFFI with him alone in the plane - he was in some danger, if he had a large dinner, of being forward of the envelop. He has an 0-360 now so I'm sure any extra weight of an 0-390 would not work for his plane.
Darrel
 
Ever try operating IO Lycoming engines in an environment with Bad /Dirty Gas and contaminates/ water in it,like is pumped out of fuel barrels. Not very fun, Obviously I'm a big fan of Carburetors on my engines. I DO use a Mister Funnel & Filter to, but Murphy's law rules! My next engine will probably be an O340 Stroker from Bart or Ken at Lycon
 
IO-390 vs. O-360

Please know that my comments about the IO-390 data were not aimed at you personally. Obviously you just got this info from someone else who, for whatever reason, thought he needed to embellish the virtues of the IO-390 engine with a little creative advertising.
 
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