Convert O-360 to IO-360?

G-Man

G-Man

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Lots of airplanes use a 180hp O-360. What would involved in converting them to IO-360 for +20hp?
Obviously, intake system.
Same block and internals?
Would the STC be airframe specific for Certified?
What about Experimental?
Etc.
 
Cylinders on the 200hp IO-360 are angle-valved and considerably more expensive that the parallel valve which the 180 O-360 and IO-360 both have. I don't think it'd be a simple cylinder swap. Cheapest alternative is to sell your engine and get a used 200hp IO-360.

I don't think that upgrade is worth it. If I was in the market for an upgrade engine, my pick would be the parallel valve 250HP IO-540 with bare bone simple factory cylinders. At this stage in my involvement with GA, I don't think I can go back to carburetors.
 
What you are asking is a major alteration and all the paperwork that goes with it.

But to build an engine for an E/AB build what you want.
 
hindsight2020 said:
Cylinders on the 200hp IO-360 are angle-valved and considerably more expensive that the parallel valve which the 180 O-360 and IO-360 both have. I don't think it'd be a simple cylinder swap. Cheapest alternative is to sell your engine and get a used 200hp IO-360.

I don't think that upgrade is worth it. If I was in the market for an upgrade engine, my pick would be the parallel valve 250HP IO-540 with bare bone simple factory cylinders. At this stage in my involvement with GA, I don't think I can go back to carburetors.
Click to expand...

Or just developed a stc to install the io version of the 180hp parallel valve engine. in the airframe.
 
The 200hp engines have a higher compression ratio. Angle valve heads are bigger so the engine gets wider so cowl and baffle mods may be difficult. You’d have to modify the fuel system to include electric and mechanical fuel pumps. Engine modification would be one approval. Installation into an airframe is another. Everything is easier if the airplane is experimental.
 
And I don't think the angle valve cylinders will fit the straight valve cases....

Frank
 
Where there's a will there's a way. Fitting an angle valve 220hp IO-400 on an exp Supercub. Zoom zoom!
 

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>> Lots of airplanes use a 180 HP O360. What would involved in converting them to IO360 for +20 HP?

Yeah, doesn't work like that! The 200 HP IO360's have angle valve cylinders... the angle give more room for larger intake valves, hence higher volumetric efficiency... the angle valve cylinder gets something like 93% fresh air/fuel charge in on each intake cycle, versus something like 83% for the more congested intake pathway O360 parallel valve engine. That's responsible for MOST of the power output difference between the engines.

The other piece is the difference in compression ratios... 8.5:1 in the parallel valve O360; 8.7:1 in the angle valve IO360. You can buy higher compression pistons for the parallel valve engines... and higher compression ratio pistons for the angle valve as well... Firewall Forward has an STC for 10:1 pistons in the IO360 that delivers 225 HP in the Cardinal RG and Mooney... but, for certification reasons, it's flat rated to 200 HP with a manifold pressure redline around 27". I've heard that some pilots "forget" to observe that redline. But, even with the redline, that means you maintain 200 HP as you climb by opening the throttle to maintain redline MP.

>> Obviously, intake system.

>> Same block and internals?

Well, these engines don't have blocks... they have a crankcase, and individually attached cylinders. You'd have to do some parts catalog perusal to figure out if there's a Lycoming-endorsed configuration attaching angle valve cylinders to your crankcase and crank... probably easier, as someone noted, to just purchase the engine you want.

>> Would the STC be airframe specific for Certified?

There's two STCs. One to modify an engine, if that's what you end up doing. And then a second to install the modified engine in your airframe. You can skip the first by just choosing an existing Lycoming engine configuration.

>> What about Experimental?

Well, experimental aircraft can roll-their-own when it comes to configuring engines. If you mean making your existing certified engine experimental, the desirable, flexible experimental category is experimental homebuilt... and you don't qualify for that. There's also experimental flight test and experimental market research, and so on. But those are all VERY restricted in what you can do with the plane, and where you can fly... and typically only endure for a limited time. Not practical or useful.

Paul
 
Why do you think the o360 and io-360 have completely different ipcs? You did look at them, didn't you?
 
Many of you folks need to read what constitutes a major alteration to an engine.

(2) Powerplant major alterations. The following alterations of a powerplant when not listed in the engine specifications issued by the FAA, are powerplant major alterations.

(i) Conversion of an aircraft engine from one approved model to another, involving any changes in compression ratio, propeller reduction gear, impeller gear ratios or the substitution of major engine parts which requires extensive rework and testing of the engine.

(ii) Changes to the engine by replacing aircraft engine structural parts with parts not supplied by the original manufacturer or parts not specifically approved by the Administrator.

(iii) Installation of an accessory which is not approved for the engine.

(iv) Removal of accessories that are listed as required equipment on the aircraft or engine specification.

(v) Installation of structural parts other than the type of parts approved for the installation.

(vi) Conversions of any sort for the purpose of using fuel of a rating or grade other than that listed in the engine specifications.
 
I think you will get absolute sticker shock switching out an O-360 for an IO-360. I bet taking an old 172 and installing a new IO-360 upgrade with angle valves is financial punishing at a level few can endure.
 
NordicDave said:
I think you will get absolute sticker shock switching out an O-360 for an IO-360. I bet taking an old 172 and installing a new IO-360 upgrade with angle valves is financial punishing at a level few can endure.
Click to expand...
Not that bad, try talking to Tom Anderson. he has a STC for it.
Last I talked to him he wanted 15k for the Paper work, header tank, and engine mount. I priced it out flying at 35 grand.
 
Are you mixing Tom Anderson’s Continental IO-360 STC into a Lycoming conversation?
 
Stewartb said:
Are you mixing Tom Anderson’s Continental IO-360 STC into a Lycoming conversation?
Click to expand...
yep.. :) that is the easiest way to get an IO anything in a 172.
 
would be much interesting to convert IO-360 to IO-390. I heard Monti Barret could do it. Is it like simply sticking IO-580 cylinders on the IO-360 crankcase or there is more involved? That's the question
 
I don't know much about IO-390s but I beieve my SAP IO-400 is something of a copy of tbe 390. One big draw for me was the counterbalanced crank. The front prop governor pad is also useful. And roller lifters. I don't believe a 360 has those things so to me a converted 360 wouldn't be equal.
 
Stewartb said:
I don't know much about IO-390s but I beieve my SAP IO-400 is something of a copy of tbe 390. One big draw for me was the counterbalanced crank. The front prop governor pad is also useful. And roller lifters. I don't believe a 360 has those things so to me a converted 360 wouldn't be equal.
Click to expand...

Some have the features you mention.
 
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