Lyc o540

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diego3v

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hallo,
I'm not good at all with engines so a need your help before asking to a maintenance center...

I have a Lyc o540 B2C5 engine. 235Hp. I would use this engine for experimental airplane. What changes a maintenance center can make to get the most of the hp?
Apart from the cost, it would be useful to install an injection instead of the carburetor?

thankyou for yor help
 

Twodeaddogs

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First, inspect the engine to make sure that it is in flyable condition then consider what aircraft it will go into. Is it going into an aerobatic aircraft or a cruising aircraft? You should check the maintenance manual to see if that exact sub model can accept fuel injection. Some can't. Also, you have to consider what propellor might be used, as some crankshafts cannot handle a constant-speed propellor. Also, depending on what aircraft it might go in to, see what kind of engine mount it may use.

regards
TDD
 

TFF

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It is all about money. You can make it into a 350 hp engine if you throw every trick in the book at it. Fuel injection is the same. Most of the time you have to change the sump to a FI one, but it is really just buying the right parts. Nothing fancy other than to do. What kind of engine do you need. Also as the compression goes up the life of the engine goes down.
 

Dan Thomas

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There are numerous O- and IO-540s. The number of cubic inches are the same but there are many differences. Can't just make changes that easily.

Generally, though, the 540 gets more HP at higher RPM. 235 at 2400, around 260 at 2700. They get 300 out of a 540 by turbocharging it, but there will be internal differences in the engine to make it stronger.

Lots of info on the TCDS: TCDS E-295 Rev 19 Lycoming Engines
 

Toobuilder

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There are several versions of the 300 that are non turbo - the unit that drags the Cherokee Six 300 around is perhaps the most common. This is an angle valve, however. Main differences are the heads, induction and a bit more compression.

But in general, the HP changes on the 540 line are most directly related to RPM and compression. Throw 8.5 pistons and FI at one and turn it to 2700, it will make 260 HP.
 

TFF

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Barrett makes plenty of hotrod 540s. Many are parallel valve. Counting back from 11 to one compression adds about 500 hrs for each compression point. 11 to 1 engines are generally 500 hr engines.
 

Kyle Boatright

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Per the TCDS, that s a low compression engine without provisions for a constant speed prop. The compression ratio can be easily changed to 8.5:1, and you can run that engine as a 250 or 260 hp engine. The case would need to be modified to accept a constant speed prop. Fuel injection would probably improve fuel consumption, but not power.
 
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diego3v

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aircraft will be a GlasairIII, aerobatics yes but just gentle voltige.

thank you for all the interesting inputs. I guess best is to check actual conditions of engine and maintenance story.
after this step, I will take care of all your advice.

thanks
diego
 

weasel

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Glasair III cowlings are already set up for a 300 HP angle valve engine but its pretty tight in there. They almost all have a rear facing sump so pay attention to the induction orientation.
 

Toobuilder

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The rear facing angle valve sump is common, inexpensive to purchase, and bolts on to a paralel valve case. Induction tubes would have to be a custom thing, but not hard. Much more cause for concern is the C/S prop provisions. As much of a ground lover the G-III is, I dont think anyone would want to fly one fixed pitch. Performance aside, you would have some significant C/G issues without the heavy angle valve and C/S prop on the nose.
 

Battson

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But in general, the HP changes on the 540 line are most directly related to RPM and compression. Throw 8.5 pistons and FI at one and turn it to 2700, it will make 260 HP.
It will make 290hp in that configuration, with the parallel valve block (the -B one which the OP has).

Barrett makes plenty of hotrod 540s. Many are parallel valve. Counting back from 11 to one compression adds about 500 hrs for each compression point. 11 to 1 engines are generally 500 hr engines.
This is a key consideration - every time you go higher above the rated hp, the shorter the engine TBO expected life becomes. The IO-540-B engine with 8.5:1 cylinders turning at 2700rpm maximum, that will have a TBO of about 1500 hrs (290hp). It's normally 2000 hrs TBO at 260hp. At 235hp you could hope for 2500 or even 3000hrs TBO.

Barrett's IO-540XP will make 330hp using your -B block, but the engine life will be considerably reduced because the thrust bearings are not designed / sized to handle that much power.

If you want maximum horsepower, and can stand to gain some weight, then you are better to sell that engine and buy an O or IO -540-K block (which takes the angle valve cylinders). They rated at 300hp like the others have said, and designed to handle it.
 

Armilite

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hallo,
I'm not good at all with engines so a need your help before asking to a maintenance center...

I have a Lyc o540 B2C5 engine. 235Hp. I would use this engine for experimental airplane. What changes a maintenance center can make to get the most of the hp?
Apart from the cost, it would be useful to install an injection instead of the carburetor?

thankyou for yor help
===========================================================================
1st, as being used on an Experimental Airplane, YOU can do anything you want to it for HP and making it more Durable!!!

2nd, Fuel Injection does not really make You more HP, it gives You a better Starting Engine, a Smoother Running Engine, and Better GPH!!!

3rd, any Engine's Life(Hours) is only as good as the Fuel Octane used, so you don't have Detonation Problems, Max Rpm's used also affect what Prop You can use, Basic Engine 101 Maintenace done, What Type of Oil is used, what kind of Heat it is subjected too, and what Type of Parts you use!!! Today, You also have many different Engine/Exhaust Coatings You can use, that don't really make more HP, but can make your Engine more durabile!!!

Building Engine's for more HP is basically the same. What Max Rpm's you want to run, What Size of Intake and Exhaust Valves you Run(What is the Max Size your engine can use), Cylinder and Head and Intake Porting(Air Flow Ratio or AFR), Carb Size(CFM) you run, your Stock Cam Spec's Lift and Duration vs what you want to you run to make more Hp. The are usually (3) Types of Cams, Solild Lifter, Hydraulic Lifter, Roller Lifters, what is your Stock Cam and does anyone make other Types for your engine?

So Sadly, most Airplane Engines just don't have many Performace Parts built for them, You have to have them usually Custom made, or even make them yourself, or Adapt other Parts to work. So let's look at some of your Engines Spec's below. Also, I don't know what your Airports offer for Fuel, but with in 50 mile radius Circle's around me, only 1 out every 21 Airports even carry 87, so 100LL is your only choice of Fuel!!! 87 Octane is good for only up to maybe 9.0cr. I can tell you may new 1979 Chevy 350 v8 with 9.6cr would knock on 87 Octane when you went to pass someone, at lower in town Speeds/rpms it ran fine.

Lycoming O-540-B2C5 engine
overhaul, exchange & shock load repair
Lycoming O-540-B2C5 specification
Model: O-540-B2C5
Manufacturer: Lycoming
Aircraft: Piper Pawnee
Horsepower: 235
Compression ratio: 7.20:1
Configuration: 6 Cylinder
Fuel system: Marvel Schebler Carburettor
Propeller: Variable Pitch
Rotation: Clockwise
RPM: 2575
541.5 cubic inch (8,874 cc) displacement

So from the Peak Flow/HP Calc http://www.mk5cortinaestate.co.uk/calculator3.php it says at 541.5 cubic inch at 2575rpms and if just 90% efficient, 363CFM and can make 242hp is possible if Designed and Built right! The Cont O-200 was rated at 2750rpms for a 2000hr TBO, so I would use that as my Max Rpms. So since 100LL can handle any Compression 7.0 to 12.0 that is what I would use. 100LL does have a 5 year Shelf Life also if your in the outback. 87 has a 6 month shelf life. Check what the CFM Rating is of your Marvel Schebler Carburettor is?

Porting can add 10-15% more HP.

A Good Tuned Exhaust can add more HP.

Using Bigger Intake/Exhaust Valves can add more HP.

Just Raising Compression does add more HP, but not as much as you think! Example on a Skidoo 670(669cc) 2 Stroke, 11.5cr 112hp bump up to 12.5cr 122hp made a 10hp difference. As the CC/CI goes up, the Hp gain also goes up. To really make lot's more Hp you need to use a Bigger Cam, bigger Valves, bigger Carb, higher Rpms used, etc! All of which can affect your total Engine Service Life in Hours!

A Turbo Option is also one way to make much more HP! As Normal Carbed Plane's go higher they make less HP! Your 235hp at Seal Level is 70.5hp less at 10,000ft. With a Turbo you have the same HP at both.

Your 541.5 cubic inch at 2575rpms if Designed and Built right with 1lb of Boost = 287hp and 431cfm
Your 541.5 cubic inch at 2575rpms if Designed and Built right with 2lb of Boost = 305hp and 458cfm
Your 541.5 cubic inch at 2575rpms if Designed and Built right with 3lb of Boost = 324hp and 485cfm
Your 541.5 cubic inch at 2575rpms if Designed and Built right with 4lb of Boost = 342hp and 513cfm

If it was me, and Money was no object, I would use a Variable Boost Turbo and Fuel Injection. Depending on it's Hours now, if it needs Rebuilt now. I would use all of the different Engine Coatings to Reduce Heat, Friction, Corrosin, in and on your Engine. Just using Ceramic Coatings on Piston Tops, Head Combustion Chambers, Cylinder Exhaust Ports, and Exhaust, can lower your over all Temps by 20%.

"Design and development[edit] https://en.wikipedia.org/wiki/Lycoming_O-540
Generally these engines produce 230 to 350 horsepower.[1] They are installed on a large number of different aircraft types.[2] Their main competitive engine is the Continental IO-520 and IO-550 series.

The AEIO version was developed for high-performance competition aerobatics aircraft. Starting at 260 hp (190 kW), the power was then improved to 300 hp (220 kW). The AEIO-540 family has achieved tremendous results in competition aircraft such as the Extra 300, CAP 232, and Zivko Edge 540."

Just My 2 Cents
Rich
 

Armilite

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For these 540 Spec's I used 8.5cr. But using these same Spec's but just changing the CR used, you can see how it affects your HP.

7.0cr = 270hp at 3500rpms
7.5cr = 282hp at 3500rpms = +12hp
8.0cr = 293hp at 3500rpms = +23hp
8.5cr = 302hp at 3500rpms = +32hp
9.0cr = 311hp at 3500rpms = +41hp
9.5cr = 320hp at 3500rpms = +50hp
10.0cr = 327hp at 3500rpms = +57hp
10.5cr = 334hp at 3500rpms = +64hp
11.0cr = 341hp at 3500rpms = +71hp
 

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Armilite

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Same 540 Spec's above I used 500cfm Carb to make 302hp at 3500rpms. Just changing Carb CFM.

300cfm = 263hp at 3500rpms
350cfm = 278hp at 3500rpms
400cfm = 288hp at 3500rpms
450cfm = 296hp at 3500rpms
500cfm = 302hp at 3500rpms
550cfm = 307hp at 3500rpms
600cfm = 311hp at 3500rpms

541 Cubic Inches needs 493cfm at 3500rpms.
 

weasel

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Please explain how that is so.

Thanks,

BJC
Are you questioning why it does not give you more HP or why it would start easier.



If the prior it is because the mixture distribution of a carb is for all practical purposes almost as good as fuel injection when at 100% power. If the later, It is an operator error (most pilots have a hard time getting the mixture right for starting and then keeping it right when transitioning to idle without interrupted fuel flow.....it can be done but the masses thing it cant :speechless)
 

BJC

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Are you questioning why it does not give you more HP or why it would start easier.



If the prior it is because the mixture distribution of a carb is for all practical purposes almost as good as fuel injection when at 100% power. If the later, It is an operator error (most pilots have a hard time getting the mixture right for starting and then keeping it right when transitioning to idle without interrupted fuel flow.....it can be done but the masses thing it cant :speechless)
Questioning the "better starting" comment, especially with a hot engine.


BJC
 
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