High HP engine mods? Lycoming thread.

[Turbo69bird]

I fully understand the clean up of an airframe making more speed.

That wasn?t really the POINT of the thread.
The thread was about making something on your RV experimental other than the freaking sticker they give you.

really there are, cams and ported cylinders and big bore kits, water methanol injection, turbos superchargers, all kids of things that have been bolted on airplanes SUCCESSFULLY The point of the thread was to have people post what THEY know of for these parts.


Maybe get a little creative. Not just ?I put a stock 180 lycoming in my plane and then followed the leader... ?

It was about experimentation within the EXPERIMENTAL community.

But apparently there aren?t too many people being Very experimental.

[Full Throttle]

I understand your frustration. Ask Skylor. He has a very fast RV-8. I think it goes over 240 MPH. He is also a very smart guy.

[Ed_Wischmeyer]

Maybe get a little creative. Not just ?I put a stock 180 lycoming in my plane and then followed the leader... ?

It was about experimentation within the EXPERIMENTAL community.

But apparently there aren?t too many people being Very experimental.

So what's the experiment? Too often in homebuilding, the term is abused to mean, I'm going to try this and see if I can get away with it. You read bogus statements like, I've got 35 hours on it and it's perfectly reliable. And what happens if the "experiment" fails?

Too often, what is labeled experimental is really just development, and sometimes sloppy development at that. And sometimes it's just screwing around, but calling it experimental, hoping to gain respectability and avoid accountability.

[Turbo69bird]

Originally Posted by Ed_Wischmeyer

So what's the experiment? Too often in homebuilding, the term is abused to mean, I'm going to try this and see if I can get away with it. You read bogus statements like, I've got 35 hours on it and it's perfectly reliable. And what happens if the "experiment" fails?

Too often, what is labeled experimental is really just development, and sometimes sloppy development at that. And sometimes it's just screwing around, but calling it experimental, hoping to gain respectability and avoid accountability.

Really so putting something different than the next guys 180 hp lycoming like a turbocharged 150 is sooooo dangerous. Last I knew Lycoming built turbocharged engines .

Wow I think everyone here should sell their RVs and buy certifieds after all they haven?t had the rigorous testing that a certified has had. And certainly by no means should you get anything with an STC, that could be dangerous too.

Man did people miss the point of this thread .
Sorry I posted at all!

[Turbo69bird]

BYW don?t even think about vinyl wrap you guys would surely blow a gasket on that thread!

[scsmith]

Originally Posted by Turbo69bird

Really so putting something different than the next guys 180 hp lycoming like a turbocharged 150 is sooooo dangerous. Last I knew Lycoming built turbocharged engines .

Wow I think everyone here should sell their RVs and buy certifieds after all they haven?t had the rigorous testing that a certified has had. And certainly by no means should you get anything with an STC, that could be dangerous too.

Man did people miss the point of this thread .
Sorry I posted at all!

Now who is being snarky?

[scsmith]

Originally Posted by Toobuilder

... With RVs the thrust device (the prop) is limited by diameter - strike one. It's also limited by reynolds number (RE) - strike two. Then we have tip speed and Mach which is a combination of prop RPM and aircraft forward speed - strike three. The bottom line is that our a ability to convert additional power to thrust is limited and is subject to diminishing returns.

Mike, changing blade pitch undoes strike three, so you CAN actually absorb quite a bit more power in a constant speed prop.

[rocketman1988]

Wow, you start a thread on engine mods, don't like that some people have differing opinions, and then it's you that's blowing a gasket...

Listen, you put it out there, not everyone is on your page...that's ok.

The guy with the turbo Honda had the same pushback.

Those of us that are using electrically dependent engines with EFII had the same pushback.

That isn't stopping us from moving forward with our own visions. You should do the same. If turbos are your thing do it! Put it out there so the rest of us can follow! Most important, have fun!

[scsmith]

Originally Posted by Turbo69bird

Question:
If the prop was maximized for that 2000 rpm wouldn?t it do the same. Like gearing in a car.
One thing I?ve learned w Pontiacs is they like to be maximized for torque and at a lower RPM can?t build them like a Chevy they won?t live. So if he made the same
Torque at a lower RpM and proped it accordingly like a 308 gear as opposed to a 4.11 gear wouldn?t that make the same amount of work? and therefore propel
The plane the same speed at a lower rpm?

This would be almost true if there was a variable-speed gearbox between the engine and the prop, so that the engine RPM and prop RPM are not coupled. If the engine RPM is the same, then the power is the same. Reducing prop RPM moves its operating point along its efficiency curve (efficiency vs advance ratio).

With a direct drive engine-propeller, you can run wide-open throttle, and vary the RPM by changing the propeller pitch. When you reduce RPM, you move along the engine horsepower vs RPM curve(assuming the mixture is set for best power), and you move along the prop efficiency vs advance ratio curve. The airplane will slow down as you reduce RPM.

An interesting side-bar to this is when you are operating LOP. Once significantly LOP, the power is pretty much directly related to fuel flow, and for the same fuel flow, the engine will produce roughly the same Hp over a range of RPM, so now you can choose the RPM for best prop efficiency to go fastest for that fuel flow.

[SJordan]

Well a 4-cylinder RV-8 qualified at 276mph this year at Reno. That’s around 290mph straight and level.