Weight and complexity are the most obvious drawbacks. It's easy to make the -8 nose heavey; adding a turbo, wastegate and the requisite plumbing/infrastructure would only exacerbate the problem. The RVs do just fine without the need for normalizing or boosting at the altitudes most people want to fly and can readily climb into the sucking on 02 altitudes. Finally, and this is Van's big argument against additional horsepower in general, is that it makes it too easy to blow right past Vne.

That said, if you manage the weight properly and keep track of the go fast knob, it most certainly could be done. Some folks have hung turbo Subarus and 540s on the nose of an 8 and absolutely love the additional power and have managed the weight gain. It's your airplane!
 
I have lost track of the airplane but there was a Santa Fe based RV-6 that had huge fuel tanks and a turbocharger that routinely operated in the 30,000 foot range. It can be done.
 
Turbo RV-8

There is an RV-8 based at a community airport south of Dallas called Eagle's Nest, that is turbo-normalized. The firewall forward work was really beautiful, and first class. I believe the builder call his Rv-8, "Greased Lighting". I remember the aircraft having heat problems inside the cowling. I haven't seen the airplane in years now. I heard that the owner stopped flying it.
 
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Jim Wright said:
Just Dreamin"
Has anyone researched the possibility of installing a turbocharger?
Superior has two models:


http://www.superiorairparts.com/PDF/FlliersDocuments/XP-360Engine/XP360Turbo_SpecSht.pdf

http://www.xp-series.com/engineModel.asp

Since our RV's have such a great climb rate and are capable of 18,000+, why not use a turbo?
Your thoughts...
Jim
Click to expand...

I had the good fortune to ask Dick VanGrunsen this same question about the RV-8 at Oshkosh a few years ago and while he did not say "yay" or "nay" about the turbocharger, he did remind me that the RV-8 was designed for a 180 HP engine.

However, I think that there are several people out there using turbocharged engines, so it is your call.
 
http://gallery.eaa326.org/main.php?g2_itemId=4906
Turbos are not for the faint of heart.
I built a Mazda Rotary with a Turbonetics 60-1 turbocharger into my RV-8.
It added YEARS to my build time. I enjoy it, you may not.
I'm ground running now, and I feel it is meeting my goals so far.
I intend to have a high rate of climb, Fly in the 10,000 to 20,000 ft altitudes, and have 0 worries about shock cooling as I blast down to land in mountain valley strips that I fly into.
I have rebuilt and redesigned components many times. This is not something you throw money at to get-er-done!
Under cowl heat is an issue.
 
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I believe Vans biggest concern with turbo engines is going past Vne at high altitudes.
Click to expand...
Updated Vans article Todd has hinted at the "problem" - the article linked to goes deeper.

In essence, VNE should be expressed as a TAS value. In practice, it is expressed at IAS, but the stated IAS assumes you are flying within the designers assumptions which are non-turbo / as you fly high the drop in HP means getting to/past VNE is impractical. A turbo invalidates those assumptions...

Nobody, as far as I am aware, can express exactly what VNE is in TAS terms... I would guess you are safe to declared IAS at, say, 8000'. The only way to really determine it is to wait until wings start falling off :eek:

Andy
RV-8 G-HILZ
RV-8tors
 
Todd and Andy bring up a good and valid point.
Re-reading Andy's link is always worthwhile.
My goals for turbocharging fall within Van's intent. Although much power can be gained by turbocharging, I am limiting that power to honor the intent of Van, and the maker of my reduction gear. Both suggest 200 HP as maximum. I have a CATTO prop that is matched to that power, so if the engine can develop excess power, RPM limits will need to be observed.
I plan to make a Vne card for airspeed @ increments of altitude to assist with safe operation.
Oh, and the next RV I build will be a 150 HP RV-9. Simple & Light.
(It's all fun) :p
 
Scott,

Back when I had my 135 HP O-290-D2 I thought about going the turbo normalized route so I could keep up. You know, size envy.

I started looking at pictures of turbo installations like these:

Cessna Corvalis
Mooney M20K/231
TSIO-540

I realized very quickly that packaging and heat dissipation will be a major issue but cash dissipation would be easy to accomplish. It became very obvious that it would be cheaper and probably safer to simply install a larger, well-tuned, engine.

If you go through with a turbo project, please keep us updated!
 
Bill;
Thanks for posting the pics of production turbo aplications.
I do like the TSIO-540, for the simple turbo drain. I mounted my turbo as high as possible under the cowl so the oil could drain back to the sump without an oil scavanging pump. I saw such an application on a turbo Aztec, and thought it was a good thing to avoid. Still, it took me 2 tries to get it right.
The TIO-540 turbo is mounted behind the engine, seemingly usable only in a twin.
My Mazda rotary is a very short and narrow engine, allowing the turbo to mount beside the block with very short exhaust header and oil drain.
I still have room under the cowl for an aftercooler, but I'm leaving that and the waste gate and blow off valve out. Everything adds weight, so I follow Kelly Johnson's addage "Add lightness and simplicate".
 
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I'm not sure I would leave off the waste gate and blow off valve out. Granted we aren't talking about an auto application here, so you may not actually need them.

Have you contacted Ed Anderson regarding your application? He can be reached through is web site, http://andersonee.com/Web/.

Ed was the second guy to fly with a rotary, has a background in turbo applications (auto and aviation), and is one of the smartest guys I know.
 
SHIPCHIEF said:
I still have room under the cowl for an aftercooler, but I'm leaving that and the waste gate and blow off valve out. Everything adds weight, so I follow Kelly Johnson's addage "Add lightness and simplicate".
Click to expand...

I'm curious how will you control the boost-just throttle?

Most people also discover that the compressor discharge temps get pretty high in the climb at altitude, even with properly matched turbos. Intercooling reduces the thermal loading on everything and is usually well worth the effort and weight.

What turbo are you using?
 
Ross & all;
Right now boost is controlled by throttle only.
The Turbo is a Turbonetics 60-1 P trim with on center exhaust housing. I forget the A/R right now,(.81?) it's intentionally loose to prevent high boost.
I have space in the cowl to add a wastegate, and an intercooler, but I emailed Greg Richter about it when he had a 13BT in his Cozy, he said to skip it unless operating shows a need for any of it.
The RV-8 will fly very well with only 150 HP, we all know that. So I can fly the plane with reasonable power, and develope more as conditions allow, or make changes as conditions dictate.
I didn't buy this set up, I created it from the products of others and my own fabrication. Changes have been made to the fuel, oil and cooling systems already, so I expect more will be required as I refine the power plant.
3 hours of ground running so far, and I expect many more before first flight.
I have run it about as hard as I dare in my yard. I'm about ready to take it to the airport and reinstall the wings. There is more space there, so it will be OK to raise the power and find out what's next...
 
Sounds like you are getting close on this very interesting project.

The 60-1 is a lot of compressor for 150-200 hp and the .81 turbine housing is not loose by aviation standards for this engine and exhaust mass flow. I suspect once you wind the engine up under higher load and rpm, you will experience significant compressor surge as you close throttle to restrict boost. I'd be very surprised if you can get along without a wastegate using this turbo but I guess we will see soon. Can't wait to see a video of it running at full song with the wings on!
 
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I have a plan for a manual control waste gate. It's simply a run of 321 SS tube from the header to the down pipe with a butterfly throttle in it, connected to a lever on the throttle quadrant.
I'll just have to call up Burns Stainless for the stock, and get back to work fabricating and tigging :)
It's not like work or anything unpleasant....
 
You can do it this way but automatic wastegate controls are pretty nice and you can't forget to open the WG before you advance throttle- which could make a nasty bang.:eek:
 
After my last post I started looking at wastegates. I bought a Deltagate when I started this whole deal. It's large and clunky, with 2 bolt flanges. :(
Now there are much smaller models w/ V-band clamp mounting that look better.
We'll see.
 
This is exactly the type of topic that makes building and flying experimentals exciting. Whether or not someone undertakes the project isn't really the point. Learning the ins, out and others experience is very good information. And I have been contemplating the idea of turbo or mechanical supercharging/normalizing for my -320 powered -8.
 
Wastegates

SHIPCHIEF said:
After my last post I started looking at wastegates. I bought a Deltagate when I started this whole deal. It's large and clunky, with 2 bolt flanges. :(
Now there are much smaller models w/ V-band clamp mounting that look better.
We'll see.
Click to expand...

The early Deltagates were crappy with numerous broken valve stem problems, poor flow, fragile diaphragms and galling valve guides. Better off with a modern TIAL unit IMO. Don't use the gaskets on the Deltagate either, they tend to fry and then the bolts come loose.
 
SHIPCHIEF said:
My goals for turbocharging fall within Van's intent. Although much power can be gained by turbocharging, I am limiting that power to honor the intent of Van, and the maker of my reduction gear. Both suggest 200 HP as maximum. I have a CATTO prop that is matched to that power, so if the engine can develop excess power, RPM limits will need to be observed.

(It's all fun) :p
Click to expand...

I've been wrong at least once before, but I believe that if you TC an engine, you HAVE to have a CS prop. Any FP prop matched to that engine's takeoff power will overspeed ad altitude due to reduced air density.
 
SHIPCHIEF said:
http://gallery.eaa326.org/main.php?g2_itemId=4906
Turbos are not for the faint of heart.
I built a Mazda Rotary with a Turbonetics 60-1 turbocharger into my RV-8.
It added YEARS to my build time. I enjoy it, you may not.
I'm ground running now, and I feel it is meeting my goals so far.
I intend to have a high rate of climb, Fly in the 10,000 to 20,000 ft altitudes, and have 0 worries about shock cooling as I blast down to land in mountain valley strips that I fly into.
I have rebuilt and redesigned components many times. This is not something you throw money at to get-er-done!
Under cowl heat is an issue.
Click to expand...

Amen to all of that.

My experience is with a normalizer super charger on the Subaru engine. Here is a brief synopsis.

Down low the device caused fuel burn to increase .5/1.0 gph for the same speed as without it. A blower requires power to turn it and that means more fuel burn. Unless the mission is up high most of the time, it is not needed.

It would maintain 30" MP up to about 12,000' but there were issues with heat that I was unable to resolve.

The drive belt is a single failure point. It jumped the pulleys 4 times in an attempt to get the wheels aligned. Usually it simply resulted in a drop in manifold pressure but one day the flailing belt penetrated the engine timing belt cover which totaled the engine and wrecked the airplane in the subsequent off field landing. There was another Subby (Randy Crothers) operating with a turbo charger some time later, he was seeing fantastic performance numbers until an oil scavenge system failed. He managed to land on a runway but it was the end of that adventure. There are a number of single points of failure with these systems.

I look back on those days and still wonder why I did it. The excursion was expensive, risky, and even if it had worked, so what? Aviators have been flying high and fast for a long time but for the most part with equipment designed for such flight. The RV is a wonderful airplane if flown within its design envelope, but 20,000' is outside that envelope - 30,000 is ridiculously outside that envelope. If you want to fly in such an environment, find the money and go with a pressurized turbine power machine. it is the civilized way to travel these days by avoiding airline travel.

Piston power up high works and has since WWII - but with limitations. A very senior friend who flew 51's out of Italy commented that engines were changed at 400 hours. We don't need such a limitation with the type of flying we do in an RV. We are not at war requiring RV intervention, yet, although I do a lot of low altitude patrolling just in case they try to sneak up on us. :)
 
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Geo said:
I've been wrong at least once before, but I believe that if you TC an engine, you HAVE to have a CS prop. Any FP prop matched to that engine's takeoff power will overspeed ad altitude due to reduced air density.
Click to expand...

This is essentially true so people who have gone the FP/ turbo route match the prop for cruise and use more boost for takeoff but it is not an ideal situation if you are looking for good overall TO/ climb/ cruise numbers.
 
David-aviator said:
There was another Subby (Randy Crothers) operating with a turbo charger some time later, he was seeing fantastic performance numbers until an oil scavenge system failed. He managed to land on a runway but it was the end of that adventure. There are a number of single points of failure with these systems.
Click to expand...

Randy's failure was due to orificing down the oil feed to the turbo (sleeve type bearings) against my reservations. The bearings disintegrated and the bits jammed the scavenge pump gears. The turbo would have failed completely in a few more minutes anyway. He was experiencing what appeared to be crankcase ventilation issues causing oil to be forced out the turbo seals I believe. This was an attempt to fix the oil leakage issue. Randy, step in and correct me if that is not right.

Randy is now fitting an Aerocharger turbo which does not use engine oil for lubrication or a conventional wastegate for boost control. It uses ball bearings, an internal oil supply and variable geometry vanes in the turbine housing to throttle the nozzle area. I would expect him to be flying again in a couple months.

The other STI turbo / 7 was almost ready for a test flight here a couple days ago but the winds were not favorable. It was decided after some discussion to do a check on the camshaft sprocket dimensions and fitment after an accident in Australia was traced to a problem with aftermarket sprockets. We hope to get this one in the books in the next couple of weeks. This 7 uses the same Garrett turbo I have, scavenge pump, filter and sensing system and is intercooled. Also fitted with a custom rad setup and modified cowling. Quite a unique machine. I hope to have some photos and video when it flies.
 
David-aviator said:
I look back on those days and still wonder why I did it. The excursion was expensive, risky, and....
Click to expand...

To answer that question, part of it seems to be the human brain producing the neurotransmitter dopamine which has numerous functions including the anticipation of pleasure. We anticipate a reward for the effort. It is why some of us build more than one airplane or try a different engine and prop.

I've been doing a 24 lecture course Stress and Your Body.
http://www.teach12.com/tgc/courses/course_detail.aspx?cid=1585
Much of what we do here as experimenters is driven by very complicated factors, some I understand and some not, but nevertheless interesting.

The bottom line here is we are not much different than other humans except our interest is in experimental aviation rather than boating, golf or spelunking. Sometimes the risks appear excessive to outsiders but from within we rationalize the risk down to a manageable level and get on with it. The anticipated end result is pleasure and sometimes that part is very illusive.

For now I am quite content to fly behind a trusty ol' Lycoming. :)
 
David-aviator said:
To answer that question, part of it seems to be the human brain producing the neurotransmitter dopamine which has numerous functions including the anticipation of pleasure. We anticipate a reward for the effort. It is why some of us build more than one airplane or try a different engine and prop.

I've been doing a 24 lecture course Stress and Your Body.
http://www.teach12.com/tgc/courses/course_detail.aspx?cid=1585
Much of what we do here as experimenters is driven by very complicated factors, some I understand and some not, but nevertheless interesting.

The bottom line here is we are not much different than other humans except our interest is in experimental aviation rather than boating, golf or spelunking. Sometimes the risks appear excessive to outsiders but from within we rationalize the risk down to a manageable level and get on with it. The anticipated end result is pleasure and sometimes that part is very illusive.

For now I am quite content to fly behind a trusty ol' Lycoming. :)
Click to expand...

I agree. I guess the reward of all this work is a sustained climb rate of 2500-3000 fpm through 20,000 feet and cruise speeds of 200+ knots and perhaps the desire for something different. Something the standard Lycoming cannot deliver. The been there, done that certainly applies to the thousands of RV/ Lycomings out there, so some just want to learn and try something new and expand the envelope so to speak (knowledge and performance). Sometimes we get more excitement and heartbreak than we bargained for though...
 
I have to agree with Ross on the turbo failure cause. I am installing a new turbo after flying for the last 130 hours or so normally aspirated. The NA setup has worked very well but it is very mild mannered compared to the boosted version I had. I miss and desire the performance enough to go through this very complicated procedure of getting all the components to fit in an arrangement where they will work together in a complimentary fashion.

I do believe the poor crankcase ventilation situation I had was the root cause of my turbo failure. I have since added two more ventilation points with all of them feeding to an oil separator with the option of draining back to the oil pan if needed. This new installation eliminates all single point failures in the turbo system, otherwise I am not sure I would be trying this again. As Ross said, the new turbo will not use engine oil, or coolant from the engine for that matter, so it is nearly completely self contained, in that it can fail and the engine can still keep it's oil and coolant and keep making power.

I suspect I must be getting to the point where I may have more time working on my firewall forward than most RVs in the world. It came supercharged, then I did the turbo setup, then rebuilt the engine with high compression pistons for normal aspiration, and now back to a new turbo setup. Fortunately for me, I enjoy learning and experimenting with this stuff. I am excited to get the new system up and running, using the lessons learned to date.

Randy C
 
RV7 Turbo Sube Photos

Here are a few firewall forward photos of the RV7 Ralph Inkster built in Calgary, Hoping for first flight in a couple weeks:

img78090.jpg


img7811z.jpg


img7812y.jpg


img7813z.jpg


img7815r.jpg
 
Ross,

Thanks for posting those photos. As you can imagine I will be studying them at length since I am creating a similar machine. It does make for a very busy looking engine compartment once everything is in place!

Very nice looking installation.

I assume the aluminum exit duct near the exhaust is for the intercooler? Did he go with the original or a different core etc?

I have so many questions that I wish I could just it in person and study awhile:)

Randy C
 
There are 3 rads on this installation, 2 in the cheeks and one behind the engine. I can't recall whether that aluminum exit duct is for that third rad or the the intercooler. I also can't recall whether Ralph used Jan's intercooler. The project has been in the works for almost 3 years now.

I'll try to take some more detailed pix next time I'm there to answer your questions. My background is portrait photography with studio lighting so I need to brush up on things a bit to get better photos, these are not great...
 
Ross;
Please do post more pictures and explain what you can. Tht's a very fine looking bit of engineering.
Davidaviator, that was a very interesting comment on why we do complicated engineering and then fly it ourselves. I'm not too sure you have it right just yet, but keep on working with it. (hint: the reasons why we do it are variable and change over the course of the project, and as we age.:) )
The art can only be expanded if we share information.
I've been off for a few days because my son finally got his Bellanca 14-19-3A together and running. The previous owner left it to sit for 15 years before he dicided to sell. The Engine (IO-470F) was a ball of rust inside. $14,000 before sales tax to rebuild, and that's just one aspect. Aircraft engines can not sit.
The first flight was last Wednesday, and I'm the only one Peter knows that the insurance Co. will cover, because I once had a 14-19-2. Peter needs 10 hours in type before the insurance will cover him. 3.2 hours down!! I'll be flying with him @ RV speeds for the next 6.8 hours until he can solo.
Meanwhile the Cessna 182 had a wet start. H3R ST-A600 extinguishers are now $145. ASK ME HOW I KNOW!! (or don't, the fire was small, but you always want to put it our ASAP).
I'll be back with the RV-8 turbo in a few weeks.
 
Chris Hill said:
Is there a viable option for adding turbo to an I/O-360? If so, where did you find it?
Click to expand...

Looking at Lycoming data, they did turbo charge and certified a few 0360's. The TO-360-C1A60 has 7.3:1 compression, develops 210HP at SL, 207HP at 10,000' and 157HP at 20,000. This engine was built for Aero Commander Rockwell.

Maybe you could find a used one and save a lot of research and development work. It sure would make an RV snort!
 
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