She Purrs Again - Flying the Raptor Prototype

[@garywhitman2540]

Peter, it may help to watch "What's wrong with Raptor's compound turbo system?" On KZbin

[@martinrenschler4046]

Isn't there oil coming out of the drive shaft, dripping onto the oil cooler? I see some oil residue but of course this could be from the total failure.

[@SwimmingBrambles]

I think it is residual oil from the oil flood. The bottom redrive unit is a sealed unit using grease in the bearings and is one of the very few assemblies which has not given rise to any issues - yet.

[@Meyersmanx1]

Please consider not hard mounting the oil cooler. Hard mounting as you have done is known to fatigue hear exchangers rapidly.

[@DVolvoguy777-x7o]

I also added a comment.

[@theoldbigmoose]

My thoughts exactly. Looking at the mounting brackets for the oil cooler, I think it is a resonance issue with the cooler vibrating.

[@extraace]

Absolutely no way some leftover egr "crud" would stop a turbo. And if anything does, the turbine would be mangled. If the squeel indeed came from the turbo, my hypothesis is on a damaged thrust bearing from the oil pressure incident and the resulting rubbing on the housing. I know you don't really listen to suggestions (I am somewhat the same), but I hope you think twice about reusing those turbos. Small price to pay in the scheme of things. At least measure the axial and radial play. If one turbo has a bearing failure in the air, at best, you'll lose boost and 2/3 of your power, but worse, possibly your new engine will inhale compressor wheel pieces, and a chance of another engine failure. If this was a boat/car or at least a twin, I would take the turbos apart to check the bearings. The balancing would be disturbed. I use a jig I made for realigning the compressor wheel and nut. I hope you consider this. I used to do flight testing and I make some high performance turboed stuff that stays on the ground. But, I purposely stay away from planes that I can work on because I tend to get impatient and rush/take shortcuts with my projects. And if it was a plane, it would probably eventually kill me. I see a lot of that in you. And I really want to see this plane succeed and not end up on the news because of rigidly mounted oil cooler cracking or a blown oring to the redrive. That really should be corrected to an ORF type seal if it hasn't yet. Last I remember the oring was pretty much uncontained radially.

[@bjarnevarme9830]

I agree.

[@ericpanning8551]

I would suggest sending the turbo's out for overhaul and replacing with one larger turbo for now. I think this will optimize performance down low and simplify the system. The first turbo needs to be larger than the second anyway.

[@DVolvoguy777-x7o]

Hi Peter, do overhaul those turbos. I think it would be plausible to have a larger turbo on one side to help with the compression levels. Please do install isolation mounts (brackets)on the oil cooler to minimize the vibrations to it. Glad you were able to source a replacement engine. Would be cool to see this airplane with a Williams turbofan. Keep up the good work sir.

[@grandenauto3214]

I don’t think a little crud is going to stop a turbo turning?? 30000 rpm?? I’d me more concerned about a bearing going out...

[@jetrep]

Okay I don't buy the theory about intake crud stopping the turbo but let's assume it's true... why would you run the engine again knowing there's more crud in the intake?

[@predragbalorda]

I can smell a Dutton lurking...

[@seaonadams]

I didn't see any vibration dampeners on your oil mount this will lead to the cracking you are seeing on that oil cooler. It also looked like the cooler was only stabilized on one axis.

[@getrav]

Congrats!!! I was so bored of KZbin without the Raptor

[@MikeyFirst]

Likewise!

[@conradsinsua7415]

the double intake track is to induce swirl in the combustion chamber,

[@antonudrp707]

The rv6ejguy just did an analysis on the compound turbo system of Peter’s new (Audi) engine. Quite interesting analysis. Hope Peter watch watch it on KZbin. Might help him with his elaborate engine diagnostics.

[@cranerapid1791]

Rv6ejguy is a complete moron. Don’t listen to a thing he says. Last time he talked about turbos he kept using single turbo data for a twin turbo even after being repeatedly told he was using the wrong number. It’s amazing how someone that ignorant could possibly think they were competent.

[@daveb4446]

Just watched his video and it was painfully incorrect. He used the corrected pressure backwards for twin turbos. It clear he has never actually used a twin turbo before.

[@doggzilla1]

His math is all wrong. Years ago I had a conversation with him about this and he was using the wrong math. He’s somehow gotten even worse math. The corrected mass flow does not double. It stays the same and is divided by the turbos.

[@philpotter2515]

@@cranerapid1791 It's really simple. He has an impressive resume of results, including Gold Sport Class Reno championships two years straight, and a self designed turbo Subaru setup in his own RV6... 18 years and still running strong. However, I can still be convinced if you are competent enough to provide an accurate step-by-step counter analysis. I'll be waiting for your video.

[@cranerapid1791]

@@philpotter2515 It’s really simple. He has no experience with twin turbos or diesels, and his engines were developed by other people. In his video he confuses inches of mercury with lbs per second of air. He’s mathematically illiterate and vastly exaggerating his expertise.

[@dazzasnipes1911]

hi Peter. In relation to the turbos may i ask did you split the turbos and use a mix of turbine and compressor bells? in a previous video involving the turbos i commented that in my own experience, some car/truck manufacturers use turbine and compressor bells machine matched for each other and you cannot swap the bells due to the tolerance differences. i once swapped the compressor side on a Mitsubishi 7.5 ton truck to save time and effort and it wouldn't boost and would squeal like crazy under load and it was because the housings was not machine matched. just something for you to look out for.

[@bigdaddie40]

This makes the most sense. Turbo heats up and tolerances get tighter.

[@zmanmd1641]

An inspection of both turbos and the intake path is the minimum requirement before the next run. Otherwise you risk ingesting a piece of FOD and damaging at least one piston on that new engine. Better safe than sorry.

[@lucianogreiner]

Man, imagine a diesel runaway when you're in the air...

[@krperry2007]

It's hard to imagine that the turbo actually stopped instantly. Maybe a larger flake blocked the inlet until it broke up? Could it also have been the inlet on the compressor side?

[@antonudrp707]

The rv6ejguy did a comprehensive analysis of the compound turbo system on Peter’s Audi engine. The vid on KZbin was quite interesting and educational. Worth watching.

[@krperry2007]

@@antonudrp707 Thanks that was very interesting. We tend to take for granted when trouble shooting that the product was engineered properly but they don't call it EXPERIMENTAL without a reason!

[@cheerdiver]

7:00 'Why would I use a part known to fail?" Experience, knowing why it failed. Yes the apparent poor weld quality of the seems is a give away, though IMO not why it failed. The mounting bracket provides no vibration insulation, rapidly cycling the aluminum to fatigue. In an iron analogy, think of bending a cloths hanger rapidly. Consider mounting the A10 Warthog to the frame, it will be a bit taxing to co-ordinate with the other pilot, but your sea level performance will be outstanding AND you'll be bullet proof. Guessing the mounting bracket (that split from the OC) is steel, due to poor bonding of Fe/Al. Better to use a mechanical means to secure, like threads which happen to be on the fitting already. The rubber hose properly mounted, could provide the needed vibration insulation (bubbles?). DO worry about Al/Fe difference in threaded material. An alt could be hydraulic 'Quick connects', due to the O-ring isolation. Would imagine a closed foam case to be optimum, vibration isolation.

[@John.Halsted]

Have you considered removing the intake manifold and acid washing it to prevent FOD? My old VW ALH TDI would get seriously fouled up with that EGR system in place.

[@rodgerhecht3623]

I hope you will follow some of the suggestions that have been posted about your turbo and the OC mounting, and the oil leaking from the redrive . Risk management is not your strong point.

[@clarkstonguy1065]

It seems possible that some of the debris created by the loss of oil pressure made its way into the turbocharger. They typically use something like a brass bushing as the shaft bearing, not roller bearings. So there is probably a metal chip embedded in the turbo bearing now.

[@glynncleaver7398]

One other thing to remember is a diesel will run on its own oil if one of the turbos let's go and it runs away shes a bit hard to stuff a rag down her throat to stop her throwing a leg or two out of bed. Second hand motor reusing parts from a lunched motor. The more I watch the more I think there's more wrong with the mind set rather than the plane

[@baomao7243]

I greatly admire your persistence. Exemplary.

[@Rpmsailor]

Sounds great and ready to go!!! I’m sure you will check it out thoroughly before liftoff!

[@bootstrapjesse]

Has anyone seen this video by rv6ejguy about the Raptor turbo chargers? If someone has a way to let peter know, maybe he should watch it.

[@cranerapid1791]

That’s because Ross is a complete idiot. Last time he talked about turbos he had to be reminded a dozen times that he was using the wrong number of turbos on his calculations. Oh, and Ross also got the fuel injection information wrong because he was using injection info for a gas engine. He’s so arrogant he’s become delusional.

[@cranerapid1791]

Just watched his video and confirmed that he’s still an idiot. He’s using the wrong corrected pressure. It doesn’t double, it cuts in half with twins.

[@daveb4446]

Just watched it and he’s got the math for the corrected pressure wildly wrong. That’s not how twins work. They don’t double the mass flow in series. They divide it.

[@kestreltom]

In my limited experience, the upstream turbo in a series compound turbo setup always has a much larger compressor & turbine compared to the downstream turbo. If the upstream turbo's exhaust turbine is too small then the exhaust manifold back pressure, also known as drive pressure, will be excessive and heat build up in the engine will also be excessive. With an upstream turbo that is too small, Peter's drive pressure ratio could be as high as 2:1 which means his exhaust manifold pressure could be 80 psi

[@cranerapid1791]

@@kestreltom twin turbos aren’t even required for this. They work extremely well at high altitudes with just a single stage. Like the P-47. The second turbo only needs to slightly increase pressure to sea level. It’s not meant to run at extreme pressure.

[@tacticalrabbit308]

What was the oil coming out of the bottom of the redrive

[@stephenwalton7079]

Take care of your turbos and they’ll take care of you. Two ways to do that. Best way if you can afford it space/weight/$ wise is to install an accumulator to bleed oil into the bearings on shut down for ten minutes. A Volvo dealer I knew used to try to sell these on every turbo car he sold. If the customer wouldn’t buy it, he threw them in for free as within the warranty period, the turbo’s bearings would get coked up with hot boiled oil and fail, usually just in time for him to have to replace the turbo at his expense. The other way is to be sure to thermal stabilize on every shut down. Different turbos have different needs but rule of thumb says three minutes at idle will greatly extend turbo life. Works on all manner of turbo from cars to recip airplanes to big jet engines. Best of both worlds, you do the hardware and the operating procedure. Good luck, keep plugging.

[@scarter176]

Get her back up to altitude and do some best glide profiles, stalls, emergency gear extension etc.

[@timlowe5318]

Yay, will be good to see her flying again, missed that. Oil cooler problem does need sorting first tho. Keep at it, Peter.

[@marulixy]

Just winding back the time to the engine out incident, I'm asking myself if there was a high oil pressure incident caused by that failing cylinder which then lead to the seal to pop and maybe also cracking open the oil cooler. At the time you were flying circuits in a kind of straight and level position. With your oil delivery and return pipes to the redrive and both turbos, could it be that you had too much oil building up in the sump as to go over the max oil level limit and thus causing back pressure through the oil return pipes and elsewhere and causing that cylinder/piston to fail as oil cannot be compressed. It would be wise to analyse the cause of that cylinder/piston damage before flying again as not to have the same event happen again. I recall the video where it sounded like a loose connection rod when you tried to start the damaged engine initially.

[@kentfield2205]

The oil leak appears to be coming from the redrive. Why is the oil so black? Did you put new oil in the new-used engine? Did you flush the oil lines prior to hooking them up to the new-used engine?

[@daveb4446]

Peter, I’ve had a similar problem. At overboost the pressure overwhelms the intake duct seals and the clamps vibrate like a flute reed as the air pushes past them. Very loud screech.

[@mishmish1968]

Thanks for the update, happy to see the engine running, looking forward to see the Raptor flying soon, all the best.

[@jgd65]

Great to see (and hear) her up and running again!

[@rfrancis1111]

Are you ok? Any updates to report?

[@dougflaugh141]

The black crud on the oil cooler came from the redrive. You can clearly see it leaking out of the bottom of the redrive.

[@andrewcox3686]

Out drive looked wet, is that normal? Earl's Perfromance makes various size oil coolers.

[@Digital-Dan]

I'd say there are ways that the old muddy standard definition video was better for creators than now. Remote observers at least think they can see the smallest details. I, as a relative rube about these things, see nothing of course.

[@Digital-Dan]

Do you need another round of approvals after the engine change? Be good to have a second pair of eyes look it over.

[@richard8181]

What's the set up on the crankcase pressure / venting?

[@kestreltom]

With regards to your compound turbo setup, are you measuring drive pressure in your exhaust manifold? It might be useful to know if your drive pressure is excessive.

[@1950harleycharley]

What a beautiful bird and she sounds soooo good! Can't wait to see you flying again and then building these for sale!

[@1950harleycharley]

Sir, you have my utmost respect! Spiro Agnew, VP of the USA under Richard Nixon used to call those who were negative about the administration,...they were known as the "Nattering Nabobs of Negativism." I appreciate your honesty when something happens, you explain it...you are making so much progress for one man. I just wish I had discovered you sooner! Salute!

[@0069yj]

My week is incomplete without your update....😂

[@PMMM9]

You really are so talented and committed. Keep up all your great work.

[@jimmonti]

Glad to see the new engine singing...Just a question about the last one... while you were waiting on the new one, did you find ant evidence of why you lost the cylinder? I know the used engines are always suspect, but would be nice to know if possible

[@imwalking1690]

It failed from lack of oil. Engine’s tend to seize without oil. By looking at how quickly it stopped, I’d say the pistons seized in the bores and broke at least one con rod.

[@jimmonti]

Yes, engines don’t like to run without oil... but I was wondering if a failure caused the oil loss.

[@dnomyarnostaw]

@@jimmonti Didnt he explain about the omitted circlip on the large rubber grommet?

[@richardbjelland2467]

question, did you consider balancing and blue printing the engine? why or why not? curious given high rpms?

[@rolandtamaccio3285]

That engine is very precise . Balancing and blueprinting will show no ROI . The power will be mostly fuel and boost .

[@richardbjelland2467]

@@rolandtamaccio3285 I don't know much about the audi diesel. They maybe balanced and blue printed, but very few engines are. There is no roi on this. Cost only, but gets rid of vibration at high rmp, my concern is all! What do you know about tolerances on the audi diesel?

[@rolandtamaccio3285]

@@richardbjelland2467 ,,, it's not that high a RPM, balancing in this engine would be more of an insurance program that you didn't get an oddball crank or flywheel . It's close to impossible that any benefit is to be found .

[@richardbjelland2467]

@@rolandtamaccio3285 when you say they are precise, German engineering,, are the tolerances tight? I know zero on audi. thanks for the imput.

[@rolandtamaccio3285]

@@richardbjelland2467 ,,, it's a cost benefit analysis thing . Musk can resupply the Shuttle for ten percent of what it would take NASA to do it . Would NASA be safer ? Theoretically . Audi has gotta be in the top five engines in the world . The obvious downside for Peter pulling one of these apart in time and money, is staggering .

[@superlight47]

Nice. Will like to see you get everything up and running in full soon.

[@rickbrandt9559]

hung boost control valve !!

[@glikar1]

The big question is, how do you reduce complexity on an automotive diesel?

[@doolittlegeorge]

By using a 2 stroke diesel motor.

[@windchase342]

Delta Hawk

[@18robsmith]

Remove the excess "emissions" junk and do a general tidy-up of the pipework. Depending on the engine there will probably be the need of a new ECU. In reality it doesn't look any more complex than say a Continental CD300 which is a 3litre V6 of similar power - the biggest visual difference between the Audi engine & the CD300 is that the Audi has sequential turbos against one-per-bank on the Continental. Edit to add - And the CD300 comes with a propeller drive system attached, but (obviously) the Audi engine doesn't.

[@predragbalorda]

@@doolittlegeorge an AIR-cooled two stroke diesel

[@scarter176]

This engine sounds better than the last one.

[@doolittlegeorge]

@@eether54 "what's that noise?"?..????..

[@jcferreira]

It does sound better.

[@willhibbardii2450]

@@rv6ejguy , Yep, I caught that too.

[@jcferreira]

I'm not an engine sound expert but the first one had this grinding sound to it but also a nice whistling sound. I guess that was caused by the turbos though? This new engine sounds more like an aircraft engine but I also heard some strange sounds.

[@willhibbardii2450]

@Marvi Wilson , Even though engines are manufactured side by side they all seem to have slight differences from each other. Peter stated that the first engine ran better over time.

[@triedproven9908]

Seems like the new engine is putting out more vibrations. That squeal sounded like a failing turbo bearing, unless something was dropped down the intake that stalled the inducer. I say pull the turbos apart since you have to wait on a new oil cooler.

[@doolittlegeorge]

"What's that noise?" channel returns!

[@martinmusial7428]

Look at Setrab or C&R racing for oil coolers, these are high quality(not cheap) oil coolers meant for racing applications that put up with high pressure, heat and vibrations. Also make sure you use rubber isolators when mounting the cooler, the vibrations can crack the brazing on coolers.

[@jacksonkirka]

Never quit!

[@karlhuber2818]

I admire Peter for what he has achieved so far, but that airplane will be a failure with this kind of engine. What kind of responsible pilot would fly that aircraft with an engine installed sourced at a scrapyard ? I know that is a cheap solution, but it could cost your life. Install a proper aircraft engine, there are modern FAA approved aircraft diesel engines available with + 300 HP . That way way you could focus on the other issues that airplane still has.

[@nateashton8282]

Improved racing makes a nice oil cooler.

[@ssmith2019]

Good On Ya !

[@pctrashtalk2069]

Earls Performance makes a range of oil coolers.

[@davedunkin725]

Keep up the good work! Never give up!

[@martinmusial7428]

so at 18psi that turbo is probably spinning 75K+ rpm, a small piece of carbon isn't stopping a turbine wheel at that point, if debris actually stopped at a turbo that quick from that high speed you would have more serious issues, I would inspect the hot side of that turbo to be sure. Also I would be more worried about the debris going through the cylinder, possibly getting caught between the piston and piston wall, or what it would do to a intake/exh valve. How are you controlling boost/WG actuator, fixed WG spring or is it done through Motec?

[@timmikep1978]

Any word if Oshkosh is happening 2021??

[@Jeff-zg5gm]

It is going to be held. They are starting to sell tickets now. Sun ‘N Fun is happening as well. Much closer to where he is now.

[@Jaxav8or]

You should have walnut blasted your intake ports on the new engine before installing.

[@57guyro]

Did you see the talk on the turbo on your plain from rv6ejguy

[@elishiner9818]

I have completely given up on buying cheap stuff online...same as that oil radiator.....junk is the standard these days and you have to pay a fortune for something that is atleast standard quality

[@ick79]

No expert and someone may have said it already In my experience when a mechanical item is stopped by force it isn't good and doesn't recover!!! With that said I would definitely look at the waist gate... Just my two cents... Lol probably only worth 1/2 a cent..

[@davejohnson7152]

Good job Peter !!!! Keep it going

[@johnylinen479]

Peter, I would suggest you take a pause. What are you trying to accomplish now with this prototype? Why did you not address the radiators when you swapped the engine? What are the next goals of your flight tests? Because of engine/prop reliability you have not been able to do actual flight test envelope expansion. You have not been able to test to max gross weight. Because you don't have a pressure vessel, you can't test pressurization. If you don't get back on track, you will never be able to use this prototype to carry passengers or do demo flights. You have done an amazing job, especially solo. You had TWO major unknowns with your project. Aircraft design and new unproven engine. I suggest you get laser focused with what you need to prove, test, and re-engineer using this prototype and get that work done. Then move on. This prototype will never be able to prove the original specifications that you posted on your web site. The reason that many were excited about your project. 4-5Pax cruise at 25K, going 250+ Knots on auto gas. Fast, Cheap, SUV.

[@bigdaddie40]

Take a look at DazzaSnipes' post on housing tolerances.

[@jekader]

Wow, that was fast! I admire your ability to get things done. Waiting for more progress updates!

[@ps3400]

Hey Peter, great to see you progressing well with this build. FYI please consider the technical detail regarding the twin turbo setup a video posted by rv6ejguy at kzbin.info/www/bejne/f5qqdqKHpcidpdU it looks like helpful technical detail to consider in a positive help to solve the power / temp issues. hope the video is of use. cheers

[@localhawk1]

Hope he will see this link ... seems to be important

[@cranerapid1791]

He’s using the wrong corrected pressure. RV6 is mathematically illiterate. I’ve worked with him before and he’s impossible to reason with.

[@cranerapid1791]

@@rustyshackleford7022 yes, but if you watch the video he clearly doesn’t understand the meaning of the turbo maps. He’s multiplying when he should be dividing.

[@jaymenna]

Peter I don't know if you are Sisyphos or the Little Train that Could. But I admire your perseverance.

[@Digital-Dan]

Just pray he isn't Icarus!

[@bd5av8r1]

Awesome! 🙂

[@willasproth]

Dope

[@flyhigh1768]

Nice!

[@mccallumcra]

I can't wait to see some more high speed taxi runs. Not being sarcastic.

[@prmpfbubub]

Great to see the Raptor with a running engine. I hope you can continue your test flights soon. How much was the engine and do you know about the age/milage?

[@madmerlin1922]

Peter please know that I'm not an A&P or a mechanic, but back in the day I use to be able to go to a radiator shop where they could custom build a radiator for my car. I don't know if that could also be used for an oil cooler but I thought I'd just throw it out there. Good work, Glad your back making videos. The only thing I miss more than your videos is my own Raptor sitting in my hanger. :-) Well done getting the new engine fitted so quickly.

[@VMCAviationVideos]

I can't wait to see the Raptor in person, or even have a flight on one.

[@willhibbardii2450]

Peter, It's remarkable how seemingly painless you've made this engine swap. Great update progress sir. It sounds very healthy to me however I think I detect a slightly different exhaust report with this engine. It doesn't seem to be quite as smooth vibration wise through the throttle ranges as the other engine. Yet it sounds more torquey. Probably like you say it will smooth out as it cleans it's self with good high-power exercise. Hope it plays out well moving forward. Cheers

[@richardbjelland2467]

engine sounds healthy!! I like the sound better than the old one. Sorry to see oil leak, but always something to fix. Can you program the thermostat to 180? Looks clean overall. 1,000,000 attabits. Glad to see turbo kicked back on. Probably was something that got ingested and exited. hope no damage. Good luck on future run ups and a decent oil cooler. Party on Wayne!!! keep the videos coming. Had really bad withdrawal symptoms!!! I am sure others did too!! Happy to see this bird in the air again!!!! Safety first!!!

[@andrewrae6755]

Concerned Peter has no one watching his back.

[@utuber2940]

Why do you need an egr in an airplane?