Non- Biased Engine Reviews -Viking

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Vigilant1

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Just sharing my personal experience and observations.
Thanks. But, taking your advice, your observations have zero validity since I didn't experience them personally and can't validate them. Why even offer such observations and then tell folks to disregard them (and similar unvalidated information)? Apparently,, info "goes bad" after one "hop," and should thereafter be disregarded.

That would sure make Jan's life easier.

Nobody lives long enough to make all the mistakes personally. So, we communicate.
 
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proppastie

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My personal experience with Viking
so what engine do you have....what type of aircraft is it ....how many hours....any issues with properly installed parts, and what is the recommended gear box metal inspection intervals from 0 hours?
 

wsimpso1

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Starting with statistics - One hba.com member has reported actual flying results with a Viking engine, and it quickly failed during test reportedly because it had an undersized intercooler. Went to the Zenith forum and found one more guy with over four hundred hours on his Viking powered plane, with five (5!) coupling failures, a pulley failure, excess oil use and a warped block. Now we are up to 11 major issues in two airplanes. Even if we give the rest of the roughly 94 installs out there a pass, that works out to 12% major issues in a pretty low time fleet. Wearout should not be a factor - theses are so-called "infant" failures. That is a bunch. That all of 11 issues occurred in only 2 of the 94 known installs strains credulity - coincidences like this just do not happen. There have to be a bunch more in the rest of the fleet that have not been reported.

For comparison, our circle of friends is around 10,000 hours in GA, with two engine issues forcing diversions for normal landings and one engine seized in flight for a forced landing. I can accept that level. But two installs and 11 major engine issues in low time engines? UGH.

Now to specifics. Engine failure due to a too-small intercooler happens from two sources - First is elevated induction temps make detonation and/or preignition occur; Second is elevated induction temps raise temps of everything from induction, heads, pistons, valves, and exhaust, which then hastens wear out. In either case, to do this quickly (boeve51's case), it might be generally raised temps, but the failure was more likely detonation and/or preignition. Was it? I would like to hear. I would also like to know how much charge air delta T was made with the original and later HX. Usually the difference in inlet temps between secure detonation margins and detonation that destroys an engine are pretty substantial, and would mean that the needed intercooler size was missed by no minor amount. So, how much larger was the new one versus the original? Double the total volume?

Then we get to the elastic coupling that has supposedly been fixed. It would sure be nice to know what the improvements were and if any issues are being seen with the new ones.

The remaining failures are an idler that came loose (build quality at Viking needs improvement), a warped block and excess oil use (used engine vetting needs improvement).

None of this makes me think that there were just some minor tweaks needed, and now all is sweetness and light. Sounds more like he screwed the pooch on both intercooler size and coupling design, beefed it up until the complaints on new engines faded, and now we get to find out how they do as they get more time on them...

Billski
 

wsimpso1

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Perhaps I was not clear in my previous comments. The engine change was due to a fault of mine, I did not upgrade to the larger inter-cooler although it was available. I was waiting for delivery of the new unit and decided to continue flight testing. I then upgraded to the larger engine and inter-cooler.

There were no failures in the PSRU units. It was easier to replace with an upgraded unit versus pulling apart and adding new upgraded parts.

So as far as failures are concerned - one: me!!

Merle
I am too customer focused to take that as a customer failure. Eggenfellner supplied an engine and intercooler combo that quickly tore up the engine. Maybe Eggenfellner tried to keep BoeveP51 from running it until he got a better intercooler out the door, but he still shipped two parts to be used together that quickly tore up an engine.

The fact that Eggenfellner had shipped three PSRU to BoeveP51 before he got one out that he could accept on BoeveP51's airplane just shows how far out of shape the process was. Now that Eggenfelner has 100 or more engines out there, perhaps his equipment is approaching adequate reliability and life for us to trust our flying with it. Or maybe not. Problem is that we do not know.

Something I think needs to be pointed out is that reliability is not an accident. You can not test in reliability if the basic scheme does not allow it. If you just run stuff and fix what breaks or otherwise behaves badly, and you have enough engines and dynos and time, you will eventually get a product reliable when run within the realm of your tests.

To get something that is really reliable in the field requires making sure that the system scheme is sound with good margins on all of the pieces of the system to cover variation in inputs from environmental, customer use, production variability, and wear/time effects. To do this, you do need to realistically define what everything has to stand and then make sure that everything has good margins to those needs.

Caveat Emptor really applies here. If any of us buys this guy's product, at least go in eyes open.

Billski
 

rv6ejguy

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Just so everyone knows here- I know Jan, have flown with him in Florida and used to supply ECUs to him back in the Subaru days. I've also talked to many of his initial Viking customers who came to me for an ECU to try to run their engines when Jan was shipping them engines WITHOUT ECUs. Some waited up to 12 months before Jan sent them ECUs which didn't work and waited up to another year after that to get ones that sort of worked. 2 years after receiving their engines, they could finally run them. The 3rd gen ECU finally solved most of the issues customers told me and that was nearly 3 years later if I recall. I'm not sure how engines could have been run/ tested in Florida without properly functioning ECUs.

These initial Viking engines had the factory Honda intake manifolds replaced with square tubing, very short, very abrupt turn, Jan designed abortions. They didn't make anywhere near the advertised hp, mainly because of this. One irrate Searey operator who contacted me removed his 110 Viking after finding it had far less performance than the 100hp Rotax 912. These intakes were much worse than the "fry pan" ones he supplied with his Subaru conversions.

Move on to today and we have Jan cutting one leg of the elastomeric coupling on his redrives. That's his TV solution after early failures on his PSRUs...

Based on my experience with Jan, he doesn't understand torsional vibration, turbos or intake manifolds even after about 20 years playing with engines going into aircraft. Maybe he has arrived at something reliable now but the early Vikings certainly were not. Only with several thousand flight hours on a few dozen examples will we know for sure. The same criteria applies to any other auto conversion or clean sheet design for that matter.

I hope the latest Viking offerings do prove safe and reliable but know that Jan has typically done very little bench or flight testing of his products before release to the public and that is why there have been numerous revisions, even on the same part sometimes. In the engine world, where I come from, you test, test, test before releasing new creations. It will usually save a lot of money and customer ill feeling down the road.
 

wsimpso1

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My personal experience with Viking has been 100% positive.

When I have ordered something from them they have always shipped it fast and gave me a tracking number. When I ask them questions they answer fast. In my experience their products work the way they say they will. I have personally seen them fly behind their own product, compete in STOL contests (and win!) and then fly cross country back home. They've always done what they said they'll do.

Their customer service is on par with Wicks, Aircraft Spruce, and McMaster. First rate in my experience.

And they continuously improve their products. While that's very difficult in certificated aviation, we here in the -->EXPERIMENTAL<-- arena should be more supportive of that. In a way, we're ALL test pilots already; whether it's in an airplane built by our own hands which contains the newest technology, or an ancient factory-built certificated aircraft with thousands of hours on the Hobbs and decades of truly unknowable history.

I trust very few people, and I won't presume to tell YOU who to trust. But I'll give you some examples of people you should NOT trust when it comes to Aviation (examples of which can be seen posted within this thread):
  • Anybody who simply parrots opinions regarding topics upon which they have zero direct FIRST-HAND experience.
  • Anybody who tells you what you should do, but can't actually walk over to their OWN airplane and point to exactly what they're talking about.
  • Anybody who sells stuff out of a trailer but who doesn't actually fly behind their OWN products.
  • Anybody touting an engine that has never powered an airplane that has ever landed at a fly-in.
I'm nobodies salesman. Just sharing my personal experience and observations.

Patrick Hoyt
N63PZ
I am qualified to analyze data and come up with reliability estimates.

The above is a positive report on customer service, but not a data point on reliability.

If you have been running a Viking engine, please tell us which engine you are flying, when it was shipped, anything you care to share on how it starts/runs/fuel burn/oil use/etc, how many hours has it flown, and if anything besides spark plugs, oil, and filters have had to be replaced. Swapped out engines and PSRU each get their own data point on hours and condition at removal from service.

Without data, all we have is two awful examples and a null report on a third airplane. From some of the discussion, we might find that engines got better the later they were built or last updated. But we sure need data to do that.

Billski
 

PagoBay

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I am qualified to analyze data and come up with reliability estimates. The above is a positive report on customer service, but not a data point on reliability.
If you have been running a Viking engine, please tell us which engine you are flying, when it was shipped, anything you care to share on how it starts/runs/fuel burn/oil use/etc, how many hours has it flown, and if anything besides spark plugs, oil, and filters have had to be replaced. Swapped out engines and PSRU each get their own data point on hours and condition at removal from service.
Without data, all we have is two awful examples and a null report on a third airplane. From some of the discussion, we might find that engines got better the later they were built or last updated. But we sure need data to do that.
Billski
If genuine inquiry is truly the purpose, and real world owners are the source of the data, then there is no shortage of information.

To paraphrase the erstwhile SciFi show, X Files, "The Data is Out There". To require that "Data" has to come running is an unrealistic approach. What is needed is simply willingness to look. Of course, that can be difficult, when one's preferred outcome may suffer.

There are plenty of Viking customers both building and flying (RELIABILITY) who are actively posting on the fully independent Zenith factory forum.
On Youtube, one can find many flying examples. Here is one Maiden flight PLUS three more flying (RELIABILITY) examples in one video.
Adam Andrews just received his Viking 195 Turbo for a Zenith SuperDuty build. He switched from a Titan due to lack of supply.
An installation of the 195T on a BD4
Award winning Rans S-20 at Oshkosh 2019
And for the truly brave, there is the Viking factory's forum of builders and completed flying installations busy resolving questions.
 

PagoBay

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When I was looking seriously at building a Zenair Cruzer, I spoke to Sebastian directly and we discussed engines and when I brought up Viking and his reply was. "well that is an option but for what its worth we dont use them"
For the sake of honesty and fairness, you should clearly state when this conversation took place? Leaving out any time reference is just not right. Zenith waited many years before adding the Viking to its engine forums. So your comment would fit historically years ago but may not match the current situation ten years on at all.

As I mentioned, a friend at the last Zenith Factory FlyIn went around and checked what engines were on the Zenith aircraft that flew in for the function. More than half were Viking engines. So shall we make a call to Sebastian and discuss your comment and see if it is still his intention to discourage this choice of engine. I think I know the answer.
 

pfarber

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While that's very difficult in certificated aviation, we here in the -->EXPERIMENTAL<-- arena should be more supportive of that.
ABSOLUTELY NOT. The word 'experimental' on our airworthiness certs does not mean 'sell a product and hope it works'. What is does mean is that the aircraft is NOT built to FAA standards. There is a reason why the word has to be visible to all occupants upon entering the aircraft.

I've followed car motors in E/ABs since the early 80s (Kitplanes used to literally pee their pants whenever they did an article about a car motor actually working in an E/AB) but those 'wild west' days a LONG gone. You ask $20k for a car motor, you need to have a working product. Sadly, the early wild west days put a very dark cloud over car motors and the companies that sold substandard products.

Working to remove those well earned reputations is all they can hope to do now.

For the cost, there is no way I would ever put a Viking or Aero motor in my car. If you look at the product and the markup its just not (to me) a sane choice.
 

wsimpso1

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The onus of demonstrating and/or proving something falls on the person or group asserting that something. Somebody says these are great engines, I say let's see some DATA on hours and issues. And I am not the one asserting these engines are acceptable, just the trained analyst who can show you how good or bad the data says we are...

Viewing the videos and other data currently in this thread, we have 10 major issues and 6 installations. That is 167% major issues per install...

Maybe, those issues are from very early examples and the issues have been fixed. But do you really believe that they went from averaging more than one issue per install all the way to zero? In the real world, if you start with really lousy results at low hours, even if you fix the first tier of things you have discovered, that just uncovers all of the second tier issues. Further evidence of still having issues is Jan Eggenfellner continuing to make improvements... Do not get me wrong, making a product better is a good thing, but if it is installed and safe and sanitary, why would he spend more money? He knows they have weak spots...

What else do we know so far?

If we give the benefit of the doubt that those 10 major issues are the entirety of major issues in the fleet, spread over 94 known installations, that is 10% major issues. Is that possible? See paragraph above... More likely is that there is a significant change in capabilities after some development. So maybe you break the data by some specific engine ship date, then tally the hours and failures. What do we have?

We do not yet have the ship point after which to start counting, we do not have fleet hours, and we do not have more than a simple count of issues. If Jan is actually doing Beta testing on the customer dime, he could at least keep some sort of record of fleet flight hours and issues.

Until other data comes along, this qualified engineer with lots of training in doing Weibull analysis has data for:
  • 417 hours and 7 major issues (Les' report https://sites.google.com/site/vikingaircraftengineissues/);
  • Unknown hours that took 2 engines and 3 PSRU (BoeveP51);
  • Unknown hours without issues (PatrickW)
  • One flight without issues (Maiden flight video in post 140);
  • One chase plane of unknown hours and unknown issues (chase plane in maiden flight video);
  • The award winning S-20 with unknown hours and unknown issues (video in post 140).
Let's presume Test Phase of 40 hours has been flown in the cases of BoeveP51, PatrickW, the chase plane, and the award winning S-20, then give 1 hour for the maiden flight. 578 hours and a minimum of 10 major issues is MTBF of 58 hours. I do not like to "words" away blown engines and PSRU's that the factory replaced because they knew they would fail, but even if we are at 7 failures instead of 10 issues, that is still an MTBF of 82 hours. Gulp. Not within my risk tolerance yet...

Here is the problem with trying to create a convincing reliability story when you have actually had failures. Your sample collects failures. The sample we have is products shipped to regular paying customers, installed on airplanes, and accumulating hours. Failures do not go away, the best you can do within the sample is hope that the first failure is not added to when you run more from the sample. Running more passes without failures only slowly dilutes the failure rate. 1/1 is 100%, 1/2 is 50%, 1/3 is 33%, 1/10 is still an abysmal 10% failures. If you get other failures, it really gets bad...

Might as well stop running when you see a serious issue, do the engineering to knock out all of the failures with substantial fixes, and then start building run time with sample size again. You have to be able to report on when the changes happened and show that your sample runs better since the changes. We start over on adding up hours and failures to see where we are. Currently the data that you guys are telling us we have is six airplanes with unknown hours and issues. Yet we know that there are about 94 installs flying. Terrific. Bring me some data on them, which stage of product development they came from, hours flown and failures seen, and I can show you the reliability on each iteration of each engine, even show you the reliability growth curve. Without adding to the real data, all we have is what is above. And that data indicates planes I do not think I would ever take out of the glide cone of a big runway.

Billski
 

Rhino

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Yes, hard data, empirical data, is definitely needed. But trying to say posts in an internet forum constitute empirical data is like saying an internet poll is an accurate measure of public opinion. We just don't have the needed data. I wonder when, and even if, we ever will.
 

Marc Zeitlin

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Yes, hard data, empirical data, is definitely needed. But trying to say posts in an internet forum constitute empirical data is like saying an internet poll is an accurate measure of public opinion. We just don't have the needed data. I wonder when, and even if, we ever will.
You are absolutely correct that data is needed and internet forum posts don't fit that definition.

However, what having a number for installs and a number for known failures gives you, as Billski aptly explained, is a rough estimate of the failure rate. Because you want a failure rate well below 10e-3, it takes 1000 successful stories to counteract ONE failure. So one failure story is far more meaningful (like, 1000X as meaningful) as a success story. If there are a lot of failures, as there seem to be with anything associated with Mr. Eggenfellner, then it takes a LOT of success stories to get the failure rate down to a reasonable place.

I had precisely this experience with Emagair in the canard community. In the first 10 or so years of their existence, we counted 35 hazardous / catastrophic failures in 15 different airplanes, all in the <200 hours/airframe period. Obviously a miserable failure rate. It SEEMS as though, through trial and error, while studiously ignoring the input of knowledgeable mechanical engineers, they've corrected their system to the point where I don't hear of failures anymore (in canards). Pretty close analogy, I think...
 

Rhino

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You are absolutely correct that data is needed and internet forum posts don't fit that definition.

However, what having a number for installs and a number for known failures gives you, as Billski aptly explained, is a rough estimate of the failure rate...
Yes, based on anecdotal information from internet posts. I just wish we had something more empirical to go on. But that's at least partly due to my statistics classes in college. I had a professor who was fanatical about using empirical data, and he'd roast you alive for advancing any hypothesis without having 100%, ironclad proof in your data and analysis. Actually I found what rv6ejguy posted to be the most informative information here of a critical nature towards Viking. It was very enlightening. I'm not saying there can't be a problem with Viking. I'm just saying we need more hard data to definitively say that. Personal experiences are great, and often very informative, but they don't constitute hard data without better sampling and analysis. Yes, there are people who've had problems with Jan's engines in some way, but there are also lots of people who think his engines are great. The stories are very interesting, but they don't constitute an empirical data set.
 

BBerson

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I read through some of the Viking website. The business model seems to be to provide the latest technology from the latest wrecked cars. The claim is these car engines are proven. I didn't see any claim that the PSRU or any Viking parts are proven. It would be difficult to provide proven packages if every package is different or latest engine, prop manufacturer or airframe. I don't see any testing to FAR33 or ASTM such as vibration surveys for each engine model, prop, as would be the case for certified or SLSA.
But that isn't unusual with experimental. I have asked several experimental providers from A to V and none do vibration surveys.
 

galapoola

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At 4:22 of this video, a good explanation of direct vs. port injection in an aircraft installation. Mark Kettering of Aeromomentum explains why they use port in their engines. Viking’s Honda engines use the stock direct. Something to consider In addition to everything else.

 

BoeveP51

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Until other data comes along, this qualified engineer with lots of training in doing Weibull analysis has data for:
Billski, The only data you have , at least in my case, is ONE engine failure and ZERO PSRU failures. The engine failure was my fault, not Viking.
You are correct in your need for data, I certainly don't dispute that. But please don't cloud the picture with content like above. For someone reading that, the implication is 5 failures. Not the case. I have never had a PSRU failure, I have had improvements made to the PSRU.

Now if you would like data regarding the number of installs, flight hours, testing hours, whatever, then why not give Jan a call and ask him.

I have no argument with your need for data or your apprehension to fly behind a Viking engine. But in the same token I certainly would not believe any of the data you are spouting since you don't have any backup info to support it. It is all conjecture at this stage. It is big unknown. I would recommend an open mind rather than a closed one.

Now possibly other folks who have been flying the Viking engine may pop in here and comment but I doubt it. My history in this forum has been very light in terms of comments due to the fact that there are so many "experts" that try to tell me everything I should know, almost every time something is stated.

oh well, time to go fix my Tailwind rather than pound a keyboard. And no, the engine did not fail again........
 

lelievre12

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At 4:22 of this video, a good explanation of direct vs. port injection in an aircraft installation. Mark Kettering of Aeromomentum explains why they use port in their engines. Viking’s Honda engines use the stock direct. Something to consider In addition to everything else.

The comparison between GDI and port injection is relevant. Unless I am mistaken, the base Viking engine on at least one model is a stock Jazz/Fit Motor.

1623419525912.png

This motor has a compression ratio of 13.5:1 which simply cannot run in an aircraft with port injection without detonation. If port injectors put in the full fuel charge prior to the compression stroke then a high compression ratio will increase gas temperatures. Boom. Detonation.

Not so much with direct injection. With GDI the fuel is injected during the compression stroke and can be timed not to meet combustible stoichiometry until the spark triggers the flame front. And even during combustion, with GDI more fuel can be added to increase/decrease/time optimum PCP.

All good stuff for cars, however I cannot think of a single successful aircraft motor that runs 13.5:1 and successfully maintains detonation margins even with GDI. Certified engines require 12% fuel margin from detonation on a standard hot day across all throttle settings and at coolant temp limits. With 13.5:1 that would require a lot of fuel ROP. I believe Jan programs well ROP across most power settings however I have never seen a test to AC 33.47-1 so its hard to know. In fact I have never seen ANY tests from Jan except static thrust. However the unofficial GPH numbers I have seen all point to BSFC numbers >.45/lb/hp which is rich, rich, rich but with 13.5:1 probably needs richer still. So much fuel probably kills any efficiency benefit of GDI and probably robs power too. So the temptation for Jan is not to do it, and hence get closer to detonation margins from such a high compression engine. Made worse particularly if run on Mogas which has way too low octane for use in the air.

Of course if the original Honda programming and knock sensors were installed then the issue can be avoided however O2 exhaust sensors are not compatible with leaded fuels so Jan removes them. No Lambda monitoring. I believe Jan also removes all the knock sensors too. No knock monitoring either. So the detonation margins are blind and rely on Jan's fixed programming of the ECU. Across the huge variety of engine operating conditions, if the needed generous ROP limits are ever wrong or too fine, overheating and engine destruction from detonation can result. All without anything on the panel to alert except strangely high coolant temps, excessive PCP and PSRU harmonic issues thereafter.
 
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CAVU Mark

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Last Friday, June 4 2021, I spent about 30 minutes behind a Viking engine in a demo flight. I found it to have plenty of torque on take-off as I was pushed back into the seat and the flight was uneventful. The owner did say he burned avgas for a while that caused one valve to stick which required a cylinder removal and polishing. He prefers to run non ethanol mogas. The engine showed around 250 hours on it. I believe these engines are also Honda outboard engines.
 

wsimpso1

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Billski, The only data you have , at least in my case, is ONE engine failure and ZERO PSRU failures. The engine failure was my fault, not Viking.
You are correct in your need for data, I certainly don't dispute that. But please don't cloud the picture with content like above. For someone reading that, the implication is 5 failures. Not the case. I have never had a PSRU failure, I have had improvements made to the PSRU.
Merle,

I am not attempting to change your mind. I am writing to everyone else contemplating these engines with a goal of educating them on how immature these engines were and likely still are.

But to your points.

Were you operating this engine as a test case for Viking, frequently called Alpha or Beta stage test? If so, we can downplay the first engine and first two PSRU as developmental prototypes. But if he shipped to you as a regular customer, they are part of the fleet. To close the loop on this, I also calculated MTBF without your data points, but with the seven failures contributed from another customer, MTBF was still abysmal.

Eggenfellner shipped an engine w/ an intercooler and PSRU to you, with the intent that you install them and fly them. The engine he shipped to your failed, and if it failed because of an undersize intercooler that Eggenfellner supplied, that is still a failure attributable to Eggenfellner... That is the way you run statistics on failures. It had been intended for use when shipped: it counts.

Then we have the first two PSRU that Eggenfelner shipped to you. Jan had intended for you to install and fly both of those at the time of shipment. None of us believe that he shipped you two more PSRU after the first just because he made them better. Nope, most of us believe that he shipped the second and third PSRU because he was concerned that the first and second PSRU had serious issues and should not be flown. Once shipped to you, they count as failures in the fleet too. Why? Because they were intended as flight articles, and if you had flown them before he shipped the replacements, you would have broken them too.

Can you restart the counting of failures and hours after mods are made? Certainly. But all hours run on the pre-mod stuff evaporates. You start over on hours and failures OR you keep all of the hours and all of the failures.

Now if you would like data regarding the number of installs, flight hours, testing hours, whatever, then why not give Jan a call and ask him.
We all know how far that is likely to go. Besides, I have not dog in this fight. Folks are telling us these engines are fine, and I have the nerve to ask for a decent basis for that assertion. With 94 known installs in the register, we should have some data. Anyone telling us that an engine is fine, I say "great, how many engines, how many hours, how many failures?" Until we either have a bunch of test cell time or fleet experience, we really do not know...

Billski
 

rv6ejguy

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The comparison between GDI and port injection is relevant. Unless I am mistaken, the base Viking engine on at least one model is a stock Jazz/Fit Motor.

View attachment 111611

This motor has a compression ratio of 13.5:1 which simply cannot run in an aircraft with port injection without detonation. If port injectors put in the full fuel charge prior to the compression stroke then a high compression ratio will increase gas temperatures. Boom. Detonation.

Not so much with direct injection. With GDI the fuel is injected during the compression stroke and can be timed not to meet combustible stoichiometry until the spark triggers the flame front. And even during combustion, with GDI more fuel can be added to increase/decrease/time optimum PCP.

All good stuff for cars, however I cannot think of a single successful aircraft motor that runs 13.5:1 and successfully maintains detonation margins even with GDI. Certified engines require 12% fuel margin from detonation on a standard hot day across all throttle settings and at coolant temp limits. With 13.5:1 that would require a lot of fuel ROP. I believe Jan programs well ROP across most power settings however I have never seen a test to AC 33.47-1 so its hard to know. In fact I have never seen ANY tests from Jan except static thrust. However the unofficial GPH numbers I have seen all point to BSFC numbers >.45/lb/hp which is rich, rich, rich but with 13.5:1 probably needs richer still. So much fuel probably kills any efficiency benefit of GDI and probably robs power too. So the temptation for Jan is not to do it, and hence get closer to detonation margins from such a high compression engine. Made worse particularly if run on Mogas which has way too low octane for use in the air.

Of course if the original Honda programming and knock sensors were installed then the issue can be avoided however O2 exhaust sensors are not compatible with leaded fuels so Jan removes them. No Lambda monitoring. I believe Jan also removes all the knock sensors too. No knock monitoring either. So the detonation margins are blind and rely on Jan's fixed programming of the ECU. Across the huge variety of engine operating conditions, if the needed generous ROP limits are ever wrong or too fine, overheating and engine destruction from detonation can result. All without anything on the panel to alert except strangely high coolant temps, excessive PCP and PSRU harmonic issues thereafter.
You seem to dwell on this detonation issue and the supposed advantages of GDI in aircraft applications.

Right from page 3-18 of the Lycoming Operators Manual: BSFC on a standard carbed O-360 producing 130hp at 2400 rpm is .43 at full rich mixture, 8.5 CR, timing fixed at 25 deg. So the Fit here isn't very impressive despite all the new tech. There is marketing and then there is cold, hard reality.

In cruise we have standard injected Lycs and Contis achieving .37 to .39 running LOP. None of these are detonating.

My 2008 port injected bike runs 12.9 CR and produces 200hp/L on 87 octane pump fuel.

Toobuilder here on HBA flies his EFI IO-540 powered Rocket running it on 87 Mogas in the heat of Mojave.

Being able to run LOP is more important than CR with regards to BSFC in aircraft operating at continuous high power settings.

There is almost no chance of detonation in cruise at altitude running LOP. As Mark says, you limit PCP via variable ignition timing to hold it short of detonation. We do this every day without breaking any engines.

Want to see what old tech can do? Here is a screen shot from a std. IO-540 RV-10, 4 place, fixed gear airplane truing 170 knots on 10 gph.:
 

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