Water Cooled Lycoming?

[Jconard]

Ross,

I was talking about this the other day with a buddy of mine...I got on the idea after hearing from a friend who installed the "nickies" on his 914, and has had a wonderful experience...I mean the LN engineering jugs.

I would buy a set of four in a heartbeat if the stud thing could be worked out....with superior heat rejection, I am guessing that cooling drag could be further reduced, as overall volume would be significantly less.

And, I would agree that Nikasil is tough stuff indeed. By the way the use of nickies on the vw conversions is worth better that 3 lbs per cylinder in weight reduction...on a lyc this may be as much as five per jug...20 lbs per engine.

I would think you would need some sort of dilavar stud though...to keep studs from getting pulled out of the engine...thoughts?

[kentb]

Originally Posted by Jconard

I would buy a set of four in a heartbeat if the stud thing could be worked out....with superior heat rejection, I am guessing that cooling drag could be further reduced, as overall volume would be significantly less.

I don't understand. The amount of heat to be removed would be the same and the heat goes out with the air. Seams like the only way to remove the heat with reduced air would be to make the air hotter.

What am I missing?

Kent

[Jconard]

The aluminum conducts heat much better, so in theory, more of the heat would be transfered down the barrel, where air already circulates, but cannot pick up as much heat because heat transfer is typically a function of the difference in the air temp and the hot surface.

The hotter the surface air flows over, the greater the rate of heat transfer...hence more quantity of heat can be removed by a given volume of air. Right now the majority of heat is remove by the aluminum cylinder heads and upper 1/3 of the barrell. In fact some cylinders are being made now without fins at the base because they contribute relatively little to cooling.

In addition, aluminum releases heat better. I was somewhat sceptical of how much difference it would make but in the other world where I play, vintage VW/ Porsche there is a parrallel.

The 914 has a largely VW engine with cast iron barrels and aluminum heads. Traditionally they ran a little warm because of the installation. This was only exascerbated by modifications.

There is a company called LN Engineering who machines barrels from billet aluminum, and then nickasil coats the bores. I now know a few folks who have installed these in 914's and early (2.0 2.2 and 2.4) 911 6-cylinder engines. The volume of air is the same, as the fan and drive ratio does not change, but across the board they all report better cooling than stock, even with modifications like more CR, More advance, and cams/headwork.

My thought was that if it could work on a lycoming, one could even further reduce the volume of cooling air, and of course there is some weight savings. The parts are spendy by car standards, but pretty cheap by aircraft standards. And LN parts are beautifully machined. They call the cylinders "Nickies".

I just figured Ross already knew of them because his ignition/injection system is pretty well regarded by the VW community.

[rv6ejguy]

Yes, I know of the aluminum jugs for the 914 engines as we have supplied LN and Raby with many EFI system for these engines. I think these are probably more of an offshoot of Porsche 930 experiences where aluminum cylinders are must for engine life at high hp levels.

Nikasil has proven to be very durable and makes more sense than wearing out jugs- the rings wear and they are cheap to replace compared to jugs. Porsche apparently has used both Nikasil and etching processes to expose silicon molecules in several engine designs successfully.

Quite right, aluminum has over twice the heat transfer rate of steel so cooling mass flow could be reduced to lower drag while reducing barrel temps. Aluminum pistons and barrels also grow and contract at similar rates so piston to bore clearances can be reduced for longer life, less blowby and lower oil consumption.

Aluminum under tension and high temps is not ideal so a tension stud to retain the assembly and place the barrel under compression would probably be prudent.

[N908RV]

Originally Posted by rv6ejguy

Aluminum/ Nikasil cylinders might be a more useful change for the Lycoming. This would reduce weight, cylinder wear, reduce piston clearance and ring end gaps for better oil control, get rid of the old fashioned break-in procedures and use of mineral oil and have far superior heat rejection to steel barrels. The only downside is the base bolted jug design. Might have to be changed to a proper tension stud type retention system like Porsche and Rotax use. This would also stiffen and strengthen the whole assembly.

I'll be up front - not a fan of the alternative engines as I had my fill with my VW in my old Sonerai. None failed, but it gave me the willies to fly behind it. Which will surprise you when I tell you that I was a VW - Porsche nut before I started in aviation and I mean nut. I have rebuilt quite a number of VW engines and 911 engines. When I first started aviatin' I used to make fun of the Lycosaur, but now like George, I have drank the Lyc Kool Aid and it tastes good and safe. Love to drive behind (or really in front of) the 911 engines or the VW engines, but once I saw the Lyc main bearing, I was sold.

Anyway, enough ranting, back on Ross' comment. I agree that Nikasil and aluminum barrels would be nice, but frankly I don't see the heating problems in Lycs to justify the change to that. About the biggest issue we ever seem to have is with oil temp - not so much cyl head temp. Every Lyc I've had always ran somewhat cool. My -8 runs about 325F CHT's on average. I too used to be concered about the bolted jug design - and they can and do fail. But speaking from Porsche 911 experience, I can assure you that I have seen many a 911 cylinder head stud fail in my day despite various attempts at moving from steel to dilavar and then special epoxy coated dilavar when they started snapping too. Not to mention the addition of time serts (makes a helicoil look like a joke) to the cylinder bases. This was because of the tension design - the steel and aluminum would expand at different rates and when the 911 went to bigger displacements it caused the original design steel head studs to pull right from the soft aluminum case. Thus the move to dilivar head studs to help with the expansion and ultimately on good overhauls, time serts to reinforce the stud base on the case.

So, maybe the Lyc guys may not be so far off the mark with the barrels bolted on the bottom with huge bolts and lots of them. It helps avoid some of the expansion issues inherent to the tension stud design.

Good postings guys, interesting reading.

-Rob

[rv6ejguy]

Its funny how some people have problems pulling studs on Corvair, VW and Porsche engines and some don't. I raced Corvairs for a while and built many including 350+HP turbo ones and some for road racing, never saw a pulled stud in any of these high hp, high heat engines????

I do know that 911/930 experience this from time to time and certainly many have reported this on VWs. I wonder what the cause is? Improper torquing somewhere in the engine's life or overheating at some point?

Perhaps it is the best idea to leave the Lycoming design alone! It does work the way it is. Why meddle?

Interesting comment on VWs. Some people have had multiple failures in not so many hours, others have hundreds of trouble free hours. I've never liked a prop bolted directly to the crank of an auto engine myself but it seems to work for many.

[Jconard]

I agree...in principle...ain't broke, why fix it?

But, as I said before if they made full length studs, it would be workable and I think interesting.

It would make the cooling requirements lower, and I think make the installation even faster.

Plus, the technology has become bullet proof. When I was younger I once hot seized a piston in a nickasil bore while at the race track. We had to use a 5 lb hammer to get the piston out and it left chunks of aluminum on the bore. We burned the aluminum off the cylinder with myriatic acid, hone the bore lightly with stoddard solvent, and finished the race weekend.

Just a thought.

The dilavar studs worked well, it was designed to overcome the expansion rate issuses with aluminum cylinders, and only snapped because of corrosion..generally from road salt. They had a wierd fabric covering and later epoxy coatings. I understand that ARP has a machined neck stud which works fine.

Ross, get LN to make a lycoming conversion!

[cooljugs]

It is so painful to read forums like this.

Yes, Liquid Cooled Air Power is still actively working on our water cooled Lycoming engine modification. No we don't have anything for sale yet mainly because we decided to develop a much more powerful version and then we were impacted by the Great Recession which decimated financing, killed off several of our vendors and generally brought everything to a standstill just like it did to pretty much the rest of the economy. Since then just trying to find a machine shop and foundry in the US that is willing and able to make our parts has been like finding a needle in a haystack! No wonder we don't manufacture anything anymore - nobody is willing or knows how to do it anymore especially if you don't plan on producing tens of thousands of something!

Our conversion applies to virtually all 360, 540 and even 720 Lycoming engines (carbureted, injected or turbo charged, geared or direct drive but not D series engines) and with minimal effort we could also apply it to the 320 series as well.

We have achieved more power per cubic inch and what can only be described as massive improvement in fuel economy when measured in BSFC and even better improvements when measured on an MPG basis due to the substantial effects of drag reduction. In addition to water cooling the engine we have also developed a much better, detonation resistant combustion chamber that operates at 11:1 compression ratio on 91 unleaded pump gas without even a hint of detonation! How about 230-245HP from a normally aspirated carburetted/magneto ignition O-360 at 2700 RPM while burning less fuel than the original aircooled O-360 counterpart? At >$6/gal you still want that archaic air-cooled version? Oh, we also cut oil consumption by 70% as well.

Our conversion replaces the cylinders, doesn't change any moving parts below the piston and adds an external gear driven water pump onto an existing accessory drive - thats it. Not complicated at all. About 6 hours work for a competent mechanic without removing the engine from the airframe. OK, so there is the need for a radiator (bolt on) and some hoses. Another 4 hours or so of work.

In fact for a complete airframe conversion, you can roll a PA28-180 into a hangar air cooled and roll it back out water cooled in 22 man hours (which includes the time needed for stripping all of the aircooled stuff off the engine, etc) without a single permanent airframe modification (our cowling just replaces the original one) and not having to remove the engine. It doesn't get simpler than that. There are plentiful details that you can view at http://www.liquidcooledairpower.com/...kee-conversion

We may not be updating our website but it doesn't mean we're dead in the water - just delayed - victims of the major recession that started in 2008. I am the single source of funding for this work and I only have so much time and money to devote to it. It hasn't helped that after 15 years I have become largely discouraged by the complete and utter lack of interest on the part of the aviation press and organizations like AOPA and EAA since I started to get this out there in 2000. We have never had any serious reporting in AOPA Pilot and other GA magazines. OEM manufacturers like Piper and Cessna and yes, even VANS aircraft have not just ignored us but slammed the door in my face (multiple times over the years under different management). Their attitude and statements like, "Why should we offer a water cooled engine when nobody is asking for it", or "There is nothing your engine can do to make our aircraft better" typify the closed minded mentality that pervades the GA industry and the desire to maintain the status quo. No further interest. Heck, when we were on the static display ramp at the 2004 AOPA convention with our Water Cooled Lycoming O-360 powered Piper PA28-180, neither Chuck Suma nor anyone from Piper or Cessna even took the time to walk over to take a look and I met with Chuck in the convention hall! That combined with a total lack of press interest was a serious reality check on the pitiful interest in innovation in GA. Only the President of Extra aircraft came over to look and then proceeded to lament on the abysmal experience they were having with the Continental Voyager 550 series engines.

Until you experience the difference between a PA28-180 with a 70 year old air cooled engine and a modern water cooled version both with the same 180HP output, I doubt that any you will understand either. The benefits to operational simplicity, fuel economy, climb, cruise and payload ability are huge! and that's running with the original carburettor and magneto ignition. Our PA28-180 can climb and fly farther and faster than a 200HP Arrow IV and we didn't even try to accomplish any serious airframe drag reduction! We had similarly impressive results with a LongEZ installation. I don't know what else would be more impressive a result than increasing the overall performance of a lowly fixed gear, Hershey winged PA28-180 to beyond that of a retractable, 200HP, semi-tapered wing sibling to the point of flying circles around it! This level of performance gain just from a water cooled conversion of the same engine is unprecedented yet it seems to be dismissed as a ho-hum result or aberration that is too complicated to be worth it. Remember that a new Archer sells for over $300K today and all you are getting is the same 70+ year old engine technology bolted to a 60+ year old airframe with a new paint job and fancy avionics.

With our water cooled modification installed on an Archer for about $60K and 22-26 hours of manpower it will fly about 10-12% faster (about the same speed as a Piper Arrow IV), climb about 60% better consume 15-35% less fuel (depending on altitude and flight phase) and likely carry about 200-250lbs greater payload. You could also expect to run unleaded fuels (91 octane or higher) without any problems and have a TBO of about 4000-5000 hours - how much more do you want? Oh wait - how about simpler operation, less maintenance and lower insurance costs than an Arrow! Finally, safer cabin heat and a much quieter (as in BMW quiet) cabin since we can now sound encapsulate the engine compartment!

Our technology also makes it absurdly simple and low risk for any OEM to modify their production line to offer both water and aircooled variants of their aircraft. Lets see, an aircooled Archer for $300K or a water cooled one for say $325K that will have the above performance and fuel economy benefits. Which one would you buy? Besides, as many have argued, who would pay $60K+ to modify a PA28-180? Come on - its just a test bed! Look beyond that airframe. If we can get that kind of performance improvement with a lowly PA28-180 (and also a LongEZ) then imagine what would be possible with more capable aircraft like the Arrow, Seminole, Seneca, VANS aircraft or any number of other Lycoming powered airframes. We are certainly not limited to Piper.

What nobody is even thinking about is the entire subject of field support which will make or break any new engine technology! Our mod is to a well known engine with millions of flight hours and tens of thousands trained mechanics to support and service it. How many aircraft mechanics do you think know anything about a compression ignition engine or have the training to work on them? Without readily available field support a new engine doesn't stand a chance!

[cooljugs]

[continued from my previous post]

Then there are the issues of unleaded fuels and the fact that we can run on unleaded 91 pump gas at 11:1 compression ratio and make way more horsepower than an aircooled engine without the risk of detonation! This is much of what you are missing due to the lack of reporting on water cooled aircraft engine technology by all of the aviations publications. I could go on but without a good interview to better understand the 'bigger' picture of GA engine development and technology not to mention the trials and tribulations of bringing something like this to market all of you can never begin to understand or appreciate the potential.

Without optimism and forward thinking from the aviation press there will be little to no incentive or ability to fund innovation for the GA market. I believed that I could improve GA by updating the archaic power plant that powers all GA piston aircraft without throwing the baby out with the bath water and I put my money where my mouth is and optimistically pushed forward into near zero visibility only to be confronted with one ill-informed nay-sayer after the next all bent on defeat or at least no faith that a little guy (like myself) instead of some faceless giant corp could actually make a something better you know, kind of like those two Wright brothers and their associate, the historically almost non-existent Charlie Taylor without whom they would not have achieved powered flight when they did with a water cooled engine!

Beyond the occasional mention of the small Rotax engines and perhaps electronic engine management in the aviation press little is publishd in regards to the sad state of affairs in piston engine development that stopped dead in its tracks 70+ years ago! While it has been recently reported in the July 2013 issue of AOPA magazine that 'Rotax has long considered building a higher-horsepower engine for the GA fleet, and even certified a V-6?but never put it into production'. Well, while Rotax is still considering Liquid Cooled Air Power has already accomplished! Do you think that anyone from AOPA even tried to contact Liquid Cooled Air Power for some input? Nope! So its no surpise that all you get is - a hope and prayer that something better will come along someday even though something better already exists and has been flying since 2001! Other than those that are trying to offer electronic fuel and ignition systems there are really no alternative engine options besides copy cat derivatives of a 70 year old engine that was primarily designed to meet the military need for forward spot aircraft.

Besides, one article will not make any difference. Many are necessary to help dispel the many myths and misinformation that has been so painfully obvous in this forum's posts. There were and have been innumerable articles about Loran when it fist appeared, then GPS, then glass panels, etc. Is it any wonder that everyone knows the benefits of that technology in relation to aviation and then started to demand it. The aviation press has published little to nothing on the subject of water cooled GA piston engines and the few articles that have been written are filled with myths and misconceptions with little to no research by the reporter.

Unless the aviation press makes a concerted effort to research and report in an unbiased manner about better engine technology and better possibilities and also educates their readers about the bigger picture of engine development, deployment and most importantly field support there is little chance of achieving any real innovation in GA piston engine propulsion. The 'build it and they will come' mentality of the tech world doesn't exist in the GA world and never will. Manufacturers want a stable status quo to keep their expenses low and margins high.

The pilot community doesn't know that any other possibilities even exist so they don't think to ask for it. There are no billionaires to fund development - actually there aren't even any millionaires to fund development and that is why most American GA aircraft companies are foreign (mainly Chinese) owned. Without inspiration and support from publications such as AOPA and others, there will be no inspiration on the part of aircraft buyers to want something better. Instead we will continue to have the situation of the last 30+ years - a stagnant GA market with cottage industry production numbers and a seriously declining pilot and aircraft owner population.

The main reason we have have air cooled piston engines is because they were originally developed for the military (like most everything we have today in aviation) to use in light forward spot aircraft that had to survive being shot at and could be easily repaired in the field. That is the legacy of the engines that we civilians fly behind. Today, other than the possibility of being shot out of the sky by an F16 or drone for trespassing near the border or some TFR there is absolutely no requirement or benefit for an air cooled engine.

Back in 1997 when I conceived this program, I was dumb (I like to think blissfully ignorant) enough to think that if I built it - you guys would come. I can assure you first hand after almost 16 years and spending more than $1M of my own money that will not happen in GA and sadly the many postings in this forum containing so many negative preconceived and outdated notions doesn't help change my view. Given that every car on the road is water cooled I am mystified at the complete disconnect there is when considering water cooled engines for GA.

I don't know where some of you got your information but I can state with certainty that nobody has ever successfully (as in an airworthy, flying version) converted an air cooled aircraft engine to water cooling - except us! The modifications and instrumentation were innovative enough to be awarded not one but 2 patents which had to hold up against the original Daimler Benz water cooled internal combustion engine patent! You are mostly holding onto tired old myths mainly connected to the abysmal failure that was the Continental Voyager 550 engine which was not a conversion and I will be glad to enlighten you as to the many things that were wrong with that engine. Continental did GA a great disservice by proving that they had no idea how to design and build a water cooled engine and also that with enough money and connections you can get even the most abysmal piece of **** certified.

To be clear - a new engine mod like ours isn't going to become widely available unless there is a demand and unless at least one OEM jumps on board. The experimental route is just too risky. One incident that may have nothing to do with the modification would kill all of the time money and effort of my entire team and I am not willing to gamble on the skills of an amateur builder for the commercial success of this program.

If you want to see change and innovation don't expect it from any incumbent manufacturer, including VANS aircraft - they have every incentive to prevent change and have demonstrated a remarkable ability to do so for the last 70+ years. I just cannot convey the value and depth of what we have done with our work in this posting. This story goes well beyond that of just developing a water cooled engine. Without some cheer leading from the press and demand from the GA consumers I can assure you that there will be little to nothing of significant innovation in engine technology likely to happen in GA.

I highly recommend that you really go through the Liquid Cooled Air Power website as it has a huge amount of information.

[Weasel]

Why not work on perfecting materials/manufacturing to produce light asemblies that can tolerate higher heat instead of lower heat? The hotter the delta temp. The less air will be needed to reject the same heat.....less drag.


I like the alum/nicasil idea.