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-   -   AC Aero (Higgs Diesel) E-330 Hawk Engine (https://vansairforce.net/community/showthread.php?t=167537)

majuro15 01-06-2019 06:46 PM

AC Aero E-330 Hawk Engine
 
Fair warning, this is a long post!

As some may have noticed, I?ve been interested in other than Lycoming options for my RV-10 build since I started six years ago. My mission, to which I?m building my airplane to achieve, is to have an efficient high performance and luxurious cross country cruiser while having flexibility to still do a sunset treetop flight from time to time. I?ve always been interested in advancement of technology and maximizing performance and efficiency. I am building a four seater to take my wife and friends/family along for the ride, so dependability and reliability is important to me as well. I am not afraid of the ?experimental? in experimental aviation, so I recognize that there is a middle ground on all of the aforementioned requirements and my middle ground may be different than others?. With that being said, in the interest of sharing information with others and educating myself along this project, I would like to share my experience with anyone who is interested in following along. I hope this can be an interactive and positive topic and will absolutely avoid anyone trying to slam the concept just because it?s not what they would do.

I?ve watched the Turbine Solutions Group, Delta Hawk, Continental, Auto PSRU, Adept Airmotive, and others all with excitement and interest but none have really gone beyond a prototype or a test stand. ACE caught my eye about four years ago with their AX-50 cylinders and ACE-540 engines. The cylinders were a new design tailored to performance and the ability to use MOGAS without all of the problems of the traditional Lycoming design. I liked it because it was enough of new technology and offered great performance / efficiency but still retained the tried and true design from Lycoming at its heart. When I contacted Andy Higgs last spring to discuss options and an order, we got side tracked with a new project he has been working on for some time. I was instantly hooked.



The newly launched Higgs Diesel E330 Hawk by AC Aero is a clean sheet, multi-fuel, spark ignited piston engine. While it is primarily meant to burn Jet A, a variety of fuels may be used with minimal performance degradation and no hardware/software changes required. The V4 design uses a modular architecture which is shown in the development of the larger E1000 V12 Condor design. A V8 version is also planned. The E330 Hawk will produce ~350 horsepower normally aspirated or ~500 HP turbocharged. It uses a unique stepped piston design and interconnected cylinders to help compress the intake air and scavenge exhaust gases. The two stroke cycle is designed to burn cleaner and more efficiently than other traditional diesel engines. This allows for lower parts count, simpler drive systems, and reduces vibrations. The crankcase encompasses the geared prop drive, accessory drive outputs, and uses a traditional pressurized lubrication system. The engine is liquid cooled using a closed loop coolant system as well as an oil cooler. It will be ~350 pounds including cooling system and accessories. Based on scaled test power plants, the Hawk will produce 275 HP at 80% power burning 8.5-9 gallons per hour. Andy is using a custom mapped ECU and closed loop systems to have a power control lever along with a prop control, eliminating any fuel mixture input from the pilot. He anticipates running a three bladed MT propeller on the non-turbo and a five bladed MT-5 on the turbo versions.




I?m working on creating a page on my build log with more information from AC-Aero so folks can learn and follow along, so I?ll update that as I get more information. You can checkout Andy's website at http://www.ac-aero.com/. I also have a PDF document with a lot of technical information on my buildlog here. Andy's been posting some updates on his FaceBook page as well that folks can look at even without a FB account (I believe).



So, back to the story, Andy asked me if I had been following his project and we started talking details. To me, it fits a RV-10 perfectly! It is a bit more powerful than a 540, but not crazy strong. It?s got great performance, fuel flexibility, simple controls, and lightweight design. I see it maximizing the performance, range, and payload of the RV-10 beautifully. As I got more and more details, I fell harder in love with it. We discussed mission, timelines, and expectations and it all seemed like it was a perfect fit. The only question left was will it work???

That?s a big, unanswered question.

I?ve been working with Andy for over a year now on the integration of the engine and we are making great progress. A few other 10 builders have jumped on board to assist even though their projects are not as far along as mine. With Andy?s help, we?ve been able to continue our builds with zero modifications needed until an engine is in hand. This was important to me because I already have a quote for a phenomenal 540 engine that will more than meet my needs. I didn?t want to get to a point where I was too far committed to an engine that I don?t have and is unproven. I?m very happy to say that thus far, it?s gone very smoothly. I already had a fuel return line built into my plane and until we need the engine mount and are ready to hang the engine, I won?t stray from Van?s plans to be able to bolt on a 540 should plans change. With that being said, I am fully committed to the Hawk engine and hope to help prepare a firewall forward package for others to add to their aircraft.

While the engine is now formally launched, there are a lot of details still confidential. I can say that the first batch of engines are being assembled now for an OEM customer in the US, with my engine being one of that batch. He has also delivered two of the V12 versions which are undergoing installation on air-frames now. He has been testing a scaled down version of the engine using the same design principles for several years with excellent results. The production version of the E330 should begin dyno testing in the next few weeks, as manufacturing has gone very smoothly with only a few minor component tweaks. Currently, we are working on cooling system and engine mount design with good progress. I already have a Show Planes cowl and will be modeling up the needed modifications with Andy?s guidance. We are targeting an April-May delivery of my engine and my goal is to be flying by the end of the year.

So, long post but hopefully entertaining and intriguing for those reading it. I?ll be happy to try and answer questions that are asked and share the information / progress updates as I get them. I will disclaim that I am not a partner, representative, or salesman for Andy or AC Aero, just a customer who is interested in helping and sharing while getting what I want!

Stay tuned as I slug my way through the ?alternate engine? story to hopefully a very happy ending!

rv6ejguy 01-07-2019 05:58 AM

Very cool Tim.

I met Andrew at Reno last year and was impressed with the engine design and him. He strikes me as a very clever guy.

Has a prototype of the engine you plan to use completed dyno testing yet and what sort of hours and power settings has it completed if you can tell us?

BrianDC 01-07-2019 06:21 AM

Very Cool. Hopefully this works and is a good alternate engine choice.

Lots of unanswered questions, but hopefully we learn more over the next year or so. Looking forward to seeing more on this new engine design.

BillL 01-07-2019 06:22 AM

I contacted Andy several times via email and never got a response. Thanks for the excellent information on the engine. I think you need to review your fuel burn numbers, they don't match the best economy bsfc in the literature.

I wonder how the top rings get lubrication. Diesels work well down to A/F maybe 18. Meaning - it will be very challenging to meet SFC and power with reasonable temperatures at altitude if remaining naturally aspirated. Well, maybe, depending on the BMEP expected, do we know the displacement? The true displacement from port closing? So many questions.

Beautiful design work, just captivating.

majuro15 01-07-2019 06:54 AM

Ross, yes he has had several prototypes running on dynos, but no numbers that can be released as of yet. He has over 4000 hours on the scaled versions and is currently testing one to destruction while experimenting with components on a few others to max out performance. His background was a career in Formula 1 engineering, so yes he's a pretty smart guy! He knows way more than I ever will about engines so I quickly get lost in the technical details.

The fuel numbers are just estimates and could be off. We won't have an accurate number until dyno testing. We'll be sure to post them as soon as we can. I'll get a displacement number for you soon, I thought I had it written down but I can't find it. He's currently working the cooling setup as he knows how many BTU/hr we need to shed so processing the formulas to figure out radiator size and air flow.

rv6ejguy 01-07-2019 08:12 AM

One of these days, someone will offer a viable alternative to the Lycoming. Let's hope Andrew's engines will be that one.

I'm interested in how a non-turbo 2 stroke diesel will work at altitude and what the BSFC will really be like as typically, they are no better than a 9 to 1 Lycoming running LOP with a good EI system. I don't buy the .204-.216 figure.

Has Andrew discussed cost and proposed product support structure in North America?

Exciting stuff, looking forward to updates as the story unfolds.

rdrcrmatt 01-07-2019 09:05 AM

As I said on facebook, I REALLY wish this would have been an option a few months ago.

Very excited about this engine!!

airguy 01-07-2019 09:56 AM

Quote:

Originally Posted by rdrcrmatt (Post 1314838)
As I said on facebook, I REALLY wish this would have been an option a few months ago.

Very excited about this engine!!

Considering they are just now heading to the dyno with the first full-size unit, it's unlikely to be a viable option for some time yet. I'm certainly hopeful it's ready for market before I start building a 10 in a couple years.

ppilotmike 01-07-2019 10:46 AM

Quote:

Originally Posted by rv6ejguy (Post 1314815)
One of these days, someone will offer a viable alternative to the Lycoming. Let's hope Andrew's engines will be that one.

I agree. Major respect to Andy for tackling this difficult challenge. I, for one, hope he's successful.

AC-AERO 01-07-2019 04:01 PM

Bill, sorry if I missed your mail, please re send it and I will answer it.
Andrew


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