Higgs engines.

[Yenn]

I see today that there is a new range of engines in the December Kitplanes edition.

They have a write up about Higgs engines, which seem to be too good to be true. The lowest HP model is FL 150J/G, which is an inverted Vee, geared engine HP at rpm, priced at US$25000.

It is supposedly compression ignition, but has spark plugs. It is a bit vague about whther it is two or four stroke, but it runs onJet A fuel. No valves.

I am always wondering about these wonderful engines, buut specially so when compression ignition requires spark plugs.

[kasper]

They are spark initiated two stroke diesels with wet sump.

 

If they work out reliable then good'ish news but at US$25k not looking to compete with Rotax but instead the Lyc-a-Conta-saurus

 

[jackc]

Would like to consider the Scarlet 5s to replace my Rotax 80hp in my Aeropup.

 

http://www.vernermotor.com/page1.html

 

 

[facthunter]

Verner have ceased production of most of those engines. Pity as they looked like they had promise. Nev

Edited December 22, 2021 by facthunter

[jackc]

They show the Scarlet 5s as being still made, but the smaller models are no longer.  I was thinking about an 80hp replacement for my 912 80hp.  Maybe a lost dream but still worth a look 🙂 

[onetrack]

The Higgs engines show a lot of promise, with simplicity, light weight, multifuel capabilities, and high HP for weight - without major design complexity.

They simply utilise a second piston below the main piston to supercharge the inlet mixture, and utilise porting, a la all 2 strokes. The supercharging of the intake charge is the crucial feature of the design.

 

As with all new designs, extended testing is needed to find the "bugs" in the design. Adequate and efficient sealing, of pistons and sump, comes to mind, straight up.

 

https://www.ac-aero.com/technologies/

 

The Allis-Chalmers tractor company had a spark-ignition diesel engine in 1936. It was called the Hesselman engine, after its inventor, the Swedish engineer Jonas Hesselman.

Scania-Vabis, Volvo, and Tidaholms-Bruk, all truck manufacturers in Sweden in the 1930's, all produced their versions of the Hesselman engine. The engine fitted to the Allis-Chalmers model LO tractor was built under licence to Hesselman by Waukesha, and called the Waukesha-Hesselman engine.

 

The Hesselman engine was a true multi-fuel engine, designed to utilise low-cost, semi-refined fuels to get around high European taxes on refined fuels.

The ASTM fuel standard for diesel (ASTM D975) was not introduced until 1931, and even after that time, there were many varieties of partly-refined fuels available.

 

The Hesselman engine ran at 6.5:1 compression, was fitted with a Bosch diesel fuel injection pump and injectors and also fitted with spark plugs and a HT magneto. The fuel was injected near TDC and the spark plug ignited the fuel.

The engine was not a true diesel, as it did not ignite fuel via the heat of high compression.

 

The Hesselman engine was a short-lived success, as other high compression full diesels, such as the Cummins Engine Co, GM with their famous 2 stroke diesel - as well as MAN and Mercedes - all produced quite satisfactory full diesel engines by 1937 - and these engines very rapidly superseded the Hesselman engine.

The Hesselman engine was unsuccessful because of its poor combustion abilities, which meant a lot of unburnt fuel went out the exhaust, and crankcase oil dilution was high. Smoke levels were unacceptable, and fuel economy was poor.

 

https://en.wikipedia.org/wiki/Hesselman_engine

 

Edited December 22, 2021 by onetrack

[facthunter]

Great minds think alike there, Jack.  Nev

[facthunter]

You can't supercharge a conventional 2 stroke but you can scavenge it. if you have some positive pressure. Oil dilution is a common problem in diesels and they go to more trouble with Piston rings than petrol engines do.. The GM had Poppet valves for the exhaust so could arrange nonsymmetrical timing to a small extent.. 2 strokes get heat on the piston every revolution and tend to melt holes in the top of the pistons. Meeting environmental standards has been a show stopper..Nev

[Yenn]

My beef was about the Higgs engine being called a compression ignition engine. If it needs spark plugs to ignite the fuel it is not compression ignition.

The use of the term "Diesel" relating really means an engine running on the design of Diesel, the German engineer who built the original compression ignitiion engines.

[kasper]

You can supercharge a two stroke if its using a second pumping piston of greater volume than the firing piston.

 

For my dream list on supercharged spark ignition two stroke engines that have actually flown I would take the Bernard Hooper stepped piston engine ... 580cc v4 = 30kw/40hp in a flying engine water cooled at 18.9kg.

 

Give me two of those on a slippery two seater ultralight with a belt redrive and I will be happy ... a LongEzi with these as a set of twins would be really nice or one of them on a sapphire ... 27hp cruise on 7LPH of avtur sounds nice 

[turboplanner]

2 hours ago, Yenn said:

My beef was about the Higgs engine being called a compression ignition engine. If it needs spark plugs to ignite the fuel it is not compression ignition.

The use of the term "Diesel" relating really means an engine running on the design of Diesel, the German engineer who built the original compression ignitiion engines.

You're going to have to change your thoughts then because some of the newest cars have compression ignition petrol engines with spark plus, but the plugs operate at a certain point to lower emissions. It looks as if these engines will replace diesels.

[jackc]

We had International TD18 Bulldozers in the Army that were petrol/diesel. You fired them up on petrol warmed them up and then cut them over to diesel.  Jut had to reverse the situation before you shut them down as it was difficult to restart again IF it was stopped on diesel.  Then the Army got wise and issued us with new CAT D7Es, no roll frames or canopies, just worked them sitting in the hot Sun,  all day 😞 

[onetrack]

Mazda's current SkyActiv-X engines use a modified HCCI (Homogeneous Charge Compression Ignition) engine design, that Mazda call SPCCI (Spark Controlled Compression Ignition). The engine runs at 16:1 CR, so definitely a diesel.

Their SkyActiv-X engine is pretty impressive in torque, power and economy figures - but the downside is, they're an exceptionally high-tech engine, with microprocessors controlling every single combustion event, as they happen. 

The problem with HCCI is it's a particularly unstable, very lean combustion process, that needs a high level of electronic control to ensure stability during the combustion events.

 

Mazda SkyActiv-X engines also utilise an air-to-water intercooler, a low-boost Roots-type supercharger, an EGR cooler that helps prevent premature combustion, electric variable valve timing actuators (that use stepper motors) for faster valve timing, and they also use a 48v electrical system.

Overall, a major step forward in engine efficiency for cars - but at the expense of extreme complexity - and probably not a design you'd want to adapt for powering your ultralight.

 

https://arstechnica.com/cars/2018/01/mazdas-skyactiv-x-shows-the-internal-combustion-engine-has-a-future/

 

Edited December 23, 2021 by onetrack

[APenNameAndThatA]

On 23/12/21 at 3:17 PM, onetrack said:

Mazda's current SkyActiv-X engines use a modified HCCI (Homogeneous Charge Compression Ignition) engine design, that Mazda call SPCCI (Spark Controlled Compression Ignition). The engine runs at 16:1 CR, so definitely a diesel.

Their SkyActiv-X engine is pretty impressive in torque, power and economy figures - but the downside is, they're an exceptionally high-tech engine, with microprocessors controlling every single combustion event, as they happen. 

The problem with HCCI is it's a particularly unstable, very lean combustion process, that needs a high level of electronic control to ensure stability during the combustion events.

 

Mazda SkyActiv-X engines also utilise an air-to-water intercooler, a low-boost Roots-type supercharger, an EGR cooler that helps prevent premature combustion, electric variable valve timing actuators (that use stepper motors) for faster valve timing, and they also use a 48v electrical system.

Overall, a major step forward in engine efficiency for cars - but at the expense of extreme complexity - and probably not a design you'd want to adapt for powering your ultralight.

 

https://arstechnica.com/cars/2018/01/mazdas-skyactiv-x-shows-the-internal-combustion-engine-has-a-future/

 

IIRC, Wheels magazine said those engines were no more economical than a normal engine of the same capacity (but a little more powerful). Mercedes tried and failed to produce such an engine. It sort of looks to me like Mazda failed but put the engine into production anyway, if you know what I mean. 

[turboplanner]

8 hours ago, APenNameAndThatA said:

IIRC, Wheels magazine said those engines were no more economical than a normal engine of the same capacity (but a little more powerful). Mercedes tried and failed to produce such an engine. It sort of looks to me like Mazda failed but put the engine into production anyway, if you know what I mean. 

SKYactiv has moved engine technology ahead in several areas:

It introduces compression ignition to petrol-engined cars so a cleaner fuel starting point. The crossover to "diesel" is now blurred with several fuel injections for emissions, and a spark introduced at some point for enhancement as well.

It meets the increased power and torque standards for the class

It lowers NOx and PM even further

It produces a low CO2 output of 90<116g/km

It lowers fuel consumption into the current ballpark

It utilises a pulse-tuned exhaust to drive the turbocharger harder, something which is dear to racers.

 

Car applications are changing.

Historically if young families wanted to travel interstate cheaply they bought a caravan and hitched it up to a Holden or Falcon. Fuel was cheap, Motels were expensive.

As the cost of fuel rose this model was slowly destroyed and caravan towing moved across to more committed camping type people in 4WDs. That this group now strongly dominates the top vehicle turnover in Australia is surprising, but there it is.

 

As Holden and Falcon models dropped out of the market the 2 litre market has been getting more and more use in longer distance travel, to the point where cars like Honda Civic can squeeze out a fuel economy on gentle highway travel of up to 4 litres/100 km, so increasingly the affordable interstate holiday trips have switched to low fuel cost and cheap motels.

 

In that application the 2 litre SKYactiv-X at around 4.6 litres per 100 km, but from Melbourne to Brisbane that's only an out of pocket compared to the Honda of about $20 to $30, so petty cash.

 

 On the other hand power is now within 14% of a VY Commodore which had a highway fuel cycle of around 9 l/100 km, so the SKYactiv will be pretty much giving the same performance on the holiday trip on about half the fuel.

 

 

 

 

 

 

 

 

[jackc]

And when it breaks out of warranty…..you throw the whole thing in the bin and start again 😞 

[onetrack]

All current motor vehicles with high levels of electronic technology are not designed to be extensively repaired, that's a thing of the past.

If you have a major electronic failure on a current model vehicle, and it's over about 8 yrs old and it has more than 150,000kms on the clock, it is often scrapped.

If you have a moderate prang which results in a "structural member" being deformed, your vehicle goes in the scrap bin, written off, and declared a Statutory Write Off, unable to be repaired or re-registered anywhere in Australia.

A structural member can be as little as a suspension component. See the advisory booklet, "Damage Assessment Criteria for the Classification of Statutory Write-Offs", it's an eye-opener.

We live in a era where automated manufacturing on a huge scale, and a lack of trained and qualified repair people - along with "unrepairable" styles of manufactured components - simply means todays products, including vehicles, have a short lifespan.

 

[turboplanner]

1 minute ago, onetrack said:

All current motor vehicles with high levels of electronic technology are not designed to be extensively repaired, that's a thing of the past.

If you have a major electronic failure on a current model vehicle, and it's over about 8 yrs old and it has more than 150,000kms on the clock, it is often scrapped.

If you have a moderate prang which results in a "structural member" being deformed, your vehicle goes in the scrap bin, written off, and declared a Statutory Write Off, unable to be repaired or re-registered anywhere in Australia.

A structural member can be as little as a suspension component. See the advisory booklet, "Damage Assessment Criteria for the Classification of Statutory Write-Offs", it's an eye-opener.

We live in a era where automated manufacturing on a huge scale, and a lack of trained and qualified repair people - along with "unrepairable" styles of manufactured components - simply means todays products, including vehicles, have a short lifespan.

 

or putting it another way, if you use the specified oil andc comply with the service details and procedures you are likely to get the car to 500,000 plus km life cycle, then it all goes in the crusher together. As you said, if you have an accident or mechanical problem it's easy to reach a write off result.

[jackc]

I own enough vehicles and spare parts to keep me in useable vehicles until I die 🙂.  NONE of this modern stuff I like, want, or NEED 🙂 

[pmccarthy]

Like the one hoss shay in the poem The Deacons Masterpiece. designed so all parts wore out at the same time.

then it collapsed - 
All at once, and nothing first, —
Just as bubbles do when they burst

 

http://holyjoe.org/poetry/holmes1.htm

[Thruster88]

On 22/12/2021 at 5:42 PM, facthunter said:

You can't supercharge a conventional 2 stroke but you can scavenge it. if you have some positive pressure. Oil dilution is a common problem in diesels and they go to more trouble with Piston rings than petrol engines do.. The GM had Poppet valves for the exhaust so could arrange nonsymmetrical timing to a small extent.. 2 strokes get heat on the piston every revolution and tend to melt holes in the top of the pistons. Meeting environmental standards has been a show stopper..Nev

This is a conventional 2 stroke with a turbocharger.  It is in production. Rotax 2 strokes rock.

 https://www.rotax.com/en/products/rotax-powertrains/details/rotax-850-e-tec-turbo.html

[facthunter]

No technical detail on it that I could find on the site and it's not offered as an aero engine where you'd think the altitude advantages would be  highlighted.  You can over pressure the entire intake /exhaust system which is like having the sea level pressure increased. I still stick to what I've said  boost a 2 stroke and you only put more out of the exhaust, unless you time it to close later which is not possible with a piston ported motor. Nev

[jackc]

Just give us a replacement for the 582 motor…..

[facthunter]

They'd still be continuing them if there was a good enough market. it's a snow sled engine anyhow but 2 strokes are never likely to have the popularity/following they once had. Power to weight they are still the best till you go turbine..  Nev

[onetrack]

The Rotax E-TEC technology is somewhat overblown by Rotax, and it appears the low oil consumption is nothing like Rotax claim. Add to that, the E-TEC technology is still basically 2 stroke design, pumping out nasty emissions, and you won't find the Rotax E-TEC engines anywhere else but snowmobiles - because the snowmobile industry has lobbied long and hard to be exempt from exhaust emission regulations - and they've largely won.

 

Snowmobile engine emission laws didn't start to apply until 2006, and they're weak and watered-down emissions laws, with engine companies producing 2-strokes being allowed to "average" emissions across all their engine product lines.

 

https://www.ecfr.gov/current/title-40/chapter-I/subchapter-U/part-1051/subpart-B/section-1051.103

 

The E-TEC advertising is slick and smooth, big on fancy "fun activities" imaging to suck in the punters, but pretty short on precise technical and emission information.

 

At least one E-TEC owner on the Youtube site is complaining the oil consumption of the E-TEC engines is double what Rotax claim.

Despite 2-stroke technology being high power output, and despite regular "major 2-stroke design advances" claims, you won't see it in aircraft or cars, anytime soon.