Propeller re-drives

[440032]

What re-drives are available these days for automotive type engines does anyone know?

Can't seem to find much of anything current on the innerwebs.

Just curious about this sort of thing, I've always wondered how well an Aussie straight six would go in an aircraft. Containing one to about 3000 RPM as direct drive might not work, or would it.

 

[RossK]

You're probably better off with the GM LFX 3.6l V6, more power for less weight and more compact.

 

The Ford Barra 6 though is near bulletproof, a nice feature for an aviation engine.

But it's long, tall and heavy.

 

Restricting the Aussie sixes to 3-3500rpm is going to drastically reduce their output,

The LFX would only put out 110kW @ 3100rpm, it's rated for 210kW@6400rpm at the crank

Adding a redrive and letting it spin to 5000rpm will push out 170kw at the crank.

I suspect any redrive for these would be custom though.

[spacesailor]

I liked the V6 Isuzu 3.2 litre, saw one in a small ' Spitfire ' at an airshow. 

spacesailor

[facthunter]

Have you had a look at how thin the crankwebs are? Nev

[Blueadventures]

There is a post on youtube about manufacturing a redrive for a Subaru 4 cylinder by Mike Hille.

 

Nice work, he's a mate that live around the corner form me and does nice work,  may be of interest to you as he also discusses his engine in this build and he pervious Zenith 750 build from raw material not a kit.

 

[440032]

Thanks - I found it, I'll take a look there.

Chrysler motor would be my poison, slant or hemi. I have a mate who has a race built Charger, routinely takes it to about 7000+ rpm.

[facthunter]

Awfully heavy type of motor.    Nev

[440032]

Yep! Mopar magic though.

 

It'll never happen, nice to wonder though.

[440032]

OH..... Slant six = 475 lb. LYC O-320 about 268.

There goes that theory right down the gurgler.

[onetrack]

The upright Chrysler Hemi sixes were some of Australia's finest engines, exceptionally durable, capable of high HP without breaking anything - but they would never make it as an aircraft engine, in 500 years.

 

Edited May 27, 2022 by onetrack

[Ian]

I think in terms of power to weight the rotary wins, both the 13B and 20B have been used successfully. They're also easier to strip and reassemble than other engines.

Subaru engines also worth a look, the key advantage is their form factor is a flat four which is similar to existing air cooled engines.

I'm not sure if the marcotte is still around  http://www.sdsefi.com/air14.html or http://www.glasairproject.com/Marcotte/Contact.html

The problem with any PSRU is that they are often built by people without the engineering knowledge or equipment to properly analyze issues such as harmonic, tribology or torsional effects. So any design which has lots of miles on it is preferable. There have been a lot of people in this area with more sales and marketing ability than engineering knowledge. Eggenfellner probably fits into this class.   

Also from a safety point of view flying something that either has a low landing speed or has two engines might be wise when using automotive engines. Not that automotive engines can't run continuously and reliably at WOT, it's simply that there's a lot to get right when going down this path and you're generally doing it all yourself. It's easy to ignore/dismiss potentially dangerous installation issues.

There's a nice article here about subaru vehicles being run continuously at high speed and high rpms which should put the whole "not designed to run continously at WOT" to bed.

https://subarudrive.com/articles/15-2-legacy-endurance-record-attempt

The EJ20 engine used in this would probably be a good starting point.

 

Personally I think that automotive engines have a raft of advantages over the existing aviation engines, mostly due to the fact that they effectively leverage an additional 70 years of engineering knowledge.

[facthunter]

You base your ideal thing on a particular motor and then it's out of production in say five years, They are also devoid of good engine mount points. I believe you design an aero motor from the ground up.  If it was easy we'd be there already.  Virtually 100% of the real planes out there are turbine because they are FAR, FAR more reliable than self destructing piston engines, but small ones are too costly and fuel consuming. . Nev

[Ian]

I agree, and it's never been more true than at the moment with the future for mass produced IC engines looking pretty bleak.

However history has demonstrated that keeping engines going remain possible for those with a desire to do so especially if you choose an engine that has a community the problems are soluble.

For example if you go with a 13B or 20B engine you can buy mounts off the shelf and there's a whole industry devoted to parts.

http://www.cozygirrrl.com/aircraftparts.htm

Turbine engines push the limits of material science and making them moderately efficient and lightweight is prohibitively expensive. If you look at the BSFC figures there's no aero turbine engines with great fuel consumption, the Europrop TP400c  recent generation expensive turbine engine consumes 213g/kW and your BMW BMW N47 2L consumes 198g/kW

 

It somewhat ironic that the rotary engine which has for 50 years been considered a thirsty engine has been considered as a more efficient combustor for turbine engines.

 

It will be interesting in the future as there's a greater push for carbon neutral transport whether the advantages of turbine engines will remain. I can't see a replacement however if fuel costs rise significantly other choices might become feasible.

 

Edited June 14, 2022 by Ian

[BrendAn]

On 14/06/2022 at 9:57 AM, Ian said:

I think in terms of power to weight the rotary wins, both the 13B and 20B have been used successfully. They're also easier to strip and reassemble than other engines.

Subaru engines also worth a look, the key advantage is their form factor is a flat four which is similar to existing air cooled engines.

I'm not sure if the marcotte is still around  http://www.sdsefi.com/air14.html or http://www.glasairproject.com/Marcotte/Contact.html

The problem with any PSRU is that they are often built by people without the engineering knowledge or equipment to properly analyze issues such as harmonic, tribology or torsional effects. So any design which has lots of miles on it is preferable. There have been a lot of people in this area with more sales and marketing ability than engineering knowledge. Eggenfellner probably fits into this class.   

Also from a safety point of view flying something that either has a low landing speed or has two engines might be wise when using automotive engines. Not that automotive engines can't run continuously and reliably at WOT, it's simply that there's a lot to get right when going down this path and you're generally doing it all yourself. It's easy to ignore/dismiss potentially dangerous installation issues.

There's a nice article here about subaru vehicles being run continuously at high speed and high rpms which should put the whole "not designed to run continously at WOT" to bed.

https://subarudrive.com/articles/15-2-legacy-endurance-record-attempt

The EJ20 engine used in this would probably be a good starting point.

 

Personally I think that automotive engines have a raft of advantages over the existing aviation engines, mostly due to the fact that they effectively leverage an additional 70 years of engineering knowledge.

i have a subaru ea81 in my gyro souped up to 100hp from the stock 80 . the belt drive reduction is really well made by someone in aus but i forget who.  all i need to do is learn how to fly it .  even though its a flat four its still too heavy for most planes.

Edited June 16, 2022 by BrendAn