Swift 100R is now ASTM

[1980Mooney]

2 hours ago, Fly Boomer said:

Unlike the Rocket, there is no legal amount of lead or batteries in the tail that will fix those numbers.

Actually there are bigger problems:

• It appears that the 180 HP Austro 330 weighs about the same as the Rocket 305 HP TSIO-520
• Installing the Austro in a M20E actually derates it at sea level from the original 200 HP Lycoming
• As you point out batteries and more lead will be needed in the tail to keep the M20E off its nose with the additional 250-300 lbs on the nose.
• UL will drop to about 500 lbs...maybe less

Maybe a fairer comparison would be the Continental CD-300 used in the Diamond DA-50RG.

• It has a dry weight of 560 lbs...probably closer to 600 lbs installed.

[McMooney]

s&g if was was retired with a bunch of money i'd maybe try and start with a chevy LZ0,  inline 6, should be alot smoother naturally  plus it's a bit closer in weight.  my poor little e would get places before it left 

[N201MKTurbo]

11 minutes ago, McMooney said:

s&g if was was retired with a bunch of money i'd maybe try and start with a chevy LZ0,  inline 6, should be alot smoother naturally  plus it's a bit closer in weight.  my poor little e would get places before it left 

That thing weighs 467 lbs. You will need two M20Es to haul that thing around.

[McMooney]

42 minutes ago, N201MKTurbo said:

That thing weighs 467 lbs. You will need two M20Es to haul that thing around.

shrug i never haul around more than 2 people anyway

[Hank]

5 minutes ago, McMooney said:

shrug i never haul around more than 2 people anyway

Me neither. 

[N201MKTurbo]

6 minutes ago, McMooney said:

shrug i never haul around more than 2 people anyway

It does make 16 HP more than your IO-360. Not world changing.

[N201MKTurbo]

1 minute ago, Hank said:

Me neither. 

I used to have a suburban and we could fill the back of that thing with stuff and it would all fit in the Mooney.

[N201MKTurbo]

One thing to consider with the auto engines; their crankshafts may not be strong enough to handle the torsional stress of driving a propellor. Home builders found that out when they put Corvair engines in their planes.

[McMooney]

4 hours ago, N201MKTurbo said:

It does make 16 HP more than your IO-360. Not world changing.

actually that's rwhp in the charts, so crank would probably be 10 to 20 percent more

Edited yesterday at 02:39 AM by McMooney

[McMooney]

4 hours ago, Hank said:

Me neither. 

man i'm feeling claustrophobic just looking at that pic

[toto]

7 hours ago, McMooney said:

s&g if was was retired with a bunch of money i'd maybe try and start with a chevy LZ0,  inline 6, should be alot smoother naturally  plus it's a bit closer in weight.  my poor little e would get places before it left 

There’s a nice series of articles in Air Facts Journal about a Chevy V-8 installed in a Skyhawk. I think this has been referenced on MS before … well worth an entertaining read. 

https://airfactsjournal.com/2020/11/the-20-an-hour-cessna-172-experiment/

 

[McMooney]

tech wise this can be done but due to economics IT NEVER WILL BE, except for the random barely engineered experimental.

 

Now back to when will i be able to light 100R on fire in my mooney

[IvanP]

6 hours ago, Hank said:

Me neither. 

This photo makes me think that our wives attended same class on how to pack for a weekend  

[Andy95W]

9 hours ago, toto said:

There’s a nice series of articles in Air Facts Journal about a Chevy V-8 installed in a Skyhawk. I think this has been referenced on MS before … well worth an entertaining read. 

https://airfactsjournal.com/2020/11/the-20-an-hour-cessna-172-experiment/

 

Interesting article, but if this were truly viable there are a few glaring issues.

That article was from 5 years ago and had numerous claims but no facts showing any of it was actually accomplished.

Most significant is the statement, “certification cost requires outside investor funding and we have not found the right partner yet.”  The obvious question is why didn’t we see this airplane at OSH in 2022?  Or 2023, 24, or 25?  The buzz would have been tremendous and certainly the “right partner” and outside investors would have been lined up ready to invest.  Instead… crickets.  The only answer is that putting a V-8 in a C-172 just wasn’t a viable solution (probably because the weight and balance just wouldn’t work.)

Everyone loves to malign our 80 year old engine technology, but the fact remains if there was something significantly better it would have been developed and improved upon a long time ago.

Our engines are optimized to produce 65-90% rated power reliably for 2000 hours. For their weight, nothing else even comes close. Any improvements to be seen (such as variable timing or better exhaust) produce only a few percentage points difference. Significant improvements simply haven’t panned out. So it isn’t government regulations or a corporate conspiracy, but instead physics, engineering, and financial sense that prevent significant changes to our engines.

[MikeOH]

4 minutes ago, Andy95W said:

Our engines are optimized to produce 65-90% rated power reliably for 2000 hours. For their weight, nothing else even comes close. Any improvements to be seen (such as variable timing or better exhaust) produce only a few percentage points difference. Significant improvements simply haven’t panned out. So it isn’t government regulations or a corporate conspiracy, but instead physics, engineering, and financial sense that prevent significant changes to our engines.

THAT paragraph is gold!

Aircraft engines are stationary; all the fancy electronics just don't increase performance significantly as variable timing isn't really required. The rest of the engine isn't in much need of improvement as it already has excellent power to weight ratio, and proven reliability.

[toto]

11 hours ago, Andy95W said:

That article was from 5 years ago and had numerous claims but no facts showing any of it was actually accomplished.

That was the first of the three articles.

https://airfactsjournal.com/2020/11/the-20-an-hour-cessna-172-experiment/

https://airfactsjournal.com/2022/10/the-20-hour-cessna-172-experiment-update/

https://airfactsjournal.com/2024/11/the-corsair-c172-v8-experiment-update-3-readers-suggestions/

[Pinecone]

On 9/22/2025 at 6:36 PM, N201MKTurbo said:

One thing to consider with the auto engines; their crankshafts may not be strong enough to handle the torsional stress of driving a propellor. Home builders found that out when they put Corvair engines in their planes.

Plus they are NOT designed for continuous operation at 75% of peak power.   They run at highway speeds at about 10 - 15% of peak power.

[Pinecone]

On 9/19/2025 at 6:27 PM, Shadrach said:

Yes, government mandated innovation is the key to success…thank God they made horses illegal in the early 1900s or the automobile would’ve never been invented and city streets would still be full of horseshit.

Yeap.  Necessity may be the mother of invention, but the Father is invention is LAZINESS.

Cars are faster and less upkeep.

[N201MKTurbo]

57 minutes ago, Pinecone said:

Plus they are NOT designed for continuous operation at 75% of peak power.   They run at highway speeds at about 10 - 15% of peak power.

Most auto engines would overheat in short order if they were making 60% power for any length of time.

most folks with a 400 HP vehicle, have probably never made 400 Hp with it. If they did, it was for a few seconds at best. To get 100% power out of a vehicle requires red line RPM at WOT at sea level. How do you do that? Towing a heavy trailer up a steep hill at the coast in first gear? How long would it last doing that?