Seriously? Another unleaded avgas thread . . . ?

[philiplane]

On 2/3/2025 at 7:40 PM, varlajo said:

What do people put into their IO-360s in Europe? 

https://www.flyingmag.com/blogs-flying-time-transition-unleaded-fuel/

The parallel valve O/IO-360's that can use 91/96 octane have been able to use Hjelmco's unleaded avgas, for more than thirty years now.

Edited February 12 by philiplane

[toto]

42 minutes ago, philiplane said:

https://www.flyingmag.com/blogs-flying-time-transition-unleaded-fuel/

The parallel valve O/IO-360's that can use 91/96 octane have been able to use Hjelmco's unleaded avgas, for more than thirty years now.

What’s the downside to the Hjelmco product?

[Hank]

6 hours ago, toto said:

What’s the downside to the Hjelmco product?

Besides that it's refined several thousand ocean miles away from the U.S.?

[toto]

43 minutes ago, Hank said:

Besides that it's refined several thousand ocean miles away from the U.S.?

Well, I mean that’s a solvable problem. GAMI doesn’t make fuel, they just make a formula to make fuel, and they license that formula. I would expect Hjelmco to do the same?

[Pinecone]

But same problem.  It doesn't work in the angle valve -360s, so Fs, Js, Ks, are out.  And it doesn't work in most big bores.

Great for Cs

But we already have UL94 here in the US that works for the same ones that the Hjelmco products work in.  I suspect that it might be quite similar to UL94, which is pretty much 100LL without the lead.

[philiplane]

If you retard the ignition timing by about five degrees on the higher compression engines, 94 octane works just fine. That is the official back up plan at Continental engines too. There is minimal power loss, so it's not a terrible trade-off. 

[Pinecone]

How much power loss?   @jetdriven has stated about the power loss between the 25 and 20 advance settings on Lycomings.

What will dropping them to 15 do for power?

And is this enough in turbo charged engines?

I wonder if @George Braly and GAMI have tried this on their test stand?

Who is doing the testing for the change to all the performance charts?  Especially for airplanes like our Mooneys with limited factory support?

Also, advance changes and POH changes will require an STC.

[bonal]

On 2/3/2025 at 11:06 AM, A64Pilot said:

The only viable, even partially affordable engine replacement that has even come close would be an STC to remove the high compression and or turbo motors and replace them with low compression carbureted ones that can burn Mogas. Every other possible engine replacement that has been even Experimentally developed cost is likely as much or more than the average Mooney sells for, I’m talking likely 100K or more once it’s completed, the cost of the engine is I’d guess only about half the total cost.

Or as I have repeatedly posted install what seems to be a $12,000 ADI system and burn either 94UL or Mogas. I do not know but bet Mogas would require some kind of airframe modification on our Mooney’s, like maybe cooling vents or another fuel pump maybe. We could implement ADI very quickly with 94UL though assuming it’s vapor pressure is the same as 100LL.

But everyone wants a magic fuel that’s just like 100 LL just without the lead. It seems that fuel just isn’t possible or it would have been done long ago, wouldn’t it?

Or I guess we could do what Brazil has been doing for decades with IO-540’s and burn pure Ethanol? Bet range would suck though.

https://en.wikipedia.org/wiki/Embraer_EMB_202_Ipanema

Seems the issue is there isn’t a way to get to 100 without the lead unless we use really volatile chems. Certainly no reason to stop development but as I’ve said in another thread we’re forced into a solution before the issues are truly resolved.  UL94 works fine for a majority of the piston fleet and installation of an ADI for the high compression and turbo motors could be a reasonable STC and could cost less than 12k once the engineering was worked out.  Nothing fancy about an ADI very old tech.  The problem isn’t our old engines they work fine doing the job they were designed for.  The problem is stupidity when it comes to government regulation. Folks don’t have a problem installing 50k worth of avionics that they don’t really need steam gauge and VOR has been getting us where we need to go for decades.  Not saying glass and GPS isn’t great but it’s pretty useless if we don’t have a reliable fuel to run our engines. So maybe a few thousand dollars isn’t bad for a solution to the engines that can’t run on 94UL.  I was given crap about my joke about not wanting to be a beta tester for the G100 but looks like that’s exactly what’s happening here in California.

[IvanP]

51 minutes ago, bonal said:

 Folks don’t have a problem installing 50k worth of avionics that they don’t really need steam gauge and VOR has been getting us where we need to go for decades.  Not saying glass and GPS isn’t great but it’s pretty useless if we don’t have a reliable fuel to run our engines. So maybe a few thousand dollars isn’t bad for a solution to the engines that can’t run on 94UL. 

For those folks who CHOSE to spend their money on improvement in safety by installing new avionics, I bet that nobody was forcing these inprovements on them (except for the ADS-B mandate). Based on the stady efforts to decommission VORs, they may not get you safely anywhere in the not so distant future. Pushing a new fuel that casues damage to the aircraft or requires major expense to be safe onto the entire piston fleet is a dfferent story. UL fuel does not improve safety of flight one bit and it appears that G100UL may cause airworthiness issues (see other thread on topic in General forum).   

The rush to mandate UL fuel is nothing but appeasement of vocal enviro groups without even marginal improvement in safety of flight operations. 

[bonal]

I think you kind of miss my point,  I have read all the points in other threads as well as other sites.  Some people think a reasonable solution is to just come up with a new engine design we know all the issues with that solution. Others suggested just de rating the engine performance to accommodate the lower octane. Light small high performance engines typically require higher Rpm to make needed power which as you know requires a gear reduction for the needed prop speed.  Also water cooling is a requirement for the increase in temperatures adds more weight.  To be honest our big air cooled engines are perfect for the job required. Simple light and produce needed power at just the right rpm to keep within propeller limits.  As for updating avionics it’s great if you can afford it and I’m not saying it doesn’t enhance safety im just saying we may have to find an affordable solution to this government created problem if we want to keep flying.  Direct injection may be  that solution.  I really don’t have any issue because my o360 would be fine on 94UL.  Back in the day lots of my friends were using water injection on there hopped up V8’s when the lead was taken out of the auto gas.  Usually very simple systems for a couple hundred dollars and worked quite well preventing detonation.  

[Pinecone]

3 hours ago, bonal said:

Seems the issue is there isn’t a way to get to 100 without the lead unless we use really volatile chems. 

Actually it appears the problem is the LOW volatility compounds.  They don't evaporate and concentrate.

[Hank]

3 hours ago, bonal said:

Seems the issue is there isn’t a way to get to 100 without the lead unless we use really volatile chems. 

I've used Outlaw Octane Boost in my car, which requires minimum 92 octane, when it was accidentally filled with 89. Memory says the label had instructions to reach up to 105, but it was many moons ago and I've slept many times since then  . . . .

[bonal]

4 hours ago, Pinecone said:

Actually it appears the problem is the LOW volatility compounds.  They don't evaporate and concentrate.

My point is, the formula for the fuel might have some complications as to how it reacts with our airplanes. Never claimed to be a chemical engineer. Being in California I might be forced to use it if I want to keep flying and I’m not comfortable with that.  Personally I’d rather have the option to go with the 94UL if the environmentalists get their wish and ban LL before a real drop in replacement becomes available.

[bonal]

7 hours ago, IvanP said:

For those folks who CHOSE to spend their money on improvement in safety by installing new avionics, I bet that nobody was forcing these inprovements on them (except for the ADS-B mandate). Based on the stady efforts to decommission VORs, they may not get you safely anywhere in the not so distant future. Pushing a new fuel that casues damage to the aircraft or requires major expense to be safe onto the entire piston fleet is a dfferent story. UL fuel does not improve safety of flight one bit and it appears that G100UL may cause airworthiness issues (see other thread on topic in General forum).   

The rush to mandate UL fuel is nothing but appeasement of vocal enviro groups without even marginal improvement in safety of flight operations. 

And I don’t disagree.  And it’s a shame that VOR’s are being decommissioned.

[Pinecone]

12 hours ago, Hank said:

I've used Outlaw Octane Boost in my car, which requires minimum 92 octane, when it was accidentally filled with 89. Memory says the label had instructions to reach up to 105, but it was many moons ago and I've slept many times since then  . . . .

What car?  Modern cars (since at least about 1996 models) can adapt to lower AKI fuel, but delivering lower performance.

The old Outlaw Octane Boost did bad things to oxygen sensors.  IIRC, it was high in methanol.  I have about 3 - 4 cans if anyone wants some.

[Pinecone]

7 hours ago, bonal said:

And I don’t disagree.  And it’s a shame that VOR’s are being decommissioned.

Not all, there is a plan to keep enough for basic enroute and approaches.  MON, Minimum Operating Network.

https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gbng/vormon

 

[Hank]

5 hours ago, Pinecone said:

What car?  Modern cars (since at least about 1996 models) can adapt to lower AKI fuel, but delivering lower performance.

The old Outlaw Octane Boost did bad things to oxygen sensors.  IIRC, it was high in methanol.  I have about 3 - 4 cans if anyone wants some.

1992 Jaguar V12. That tank rank well after about 15 miles' driving, so it could mix in. It's supposed to go into the tank before the gas, but the attendant put in Plus instead of Super; she knocked on the highway despite flat coastal Carolina terrain.

Is there an octane boost that will mix with UL 94 to approach 100LL performance?

[Pinecone]

1 minute ago, Hank said:

1992 Jaguar V12. That tank rank well after about 15 miles' driving, so it could mix in. It's supposed to go into the tank before the gas, but the attendant put in Plus instead of Super; she knocked on the highway despite flat coastal Carolina terrain.

Is there an octane boost that will mix with UL 94 to approach 100LL performance?

OK, my 85 Dodge Daytona Turbo Z did not like the stuff.  Ran like crap for a tank or two of unaltered pump gas.

I am sure there are, but they are not approved and likely have more issues that G100UL.

The 80s F1 cars were getting 1500 HP or more on 1.5 liter turbo engines.  That ran almost straight toluene.

[Hank]

5 minutes ago, Pinecone said:

I am sure there are, but they are not approved and likely have more issues that G100UL.

The 80s F1 cars were getting 1500 HP or more on 1.5 liter turbo engines.  That ran almost straight toluene.

I don't want to run my Mooney on straight Toluene.

[Pinecone]

Agreed

And some racing is using some pretty radical stuff.  Paint removal is a minor concern.