Based on the G100UL fuel leak thread what's your position?

[MikeOH]

Just now, Marc_B said:

continued to 3/5/25 at 9:30a local

Thanks.  Where did you find that? I didn't see it on the website.

[Marc_B]

From the case look up there was a location to go to download documents, but was also a tab for Tentative Ruling.  I think it's a preliminary report.

https://eportal.alameda.courts.ca.gov/

[MikeOH]

A little background on the judge in this case.  Draw your own conclusions about his possible bias:

 

[mluvara]

3 hours ago, Marc_B said:

From the case look up there was a location to go to download documents, but was also a tab for Tentative Ruling.  I think it's a preliminary report.

https://eportal.alameda.courts.ca.gov/

 

[EricJ]

Interestingly, this showed up on my FB feed the other day.   Back when I was looking at how the Germans got the Daimler DB605 to make 1800 hp on high boost and relatively low-octane fuel, it appeared that combinations of methanol injection and aftercooling (intercooling) were frequently cited for being enabling technologies.

This graphic suggests that variations of the same were used on the Packard-Merlin in the P-51.   The aftercooler around the centrifugal supercharger at the rear of the Merlin is not new to me, but I'd not seen the ADI injection before.  I'm wondering if that wasn't a postwar modification for the air racers. 

 

[Sabremech]

4 hours ago, EricJ said:

Interestingly, this showed up on my FB feed the other day.   Back when I was looking at how the Germans got the Daimler DB605 to make 1800 hp on high boost and relatively low-octane fuel, it appeared that combinations of methanol injection and aftercooling (intercooling) were frequently cited for being enabling technologies.

This graphic suggests that variations of the same were used on the Packard-Merlin in the P-51.   The aftercooler around the centrifugal supercharger at the rear of the Merlin is not new to me, but I'd not seen the ADI injection before.  I'm wondering if that wasn't a postwar modification for the air racers. 

 

Definitely post war. Nothing like that on the two P-51’s we had. 

[EricJ]

22 minutes ago, Sabremech said:

Definitely post war. Nothing like that on the two P-51’s we had. 

That was my suspicion, which suggests that the wartime Packard-Merlin engines were making ~1700 hp mostly with intercooling (aftercooling) with 100/130 fuel and ~60" MAP.   The air racers run much higher MAP so maybe this was a modification that enabled that.

[PT20J]

Maybe this will help explain things 

34811808-North-American-P-51-Mustang-Pilot-Training-Manual.pdf

[mluvara]

5 hours ago, EricJ said:

Interestingly, this showed up on my FB feed the other day.   Back when I was looking at how the Germans got the Daimler DB605 to make 1800 hp on high boost and relatively low-octane fuel, it appeared that combinations of methanol injection and aftercooling (intercooling) were frequently cited for being enabling technologies.

This graphic suggests that variations of the same were used on the Packard-Merlin in the P-51.   The aftercooler around the centrifugal supercharger at the rear of the Merlin is not new to me, but I'd not seen the ADI injection before.  I'm wondering if that wasn't a postwar modification for the air racers. 

 

I have a bit of experience in this area, as I spent 2003-2015 crewing on numerous aircraft at Reno (including several that won Unlimited Gold) and supplying telemetry systems to them. I also worked as a party to the NTSB investigation to the 2011 Galloping Ghost crash because I built the telemetry system.

That aside, ADI was a system adopted for the high power race engines. On the Merlins, the after cooler was removed in favor of a tube induction system after the supercharger. It usually had an automatic system that would come on with a manifold pressure switch and feed the ADI fluid into an area of the supercharger (if I recall correctly). Failure of this at 130” MAP for a carbureted system would result in a pretty instant catastrophic result if not caught quickly. On the  other hand, a fuel injected 3350 on a Sea Fury actually would not suffer the same instant fate if the ADI failed and induction temp resultingly increased. I remember we ran a good portion of a lap when the ADI system failed at high power on the Sea Fury. The real time telemetry saved numerous engines because of system failures.
 

I just feel the extra complexity could be an issue for GA because it’s another system to maintain, care, and feed. One needs to carry methanol to mix with water, or have a supply at airports. It’s another preflight item.

Edited Saturday at 02:49 AM by mluvara

[A64Pilot]

On 2/28/2025 at 9:02 PM, PT20J said:

Maybe this will help explain things 

34811808-North-American-P-51-Mustang-Pilot-Training-Manual.pdf 46.48 MB · 8 downloads

Mind telling me which of the 106 pages cover it?

[A64Pilot]

So, what’s the plan for you California guys when they outlaw 100LL then?

Hope isn’t a plan.

FAA says G100UL is perfectly safe and viable for ALL piston aircraft?, George says it’s readily available. What do you think some Judge that has zero knowledge of GA is going to rule? Do they have a choice? Just asking as I’m no Lawyer but if I understand they may be only one way this could go, unless the FAA steps in and temporarily blocks the sale or similar.

I believe the number of States that follow California CARB wise is 17? Think they will follow California in banning 100LL? Is that enough market share for the refining of 100LL to no longer be viable?

I have no idea but think this could get ugly, I hope not, but hope isn’t a plan

Edited 14 hours ago by A64Pilot

[PT20J]

1 hour ago, A64Pilot said:

Mind telling me which of the 106 pages cover it?

HINT: There's an Index a the end. Look for "Coolant system."

[A64Pilot]

You could have just said page 24.

I saw no mention of ADI.

It’s my understanding that ADI in US Military aircraft didn’t become a “thing” until they had motors capable of pulling enough boost to require it even with the higher Octane fuel available, ref the below link on the 4360 engine ops. Before then engine design was driven by available fuel.

Look under wet or dry T/O and climb, ADI reduced fuel flow by 500 lbs an hour yet increased HP by 250 HP. They didn’t have to have ADI with I think 115/145 Octane fuel but it saved fuel and increased power. Assuming they had the torque available, the big motors had gear box limits like turboprops do.

I’ve read but do not know of course that the engine in the early model BF-109’s wouldn’t benefit from 100 Octane, it just didn’t make enough boost that it could, like the R-1340 for instance, being an old design engine, designed before there was 100 Octane you can run one at the same boost on 87 Octane car gas as you can with 100 Octane.

In short the Military use of ADI wasn’t to enable lower Octane fuel, but to enable increased power, on engines that could handle more power, which is honestly the same thing said differently but that took Turbo’s, Superchargers or sometimes TurboSuperchargers capable of pulling boost in excess of what even high Octane fuel could handle, and gearboxes etc that could take higher power.

https://enginehistory.org/Operations/R-4360Ops/r-4360ops1.shtml

Our use would be to keep current power on fuel that’s only 6 Octane lower, that’s a very mild and very safe use of ADI

Edited 2 hours ago by A64Pilot

[A64Pilot]

On 2/28/2025 at 8:52 PM, EricJ said:

That was my suspicion, which suggests that the wartime Packard-Merlin engines were making ~1700 hp mostly with intercooling (aftercooling) with 100/130 fuel and ~60" MAP.   The air racers run much higher MAP so maybe this was a modification that enabled that.

60” MP really isn’t that much boost, it’s only 15 PSI roughly, if I do the Math correctly, still drinking morning Coffee and brain hasn’t engaged fully yet.

My Motorhome for example pulls 30 lbs of boost, but automotive boost is PSIG so need to add the 15 PSI atmospheric to get to PSIA that aircraft indicate. 

So my Motorhome pulls 90” boost, yes it’s a Diesel and therefore not constrained by detonation margins because detonation in a properly operating Diesel isn’t possible. But it’s a Motorhome not any kind of performance motor.

Tractor pull motors can run as high as 300 lbs of boost, what’s that, something over 9,000” MP?

I wonder what the Reno racers pull? I would assume at least three times what the Military P-51’s saw? No idea really