Warbird Information Exchange

Steve and Voodoo arriving to the Reno just days after breaking the world speed record.
https://www.youtube.com/watch?v=gUhVbQYds4o

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Jason Schillereff

Cool video, thanks for sharing that with all of us!

Okay, I have to ask, as I know everybody wants to know the answer, but are you going to upload the cockpit footage from Voodoo's Gold Race on Sunday? TIA!

Cool Does anyone know what the problem with the engine was on the record last run?

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Magister Aviation
It's all in my book

Steve-o was losing oil pressure right after the third run. Because of that he had to make his turnaround earlier than normal as it was a race to get in the 4th run before the engine let loose and quit. The record attempt required 4 runs through the gate, each time in opposite directions. If he hadn't turned early, there was the chance that the record would not be set due to engine failure/seizure and the whole effort would have been for naught.

Thanks!

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Magister Aviation
It's all in my book

Anyone who knows which power settings were used and output achieved?

Reportedly, for the record attempt, Steve-O used full throttle and prop the whole time. I've heard that it is in excess of 160" MP and approx. 3100-3200 rpm. The output was just short of 4000 h.p.

Well done as always Jason, thank you...

Lynn

Thanks for the data ... ... !

If I recall correctly, "wartime" max settings for a Merlin is 3000 rpm and 25 lb/in^2 boost. 25 lb/in^2 boost converts to some 80" MP, right? That makes 160" MP quite impressive.

"Wartime" max settings for a Mustang Merlin engine are 67" MP and 3000 rpm. Remember though, that this engine bears little resemblance to a stock wartime Merlin. It has been extensively modified with parts from other engines, including Allison connecting rods, which are much more beefier than Merlin connecting rods. There are a lot of modifications which allow a much higher BMEP, and consequently a higher MP and HP than a stock Merlin.

BTW, I don't know about conversion of MP into boost, so I have no idea about your numbers.

My line of thought is that boost is in addition to atmospheric pressure (14.7 lb/in^2 or 29.92 inHg)
25 lb/in^2 boost + 14.7 = 39.7 lb/in^2 MP
14.7 lb/in^2 converts to 29.92 inHg giving 39.7 lb/in^2 MP = 80.8 inHg MP

The other way around for 67" MP
67 - 29.92 = 37.1 inHg boost = 18.2 lb/in^2 boost

Aircraft Engines Of The World by Paul Wilkinson is my source for the conversion numbers.

Spitfire the History by Morgan/Shacklady states for the Mk IX and Merlin 66, 18 lb/in^2 boost on 130 grade fuel and 25 lb/in^2 boost on 150 grade fuel.

As you point out, this racing engine has little in common with a stock Merlin but still impressive!

Thanks everyone!!
Too answer the question, yes I'm putting together the gold race video now and will add the cockpit footage to it as well. About the engine power output during the record run (and Reno), on top of the other engine mods, they also use 160 octane race fuel that has additives put in as well to boost the octane even higher!!
Jason

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Jason Schillereff

That is correct only early on, with the standard 100/130 octane fuel, but later in the war, beginning in the summer of 1944, with British-produced 100/150 octane fuel available, Merlin-engined Mustangs were cleared for even higher power settings than that. With 100/130 octane fuel, the V-1650-7 was only cleared for 61" MP max power and 67" MP WEP. When 100/150 octane fuel became available starting in June 1944, the V-1650-3/-7 was initially cleared by the VIII Fighter Command for 72" MP WEP, and later increased this to match the British, who, using the same 100/150 octane fuel, cleared their Merlin-powered Mustangs for 81" MP WEP. This is why from late P-51D-15-NA/P-51D-5-NT production onward, all P-51D's (and most K's) came from the factory with 100"-span manifold pressure gauges, replacing the earlier 75"-span gauges. Also, for this reason, when the switch in fuel came, the British replaced the manifold pressure gauges in their Mustang III's (B/C's) from the 75"-span to the British +25 lbs boost gauges - all of the British Mustang IV's and IVa's were manufactured late enough that they all already had 100"-span manifold pressure gauges from the factory and didn't need replacement gauges. Furthermore, using U.S.-produced 115/145 grade fuel, the VII Fighter Command P-51s on Iwo Jima also ran 80" MP WEP. The V-1650-9 Merlin, as installed on the P-51H, could run 90" MP WEP, on water-injection.

Jason, for the past couple of days, after work I've spent an hour or so watching videos from your YouTube channel. This means I kinda know what to expect from the in-cockpit stuff, and I'm very excited!

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Zac in NZ
#avgeek, modelbuilder, photographer, writer. Callsign: "HANDBAG".
https://linktr.ee/zacyates

"It's his plane, he spent the money to restore it, he can do with it what he wants. I will never understand what's hard to comprehend about this." - kalamazookid, 20/08/2013
"The more time you spend around warbirds the sooner you learn nothing, is simple." - JohnB, 24/02/22

Interesting, I didn't know that the P-51H was equipped for water injection. Was methanol/water an alternative or "antifreeze" was never needed?