Miss America - Chasing Her First Gold Win

[GRNDP51]

After 2017, I was concerned that there wouldn't be much worth following in the Unlimited class anymore. The return of Dr. Hisey and Miss A reignited this spark (at least for me), and I've been very excited watching Hisey's return to Reno.

I have been given some hints to Miss A's progression since the return in 2018. VERY cryptic hints, as the team likes the surprise factor.

The goal in 2019 wasn't to win, but to perform well. If that happened, the 2020 goal was supposed to be Miss A's first Unlimited Gold win. The team was happy with the mod program for 2019, but had even bigger plans for 2020.

Those plans were of course pushed back to this year, and Miss A is ready to win. As of now, I have no confirmation on what has been done, but Miss A is going through her 15 hour test period prior to racing at Reno. This is the first year this test period has been needed, so as expected, the 2021 mod program is the most ambitious so far.

So let's open up discussion and speculation! For those in the know, what would necessitate a test program like this? Major airframe mods? Cooling changes? Experimental mods?

What I've been given so far is that the plane is lighter, and the most important hint so far, "she has more floor clearance". That is very much up to interpretation!

Aside from this test period (on the stock engine), the race engine from 2019 is toast, but the Rick salvaged some parts to put together the new engine for 2021. New case and crank specifically.

Here's to a win in 2021 Miss America!

[Reever]

Re: Miss America - Chasing Her First Gold Win

First thought that pops into my head is airframe mods.

[GRNDP51]

Re: Miss America - Chasing Her First Gold Win

I made this thread a few hours early, I just saw some photos after the flight today. It has the Ridge Runner scoop, but the inlet looks even smaller than RR's.

So now the question is, how does this work with cooling? Miss A won't be using a tube engine, but with the inlet being so small something has to have changed (?). I remember reading the RR thread that their scoop bypassed the oil cooler and shot air straight to the radiator. Could they be using a hybrid boil off system with the heat exchanger setup that Galloping Ghost had?

[CubersWrist]

Re: Miss America - Chasing Her First Gold Win

Smaller inlet should mean better cooling because the volume expansion slows the air down. This is good for thermal heat transfer because slower air has more time to pick the heat off the radiator fins. Sam Swift is doing this with his 3D printed inlets. We're dealing with this on Race #30 as well trying out some new baffling.

And then the simple ingredient to a smaller inlet is to add more spray bar water.
To take this to an extreme we barely even feed the oil cooler with air anymore. We basically have a boil-off oil system.

[GRNDP51]

Re: Miss America - Chasing Her First Gold Win

Smaller inlet should mean better cooling because the volume expansion slows the air down. This is good for thermal heat transfer because slower air has more time to pick the heat off the radiator fins. Sam Swift is doing this with his 3D printed inlets. We're dealing with this on Race #30 as well trying out some new baffling.

And then the simple ingredient to a smaller inlet is to add more spray bar water.
To take this to an extreme we barely even feed the oil cooler with air anymore. We basically have a boil-off oil system.

Interesting thought. So the inlet is directed to the radiator which should be enough to keep it cool with slower air, and the oil cooler is cooled with spray bar.

From this picture https://www.flickr.com/photos/50393882@N00/49830428153/ , it appears that the smaller exit for the oil cooler was closed off since the oil cooler wasn't there anymore. Makes me curious if MA had this redesigned so the inlet mainly feeds the radiator, and if the oil cooler is in the stock position, water sprays it and exits like normal. The photos I have aren't good enough to see up close/underneath the scoop at all.

[Race5]

Re: Miss America - Chasing Her First Gold Win

I made this thread a few hours early, I just saw some photos after the flight today. It has the Ridge Runner scoop, but the inlet looks even smaller than RR's.

So now the question is, how does this work with cooling? Miss A won't be using a tube engine, but with the inlet being so small something has to have changed (?). I remember reading the RR thread that their scoop bypassed the oil cooler and shot air straight to the radiator. Could they be using a hybrid boil off system with the heat exchanger setup that Galloping Ghost had?

No tube likely means no Allison rods. He'll be lucky to make it without putting holes in the case again.

[wingman]

Re: Miss America - Chasing Her First Gold Win

Ridge Runner and most of the other Big Dog Unlimiteds removed the liquid to air oil cooler from the scoop altogether. They replace it with a liquid to liquid "heat exchanger" under the hood. I think the silver gadget in this photo is the heat exchanger. North American went to this heat exchanger on the P-51H. This change eliminates a lot of plumbing, and gives much more freedom in redesigning and shrinking the doghouse.

Rolls Royce rods have been to the moon at Reno. Tsunami did 500 mph with them and I don't remember her blowing up many engines.

Neal

[GRNDP51]

Re: Miss America - Chasing Her First Gold Win

Ridge Runner and most of the other Big Dog Unlimiteds removed the liquid to air oil cooler from the scoop altogether. They replace it with a liquid to liquid "heat exchanger" under the hood. I think the silver gadget in this photo is the heat exchanger. North American went to this heat exchanger on the P-51H. This change eliminates a lot of plumbing, and gives much more freedom in redesigning and shrinking the doghouse.

Rolls Royce rods have been to the moon at Reno. Tsunami did 500 mph with them and I don't remember her blowing up many engines.

Neal

Thanks for the insight Neal. I looked at photos of Strega and I don't see the heat exchanger. I'm confused because I thought all racers with tube engines just moved the oil cooler to the aftercooler radiator position beside the coolant radiator. If RR needed the heat exchanger, and Strega doesn't...? I'm missing something.

[wingman]

Re: Miss America - Chasing Her First Gold Win

I really don't know much specifically about how Strega or others cool their oil -- my understanding has always been that they use some form of "heat exchanger". I certainly don't think there's any room in Strega's scoop for a conventional oil cooler. Interesting questions....

Neal

[Lockheed Bob]

Re: Miss America - Chasing Her First Gold Win

I have a photo(1949) of Anson Johnson's P 51 with no scoop as I believe he installed the radiators in the wings?

[AAFO_WSagar]

Re: Miss America - Chasing Her First Gold Win

I have a photo(1949) of Anson Johnson's P 51 with no scoop as I believe he installed the radiators in the wings?

Again, the memory thing but... I remember Bill Rogers saying the words "boil off" in regards to something they were doing or did to MAII... *IF* they did, there should be an article somewhere in the archives....

[Lon Moer]

Re: Miss America - Chasing Her First Gold Win

I made this thread a few hours early, I just saw some photos after the flight today. It has the Ridge Runner scoop, but the inlet looks even smaller than RR's.

So now the question is, how does this work with cooling? Miss A won't be using a tube engine, but with the inlet being so small something has to have changed (?). I remember reading the RR thread that their scoop bypassed the oil cooler and shot air straight to the radiator. Could they be using a hybrid boil off system with the heat exchanger setup that Galloping Ghost had?

That settles the possibility of Dan Martin showing up with Grim Reaper.

But if MA is running the RR go fast parts, ....why not the Sparrow engine ??

[GRNDP51]

Re: Miss America - Chasing Her First Gold Win

That settles the possibility of Dan Martin showing up with Grim Reaper.

But if MA is running the RR go fast parts, ....why not the Sparrow engine ??

MA has all of the RR race parts. Dan would have to start fresh with race mods on Grim Reaper.

Regarding the engine, I think it would look like betrayal to go with someone other than Rick.

[Smee Again]

Re: Miss America - Chasing Her First Gold Win

Strega uses a completely different method for oil cooling, so you won?t see the heat exchanger. Also keep in mind that a tube has nothing to do with any part of the oil/coolant cooling - only a more direct flow of the fuel/air charge from the blower, with copious amounts of ADI added to keep induction temps under control.

My understanding is Miss A does have some of the mods we ran on the 2009/2010 versions of RRIII, of which the scoop mod was one of the most significant. As previously stated, the mod allows for removal of the oil cooler so air flow is no longer split between oil cooler and radiator - all flow is directed to the radiator face. The Merlin radiator is actually divided into two sections - 2/3 used for engine coolant, and 1/3 for aftercooler. Since there is no longer an aftercooler on a tube motor, in our case, the aftercooler portion was used for the heat exchanger for oil cooling. In the case of RRIII, this involved moving the battery back into the hell hole and putting a P-51H model heat exchanger in it?s place. Not sure how Rick will handle the aftercooler/tube situation in Miss A?s motor, but no aftercooler means a boat load of ADI at race power settings. In any case, I wish them luck in 2021. Should be an interesting week.

Smee

[Big_Jim]

Re: Miss America - Chasing Her First Gold Win

Just for the record....the technical response to this post is that Miss America already has a Reno Gold win. 1994. Alan Preston.