Quote:
Originally Posted by dar636
The Unlimited Hydro's and Reno Unlimited's share many similarities. I too grew up in Seattle/Bellevue summers with the sound of the Merlin's and Griffons rumbling off in the distance waiting for Dad to let us know if were going to be able to take the boat out Friday or Saturday (never could afford Sunday) and watch the practicing.
As a old dude, I'd pay to see and hear the V12's run any day, but race? Not sure anyone's going to push those throttles up to 120+ inch MAP settings again.
I have a hangar neighbor at the Auburn airport who put himself through college working on the "Miss Bardahl" boats, from number two to five, as crew member and then crew chief. He told me the Reno guys used to contact them frequently for tech info sharing and described the differences as the boat engines were subjected to higher abuse loads. They ran small no mass props that constantly came in and out of the water and had over speed 'bursts" each time. The Reno guys were interested as the aircraft engines never experienced anything similar. He and another former crew member discovered boat number three and bought and restored her.
From the hydro museum:
"Then ex crew member Dixon Smith heard of Bardahl’s whereabouts and decided to buy it from the museum as a private owner. Smith injected nitrous oxide into Bardhal’s World War II Rolls-Merlin engine, redefining the word ‘speed. Dixon rebuilt it to run the hydroplane.
Only 30 percent of the original material was salvaged due to years of corrosion and neglect. Yet after extensive work and the help of an innovative team, Smith and three of Bardahl’s original crew, who had taken the boat out of Mission Bay in 1965, re-launched the boat on Lake Washington on July 7, 2007.
He is second from the left.
Not to hijack the post, but if you enjoy the sound of Merlins and like racing, this is as good as it gets - right to the end. Voodoo's engine didn't have another minute in it after this race:
https://www.youtube.com/watch?v=YvRmZZZEzF8 |
I saw that boat at the Greenwood car show. Can't remember if it was this last summer, or the one before. Absolutely stunning.
And yes, absolutely the biggest issue with the reciprocating engines is the sudden unloading and over-rev when the prop comes out of the water. They only run with the "bottom" blade in the water as it is, in other words, the prop nut is at about the water line.
The Merlin and Griffon engines would always shear the supercharger drive - that was the predominant failure mode. The turbo Allisons, not running the mechanical supercharger, never had that problem. That was, of course, not the only failure mode.
The U-3 crew have apparently solved the reliability issues. They have been at it an awfully long time, and have proven to be quite competitive. They win big races - they are not just a novelty, running on nostalgia. They are quite serious about it and honestly believe their turbo Allison to be an advantage under today's rules.
Quote:
Originally Posted by sammyg2
And that's sort of what I was getting to in a rounda bout way:
You can hop up a ford model A all you want but it's still a model A.
the Allison V12 was first developed in the early 1930s.
If they had a modern high HP version of a huge engine, the coolness factor would be over the top.
They get about 3000 hp out of the lycoming turbines. That's about the same as they are getting out of the allisons now.
Imagine if they built an unlimited hydro with two gnarly twin-turbo V-12s putting out 2000 hp each, or maybe a lightweight V16 with 4000 hp. And then built a boat big enough to handle all that power in rough water!
They wouldn't be able to print the tickets or sign up the sponsors fast enough.
We've have entire threads dedicated to how cool those modern engines would be instead of a pre-WWII museum piece.
Lets just hope they don't get stoopid and try electric or hybrid nonsense, that would certainly mean the end.
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These big motors are more "advanced" than a lot of people realize. Single overhead cams, four valves per cylinder actuated by rocker arms. The oddest feature of their design (I think anyway) is the cylinder banks are not staggered from one another. Opposing cylinders sharing the same rod journal are on the same centerline. As a result, they have to run the "knife and fork" setup on the big end of the rods, ala Harley-Davidson. I'm not sure that it is inherently weaker, just kind of odd. I wonder what the thinking was.
But, yeah, absolutely - if there were a modern version produced, and unlimited racing turned to them and abandoned the turbines - boy howdy, would their spectator appeal skyrocket. There certainly cannot be much of a market, unless the Reno boys jumped aboard. Even then I doubt it would be worth anyone's time and money to develop one.