Hot Multi's - Pictures

[Old fiberglass]

The wing/boat adjustable flap concept is an interesting one. The flap increases the camber of the wing the further it is pushed down creating more lift. As Rich and Gene point out the flap creates "adjustable" positive/back pressure under the wing creating positive lift at speed. The other wild card is the boat is always running in ground effect which is typically half the length of the wing/lifting device. Airfoils are more efficient in ground effect with the cushion of air under them.....hence less aerodynamic drag. Of course this is when the boat is actually more or less flying. Prior to that is has the drag of the water to factor in to it.

With a wing the motors are set at a negative angle. At speed this pushes the nose down and pivots the ass end up with aid of the flap. If power is pulled at speed too rapidily the nose will ballon up. To me this proves the motor thrust angle and flap work together to fly the wing.

Not saying I know it all.....just talking through it.

[T2x]

'Basic Aerodynamics'-----"-for maximum lift, a positive pressure will exist on the lower surface, but this will account for approximately one-third of the net lift." Rich---aviator stuff, but it does describe a basic airfoil section----Gene

I understand how an airfoil works, but the data shown above is for a wing at altitude. Our use is essentially a ground effect situation with much higher air compression beneath the airfoil. A good comparison would be one of those ducted fan hovercrafts, which have very little lift on the top surface and tremendous force beneath. This is the same concept that leads to adjustments in attack angle and compression changes in tunnel boats as they increase in speed. Very little is has changed above the sheer line in tunnel boat design over the years, but the reduction in tunnel compression has been significant allowing them to raise terminal speeds from the low 80's to above 140.

[T2x]

With a wing the motors are set at a negative angle. At speed this pushes the nose down and pivots the ass end up with aid of the flap. If power is pulled at speed too rapidily the nose will ballon up. To me this proves the motor thrust angle and flap work together to fly the wing.

Not saying I know it all.....just talking through it.

I agree with the above completely regarding the 18 footer . So far our 20 footer shows no inclination to settle at the stern if you back off abruptly at speed. It also seems to generate less lift than the 18 overall. This was specifically referred to by Dave Switzer as part of his design changes with the larger boat. Until I take her into the 120's we won't know precisely how different the 2 designs are at the max speed recorded by an 18 footer. To my knowledge, no one was able to get a 20 footer anywhere near that speed with the power available back in the day, and we may already have pushed ours faster than any of the others. I've driven quite a few tunnels and cats above 110 and so far the 20 footer seems more level and evenly balanced at that speed than anything else I've experienced. Of course the larger cats (above 35 feet) have a completely different scale speed for reference but all of them seem to get lighter in the bow as you accelerate. So far....the wing does not. Since it was 12 degrees at my house this morning and the port powerhead is apart....we will have to wait until next season for more info.

T2x

[GENE LANHAM]

Forty plus years later---still can't hear, and the hearing aids are getting bigger and more expensive$$ At Parker I stuffed cotton balls soaked in Vaseline--UGH!

Hearing protection, 1970: Helmet is off, getting ready to change another Speedmaster.

Willabee: I think the back of the head is Stoney? or Richey? This was the first big race after Mr. Kiekhaefer 'retired', lots of changes had been made in the Race Team--

edit---sorry about the poor quality 40 yr. old super 8/DVD---I'll try a different 'capture'----

[2us70]

Standing next to a running fire engine and running with that siren all those years didn't help either.

[GENE LANHAM]

Standing next to a running fire engine and running with that siren all those years didn't help either.

Hey Jim----it would take another old firefighter to remind me of that!! The 1000 cu. in. Hall Scott 'Invader', 2300 RPM, pumping 1500 GPM, for a few hours---and then there were the 'screaming' 2 stroke Detroits---they eventually provided us with those 'mickey mouse' ear muffs----Gene

[Old fiberglass]

Gene what were average cruise speeds on the straights during a race in your wing ??

[GENE LANHAM]

Gene what were average cruise speeds on the straights during a race in your wing ??

100. Dave and Bob should get all the credit---designing and building a boat that advanced, over forty five years ago!! Any of the 18's, with a decent setup; a pair of good 99 cu in engines, were comfortable and predictable, and capable of speeds over 100 mph----

[willabee]

.....Willabee: I think the back of the head is Stoney? or Richey? This was the first big race after Mr. Kiekhaefer 'retired', lots of changes had been made in the Race Team--

I can't tell who that is, pic is just too dark. But, speaking of Stoney, I have a great picture of him in the prop truck thanks to Molly's collection.

I don't know what it is about prop guys, but they all seemed to be such super nice people. Schwebs, Hetzel, Henrich and this man, Keith "Stoney" Hurst. When I started at Merc, Don Schwebs was the Foreman of the prop lab in Oshkosh and Bob Hetzel was his Leadman. Schwebs decided to transfer to Lake X to work with Offshore and Hetzel became the new Foreman, he hired Hurst.

A while after the Race Team was formed, Garbrecht converted the garage in the office building into a prop shop and arranged to have Hurst transferred to Racing. Just like the men before him, Keith was an immediate help to the racers and was very well liked. He tended to follow country & western music and wore cowboy boots and one day someone called him "Stoney" ..... the nickname stuck. I traveled with him to many races in the parts truck Day Tripper and it was always a good trip.

I flew out to the Long Beach race in 71. After the event, Stoney told me that he didn't feel very good and asked if he could fly home instead of spending four days driving. That wasn't like him, so I told him that I'd get his truck home and that he was to go to a doctor to see what was wrong. It wasn't good news.....he had cancer. He got treatments, was told he was good to go, but it came back. I'm not sure, but I'm thinking that just about a year after he was at this race, working with and helping others, laughing at a good joke and definately enjoying those California girls in their little bikinis, he was gone.....very sad.

I like the little note Molly put on the picture....."the racers buddy". There's no doubt, Stoney was that all right. He'd try to help anyone that asked, always had time to listen and enjoyed talking about B&B's while having a cold beer. I'm glad our paths did cross, he was a good friend.

[GENE LANHAM]

I don't know what it is about prop guys, but they all seemed to be such super nice people. Schwebs, Hetzel, Henrich and this man, Keith "Stoney" Hurst.

Agree with Willabee about 'super nice people'. I was privleged to know Keith and Don and was able to stay in touch with Don during his many years at the Lake.

June 1970, GG took the Race Team to the 'Bahamas 500'. Keith was not too happy. He thought 'offshore' was a waste of effort and good equipment, "4 boats, 16 engines, 16 props, and all the spares!" And the race was a logistical nightmare. Crews, parts, fuel, at two locations, in a foreign country----

Everyone's efforts paid off, and an outboard won the '500' for the first (and only) time. Doug Silvera/John Stenbeck in the 32' Bertram with 4 'Super BP's'.

I'm sure Butch and Charlie will remember some other prop guys, 'super nice people', Arne---Knocky---Oliver---Jeff

[velox]

Agree with Willabee about 'super nice people'. I was privleged to know Keith and Don and was able to stay in touch with Don during his many years at the Lake.

I'm sure Butch and Charlie will remember some other prop guys, 'super nice people', Arne---Knocky---Oliver---Jeff

I remember Oliver Land and got in touch with him not too long ago. I would go to his shop and hang until he would get out his top secret blade profiles and build me a "super prop"
He was the best OPC prop guy in S. Florida and was my best friend. Richie was the best at boat repairs and was also my best friend. Butch Stokes and Don Pearson were the best Mercury mechanics around and were also my "best friends". Are you starting to get the drift? HAHA Actually they were all great friends and all that are still alive are still best friends today.
Damn, I wish I could do it all again!

[jackie wilson]

I always knew I was a nice guy, but I almost forgot I was a prop guy too. ha ha ha!!!

Me too James !!!!!!!!!! i always thought i was a nice guy, but never a prop man-----i always had Rolla to look after my interests.

[jackie wilson]

I remember Oliver Land and got in touch with him not too long ago. I would go to his shop and hang until he would get out his top secret blade profiles and build me a "super prop"
He was the best OPC prop guy in S. Florida and was my best friend. Richie was the best at boat repairs and was also my best friend. Butch Stokes and Don Pearson were the best Mercury mechanics around and were also my "best friends". Are you starting to get the drift? HAHA Actually they were all great friends and all that are still alive are still best friends today.
Damn, I wish I could do it all again!

You have it right there Charlie-----the friends of then are still the friends of now----that's the problem--can't get rid of the buggers----they are there for life.
Rolla always thought Don H. was the other great prop guy [next to he himself] but the guy who got me out of deep poo-poo at Parker was Hetzel.!!!! long story for another day

[GENE LANHAM]

[QUOTE=willabee;2091120]I like the little note Molly put on the picture....."the racers buddy". There's no doubt, Stoney was that all right. He'd try to help anyone that asked,QUOTE]


Looking closely at this picture from Molly, I see nothing but Mercury's three blade Speedmaster props, a few 'lefts' behind the drill press. Not a Record or Rolla in sight. There is a pair of these laying in my toolbox, I got them from Stoney at Parker, 1970.

[jackie wilson]

Rolla only ever did the prototypes , then moved on. Betcha it wasn't mercury who came up with the first 3 blade
Remember the first 4 blade i ever saw-----Auronzo----up in the Dolomites,late 60's i think, Rolla lent it to Downard, [ who was Mercury flavour of the month at that time] he won all the races at a canter, Molinari was there and Scotti and Velden, but they all ran the 3 blades.