.67 in a .45(38 inch SD3)

[Andy Greene]

Just wondering outloud if any of you guys have played with a .67 in a 38 inch-.45- Seaducer SD3 ??

 

[ALLAN YUEN]

Use it for good S.A.W I talked Jerry about switch .67 for SD3 40 mono but he says can fly over floppy that's risk <_< you will get DNF and lost points

 

[Andy Greene]

The B-Mono (.45) record he set was with an A-Mono hull (.21) boat- he said the same was true with that boat.IF he could get it to stick-it was WICKED fast. Anyone have any hands on experience with this setup ??? Other than the crazy Broward Sheriff - LOL-Kidding Jerry.

 

[tnrcboatracer]

It is very common in SAW to use a cut down or smaller hull for a particular engine class. This logic will not work for racing, as the hull will be way over HP'd and will likely get a bunch of DNF's. Also during SAW trials, the water is typically much flatter that churned up race water, and course corrections to avoid other boaters are non-existant.

 

[Andy Greene]

It is very common in SAW to use a cut down or smaller hull for a particular engine class. This logic will not work for racing, as the hull will be way over HP'd and will likely get a bunch of DNF's. Also during SAW trials, the water is typically much flatter that churned up race water, and course corrections to avoid other boaters are non-existant.

Were would you start prop wise ?? For a saws type application of course . Common start with the .45 boat/motor combo is a 450/3 configured to desired spec. Were would one start with a .67 in the same boat ?

 

[tnrcboatracer]

I'd start with something like an X457. A cut down X460 or X462 may also work.

 

[John Finch]

X series props don't cut it for straightaway. They accellerate quick but top out to fast. They act as a governor as the front angle that enters the water is not aggessive enough for higher speeds. 14 and 16 series are better for straightaways. At one time I held the 20, 40, 60, and f mono impba records all at the same time with the same boat. I just changed engines. It was smaller than the boat you are talking about, so you can make it work for record trials. Don't try to heat race it, or you will be disapointed.

 

[Andy Greene]

X series props don't cut it for straightaway. They accellerate quick but top out to fast. They act as a governor as the front angle that enters the water is not aggessive enough for higher speeds. 14 and 16 series are better for straightaways. At one time I held the 20, 40, 60, and f mono impba records all at the same time with the same boat. I just changed engines. It was smaller than the boat you are talking about, so you can make it work for record trials. Don't try to heat race it, or you will be disapointed.

Thanks for the input John, If you dont mind me asking , what hull were you using and what size /weight was it ?? 4 Mono records with one hull is impressive....

I guess a conversation with Mr.Brown about 14-16 series mono props is in order. For SAWS of course.

Andy

 

[John Finch]

I will have to go back to my notes as it was a long time ago. I remember I was running 86 mph on the stalker with a CMB 67 but didn't follow thru with the record attempts with that setup because I switched to riggers to work on the 100 mph goal with Kentley who got me interested in the 100 mph team hydro efforts. While we were working on the hydro stuff Jerry took all the mono records except the 20 mono. Kentley porter kept me focused on the 20 because of our team efforts and his love of the 20 size engines. I need to re-visit those days. I will look up the info in my notes when I get home later today and then post the information for you.

 

[Andy Greene]

I will have to go back to my notes as it was a long time ago. I remember I was running 86 mph on the stalker with a CMB 67 but didn't follow thru with the record attempts with that setup because I switched to riggers to work on the 100 mph goal with a hydro. While I was working on the hydro stuff Jerry took all the mono records except the 20 mono. Kentley porter kept me focused on the 20 because of our team efforts. I need to re-visit those days. I will look up the info in my notes when I get home later today and then post the information for you.

Thanks John, looks like Im gonna have to get a recovery boat for lake X so I can do some testing, its the only place long enough around here . The records are a bit out of reach for me,but some decent speed patches would be cool.

Andy

 

[John Finch]

ok, found my notes from November 97. It was a 33 inch boat. It was a 46 inch Twin Craft that I cut to 33 inches in length. I put a wood deck on it and the sides were only 1/2 inch high. The transom was in tact because I took the length off the front of the boat. I used a CMB 67 with a mac 13 cc pipe at 10 1/4 inches from the center of the engine to the widest part of the pipe. I used an H-22 prop with a lot of cup at the trailing 1/3rd of the blade. The rudder was 2 inches deep into the water. The prop drive dog was 3 5/8ths from the transom and the rudder was just to the right of the prop and slightly ahead of the prop. The rudder was tilted 4 degrees to the right. Prop pitch was 3.8 and top speed was 74 mph. The 86 mph runs I got later that month were with a different prop, but my notes jump right into the hydro testing in this book. I will check some of my other books after dinner.

Dinner is over. I found another book. 7 1/2 lbs ready to run less fuel. In 1995 It was going 75 mph with an ops 65. Same boat. It was the first mono to set an IMPBA record over 70 mph June of 95 in Elmira N.Y. with an ops 45 engine and an Irwin quiet pipe. Used a 1455 prop and weight was 7 lbs even. Well, it was a nice trip down memory lane. Good luck with your project.

 

[Andy Greene]

ok, found my notes from November 97. It was a 33 inch boat. It was a 46 inch Twin Craft that I cut to 33 inches in length. I put a wood deck on it and the sides were only 1/2 inch high. The transom was in tact because I took the length off the front of the boat. I used a CMB 67 with a mac 13 cc pipe at 10 1/4 inches from the center of the engine to the widest part of the pipe. I used an H-22 prop with a lot of cup at the trailing 1/3rd of the blade. The rudder was 2 inches deep into the water. The prop drive dog was 3 5/8ths from the transom and the rudder was just to the right of the prop and slightly ahead of the prop. The rudder was tilted 4 degrees to the right. Prop pitch was 3.8 and top speed was 74 mph. The 86 mph runs I got later that month were with a different prop, but my notes jump right into the hydro testing in this book. I will check some of my other books after dinner.
Dinner is over. I found another book. 7 1/2 lbs ready to run less fuel. In 1995 It was going 75 mph with an ops 65. Same boat. It was the first mono to set an IMPBA record over 70 mph June of 95 in Elmira N.Y. with an ops 45 engine and an Irwin quiet pipe. Used a 1455 prop and weight was 7 lbs even. Well, it was a nice trip down memory lane. Good luck with your project.

WOW !!!! - John , thank you for sharing such detailed notes.

Why the 4 deg. angle in the rudder?

The 74 to 86 jump was a BIG one . Was it prop or did you change the over-all setup ? Im not asking you to dig out the old notes or share more than you have been MOST generous to share already, just wondering if you remember what knocked down the next hurdle off the top of your head ?

Once again- Thanks , Look forward to meeting you one day. Come on down and give Marty a run for his money, somebody needs too-he's getting rusty -LOL.

Andy

Oh yeah, the new avatar picture? Santa and a Barbie in race boats??? cant tell- my wife would kill me-LOL.

 

[tnrcboatracer]

I was thinking of the X4xx series for oval racing, sorry. I de-tongue the X series props to remove the speed limiter. (makes them like the M series). X6xx series for SAW.

 

[John Finch]

I was thinking of the X4xx series for oval racing, sorry. I de-tongue the X series props to remove the speed limiter. (makes them like the M series). X6xx series for SAW.

I screwed up too. Hard to keep up with it all. The 86 mph runs were when I switched to the Picco 67 and jacked the timing up to 200 degrees in a notch pattern. I was getting the pipe to turn on two times with that exhaust setup with the same pipe. I believe the prop was the same, but I don't recall for sure. The boat was not changed. With record trial setup the boat is not really touching the water much. It is really flying accross the water. The tilted rudder was the trim tab. The tilt, along with a tad of left rudder, kept the boat level. Things change every time you go faster. The hardest part of flying the boat is getting the rudder, which is the only control you have on the boat, to fly the boat just right. You can also adjust the attitude of the boat with the prop. Andy Brown has the knowledge on knowing how to do that best. Then the lift under the boat vs. the weight of the boat needs to be adjusted for the speed it runs, because as it goes faster it packs more air under the hull. The cg should be right at 30 percent of the distance from the transom to start. You can then add weight to the bow as needed or add it right at the cg if the boat is too light. I prefere making the boat narrower on the next build after I get the facts on the present boat. Then I can increase speed and also reduce

weight.

Those are elves racing the 42 inch twincraft and cracker box in my front yard. We are one of those who spend weeks decorating for Christmas. The only boating at our house between now and Christmas is what you see in the photo.

 

[Don Ferrette]

.......Those are elves racing the 42 inch twincraft and cracker box in my front yard. We are one of those who spend weeks decorating for Christmas. The only boating at our house between now and Christmas is what you see in the photo.

Yup, from now until December 26th we refer to John by his holiday nickname- Griswald. John says they've scaled back some this year, I figure I'll know in a couple weeks when dusk hits. If my house lights don't dim when all his automatic timers throw the juice to the exterior decorations and there isn't that sub atomic glow off in the distance towards his house I'll know he was telling the truth. :lol: :lol: :lol: :lol:

 

[Norm Doerr]

.......Those are elves racing the 42 inch twincraft and cracker box in my front yard. We are one of those who spend weeks decorating for Christmas. The only boating at our house between now and Christmas is what you see in the photo.

Yup, from now until December 26th we refer to John by his holiday nickname- Griswald. John says they've scaled back some this year, I figure I'll know in a couple weeks when dusk hits. If my house lights don't dim when all his automatic timers throw the juice to the exterior decorations and there isn't that sub atomic glow off in the distance towards his house I'll know he was telling the truth. :lol: :lol: :lol: :lol:

So would the Astronauts on the Space Station see it?

 

[John Finch]

.......Those are elves racing the 42 inch twincraft and cracker box in my front yard. We are one of those who spend weeks decorating for Christmas. The only boating at our house between now and Christmas is what you see in the photo.

Yup, from now until December 26th we refer to John by his holiday nickname- Griswald. John says they've scaled back some this year, I figure I'll know in a couple weeks when dusk hits. If my house lights don't dim when all his automatic timers throw the juice to the exterior decorations and there isn't that sub atomic glow off in the distance towards his house I'll know he was telling the truth. :lol: :lol: :lol: :lol:

So would the Astronauts on the Space Station see it?

Not "Deck the Halls" movie stuff. Just somewhat Grisswald.