Octura 1450 props

[Tim_Duggan]

Back to the 1450 topic.....Sorry guys we were racing around in here..... .

Thats OK Joe. If we can keep it specific to 20 riggers / Heat race props / achievable speeds, it's what the thread is all about.

Anyone else planning on doing any prop development for 20 riggers this season??

Anyone had any success with modifying the ABC H1716, H1914 etc for better 20 rigger performance?

 

[Don Ferrette]

Yes, Don won 40 hydro. I said that Joe's boat was the most impressive 40 boat there. No question about that....Don was consistent and put up points. I tend to look at boats and how they perform more now that look at the winner. I am interested in what people are doing to get the optimum performance. I can learn the most that way and maybe put some of what I see into my boats. I saw the way that Joe's boat handled the race water and have added a little to the wheelbase of my design because of that.
I sure didn't have the best 60 boat either, but I backed into it.

Marty there's an old saying- "never show a dollar when a dime will do". Don't think my 40 Shooter ever saw WFO once that weekend.

Plus one tends to be a tad less reckless with a boat that is rather difficult to replace.

That's all that needs to be said there. Now back to your regularly scheduled programming......

 

[Marty Davis]

Yes, Don won 40 hydro. I said that Joe's boat was the most impressive 40 boat there. No question about that....Don was consistent and put up points. I tend to look at boats and how they perform more now that look at the winner. I am interested in what people are doing to get the optimum performance. I can learn the most that way and maybe put some of what I see into my boats. I saw the way that Joe's boat handled the race water and have added a little to the wheelbase of my design because of that.
I sure didn't have the best 60 boat either, but I backed into it.

Marty there's an old saying- "never show a dollar when a dime will do". Don't think my 40 Shooter ever saw WFO once that weekend.

Plus one tends to be a tad less reckless with a boat that is rather difficult to replace.

That's all that needs to be said there. Now back to your regularly scheduled programming......

Don:

I intended no disrespect for your achievment. It is difficult to win a class and even tougher to get a perfect score.

I was ONLY commenting on Joe's boat and the way that it ran. I tend to look at that more than anything now, trying to see things that will help me with my own boats. I did that and plan to add a little wheelbase to my design (which finished second by the way).

 

[Don Ferrette]

Yes, Don won 40 hydro. I said that Joe's boat was the most impressive 40 boat there. No question about that....Don was consistent and put up points. I tend to look at boats and how they perform more now that look at the winner. I am interested in what people are doing to get the optimum performance. I can learn the most that way and maybe put some of what I see into my boats. I saw the way that Joe's boat handled the race water and have added a little to the wheelbase of my design because of that.
I sure didn't have the best 60 boat either, but I backed into it.

Marty there's an old saying- "never show a dollar when a dime will do". Don't think my 40 Shooter ever saw WFO once that weekend.

Plus one tends to be a tad less reckless with a boat that is rather difficult to replace.

That's all that needs to be said there. Now back to your regularly scheduled programming......

Don:

I intended no disrespect for your achievment. It is difficult to win a class and even tougher to get a perfect score.

I was ONLY commenting on Joe's boat and the way that it ran. I tend to look at that more than anything now, trying to see things that will help me with my own boats. I did that and plan to add a little wheelbase to my design (which finished second by the way).

I know that my friend, it's all good! Joe's stuff is always fast, wish my untested boat "gremlins" had not shown up there in F hydro and twin so we could have raced! B)

Now back to these 1450's..............

 

[Chris Wood]

you can obtain real good rpm with a FULL BLADE 1450.

you just can't cup them like you would normally do.

i am not even going to try and explain as you would have to see to understand.. but i am with marty.. full blade.. i have tried a smaller blade dia and it is no good for me.. plus full blades are smoother in traffic and race water.

chris

 

[Norm Doerr]

What about the 1452 slightly cut.. Anyone done that yet? I think that may be on our list of stuff to do not sure if we got that far.

 

[Brad Christy]

Norm,

Dave Roach has a 1452 we're going to try this spring if the weather ever turns predictable.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[Marty Davis]

Norm,
Dave Roach has a 1452 we're going to try this spring if the weather ever turns predictable.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

Brad:

I saw Dave cut an X452 a little for an outboard and it was awesome.

 

[Tim_Duggan]

I'm testing full diameter blade 1450's this weekend. (for lap times - relevant for a good heat race set-up.)

As it's easier to remove material from a prop than it is to add it back on, I'm going to start with conservative pitch and work it up until it's no longer effective. Only then will I start removing tongue area.

Hulls - FF21 (KIT built - not plans) 3.75Lb's less fuel.

Engines - Modified Novarossi 7 port RX21 14.0mm crank. Modified Novarossi 7M, 7 port 14.0mm crank.

Pipes - OPS3280, AB21SS, and SPP TD21 & NR21OB.

Tim.

 

[dave roach]

Marty

I still have that x452 prop and a guy in are club try it on his 7.5 tunnel and it was so fast he couldn't drive it.

Dave Roach

Tim

Back to the 1450

The prop to try is the abc1716 full blade

 

[Tim_Duggan]

TimBack to the 1450

The prop to try is the abc1716 full blade

Dave,

Thanks for the info. According to the ABC prop chart, the 1716 is only 43.8mm diameter. Do they have a lot of blade area and pitch to load the engine, or are they being run deeper than the bigger diameter blades? I don't have one to look at unfortunately.

 

[dave roach]

Tim

Brad and I run the strut center line of the prop shaft to the bottom of the rear sponsons this is on the blackjack.The 1716 prop has a lot of blade area.

Dave Roach

 

[Marty Davis]

MartyI still have that x452 prop and a guy in are club try it on his 7.5 tunnel and it was so fast he couldn't drive it.

Dave Roach

Tim

Back to the 1450

The prop to try is the abc1716 full blade

Dave:

I tried it and found that it was very fast but didn't launch well. Cavitated a ton before it hooked up. On water that was less than smooth, it did not stay hooked up. One thing, it did run 75 mph. Just not the type prop that I can feel good about racing with.

Marty Davis

 

[dave roach]

Marty

That sounds like a little strut adjustment.

Dave

 

[Tim_Duggan]

Adjusting the strut deeper should help with keeping it hooked up, but might make it even harder to launch. Aren't 20 riggers great!

I've been running the 46mm diameter props deeper than "normal" on my boat to keep them hooked up in bumpy water. (Bottom of the strut 1/8" below bottom of the sponsons.) Unfortunately in Australia we tend to race in bumpy water more often than not.

 

[ozbryan]

I'm testing full diameter blade 1450's this weekend. (for lap times - relevant for a good heat race set-up.)As it's easier to remove material from a prop than it is to add it back on, I'm going to start with conservative pitch and work it up until it's no longer effective. Only then will I start removing tongue area.

Hulls - FF21 (KIT built - not plans) 3.75Lb's less fuel.

Engines - Modified Novarossi 7 port RX21 14.0mm crank. Modified Novarossi 7M, 7 port 14.0mm crank.

Pipes - OPS3280, AB21SS, and SPP TD21 & NR21OB.

Tim.

I guess id better pack my boat then.... :blink: LOL :lol: :lol: hadnt planed on bringn it.. but ok you got me sold! I love drivin that thing!

 

[Tim_Duggan]

My 1450 testing got delayed The engine was hurting plugs on a known set-up so it's new bearings time. The second boat had a radio issue so it just wasn't meant to be!

 

[mtruex]

My 1450 testing got delayed The engine was hurting plugs on a known set-up so it's new bearings time. The second boat had a radio issue so it just wasn't meant to be!

any news on the prop testing?

 

[Marty Davis]

One prop that needs consideration is the 50x69 ABC. It is essentially a 1450 that is slightly smaller in diameter. I think that Andy Brown used a 1450 to cast it and you get a little shrinkage. I have had 50x69's that are just as good as 1450's. The diameter of the 50x69 stays hooked up very well in race water and is probably about the least diameter that I would run for racing. I use the 50x69 on the Duplicator that was made for the 1450 as well as the 1450 on the Duplicator that was made for the 50x69. Works just fine.

The duplicators that I use do not have stok (still can't spell that) tongue pitch so my results are probably not helpful to this analysis.

 

[shoboat]

Boaters,

We have had excellent results with a 1450 cut to a H-7 profile recently.

The 50 x 69 is also working very well with .1 & .2 radi removed a little

bit up from the hub. We are also working with a 1518/3 from ABC with a real

RPM set up that is showing some promise.

Martin,

Have you tested those other propellers yet?

Thanks,

Mark Sholund