Scale strut, flat or round bottom?

[Terry Keeley]

Helping a budy reserect his "Miss Supertest" built from Newton plans, he's totally gutted it and is gonna update all the gear, here's what he's into:

Wondering if he should go with a flat bottom strut or rounded?

 

[Duck899]

Pro's and con's to both I suppose.... I've run both.....I would go with the flat bottom. It helps to keep the back end up in the corners and helps to eliminate some of the hopping that round nose's can do as the speed drops in the corners and along with that, the back end. I ran an Erickson 2.2/3 blade prop on my old 1953 Such Crust V back in the 90's and even with all the lift that prop had it would still drop the rear with a round bottom strut. I went to a flat bottom strut and the hopping was lessened and the speed through the corners was better. You can always round off a flat bottom strut later if your not satisfied with the boat ride.....

Here is a link to some pics from district 16 of our classic scales and alot of Paul Omerzu's Miss Supertest III. Paul is running modern speedmaster hardware with a flat bottom strut and that boat corners well.....

Classic scales from District 16

 

[ALLAN YUEN]

Best use flat bottom

 

[Terry Keeley]

Thanks for the replys guys, makes sense and I'm not a scale guy.

Rob, any idea what prop(s) Paul runs on his?

 

[Duck899]

Thanks for the replys guys, makes sense and I'm not a scale guy.
Rob, any idea what prop(s) Paul runs on his?

X-457/2 and I think that scale has about a pound of lead in the left sponson if memory serves me correctly. Someone took some video of it running for the first time this year. I'll have to find out where it is and post it on you-tube. It runs well even powered by an OPS 67.....

 

[SayMikey]

Thanks for the replys guys, makes sense and I'm not a scale guy.
Rob, any idea what prop(s) Paul runs on his?

1457 or 1460

 

[Terry Keeley]

Thanks for the replys guys, makes sense and I'm not a scale guy.
Rob, any idea what prop(s) Paul runs on his?

X-457/2 and I think that scale has about a pound of lead in the left sponson if memory serves me correctly. Someone took some video of it running for the first time this year. I'll have to find out where it is and post it on you-tube. It runs well even powered by an OPS 67.....

That's what my buddy was running too but he had problems with it blowing off, think a flat strut, deeper will help. That's why I suggested the 1457 as Mikey said.

Do you know if Paul was using air dams or anything else to keep it on the water?

He's got an OPS in his too...

 

[Duck899]

Thanks for the replys guys, makes sense and I'm not a scale guy.
Rob, any idea what prop(s) Paul runs on his?

X-457/2 and I think that scale has about a pound of lead in the left sponson if memory serves me correctly. Someone took some video of it running for the first time this year. I'll have to find out where it is and post it on you-tube. It runs well even powered by an OPS 67.....

That's what my buddy was running too but he had problems with it blowing off, think a flat strut, deeper will help. That's why I suggested the 1457 as Mikey said.

Do you know if Paul was using air dams or anything else to keep it on the water?

He's got an OPS in his too...

No air-dams....that, I know for sure....just lots of weight up front in the sponsons.

 

[Terry Keeley]

Here's a shot from 1989 he sent if interested:

Apparently they ran the cowl when she set the speed records in the late 50's...

 

[P THOMAS]

Speedmaster has a longer strut good for roundnoses. It is like thier cat strut but with a flat bottom

Speedmaster Large 3 ¾ deep flat bottom extended strut for ¼ cable

 

[Duck899]

Here's a shot from 1989 he sent if interested:

Apparently they ran the cowl when she set the speed records in the late 50's...

Very nice!!!!....

 

[Terry Keeley]

Speedmaster has a longer strut good for roundnoses. It is like thier cat strut but with a flat bottom
Speedmaster Large 3 ¾ deep flat bottom extended strut for ¼ cable

Thanks Phil, he's keeping that in mind, saw it in your gallery.

He built it exactly to Newton's plan 106, hull has a flat afterplane, will he end up with the strut deeper than just "on the table"? (with the hull level). :huh:

 

[shoboat]

Terry,

Some of the ABC older propellers work GREAT on roundnose hulls.

57 x 76, and 60 x 80. Some of the better running roundnoses

are running ABC propellers.

Some Suggestions,

Mark Sholund

 

[Greg Hahn]

Terry,
Some of the ABC older propellers work GREAT on roundnose hulls.

57 x 76, and 60 x 80. Some of the better running roundnoses

are running ABC propellers.

Some Suggestions,

Mark Sholund

I agree with Mark, I've had good luck with a cupped 60 x 80, enough lift but not too much on my 68 Bardahl.

gh

 

[Bob Morton]

Hi Terry,

I have had good results with 62x80 on round nose hulls.

Bob

 

[Terry Keeley]

Thanks for the suggestions guys, I've talked him into taking some pics along the way so I'll post them in a new thread...

 

[Scott Schneider]

Here a pretty equivalent set up on a Gas thunderboat.

Speedmaster extended flat bottom strut, Straight blade rudder cut down running forward of the prop

 

[Terry Keeley]

Here a pretty equivalent set up on a Gas thunderboat.Speedmaster extended flat bottom strut, Straight blade rudder cut down running forward of the prop

Looks good except the drive dog has to be forward of the transom for 1/8th scale, at least in IMPBA.