What does it take?

[Joe Reese]

What does it take to stay legel and race a sport 40?

I hear that in the unlimited class they allow transom mounted struts.

What About our RC hulls? Will this rule apply to us?

 

[Don Ferrette]

Please don't drag this up again, this horse has been beat to death already. Sport 40 struts stay under the boat.........

 

[wingnut]

i second the motion

 

[Paul Pachmayer]

Hello Guys,

Please don't drag this up again, this horse has been beat to death already. Sport 40 struts stay under the boat.........

I'm curious, why is this such a big deal? I do understand the 1/8th scale reason but on a sport hull......

Paul.

 

[P THOMAS]

What does it take to stay legel and race a sport 40?

You might try to read a rule book if you have one.

dont think any unlimited has a transom mounted strut, any ways it sport 40 hydro not scale hydro you dont have to build it like the big boats do.

Come on down to Dist 4 races you will see lots of sport40 racing.

Get it going there you will have fun.

 

[missbudpilot55]

Sport 40 was supposed to simulate the unlimited light hydroplanes, I have never seen one of them with a transom mounted strut. Don't see the big deal about everyone wanting to transom mount a strut anyway, there is not a advantage to this on a 3 point hydro, I proved this 20 years ago with an old Octura "Whie Heat IV" hydro, modified the rear of the hull from 4 point to 3 point built 2 of them one with the strut under one with the strut on transom. Actually the boat with the strut under the hull ran and handled better.

Bill Diedrich

Ventress, LA B)

 

[Joe Reese]

The Sport 40 is new to me. I was just wondering! arent we all?

So strut under the hull it is!

How will it seal?

Can the prop extend out the back but not past the rudder?

 

[Joe Reese]

Phill,

Would this engine fit into one of your hulls?

Take a look!

Shoot the pics wont turn up, any way www.mhzusa.com has a turbin engine tested for the water.

 

[Don Ferrette]

The Sport 40 is new to me.  I was just wondering! arent we all? So strut under the hull it is! 

How will it seal? 

Can the prop extend out the back but not past the rudder?

75796[/snapback]

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Joe-

The strut doesn't need "sealing" since when the boat is on plane that area ain't touchin' the water. I've seen some people put silicone around that area but I've never had a problem. Just keep the slot you cut for the strut fairly close to the strut blade size. B)

 

[Mike Hughes]

Sometimes if the hole is large enough you might get some water in there on launch. Can cause problems with the vibration of the bottom of the boat. It bounces the the water up into the carb and that ain't good. I try and keep it just big enough.

Mike

 

[Paul Pachmayer]

Hello Guys,

Sport 40 was supposed to simulate the unlimited light hydroplanes, I have never seen one of them with a transom mounted strut.

I bet you've never seen one with a strut running parellel with the water surface either. If you want to split hairs you might as well run a fixed strut and a straight shaft, like the real thing.

Don't see the big deal about everyone wanting to transom mount a strut anyway, there is not a advantage to this on a 3 point hydro

Hmm, lets see. Advantage 1, easy to install. Advantage 2, no hole fitting in the bottom of the boat. Advantage 3, moving the strut a bit further back, say 2 inches on a shorter boat does help handling.

I'll agree with you that from a running/performance stand point it really doesn't make much if any difference. I run FE boats and we can hang our struts off the transom, on the other hand we run 1/8th scale hulls and follow IMPBA rules on strut placement. On my 1/8th scale it was a PITA to mount the strut but it works fine.

I'm still trying to figure out why this is such a sore subject.

Paul.

 

[P THOMAS]

The Sport 40 is new to me.  I was just wondering! arent we all? So strut under the hull it is! 

How will it seal? 

Can the prop extend out the back but not past the rudder?

75796[/snapback]

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Only thing to do is keep the strut under the hull , not any part sticking out from under the hull at the transom. The drive dog is ok to be past the hull bottom.

the way the slot is cut is important, you want is straight so the strut wont steer the boat left or right, and keep it neat so that there wont be any big gaps to let water in. You can use some sealer once you get the strut setting you like.

We had one boat that would die soon after launching Found that the strut leading edge wasnt sharpened all the way up to the hull and was scooping water into the boat. They ran the boat with out the cowl and you could see water shooting from the strut slot all the way up to the engine.

 

[Don Ferrette]

Sometimes if the hole is large enough you might get some water in there on launch. Can cause problems with the vibration of the bottom of the boat. It bounces the the water up into the carb and that ain't good. I try and keep it just big enough. Mike

75809[/snapback]

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Exactly. That's what I was getting about the fit of the strut thru the hull but Mike made it clearer. You should have a way for water to get OUT of the tub (like an auto bailer) as it's going to get it there from elsewhere (under cowl, scoop, etc) anyway.

 

[Don Ferrette]

the way the slot is cut is important, you want is straight so the strut wont steer the boat left or right, and keep it neat so that there wont be any big gaps to let water in. You can use some sealer  once you get the strut setting you like. 

75823[/snapback]

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Assuming you have a properly built hull just use a T square & strike a line off the transom where you want to put the strut blade. Check it against the inside edges of the front sponsons, all three should be parallel. If not, well...... you got bigger problems.

 

[Joe Reese]

So mount the strut forwared of the transom, parallel to the sponsons, set the prop one to two inches rear of the transom. seal with silicon to prevent water spray.

Then I'm legal.

What dose it take to find the best plase for the rudder.

Scale have the rudder directly behind the prop. Now I was told the best location is off set to the right. Is off seting the rudder legal?

 

[Don Ferrette]

What dose it take to find the best plase for the rudder.  Scale have the rudder directly behind the prop. Now I was told the best location is off set to the right.  Is off seting the rudder legal?

75843[/snapback]

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I've not seen a scale ever have the rudder behind the prop. Set your rudder to the LEFT side of strut.

 

[Joe Reese]

To the left? Your the pro...

What about a Rigger? there to the right.

To the left? Could you explain to me why the left?

 

[Don Ferrette]

To the left? Your the pro...What about a Rigger? there to the right.

To the left?  Could you explain to me why the left?

75846[/snapback]

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Well there are differing opinions on this but thru extensive testing I've found that scale & sport boats tend to corner better with the rudder placed on the left. Whatever action happens on the rear has an opposite affect on the front. In other words the left rudder placement helps keep the right sponson & turn fin planted better, reducing the tendency to slide. Now on riggers I run the rudder on the right as typically they don't need help keeping the right sponson down & don't "float" as much since there is less underside surface to trap air. Clear as mud eh?

 

[Joe Reese]

You anwered the nest question I had. Where is the turn fin? On the right sponson. Clear as mud!

 

[Don Ferrette]

I found a better pic so go back & look at previous post, should help some.