Sport 20 hull weight

[Jr Branham]

Hey Gang,

What is the approximate weight of a sport 20 hull....bare hull only, either in glass or wood. Thanks

 

[TomMoorehouse]

hey JR..... did you ever use that plug you got from andy to make a sport 20?

 

[Jr Branham]

Tom,

I actually own the molds, not the plug. I did lay-up a few hulls, Andy K. has one of the hulls now, I think he has been too busy to rig it out. I made a promise not to run nitro again, but this is getting interesting. Maybe I need to crank up the shop heater and start slinging some resin.

Jr. Branham

 

[Scott Schneider]

:huh: One of Bob Tuttles wood hulls, sealed up ready for paint w/cowl 2# 6 1/2oz.

Complete set up RTR no fuel 6 1/2#'s plenty light enought and at the speed we run at could be built heavier and have no problems. Scott

 

[PHIL THOMAS]

The sport20 i built from wood weighed 5lb i think that was ready to run. it ran ok 50-51 mph stayed on the water. when i get the epoxy one done maybe it will need a lead lining. LOL

PHIL

 

[Paul Pachmayer]

Hello Guys,

sealed up ready for paint w/cowl 2# 6 1/2oz.

WOW! That's some weight, my 1/8th scale boat will end up at just 1 pound more than that. If I'm going to build one of these I'll have to get over the weight issues on a nitro boat.

Do these things really take that much abuse from the engine that you have to build them so heavy?

Paul.

 

[Scott Schneider]

:huh: Do these things really take that much abuse from the engine that you have to build them so heavy?

Thats heavy? I would ask why you built a scale so light and fragle?

A complete sport 21 boat sealed and ready for paint at that weight is NOT heavy at all.

 

[Paul Pachmayer]

Hello Scott,

Thats heavy? I would ask why you built a scale so light and fragle?

LOL, I guess you never ran fast electrics. The hull I built will be pretty much bullet proof at that weight. I "could" have built it lighter than that but it would have taken too much screwing around with the original design.

Bottom line, a hull in the 30 inch range that I would run wouldn't weigh any more than 1 and a half pounds and it would take regular race abuse no problem.

A complete sport 21 boat sealed and ready for paint at that weight is NOT heavy at all.

That's why I'm asking the questions.

Paul.

 

[Scott Schneider]

Paul, It's all good fun debating the merits of low weight but I have raced Sport 20 hulls for 5 years and set many fast times and even a national record with then.

Keep in mind that once you get them into the high 50's they are a riding on a cushion of air and floating as they lightly rock side to side against gravity. The lighter they are the more they must be aerodynamicly ballanced and must maintain a very accurate and consistant angle of attack at ALL times or they will fly off the water !!

We in the class have seen many a boat built for low weight that was LIGHT as a KITE ! and looks like one too.

These little sport hydros are moving so fast and packing sooooo much air that extra weight helps to dampen the wave slamming lift that upsets ride height and angle of attack.

A heavy boat is a tad harder to get launched but is FAR more stable at speed and does not give up top end because it gets up on the air cushion and runs just as free of drag.

Scott

 

[Grimracer]

Paul

Regular is relative.

Remember we can afford to build in extra weight in our boats without paying the penalty of heavy batteries during our runs.

Our sport 20 boats are about 4.5 lbs RTR and run high 40 to low 50s.. This is good racing speeds..

One more note…please do not take this wrong… Your Atlas boat is likely the first 1/8 scale boat you have built. (FE or other) Its most likely the first 1/8 scale boat you will have ever drove and its also likely that you have never seen a good 1/8 scale race… The term Nubie…might apply to this even after racing for as long as you have…what 3 years..Im guessing here from as long as I have known you..

I have seen nitro 1/8 scale boat weight between 9 and 22 lbs.. The 9 lb boats are not any faster then the 22 lb boats on most of the race course we run.. Its not as much the weight as it is the setup.. A 9lb boat is a kite most of the time and the 22 lb boats are tractor trains for sure but end up furnishing most heats.. As you know balance is the key..

My vote is for a 12 to 15 lb scale boat.

60 mph…that is a good heat racing speed for a scale boat.

Just so everybody knows the score and im not trying to pull anybodys leg…I also have never drove or raced a 1/8 scale boat. I have built a few however.. After watching the scale boats run and race over the last 10 years is my turn to give it a try… should be fun.. O yea…The term Nubie…might apply here also..hehehe

I do however have a few years of sport 20 and a little sport 40 under my belt…

Two boats in the works…77 O boy and a 82 O boy…..O BOY

Grimracer

 

[Paul Pachmayer]

Hey Grim,

Our sport 20 boats are about 4.5 lbs RTR and run high 40 to low 50s.. This is good racing speeds..

Cool! The Q-Sport boats (18 cells) are about the same speed wise but are about 1 to 1 1/2 pounds heavier.

One more note…please do not take this wrong… Your Atlas boat is likely the first 1/8 scale boat you have built. (FE or other)

I follow you, wouldn't take it wrong. You got that right though, this is the first 1/8th scale I've built and I've never seen one run.

My vote is for a 12 to 15 lb scale boat.60 mph…that is a good heat racing speed for a scale boat.

See, your right on target. My AUW should be around 12 or 13 pounds. I've got a combo figured for around 50mph but I'm hoping for more. The motor I'm using is capable of 3000 watts and 33000rpm at the prop.

As far as Nubie goes, I do have experiance with big hydros, don't forget I built that Super Sport 45 on 24 cells which took first honors the 3rd time it hit the water. Sport Hydros are my bag baby.

With electrics I've got a TON of options on weight placement, I can change the cg on the boat by just moving the cells an inch or two. Now with nitro I'm lost no question so I need to turn to you guys for the help. I can build it but that's where it ends, I wouldn't know one end of a tuned pipe from the other, lol.

Okay, now you got me and I'll build one. All I need is one of those nice fg cowls you make and a list of parts.

Paul.

 

[Paul Pachmayer]

Hey Scott,

Paul, It's all good fun debating the merits of low weight but I have raced Sport 20 hulls for 5 years and set many fast times and even a national record with then.

I think what's happening here is our boats of the same size and relative speeds come out to the same basic weights. The difference is how we're putting the weight in the boat, heavy boat with light motor or light boat with heavy cells.

So if I have a boat that's a bit over 1.5 pounds I'll need to "add" a bit of weight to it? I have one in mind but it might not be the way to go.

Paul.