Black Jack .21

[Richard Dahlheimer]

I would like to have a discussion on Black Jack set up. With out a front boom block to change AOA of front sponsons, how does one loosen up the ride of the boat? Prop ideas, strut settings, and anything else would be most helpful. Thank You, Richard D

 

[dave roach]

Hi Richard

You have a PM

Dave Roach

 

[Tim Kish]

I would like to have a discussion on Black Jack set up. With out a front boom block to change AOA of front sponsons, how does one loosen up the ride of the boat? Prop ideas, strut settings, and anything else would be most helpful. Thank You, Richard D

Boat is totally adjustable by simply shimming the rear sposon tube , as well as changing the strut hight and angle.

My boat is set up with the strut dead zero , the strut is exactly .830 deep from the bottom of the tub to the bottom of the strut.

I am using two .02 shims under each boom mount but it needs more for the prop I want to run.

Both sponsons are set at 4.5" from the tub to the sponson.

Props tested

1445

1450

H-7

H-10

S-15

50/69

50/69 cut

I found that the 1450 and H-7 were the best for over all performance , heat racing.

I have been working with the 50/69 cut trying to find a sweet spot on this boat because it is truly amazing with that prop.

The boat is very fast (mid seventies) very stable but very touchy on the stick , you have to really drive the boat with this prop or it will get away from you in a flash.

I am running a Nova with Irwin -S pipe just under thee inches and it screams.

I am not saying that my set up is the way to go with this boat , but it is working for me.Both Brad and Daves boats are awseome on the water and may be set up completely different than my boat.

Hopefully Brad can jump in and add a little more info.

Very well planned and built boat .

Tim K

 

[shoboat]

Tim,

The H-6 works very well also,this is one of the propellers that Brad uses when

he comes to London. The 1450 B/C needs to be tweaked to your set up, but it is

very friendly on the water. I just cut a 1452 down to 46 mm and hope to try this

one out very soon. The C.O.B. pitch is where all the speed is in these propellers.

Also, try to keep your pipe lengths as short as possible with 178* exhaust timing.

Open up your intakes a little more to bring in more Nitro.

Have Fun Testing,

Mark Sholund

 

[Richard Dahlheimer]

Tim,
The H-6 works very well also,this is one of the propellers that Brad uses when

he comes to London. The 1450 B/C needs to be tweaked to your set up, but it is

very friendly on the water. I just cut a 1452 down to 46 mm and hope to try this

one out very soon. The C.O.B. pitch is where all the speed is in these propellers.

Also, try to keep your pipe lengths as short as possible with 178* exhaust timing.

Open up your intakes a little more to bring in more Nitro.

Have Fun Testing,

Mark Sholund

Thanks guys for the information. Yes, i like the way my Black Jack drives. Tim, thanks for the detailed set up info. I will try a deeper strut setting. Right now, i have the bottom of the strut even with the bottom of the sponsons. Dave Roach, i will call you tonight. Richard D

 

[shoboat]

Richard,

Just remember the deeper strut you go the more you reduce the angle of attack

on the front sponsons. You will pick up more propeller efficiency however. I would

open up the holes on the front boom tubes and adjust them up for more angle of

attack. You could also grind down the rear boom blocks to get the angle that you

are looking for. 4.3* AOA works very well for me on my Stealth 21.

Have Fun Testing Richard,

Mark Sholund

 

[dave roach]

Mark

Brad and I don't run that much attack angle on the blackjack if you do you are looking for bigger problems.

Dave Roach

 

[Ron Zaker Jr]

I would like to have a discussion on Black Jack set up. With out a front boom block to change AOA of front sponsons, how does one loosen up the ride of the boat? Prop ideas, strut settings, and anything else would be most helpful. Thank You, Richard D

Boat is totally adjustable by simply shimming the rear sposon tube , as well as changing the strut hight and angle.

My boat is set up with the strut dead zero , the strut is exactly .830 deep from the bottom of the tub to the bottom of the strut.

I am using two .02 shims under each boom mount but it needs more for the prop I want to run.

Both sponsons are set at 4.5" from the tub to the sponson.

Props tested

1445

1450

H-7

H-10

S-15

50/69

50/69 cut

I found that the 1450 and H-7 were the best for over all performance , heat racing.

I have been working with the 50/69 cut trying to find a sweet spot on this boat because it is truly amazing with that prop.

The boat is very fast (mid seventies) very stable but very touchy on the stick , you have to really drive the boat with this prop or it will get away from you in a flash.

I am running a Nova with Irwin -S pipe just under thee inches and it screams.

I am not saying that my set up is the way to go with this boat , but it is working for me.Both Brad and Daves boats are awseome on the water and may be set up completely different than my boat.

Hopefully Brad can jump in and add a little more info.

Very well planned and built boat .

Tim K

Tim,

Really good info,we more of this type of posting on the site.

Ron Jr

 

[F.Orlic]

I would like to have a discussion on Black Jack set up. With out a front boom block to change AOA of front sponsons, how does one loosen up the ride of the boat? Prop ideas, strut settings, and anything else would be most helpful. Thank You, Richard D

Boat is totally adjustable by simply shimming the rear sposon tube , as well as changing the strut hight and angle.

My boat is set up with the strut dead zero , the strut is exactly .830 deep from the bottom of the tub to the bottom of the strut.

I am using two .02 shims under each boom mount but it needs more for the prop I want to run.

Both sponsons are set at 4.5" from the tub to the sponson.

Props tested

1445

1450

H-7

H-10

S-15

50/69

50/69 cut

I found that the 1450 and H-7 were the best for over all performance , heat racing.

I have been working with the 50/69 cut trying to find a sweet spot on this boat because it is truly amazing with that prop.

The boat is very fast (mid seventies) very stable but very touchy on the stick , you have to really drive the boat with this prop or it will get away from you in a flash.

I am running a Nova with Irwin -S pipe just under thee inches and it screams.

I am not saying that my set up is the way to go with this boat , but it is working for me.Both Brad and Daves boats are awseome on the water and may be set up completely different than my boat.

Hopefully Brad can jump in and add a little more info.

Very well planned and built boat .

Tim K

Not sure if 75 mph boat will ever feel even close to one running 65-67 mph.

They become very light and sensitive when speeds are that high up regardlessof the setup, at least that is my experience.

It would be so nice to get back that 50x69 cut in near future.

 

[Tim Kish]

I would like to have a discussion on Black Jack set up. With out a front boom block to change AOA of front sponsons, how does one loosen up the ride of the boat? Prop ideas, strut settings, and anything else would be most helpful. Thank You, Richard D

Boat is totally adjustable by simply shimming the rear sposon tube , as well as changing the strut hight and angle.

My boat is set up with the strut dead zero , the strut is exactly .830 deep from the bottom of the tub to the bottom of the strut.

I am using two .02 shims under each boom mount but it needs more for the prop I want to run.

Both sponsons are set at 4.5" from the tub to the sponson.

Props tested

1445

1450

H-7

H-10

S-15

50/69

50/69 cut

I found that the 1450 and H-7 were the best for over all performance , heat racing.

I have been working with the 50/69 cut trying to find a sweet spot on this boat because it is truly amazing with that prop.

The boat is very fast (mid seventies) very stable but very touchy on the stick , you have to really drive the boat with this prop or it will get away from you in a flash.

I am running a Nova with Irwin -S pipe just under thee inches and it screams.

I am not saying that my set up is the way to go with this boat , but it is working for me.Both Brad and Daves boats are awseome on the water and may be set up completely different than my boat.

Hopefully Brad can jump in and add a little more info.

Very well planned and built boat .

Tim K

Tim,

Really good info,we more of this type of posting on the site.

Ron Jr

Thanks Ron

I am a firm believer that sharing info only helps create better competition and also helps people get through the difficulties of setting up a new hull that can often turn them off the hobby.

Richard

Do yourself a favour and listen to Dave , he and Brad have been racing this hull for some time now and as I said both their boats are working good (Brad it's time for a set up sheet).

I am running just under 3 AoA and was running close to 2 and the boat did not slow down 1MPH ,I only raised them back up because I ran into a problem that I thought was directly related to that setting only to find out later it was not.

Next test session I will tighten it up again.

One thing I have noticed in my years of testing is that when you set the sponsons to steep the boat tends to bounce over the waves instead of skip across them making it very difficult to control at speed during a race .

Tim K

 

[shoboat]

Tim,

How can you tighten down your AOA and not need more HP to go just as fast?

Are you changing your strut settings when you reduce your AOA?

With 2* on your front sponsons that Nova has to work pretty hard to keep the

same speeds as with 3* AOA. Tim do you use a digital angle finder for your

adjustments? Tim, try the 50 x 69 CUT on your S-15 the next time you get a chance

to test.

Interesting Stuff,

Mark Sholund

 

[Tim Kish]

I would like to have a discussion on Black Jack set up. With out a front boom block to change AOA of front sponsons, how does one loosen up the ride of the boat? Prop ideas, strut settings, and anything else would be most helpful. Thank You, Richard D

Boat is totally adjustable by simply shimming the rear sposon tube , as well as changing the strut hight and angle.

My boat is set up with the strut dead zero , the strut is exactly .830 deep from the bottom of the tub to the bottom of the strut.

I am using two .02 shims under each boom mount but it needs more for the prop I want to run.

Both sponsons are set at 4.5" from the tub to the sponson.

Props tested

1445

1450

H-7

H-10

S-15

50/69

50/69 cut

I found that the 1450 and H-7 were the best for over all performance , heat racing.

I have been working with the 50/69 cut trying to find a sweet spot on this boat because it is truly amazing with that prop.

The boat is very fast (mid seventies) very stable but very touchy on the stick , you have to really drive the boat with this prop or it will get away from you in a flash.

I am running a Nova with Irwin -S pipe just under thee inches and it screams.

I am not saying that my set up is the way to go with this boat , but it is working for me.Both Brad and Daves boats are awseome on the water and may be set up completely different than my boat.

Hopefully Brad can jump in and add a little more info.

Very well planned and built boat .

Tim K

Not sure if 75 mph boat will ever feel even close to one running 65-67 mph.

They become very light and sensitive when speeds are that high up regardlessof the setup, at least that is my experience.

It would be so nice to get back that 50x69 cut in near future.

50/69 cut :lol: At least you didn't call me Al , Talk to you Friday.

Mark

Maybe my choice of words were not the best , tightening the sponsons will slow you down but in this case it was very little and at the speeds the boat is running it was well worth it.

You have to keep in mind that I am talking heat race set up , so I am always looking for a balance between speed and drive ability. One is useless without the other. I do have a digital angle and all my boats are set up at work on the layout table ,one of the perks of being in the Tool and Die Ind. for almost twenty four years now.

Yes that little Nova is making some big power , thanks to a good friends advice B) .

Tim K

 

[Brad Christy]

Richard,

The boat you've got is the very first BlackJack I ever built and it was somewhat of a "ranging shot". It ended up VERY close, but the AOA was a bit low. I improved the AOA on that boat, but it might yet be a bit tight on the water. It always did seem to be a little TOO stable, even though the speed was adequate.

Dave and I are running an AOA of 3.1-3.3 degrees. To acheive this angle with the tub at the right attitude on your table (rear sponsons .200" off the table), you are looking at 3.7-3.9 degree from the bottom of the tub. If you can't achieve this with your boat, give me a call and we'll talk about what we can do to get you to it.

Tim,

Get an H-6 from Mark, cupped 3.6", and try a de-tongued H-10, stock pitch and diameter. If you can turn a de-tongued 1650, you'll be looking at........... No, I can't say it. That speed doesn't exist...... Sorry.........

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[Tim Kish]

Come on Brad say it :lol:

I have the H-10 will try it this weekend modified.

Mark what about the H-6 ?

Tim K

 

[Ron Zaker Jr]

Come on Brad say it :lol:
I have the H-10 will try it this weekend modified.

Mark what about the H-6 ?

Tim K

Heck I'll say it,80 plus.

Ron Jr

 

[dave roach]

Come on Brad say it :lol:
I have the H-10 will try it this weekend modified.

Mark what about the H-6 ?

Tim K

Heck I'll say it,80 plus.

Ron Jr

Ron,

Maybe for you.

 

[Brad Christy]

Ron,

Thanks. I dared not........

Coming from a man who's been there....

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[Kim J]

What does C.O.B. pitch mean ?

I know about LE pitch, TE pitch and pitch progression including cup.

Kim

 

[dave roach]

Kim J

The C.O.B. means Center Of Blade.

Dave Roach

 

[Tim Kish]

Tested a couple more props today.

De-tongued 1650 , pulled it fairly easy but just on the edge of being to much prop ,maybe with a little more work.

S-15 cut like the Orlic 50x69 , Terrible , boat hopped and pulled hard to the right at speed.

1450 cut like the Orlic 50x69 worked very well just a little slower.

With every prop tested I tied changing sponson angles and strut height , to get the most of each prop except for the S-15.

I managed to get the 50x69 pretty close for heat racing but it is still on the edge , I guess that's why we have throttle control.

I would like to add that Franks prop is a testimate of all his time spent testing , there is at least three mods to this prop that I can see.

I know he developed it over a period of time on his boat and it is something special , Good job Frank and yes you can have it back now :lol: .

Tim K