Just a question????

[FloridaScaleBoater]

While showing my new Cajun Bullet to one of my fellow racer's down here in Florida,

He noticed I had a 3 bladed prop mounted on it, and made the statement "you know, NOBODY runs a 3 bladed prop on an outrigger, don't you"

Now, I am no were near done setting this thing up, and only had that particular prop on there, cause that is what I found to give me the best speed (so far).

Now, is there a hard & fast rule that riggers DO NOT run with 3 bladed props, or just not the norm.

I will admit, I am having NO LUCK getting this thing to run, with, what everyone is telling me it should

Boat is a 21 Cjun Bullet, with a CMB green head Valvola, head clearance set @ .014" AB 21 fat pipe set @ 8-1/2" burning Otto 60% fuel

All boat angles & depth's set per Bob Finn's instructions

have tried to run the H-4 that was sent with the boat 1445 W/ 3.6 (haven't made it back to the lake to try a stock 1445 yet)

The best the boat runs with, so far is a 40X52/3 and I'd say no faster than about 45 MAYBE 50 MPH

I'm becoming frustrated, to say the least

Any help out there?

 

[John Knight]

Rick,

The 3 blade props generally will not work well on riggers, especially the 20's. The 60's and larger ones can run the 3 blade but it becomes rather unpredictable, especially in the turns. The H-4 and 1445 should work fine to get it going decently.

Suggestions for improvements:

* Pipe too long. Move it in to 8" and run it with the H-4.

* Set head clearance to .008, .014 is way too much for a 20 engine.

 

[Buckshot]

No wonder it won't run well!!!! .014" head clearance is double what it should be!!!!

As far as the three blade prop thing goes, it is not true. Some people love three blade props. They can be ran on riggers. Just don't know of any that work well on a 20 hydro.

 

[shawdaddy]

Rick, Set the pipe @ 3.25" to 3.5" I measure mine from the plug back. I agree with all who have replyed about the head clearance, bring it down to about .007". As fare as the three blade props go my .12 loves a three blade prop(V937). I setup changes but it is fast. Ryon Shaw

 

[Brad Christy]

Rick,

I'm going to double reinforce what everyone has said so far: Set your head clearance at .006-.008" and you'll be amazed at the difference it will make. I run the MAC, with .006" head clearance, through an OPS 3280 pipe, and I can turn a de-tongued H-10 all day long, at just over 70MPH, when everything else is right.

To answer your question, no there is no reason not to try a three blade prop. In general, though, the two blades work better because you can get the RPM up alot easier. this is especially important on a 20 hydro.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[FloridaScaleBoater]

OK, I hear everyone's suggestion about head clearance, but I don't really agree with it!

I have basically the same engine (red head vice green head) in a Seaducer mono set @ .014" & it is wicked fast (perfect score for the weekend @ the winternats)

And this is the same engine (I mean pulled this engine outa my sport & put it in the rigger) and it ran fine there.

John, shortening the pipe to 8" I feel will just amplify my problem, if it won't launch at 8-1/2" it sure ain't gonna make the low end power to launch @ 8"

Ryon, I think your measurements, your thinking of a rear exhaust (wrap around 180* header) I have a front exhaust Valvola (same as Mac)

 

[John Knight]

Rick,

Take it from several hard core rigger guys that have replied. Drop the head clearance as noted. It will make a difference in rpm and torque. I also know of a racer that ran a 20 rigger (Eagle) with a MAC (Valvola is the same) with a fat pipe at 7 1/8" to 7 1/4" and pulling a H-10 prop going 70+ mph.

Dropping the head clearance and pushing in the pipe will generate more rpm that you are NOT getting now. Then fine tune with the pipe length (you should be going shorter) to get a consistant needle and then the prop that will work best for the boat and setup. Use the H-4 to start with.

John

 

[Chris Wood]

a mono and hydro are different animals.. you can get away with alot more clearance in a mono.. hydros need torque to get on plane.

and a pipe that is to long will cause you fits and chase other things as well.. put the pipe @ 8 and run it.

and if it won't pull a 1445 stock you better take a look at either the motor.. or the boat.. as that prop should pull without a doubt no problem. ..

one thing you didn't mention is your strut angle.. do you have any negative in it if so how much. 21 boats like alot of negative strut angle.. ( most anyway ) that helps on launch.. plants the nose in the turns ect. if you are trying to launch the boat with a flat strut that could be part of it.. remember a 21 has NO POWER.. so you do anything to make it harder and you will pull your hair out.

let me know what your strut is and if i can help let me know.

chris

 

[Tom Foley]

Get the overall weight down anyway you can , batteris etc . Shrink the head clearance as stated , make sure the prop is thin and very sharp , wetsand the bottom of the boat , make sure the rudder is as small as possiible and try the Otto HOT (70 % )fuel . All the mod outboard guys are running stout compression and mega nitro . you may want to get a hold of Marty as well . good luck Rick ....can't wait to SMOKE you in Melbourne !!!! :lol: :lol: :lol:

actually my goal is to get mine as fast as Brett's or Ray's !!

CMDI does a heck of a job on a 1445 but trimmed 1450's are hot also .

 

[FloridaScaleBoater]

a mono and hydro are different animals.. you can get away with alot more clearance in a mono.. hydros need torque to get on plane.
and a pipe that is to long will cause you fits and chase other things as well.. put the pipe @ 8 and run it.

and if it won't pull a 1445 stock you better take a look at either the motor.. or the boat.. as that prop should pull without a doubt no problem. ..

one thing you didn't mention is your strut angle.. do you have any negative in it if so how much. 21 boats like alot of negative strut angle.. ( most anyway ) that helps on launch.. plants the nose in the turns ect. if you are trying to launch the boat with a flat strut that could be part of it.. remember a 21 has NO POWER.. so you do anything to make it harder and you will pull your hair out.

let me know what your strut is and if i can help let me know.

chris

Chris, per Bob Finns advise, strut is set with 3/32 shims under rear sponsons trailing edge of strut touching table IE: strut 3/32" deeper than rears with 1/2deg neg of angle

 

[FloridaScaleBoater]

Get the overall weight down anyway you can , batteris etc . Shrink the head clearance as stated , make sure the prop is thin and very sharp , wetsand the bottom of the boat , make sure the rudder is as small as possiible and try the Otto HOT (70 % )fuel . All the mod outboard guys are running stout compression and mega nitro . you may want to get a hold of Marty as well . good luck Rick ....can't wait to SMOKE you in Melbourne !!!! :lol: :lol: :lol: actually my goal is to get mine as fast as Brett's or Ray's !!

CMDI does a heck of a job on a 1445 but trimmed 1450's are hot also .

Tom, Don't know weather it will be raedy for Melbourne.

I've got lotsa work to do before then..

Yes, Bretts boat GITZIT, don't it, that is my bench mark, too bad Ray got rid of his RR it was stout also

So, your planning to be in Melbourne? You need to drag that SLACKER partner of yours with you!!!

He know's who I'm talking about

 

[Tom Foley]

Get the overall weight down anyway you can , batteris etc . Shrink the head clearance as stated , make sure the prop is thin and very sharp , wetsand the bottom of the boat , make sure the rudder is as small as possiible and try the Otto HOT (70 % )fuel . All the mod outboard guys are running stout compression and mega nitro . you may want to get a hold of Marty as well . good luck Rick ....can't wait to SMOKE you in Melbourne !!!! :lol: :lol: :lol: actually my goal is to get mine as fast as Brett's or Ray's !!

CMDI does a heck of a job on a 1445 but trimmed 1450's are hot also .

Tom, Don't know weather it will be raedy for Melbourne.

I've got lotsa work to do before then..

Yes, Bretts boat GITZIT, don't it, that is my bench mark, too bad Ray got rid of his RR it was stout also

So, your planning to be in Melbourne? You need to drag that SLACKER partner of yours with you!!!

He know's who I'm talking about

You mean ANDY !!!!!!!!! Never happen . :lol: :lol: :lol:

 

[Chris Wood]

a mono and hydro are different animals.. you can get away with alot more clearance in a mono.. hydros need torque to get on plane.
and a pipe that is to long will cause you fits and chase other things as well.. put the pipe @ 8 and run it.

and if it won't pull a 1445 stock you better take a look at either the motor.. or the boat.. as that prop should pull without a doubt no problem. ..

one thing you didn't mention is your strut angle.. do you have any negative in it if so how much. 21 boats like alot of negative strut angle.. ( most anyway ) that helps on launch.. plants the nose in the turns ect. if you are trying to launch the boat with a flat strut that could be part of it.. remember a 21 has NO POWER.. so you do anything to make it harder and you will pull your hair out.

let me know what your strut is and if i can help let me know.

chris

Chris, per Bob Finns advise, strut is set with 3/32 shims under rear sponsons trailing edge of strut touching table IE: strut 3/32" deeper than rears with 1/2deg neg of angle

try this just to see.. anytime you put the strut lower than the rears that LOADS THE MOTOR MORE.. put the strut FLUSH with the rears and try a min of 1 degree negative angle.. let me know how that works.

chris

 

[Marty Davis]

Rick:

Suggest that you set up the boat exactly like this: http://rcboat.com/setup.htm and then get an H7 and run it stock. Should be very good running boat then.

Marty Davis

 

[FloridaScaleBoater]

Get the overall weight down anyway you can , batteris etc . Shrink the head clearance as stated , make sure the prop is thin and very sharp , wetsand the bottom of the boat , make sure the rudder is as small as possiible and try the Otto HOT (70 % )fuel . All the mod outboard guys are running stout compression and mega nitro . you may want to get a hold of Marty as well . good luck Rick ....can't wait to SMOKE you in Melbourne !!!! :lol: :lol: :lol: actually my goal is to get mine as fast as Brett's or Ray's !!

CMDI does a heck of a job on a 1445 but trimmed 1450's are hot also .

Tom, Don't know weather it will be raedy for Melbourne.

I've got lotsa work to do before then..

Yes, Bretts boat GITZIT, don't it, that is my bench mark, too bad Ray got rid of his RR it was stout also

So, your planning to be in Melbourne? You need to drag that SLACKER partner of yours with you!!!

He know's who I'm talking about

You mean ANDY !!!!!!!!! Never happen . :lol: :lol: :lol:

No, I've given up on Andy.

We now have a new whippin boy, in the form of Bill Gibson

 

[FloridaScaleBoater]

a mono and hydro are different animals.. you can get away with alot more clearance in a mono.. hydros need torque to get on plane.
and a pipe that is to long will cause you fits and chase other things as well.. put the pipe @ 8 and run it.

and if it won't pull a 1445 stock you better take a look at either the motor.. or the boat.. as that prop should pull without a doubt no problem. ..

one thing you didn't mention is your strut angle.. do you have any negative in it if so how much. 21 boats like alot of negative strut angle.. ( most anyway ) that helps on launch.. plants the nose in the turns ect. if you are trying to launch the boat with a flat strut that could be part of it.. remember a 21 has NO POWER.. so you do anything to make it harder and you will pull your hair out.

let me know what your strut is and if i can help let me know.

chris

Chris, per Bob Finns advise, strut is set with 3/32 shims under rear sponsons trailing edge of strut touching table IE: strut 3/32" deeper than rears with 1/2deg neg of angle

try this just to see.. anytime you put the strut lower than the rears that LOADS THE MOTOR MORE.. put the strut FLUSH with the rears and try a min of 1 degree negative angle.. let me know how that works.

chris

Will do Chris,

Will probably be a few days, before it happens though

 

[FloridaScaleBoater]

Rick:
Suggest that you set up the boat exactly like this: http://rcboat.com/setup.htm and then get an H7 and run it stock. Should be very good running boat then.

Marty Davis

Sounds good Marty, will check measurements agains this set up sheet.

But I do have a question, if the boat/engine combo will not launch, get up on pipe with the smaller diameter, and pitch of an H-4 @ 1.68 X 2.6 or a 1445 @ 1.77 X 2.48

and you want me to try an H-7 which is 1.87 X2.85

That just doesn't make sence to me, please explain

 

[shawdaddy]

Rick, What are you AOA numbers? Ryon

 

[Brad Christy]

Rick,

.014" head clearance is WAY too much for any .21 engine. I've only got .015" under the (.91) heads of my inline twin!. Head clearance is the root of your problem. Somewhere around .006" is where you should be. You can do all the set-up changes you want. If you don't correct the head clearance, you will never get off the bank with any prop worth running. You might even consider changing the head clearance in the mono engine and pick up the 10+MPH you're losing there while you're at it.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[John Knight]

Rick,
.014" head clearance is WAY too much for any .21 engine. I've only got .015" under the (.91) heads of my inline twin!. Head clearance is the root of your problem. Somewhere around .006" is where you should be. You can do all the set-up changes you want. If you don't correct the head clearance, you will never get off the bank with any prop worth running. You might even consider changing the head clearance in the mono engine and pick up the 10+MPH you're losing there while you're at it.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

Totally agree with Brad. Follow my recommendations with the clearance and pipe. Otherwise you will NEVER see any improvement and you will be saddled with what you ahve now. Don't fight the suggestions. You asked for help, it has been given, and hopefully you will follow it.