.21 rigger with nova DD question

[vision race boats]

I have a nova DD running a CMB nitro pipe at 7 7/8" with a 1445, the boat accelerates off the corners very strong and about 1/2 way down the straight the engine just stops pulling, the way it accelerates you would think it was gonna rev to the moon but it kinda lays down like it hits a wall,I would guess by listening to it that the RPM's fall just a little around half track. Any suggestions. Thanks for the help.

 

[Eric Canto]

You need to shorten the pipe or add cup to the prop........maybe both

 

[Ron Jefferson]

Not enough prop is my guess.

 

[gooycheese]

1445 might be a lttle small, I run a h7 on my jae boat. 7 7/8 is about where im at.

 

[Terry Keeley]

Cut the water back!

 

[vision race boats]

Thanks for the input everyone, i was thinking with that small prop that it would really keep revving and not sound like its laying down but maybe the pipe just needs to be shorter to do that. I have a T after the rudder bleeding off some of the water. Thanks again for the help.

 

[dave roach]

Try a H-7 3.6 inches pitch or a 1716 prop.

 

[shoboat]

Rich,

What kind of boat are you running?

More propeller if you are running out half way down the track.

Any ski on the boat? How much Nitro %?

If it is an Eagle SGX, try one of the H-7's that I sent to the Germans

that are coming. John Otto has them. I think you will like it?

Just ask them if you could try one of them, I did four of them alike.

I may have one more here I will look tomorrow.

Thanks For Sharing,

Mark Sholund

 

[Terry Keeley]

Thanks for the input everyone, i was thinking with that small prop that it would really keep revving and not sound like its laying down but maybe the pipe just needs to be shorter to do that. I have a T after the rudder bleeding off some of the water. Thanks again for the help.

You'll need to be able to restrict it more than that if you want to keep it from going rich 1/2 track...

 

[Glenn Quarles]

Yes more prop!

GQ

 

[Chris Wood]

Way way to small if prop

 

[vision race boats]

Rich,

What kind of boat are you running?

More propeller if you are running out half way down the track.

Any ski on the boat? How much Nitro %?

If it is an Eagle SGX, try one of the H-7's that I sent to the Germans

that are coming. John Otto has them. I think you will like it?

Just ask them if you could try one of them, I did four of them alike.

I may have one more here I will look tomorrow.

Thanks For Sharing,

Mark Sholund

Hi Mark. The boat is basically like the newest eagle with a center ski only, and i am running 60%, the 1445 that i am running now has 3.4 cup, let me know what you would recommend trying and i will see what John has at the race this weekend and send you a couple of props to work. Thanks again everyone for all the help.

 

[shoboat]

Rich,

I think an H-7 at 3.46" with a reduced diameter at 45.75mm would be a Rocket

on that set up. If you are going to stay with Octura the next step up a 1450 at

3.60" with reduced diameter just under 46mm will be Very Good also. The H-5

which is basically a reduced 1450 is just what you are looking for.

Thanks,

Mark Sholund

 

[vision race boats]

Rich,

I think an H-7 at 3.46" with a reduced diameter at 45.75mm would be a Rocket

on that set up. If you are going to stay with Octura the next step up a 1450 at

3.60" with reduced diameter just under 46mm will be Very Good also. The H-5

which is basically a reduced 1450 is just what you are looking for.

Thanks,

Mark Sholund

Thanks Mark,i will see if i can get a few prop from Otto this weekend and send them your way.

 

[John Knight]

Rich,

Get with Tom Foley and/or Marty for the race this weekend. Likely they have exactly what you need. The 1445 is too small of a prop for that boat and engine. I have great success with the H-7 and a cut down 1450. A H-5 may be harder to find at the race.

 

[JUSTINROGERS]

Rich i have a grim 45x68 prop. According to the specs its the same as a h-5. I got it to try on my JAE. You can try it out this weekend if you would like. Mark is the grim prop close to the h-5?

 

[dave roach]

Justin

If you can find a H-7 prop have Andy Brown to pitch it up a little.

Dave

 

[JUSTINROGERS]

Im running an h-7 now. Going to try my new props Thursday

 

[Ron Jefferson]

ABC 50X69 might be a good choice but you'll want to get the cup to 3.4 to go fast. 3.6 shouldn't be a problem if your boat is light and launches easy. I find the ABC props to be smoother than Octura. On my boats anyway.

Ron

 

[ALLAN YUEN]

Hi Rich what size hole did you drill on water jacket head ? or stock nipple brass big hole ? I tried to use ABC H-7 no success for my 21 SGX . I knew to depend on rough or smooth water . I use 1445, 1450 and 1650 " Top sercet " by Chris Grimm