20 hydro props

Ron Jefferson · Mar 31, 2012

OMG! 80mph 21 boat. Where's Preston? Lol

Ron

Ian Inverarity · Mar 31, 2012

shoboat said:
Greg,

Needs more?

More camber in the middle of the blade.

3.8" of cup is not helping you at all, it is killing your RPM.

You can go over 80+ MPH with only 3.46" to 3.60" of cup.

The center of blade pitch or adding more camber into the blade

will help the boat accelerate better and be more responsive for heat racing.

Honestly, just trying to help you learn more about propellers.

Have Fun Testing,

Mark Sholund

Mark,

You have my attention! I would like to buy a prop for my 21 hydro: Zippkit JAE21, Novarossi 35+ with lowered sleeve and higher comp head button, SPP NR pipe as short as it will go on a 180 header, 3lb 14oz boat, 60% nitro, sea level.

Ian.

Luca Gray · Mar 31, 2012

Pulsetech said:
Luca i have only seen 3 boats that are capable of it here and mine is the slowest

Greg

Greg

Which 3 boats?

cheers Luca

dave roach · Mar 31, 2012

Saymikey

Try a ABC 1716 prop as will.

Dave Roach

shoboat · Apr 1, 2012

Aussie's,

Try a 1452 on your JAE's they work very well.

If that is still not enough cut down a 1455 to 52mm.

We have had some success recently with a 2014 also.

Just a few ideas to try. FYI, it takes an outstanding prepared

21 motor to have the RPM available to go over 80 MPH.

I am backed up right now for about a month.

Thanks,

Mark Sholund

Ian Inverarity · Apr 1, 2012

shoboat said:
Aussie's,

Try a 1452 on your JAE's they work very well.

If that is still not enough cut down a 1455 to 52mm.

We have had some success recently with a 2014 also.

Just a few ideas to try. FYI, it takes an outstanding prepared

21 motor to have the RPM available to go over 80 MPH.

I am backed up right now for about a month.

Thanks,

Mark Sholund

Mark, I have a couple of 2014's I am playing with. My order still stands, I am not in a hurry, let me know.

Ian.

Richard Dahlheimer · Apr 1, 2012

shoboat said:
Aussie's,

Try a 1452 on your JAE's they work very well.

If that is still not enough cut down a 1455 to 52mm.

We have had some success recently with a 2014 also.

Just a few ideas to try. FYI, it takes an outstanding prepared

21 motor to have the RPM available to go over 80 MPH.

I am backed up right now for about a month.

Thanks,

Mark Sholund

Mark, what dia is the 1452 that works well on JAE .21? What cup? Thanks, Richard

Mike Larson · Apr 2, 2012

Richard.. I'm cutting them down to 46mm, which really instills a labor intensive prop... after the tongues and a barr cut it takes some shop time to thin it, and balancing is a chore after it doesnt resemble anything you started with.... i'm just starting testing on this particular prop as we had good luck on a kit boat/stocker 5 port, last year but anything over 3.2 had negative results.... guys with grunt, higher nitro than i care to test, and a good boat should see the speed increase easily on the higher cup numbers.... I'm still "seasoning to taste".... and true to form, the ski style hulls ( the ones i have anyway) really allow people to pull more cup/pitch right off the bench, which has me looking backwards at the 1450's I've done in the past..... your G2 should love this blade..... I just did a pre season winter dust off, and the props will switch from there..... Test 'em up my friend.... Mike

Richard Dahlheimer · Apr 2, 2012

Hello Mike, i tried a 1452 last fall on my 1st gen. blackbird. 1452 was reduced to 46mm-3.2 cup if i remember. Should have saved it for the G-2 i guess. The 1452 was not good on the 1st gen boat. Lots of hop and near vertical roost. Richard

shoboat · Apr 2, 2012

Richard,

It runs full blade on a JAE 21 with a Stout Motor Package, most won't pull them

with good RPM.

Cutting them down is hit or miss. You would be better off resetting the strut height

To .7 radii and keep the blade area.

Thanks,

Mark

Andy Brown · Apr 2, 2012

At the Brandon race a couple of weeks ago we ran a tongue cut, back cut 1445 with 2.7" cup (no typo). If it was not the fastest 21 rigger there it was right there.

Lots of different ways to get to Oz!

But to get back on topic, the fastest race prop we ever used on the nova with the S pipe as short as it would go was a 46mm H-7 with 3.7".

Ian Inverarity · Apr 2, 2012

Andy Brown said:
But to get back on topic, the fastest race prop we ever used on the nova with the S pipe as short as it would go was a 46mm H-7 with 3.7".

Andy, how quick?

Andy Brown · Apr 2, 2012

nitrocrazed said:
Andy Brown said:

But to get back on topic, the fastest race prop we ever used on the nova with the S pipe as short as it would go was a 46mm H-7 with 3.7".

Click to expand...

Andy, how quick?

That was back in 1998-99 when we were still running the old SG with the Nova and S pipe. Two rear sponsons, no ski. Ran a consistant 74 mph any time of the year.

Interesting note is that it would also hit 74mph with a 1445 cupped 3.7". No other changes. This was in heat trim and would hit that speed about 100' out of the turn.

Ian Inverarity · Apr 2, 2012

Nice! B)

aaron alberico · Apr 2, 2012

Andy

About 5 years ago I was running 73-75mph with 1445, 3.6cup detounged....

Richard Dahlheimer · Apr 3, 2012

shoboat said:
Richard,

It runs full blade on a JAE 21 with a Stout Motor Package, most won't pull them

with good RPM.

Cutting them down is hit or miss. You would be better off resetting the strut height

To .7 radii and keep the blade area.

Thanks,

Mark

Mark, could you explain the .7 radii? Thanks, Richard

shoboat · Apr 3, 2012

Richard,

70% out from the hub of the propeller make a mark.

Now that is where you need to set your strut height. If you

Mark your other propeller at .7 radii then just adjust the

difference. Very easy way to set up bigger propellers on any

boat. This is why most people can't run bigger propellers because

they don't adjust to .7 radii on the propeller with their strut. Call me

if you have any questions: 231-590-3023

Steve P · Apr 4, 2012

Mark ,

So the distance from the bottom of the boat to the bottom of the strut is equal to 70% of the blade. radius

A drawing might help.

RodneyPierce · Apr 4, 2012

Steve P said:
Mark ,

So the distance from the bottom of the boat to the bottom of the strut is equal to 70% of the blade. radius

A drawing might help.

AHHH!! If this is the case, it makes sense. I couldnt understand it before.

Andy Brown · Apr 4, 2012

RodneyPierce said:
Steve P said:

Mark ,

So the distance from the bottom of the boat to the bottom of the strut is equal to 70% of the blade. radius

A drawing might help.

Click to expand...

AHHH!! If this is the case, it makes sense. I couldnt understand it before.

Yep, that sounds about how I set my prop depth for SAW.

20 hydro props

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