What's This?!?!

[Chris Wood]

ANDY,

To props i would like to see.

a TRUE 1450 dia. ( kinda like the old style but with a small hub )

and a 1442 dia prop

chris

 

[Don Ferrette]

A while back we had a thread going about how it would be nice if there was a 1645, perhaps this is a good time to re-visit that idea. B)

 

[BACKEMF]

Is there a list I am missing? Because I have no idea what to order for racing Fast Electric monos and Sport Hydros????

Lift is not needed, less than the B series 4-shure.

I know I'm a minority here but, any help would be appreciated.

 

[dave roach]

Don

I beleave Brad Chirsty brought this up a long time ago and Brad and I couldn't get Jim at abc props to bit on this one.Brad and I has been tring to get a 1645 prop made for a long time.Go back and read the post that Brad made.At that time when Brad posted the 1645 there were about 20 guys that would take them.I beleave the 1645 prop would make a good 20 prop.

Dave Roach

 

[shoboat]

Andy,

A 1647 would be a better propeller with more options.

Keep Producing ,They Look Great,

Mark Sholund

 

[AndyBrown]

A 1450 cut 45mm cupped 3.2" Would be almost identical to a 1645 if Octura made one.

The fastest race prop we ever ran is an H-7 cut 46mm cupped 3.7" That would be close to an 1846, but the progression is not true.

The 1645 would be a good 'middle of the road' prop.

 

[Jorgen Andersson]

Hello

Yes, I agree with you Andy, the H7 is the fastest race prop I have had working well on my 21 hydros.

I use 47mm diameter and 3.7 cup.

It took some fine tuning with the boat/engine before I really could say that this prop works well as a race prop. Before I got it all together, the H7 was a bit much out of the corners after a few laps of hard and tight racing.

Now it feels like the H7 is unloading the engine really well down the straights.

I reach 35.000-35.500 rpm under full load at the end of the straights so the speed is good for heatracing. Maybe we use a little bit longer pipe lenghts than some of you in the US does?

In this case I use 7.9" (200mm)

Drivability is a key word for me when I set up a boat, I must be able to slow down for a dead boat after 4 laps of hard and tight racing and be able to get good pick up and acceleration instantly after slowing down and now it works fine with the H7.

The boat feels no different with the H7 in the corners compared to a 1445 3.7, it is very stable and have a good drive.

One little difference between the 1445 and the H7 I have noticed, is that the H7 helps holding down the nose a little bit better at the end of the straights. This could be important towards the end of the heats when the tank is almost empty and the front is light....

So please make some billet props in these sizes so we can test!

Thanks

Jorgen

 

[Brad Christy]

Andy,

I am currently running an H-6, 46mm, cupped to 3.6 and de-tongued. It is the fastest prop we have tried to date, faster than ANY H-7 we've tried. We also like the H-10, stock other than de-tongued, but it is a little "stiff" in the turns. The H-6 comes out of the turns the same speed it goes into the turns and it launches easier than the H-10, too.

Personally, I would be happy with nearly anything 45-47mm with 72-76mm pitch, two or three blade. I did not get good results from ABC three blade props (hopping), but your props will undoubtedly perform differently (better or worse???) so I'm up for a go at it...

Let us know when you've got something for us to test.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[Jim Caldwell]

Have you ever tryed the P747 on your .21 riggers? Works good for me.

 

[Jorgen Andersson]

Hello

Brad:

It is always interesting to compare results between racers.

The H6 does not get enough speed for me. The H10 gives more speed and the boat performs well but is clearly slower than the H7. I find H6 and H10 to be to "small" for my applications, not by much, but still so. They both have good cornering speed but not much more at the end of the straights.

May I ask what exhaust timing and approx pipe lenght you run at this set up?

Jim:

No, I have not tested that prop on a 21 rigger. How is it, if you compare with the more "common" props like a 1445 3.5 cup?

Thanks

Jorgen

 

[Jim Caldwell]

Much faster on a motor with good tourqe.

 

[shoboat]

Jorgen,

I have something new for you to try,it should be better than the H-7

that you are currently running. I just need to get it off the balancer.

Hint: 46 x 84.

Have Fun,

Mark Sholund

 

[racerred]

Just got the sport 40 prop this past weekend from John at ft. lauderdale going to try it this weekend looks real nice Robert

 

[AndyBrown]

Andy,
I am currently running an H-6, 46mm, cupped to 3.6 and de-tongued. It is the fastest prop we have tried to date, faster than ANY H-7 we've tried. We also like the H-10, stock other than de-tongued, but it is a little "stiff" in the turns. The H-6 comes out of the turns the same speed it goes into the turns and it launches easier than the H-10, too.

Personally, I would be happy with nearly anything 45-47mm with 72-76mm pitch, two or three blade. I did not get good results from ABC three blade props (hopping), but your props will undoubtedly perform differently (better or worse???) so I'm up for a go at it...

Let us know when you've got something for us to test.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

The pitch maps on the H-6 and H-7 are so close they almost can't be measured. Depends on how they come out of the mold. If one is faster than the other it only has to do with how they are modified and finished.

Both props started life as a 1452.

I'll be making three 21 rigger props to start with. The smallest will be in the range of a 1445 cupped 3.2" and the largest will be in the range of the H-6/H-7 cupped 3.7".

To start with I'll make 3 blades.. Than I'll make two blades. Will start at 47mm.

 

[Rigged]

Any chance you will make a 67mm 3 blade with less pitch? At 120mm = 4.72"... thats a bit more then a stock 6717/3 which is 4.48" which can be a bogger itself in the turns without jacking the strut way up on a cat.

 

[Jorgen Andersson]

Andy

Sounds good, let us know when ready and you will get a test report very fast.

Personally I think the slightly larger diameter on the H7 is the reason why I find it more efficient.

I just measured my favorite H7 and it is 47.5mm in diameter, which is full diameter.

Thanks

Jorgen

 

[AndyBrown]

Any chance you will make a 67mm 3 blade with less pitch? At 120mm = 4.72"... thats a bit more then a stock 6717/3 which is 4.48" which can be a bogger itself in the turns without jacking the strut way up on a cat.

There are 1000 ways to arrive at a pitch number. My first gas mono and Cat props are middle of the road choice based on my years of preparing gas props.

What is a good mono and Cat race speed....and at what rpm? Not the fastest speed just a good competitive speed.

 

[Rigged]

Any chance you will make a 67mm 3 blade with less pitch? At 120mm = 4.72"... thats a bit more then a stock 6717/3 which is 4.48" which can be a bogger itself in the turns without jacking the strut way up on a cat.

There are 1000 ways to arrive at a pitch number. My first gas mono and Cat props are middle of the road choice based on my years of preparing gas props.

What is a good mono and Cat race speed....and at what rpm? Not the fastest speed just a good competitive speed.

Mono... 55-58mph, cat around the same.. 55-60, turning around 17,500

 

[SteveSpear]

Andy,

Any chance you cutting out any 1/4" bullet nose drive dogs and 1/4" bushings? Donna has been telling me "next week" for the last six weeks.

 

[AndyBrown]

Andy,Any chance you cutting out any 1/4" bullet nose drive dogs and 1/4" bushings? Donna has been telling me "next week" for the last six weeks.

Steve,

I made some.

I'll make sure you get whatever you ordered. Sorry about whatever caused the delay.

Thanks and good boating,

Andy