What's a good ABC single 90 hydro prop?

[Terry Keeley]

Latest chart attached...

 

[K F Wheeler]

Thanks for posting that Terry.
Been trying to get ABC to post a link like that.

Ken

 

[David Murany]

Oval boat or SAW boat? 2719 and 2717 are good for heat racing. 2721, 2723 for SAW boats

 

[Terry Keeley]

Heat racing, I have a 2619 and measured the LE (my standard) at 4.8" which is more what I'm looking for. Think it'd be too small?

The 1667's I've been running are around 66mm diameter so closer to 2.6".

Are guys smoothing out some of that big TE "kick"?

 

[Tim Kish]

Watching closely, just started playing with my F hydro and so far the 1667 is my go to.

 

[shoboat]

Tim,

The ABC 2617, 2619, & the 2717 have more Leading edge pitch in them, and will run very well. However, some still like the old reliable 1667’s with some “enhancements“ added to them.

Terry,

I would grind out some of the trailing edge cup or “kicker”
on the front side of the blade if I was you.

Enjoy Testing,

Mark

 

[Alan Elzer]

Thanks for new ABC chart Terry

 

[dwilfong]

Terry most all the blades are the same pitch just larger diameter and some kicker added to the trailing edge.
Remember same pitch with more diameter is a different ratio 1.6/1.7/1.8/1.9 can all be the same pitch with just a change of diameter.
He used the same algorithm and that made many of the blades the same pitch profile in different diameters.
Measured many of the blades across the whole 70% mark and thy came out the same or close with different diameters and added kicker.
Jim has removed some of the trailing edge kicker compared to the first run of blades. you need to check them at the last 10deg of the trailing edge to see.
Some had 14" of pitch on the kicker. the new ones seam to come in at 8" or less the last time I played with them.
If you remove to much thy will unload the eng but lose top speed.
Depends on the boat and how light it is on the water.
Find the diameter that ran best say a 1667 and then go with that to start testing.
The woop on the trailing edge is the key to tuning them to your set up depending on nitro content of the fuel. (nitro needs load to burn good)
Also larger the rake the more the nose of the boat wants to lift up at top speed.
You can plant it down with strut angle but that will reduce forward thrust some.
hope this helps some.

 

[shoboat]

David,

Some of what you say is correct, but the pitch ratio is different
on the 1.4 through the 2.7 pitch ratios. They all have different pitches, they do Not all have the same pitch in all the blades with
just different Diameters. When you measure the cup on the trailing edge is does not mean 14” of actual pitch, even your engines could not pull 14” of true pitch. The rake angles really
just change the lift of the transom. More rake less lift. If you need
more transom lift just go with the next diameter up or adjust the
depth of your strut.
It looks like the fishing out West was still pretty good for you. Nice photos of our beautiful country here in America.

Thanks,

Mark

 

[Joe Warren]

2717 Untill boat it dialed in, Then change to 2719

 

[K F Wheeler]

There is STILL a newer chart. STILL says 1-1-2022... That chart only shows one 1515 prop listing. My chart that I still have not figured how to send a link to I. W. shows three. Don't know how many others are omitted from that chart that Terry posted...

Ken

 

[dwilfong]

David,

Some of what you say is correct, but the pitch ratio is different
on the 1.4 through the 2.7 pitch ratios. They all have different pitches, they do Not all have the same pitch in all the blades with
just different Diameters. When you measure the cup on the trailing edge is does not mean 14” of actual pitch, even your engines could not pull 14” of true pitch. The rake angles really
just change the lift of the transom. More rake less lift. If you need
more transom lift just go with the next diameter up or adjust the
depth of your strut.
It looks like the fishing out West was still pretty good for you. Nice photos of our beautiful country here in America.

Thanks,

Mark

Mark if you use a Orlic gauge you can measure every 5 deg of blade movement and map it and if you do that to enough of the 38 bar props you will see what I mean.
Yes all the 1.4 will have different pitch in different diameters.
The ratio is calculated on the diamiter and the pitch.
So a smaller diamiter prop can share the same pitch with a larger diamiter prop and have a diffrent ratio.
Also just adding more woop will change the ratio with out changing the blade profile and pitch on the rest of the blade.
But if you map the whole blade in different diameters and ratios you will see that many of the blades are the same pitch excluding the woop at the end.
Many of the blades share the same profile and just change the diamiter and the woop .
It makes it easer to make all those diffrent props with only a few profiles that only need adjustment to the diamiter and woop in the program.


Yes the last >10% is 14" on some of the older props.

P.S.
I ran this by Eric when I found this out playing will all those diffrent props also.
Kinda blew my mind when I seen this unfold as I lined all the props up on my leger to compare them.

 

[shoboat]

David,

I got out my Orlic pitch gauge and I see what you are talking
about. What is nice about the current ABC propellers is how
many choices we have now and the different rake angles and
blade area combinations that are available. No other manufacturer has committed such an effort to move forward
model boating like Jim Schaefer has recently in the last ten or
twenty years. Jim your efforts are MUCH APPRECIATED !!!

Jim Thanks For All You Do For Model Boating,

Mark Sholund

 

[Terry Keeley]

So what you're saying (as an example) is a 2515 gets blown up and becomes say a 2717? I really don't see how that's possible.

The pitch number is the ratio of the pitch and diameter, simply blowing up a whole prop doesn't twist the blades.

On the other hand if you cut down the diameter on a prop you will end up with a higher pitch ratio as you are now measuring the pitch closer to the hub (of the original).

For example I run 1657's on my 40 boat, the stock pitch at 75% is supposed to be 57mm x 1.6 = 91.2mm or 3.59" I have a couple of old 3/16" shaft 1667's I cut down to 57mm and at 75% they have about 4" of pitch as that number came from 60% out from the hub of the original prop.

So the cut down 1667 has a pitch ratio of 57mm / 102.6mm (4") = 1.8, so now I effectively have an 1857.

Andy did a lot of this years ago cutting down 1470's etc.

 

[Timbo Whalen]

David,

Some of what you say is correct, but the pitch ratio is different
on the 1.4 through the 2.7 pitch ratios. They all have different pitches, they do Not all have the same pitch in all the blades with
just different Diameters. When you measure the cup on the trailing edge is does not mean 14” of actual pitch, even your engines could not pull 14” of true pitch. The rake angles really
just change the lift of the transom. More rake less lift. If you need
more transom lift just go with the next diameter up or adjust the
depth of your strut.
It looks like the fishing out West was still pretty good for you. Nice photos of our beautiful country here in America.

Thanks,

Mark

That's what I always thought....pitch ratio is just that, a common ratio across the board, that changes actual pitch of a given prop due to the diametric influence of a given size.

 

[Jeff Lutz]

So what you're saying (as an example) is a 2515 gets blown up and becomes say a 2717? I really don't see how that's possible.

The pitch number is the ratio of the pitch and diameter, simply blowing up a whole prop doesn't twist the blades.

On the other hand if you cut down the diameter on a prop you will end up with a higher pitch ratio as you are now measuring the pitch closer to the hub (of the original).

For example I run 1657's on my 40 boat, the stock pitch at 75% is supposed to be 57mm x 1.6 = 91.2mm or 3.59" I have a couple of old 3/16" shaft 1667's I cut down to 57mm and at 75% they have about 4" of pitch as that number came from 60% out from the hub of the original prop.

So the cut down 1667 has a pitch ratio of 57mm / 102.6mm (4") = 1.8

So I now have a 1857. Andy did a lot of this years ago cutting down 1470's etc.

Terry,I have a lot of the new props. I want to point out and assure you that as the pitch ratio goes up the LE pitch is higher on the new props. So a 2619 has more LE pitch than a 2617. Jim has made no changes to the 2 blades from years ago on the TE either. The only ones with 14” are much bigger like 2823’s etc. Your 2619 has probably around 11” of TE 30 degree kick. Definitely knock that down some and go from there . Jeff Lutz

 

[dwilfong]

Terry,I have a lot of the new props. I want to point out and assure you that as the pitch ratio goes up the LE pitch is higher on the new props. So a 2619 has more LE pitch than a 2617. Jim has made no changes to the 2 blades from years ago on the TE either. The only ones with 14” are much bigger like 2823’s etc. Your 2619 has probably around 11” of TE 30 degree kick. Definitely knock that down some and go from there . Jeff Lutz

You are comparing 2 different ratios on the same diameter thy will have different lead in.
Now try measuring diffrent dimeters and diffrent ratios and do many diffrent ones in each size. Now do this mapping each prop every 5 deg at the spot on the lead in that has the small woop in it.
Then look at the results and tell me what you see???????
Exclude the last 5% deg on the trailing edge.

 

[Jeff Lutz]

You are comparing 2 different ratios on the same diameter thy will have different lead in.
Now try measuring diffrent dimeters and diffrent ratios and do many diffrent ones in each size. Now do this mapping each prop every 5 deg at the spot on the lead in that has the small woop in it.
Then look at the results and tell me what you see???????
Exclude the last 5% deg on the trailing edge.

I’ve made my points and I was talking directly to Terry. Terry focuses on LE pitch and my comments were mainly discussing that.

 

[dwilfong]

I’ve made my points and I was talking directly to Terry. Terry focuses on LE pitch and my comments were mainly discussing that.

DANG........................ ain't you special............LOL

 

[Jeff Lutz]

DANG........................ ain't you special............LOL

My post on this thread was nothing more than positive information about something that matters. With the talk shows we use to see out of you, it’s clear who is “special”