Octura 1450 props

[Tim_Duggan]

Marty,

After spending a little time with the pitch guage and a 1450, and going by the comments I've received so far - I'm theorising that I need to try a different line of thought to the original L/E pitch idea.

Reducing blade area on this prop without reducing diameter seems to be the feedback I'm getting so far. Several people have said don't reduce the diameter at all, yet my current hot 1450's have had the diameter reduced to 46 - 48mm, rather than removing substantial leading edge and/or Barr cutting.

I'm planning on doing some direct lap speed comparisons based on full diameter blades with reduced blade area vs. a reduced diameter with similar if not the same load @ the engine and therefore pipelength etc, as soon as my "raw" 1450's arrive. (I was hoping I'd have them for this coming weekend, but not to be unfortunately).

Tim.

 

[Marty Davis]

Marty,After spending a little time with the pitch guage and a 1450, and going by the comments I've received so far - I'm theorising that I need to try a different line of thought to the original L/E pitch idea.

Reducing blade area on this prop without reducing diameter seems to be the feedback I'm getting so far. Several people have said don't reduce the diameter at all, yet my current hot 1450's have had the diameter reduced to 46 - 48mm, rather than removing substantial leading edge and/or Barr cutting.

I'm planning on doing some direct lap speed comparisons based on full diameter blades with reduced blade area vs. a reduced diameter with similar if not the same load @ the engine and therefore pipelength etc, as soon as my "raw" 1450's arrive. (I was hoping I'd have them for this coming weekend, but not to be unfortunately).

Tim.

Tim:

Good conclusion....

Diameter is great for race water to keep the prop "hooked up". There is a sacrafice in the amount of speed that you can get though, and you nailed the probable cause. I think that the LE pitch is limiting the terminal speed some. I hope that you optimize the prop some using Barr Back Cut and then work on the LE. I think that you will find some additional speed there. It is difficult to make very small changes to the LE (what you have to do) to get it better. Andy is a Master at that and I have not learned to do that very well.

Also don't forget to work on the outer edges to hold the water on the blade so that it exits where the pitch is.

Keep me posted, I am sure that I will learn something from your efforts!

I would strongly urge you to get the duplicators so that you have a great start point as well as the ability to fix poorly bent props You will have a LOT of those if you do a lot of testing.

 

[Tim_Duggan]

Diameter is great for race water to keep the prop "hooked up". There is a sacrafice in the amount of speed that you can get though, and you nailed the probable cause.

This has always been a particularly strong aspect of my particular set-up on my boat, even with the smaller diameter - but I do run my strut deeper than most. This has one negative side effect though, and if I can rid that side effect by using more diameter and a slightly higher strut - it's a positive thing already.

Keep me posted, I am sure that I will learn something from your efforts!

I think that's not very likely Marty! I'm but a mere prop rookie! I would definately share my findings should there be anything useful!

I would strongly urge you to get the duplicators so that you have a great start point as well as the ability to fix poorly bent props You will have a LOT of those if you do a lot of testing.

. How effective do you think a prop off the duplicators will work with only a 50% nitro content @ sea level? I want to avoid going higher in %, in fact I plan on going to less nitro eventually.

 

[Ron Jefferson]

Marty,After spending a little time with the pitch guage and a 1450, and going by the comments I've received so far - I'm theorising that I need to try a different line of thought to the original L/E pitch idea.

Reducing blade area on this prop without reducing diameter seems to be the feedback I'm getting so far. Several people have said don't reduce the diameter at all, yet my current hot 1450's have had the diameter reduced to 46 - 48mm, rather than removing substantial leading edge and/or Barr cutting.

I'm planning on doing some direct lap speed comparisons based on full diameter blades with reduced blade area vs. a reduced diameter with similar if not the same load @ the engine and therefore pipelength etc, as soon as my "raw" 1450's arrive. (I was hoping I'd have them for this coming weekend, but not to be unfortunately).

Tim.

Tim:

Good conclusion....

Diameter is great for race water to keep the prop "hooked up". There is a sacrafice in the amount of speed that you can get though, and you nailed the probable cause. I think that the LE pitch is limiting the terminal speed some. I hope that you optimize the prop some using Barr Back Cut and then work on the LE. I think that you will find some additional speed there. It is difficult to make very small changes to the LE (what you have to do) to get it better. Andy is a Master at that and I have not learned to do that very well.

Also don't forget to work on the outer edges to hold the water on the blade so that it exits where the pitch is.

Keep me posted, I am sure that I will learn something from your efforts!

I would strongly urge you to get the duplicators so that you have a great start point as well as the ability to fix poorly bent props You will have a LOT of those if you do a lot of testing.

Prop duplicators...

Maybe we need to move this thread to the "for sale" forum? Props are cheap and by far the best performance advantage over any other mod. I believe in trimming the attitude of the boat with a small easy to turn prop. Then tweak, bend and grind on something more suited to your application. If you're not real good at finishing. Measure what you have created and have Andy do one up for you. A prop from any other boat/set-up is only wishfull thinking.

Ron

 

[Marty Davis]

Marty,After spending a little time with the pitch guage and a 1450, and going by the comments I've received so far - I'm theorising that I need to try a different line of thought to the original L/E pitch idea.

Reducing blade area on this prop without reducing diameter seems to be the feedback I'm getting so far. Several people have said don't reduce the diameter at all, yet my current hot 1450's have had the diameter reduced to 46 - 48mm, rather than removing substantial leading edge and/or Barr cutting.

I'm planning on doing some direct lap speed comparisons based on full diameter blades with reduced blade area vs. a reduced diameter with similar if not the same load @ the engine and therefore pipelength etc, as soon as my "raw" 1450's arrive. (I was hoping I'd have them for this coming weekend, but not to be unfortunately).

Tim.

Tim:

Good conclusion....

Diameter is great for race water to keep the prop "hooked up". There is a sacrafice in the amount of speed that you can get though, and you nailed the probable cause. I think that the LE pitch is limiting the terminal speed some. I hope that you optimize the prop some using Barr Back Cut and then work on the LE. I think that you will find some additional speed there. It is difficult to make very small changes to the LE (what you have to do) to get it better. Andy is a Master at that and I have not learned to do that very well.

Also don't forget to work on the outer edges to hold the water on the blade so that it exits where the pitch is.

Keep me posted, I am sure that I will learn something from your efforts!

I would strongly urge you to get the duplicators so that you have a great start point as well as the ability to fix poorly bent props You will have a LOT of those if you do a lot of testing.

Prop duplicators...

Maybe we need to move this thread to the "for sale" forum? Props are cheap and by far the best performance advantage over any other mod. I believe in trimming the attitude of the boat with a small easy to turn prop. Then tweak, bend and grind on something more suited to your application. If you're not real good at finishing. Measure what you have created and have Andy do one up for you. A prop from any other boat/set-up is only wishfull thinking.

Ron

Ron:

I take it that you don't like me mentioning something that will help everyone running a 20 hydro. FYI: I have NOTHING to do with Prop Duplicators since I sold the business to Frant Bonanno several years ago. I had him make the dulicators mostly so that I could be sure to have the prop duplicated. I decided that it would be good for anyone wanting to have a great prop for their 20 hydro.

I am sorry that I offended you by offering the information about how to get these duplicators.

I guess I volunteered too much information

 

[Ron Jefferson]

Marty,After spending a little time with the pitch guage and a 1450, and going by the comments I've received so far - I'm theorising that I need to try a different line of thought to the original L/E pitch idea.

Reducing blade area on this prop without reducing diameter seems to be the feedback I'm getting so far. Several people have said don't reduce the diameter at all, yet my current hot 1450's have had the diameter reduced to 46 - 48mm, rather than removing substantial leading edge and/or Barr cutting.

I'm planning on doing some direct lap speed comparisons based on full diameter blades with reduced blade area vs. a reduced diameter with similar if not the same load @ the engine and therefore pipelength etc, as soon as my "raw" 1450's arrive. (I was hoping I'd have them for this coming weekend, but not to be unfortunately).

Tim.

Tim:

Good conclusion....

Diameter is great for race water to keep the prop "hooked up". There is a sacrafice in the amount of speed that you can get though, and you nailed the probable cause. I think that the LE pitch is limiting the terminal speed some. I hope that you optimize the prop some using Barr Back Cut and then work on the LE. I think that you will find some additional speed there. It is difficult to make very small changes to the LE (what you have to do) to get it better. Andy is a Master at that and I have not learned to do that very well.

Also don't forget to work on the outer edges to hold the water on the blade so that it exits where the pitch is.

Keep me posted, I am sure that I will learn something from your efforts!

I would strongly urge you to get the duplicators so that you have a great start point as well as the ability to fix poorly bent props You will have a LOT of those if you do a lot of testing.

Prop duplicators...

Maybe we need to move this thread to the "for sale" forum? Props are cheap and by far the best performance advantage over any other mod. I believe in trimming the attitude of the boat with a small easy to turn prop. Then tweak, bend and grind on something more suited to your application. If you're not real good at finishing. Measure what you have created and have Andy do one up for you. A prop from any other boat/set-up is only wishfull thinking.

Ron

Ron:

I take it that you don't like me mentioning something that will help everyone running a 20 hydro. FYI: I have NOTHING to do with Prop Duplicators since I sold the business to Frant Bonanno several years ago. I had him make the dulicators mostly so that I could be sure to have the prop duplicated. I decided that it would be good for anyone wanting to have a great prop for their 20 hydro.

I am sorry that I offended you by offering the information about how to get these duplicators.

I guess I volunteered too much information

Marty,

No offence taken.

I'm sure your intentions are good. However, lets be honest here. Hull, sponson angle, strut adjustment, weight, pipe, cg etc. has as much to do with the overall package as any duplicated prop. You know as well as I do that you can't bolt the best prop in the world onto a bastard boat and expect miracles. Your "great prop" may or may not work for me or anyone else, depending on our application.

This has nothing to do with me liking you "mentioning something that will help everyone running a 20 hydro" because we both know it won't. It's more about the reality that it may only work for a select few. Lets keep it real!

Ron

 

[SayMikey]

Marty,After spending a little time with the pitch guage and a 1450, and going by the comments I've received so far - I'm theorising that I need to try a different line of thought to the original L/E pitch idea.

Reducing blade area on this prop without reducing diameter seems to be the feedback I'm getting so far. Several people have said don't reduce the diameter at all, yet my current hot 1450's have had the diameter reduced to 46 - 48mm, rather than removing substantial leading edge and/or Barr cutting.

I'm planning on doing some direct lap speed comparisons based on full diameter blades with reduced blade area vs. a reduced diameter with similar if not the same load @ the engine and therefore pipelength etc, as soon as my "raw" 1450's arrive. (I was hoping I'd have them for this coming weekend, but not to be unfortunately).

Tim.

Tim:

Good conclusion....

Diameter is great for race water to keep the prop "hooked up". There is a sacrafice in the amount of speed that you can get though, and you nailed the probable cause. I think that the LE pitch is limiting the terminal speed some. I hope that you optimize the prop some using Barr Back Cut and then work on the LE. I think that you will find some additional speed there. It is difficult to make very small changes to the LE (what you have to do) to get it better. Andy is a Master at that and I have not learned to do that very well.

Also don't forget to work on the outer edges to hold the water on the blade so that it exits where the pitch is.

Keep me posted, I am sure that I will learn something from your efforts!

I would strongly urge you to get the duplicators so that you have a great start point as well as the ability to fix poorly bent props You will have a LOT of those if you do a lot of testing.

Prop duplicators...

Maybe we need to move this thread to the "for sale" forum? Props are cheap and by far the best performance advantage over any other mod. I believe in trimming the attitude of the boat with a small easy to turn prop. Then tweak, bend and grind on something more suited to your application. If you're not real good at finishing. Measure what you have created and have Andy do one up for you. A prop from any other boat/set-up is only wishfull thinking.

Ron

Ron:

I take it that you don't like me mentioning something that will help everyone running a 20 hydro. FYI: I have NOTHING to do with Prop Duplicators since I sold the business to Frant Bonanno several years ago. I had him make the dulicators mostly so that I could be sure to have the prop duplicated. I decided that it would be good for anyone wanting to have a great prop for their 20 hydro.

I am sorry that I offended you by offering the information about how to get these duplicators.

I guess I volunteered too much information

Marty,

No offence taken.

I'm sure your intentions are good. However, lets be honest here. Hull, sponson angle, strut adjustment, weight, pipe, cg etc. has as much to do with the overall package as any duplicated prop. You know as well as I do that you can't bolt the best prop in the world onto a bastard boat and expect miracles. Your "great prop" may or may not work for me or anyone else, depending on our application.

This has nothing to do with me liking you "mentioning something that will help everyone running a 20 hydro" because we both know it won't. It's more about the reality that it may only work for a select few. Lets keep it real!

Ron

Thanks for the email addy i been looking for it since i lost it a couple years ago. I have a 1455 dup and like it. Marty have you tried an h-4 or h-7? I know this thread is about 1450 but others are using these with some sucess?

 

[Tim_Duggan]

Mikey,

I find the H7 with 3.75" cup a great prop on my boat. Well worth trying in my opinion.

Tim

 

[Ron Jefferson]

Marty,

Please don't get me wrong. I have a utmost respect for your knowledge and ability. What I want everyone to realize is that your "perfect prop" is totally dependant on someone having the ability to put the total package together the same as yourself. That pounding a prop on a tool will not give you the ultimate .20 hydro.

In fact, they should understand that a modified prop can give them as much grief as a way over modified engine. I speak from experience as the first motor I ran in a mono was modified from Ackerman for a hydro. Not a bad motor from the builder, but the wrong application.

I believe for the both of us, it's the love of a tiny engine screaming and producing speeds of the bigger boats that turns our crank. It's just not a class for the not so patient, or less detail oriented hobbiest. Definately not a rookie class. Hope you understand...

Ron

 

[ALLAN YUEN]

I got my new CMDI OCT 1650 S&B cut 45mm. I wait that I will run test in spring I will see happen

 

[Norm Doerr]

No offense to anyone. BUT the major purpose of the duplicator is that you can take pitch out of a prop, put pitch in a prop and go back to your benchmark anytime you goof one up.. The instructions alone are good information on cutting , where to bend the blades and etc. I have spent literally HOURS at the pond with the plyers and learned a lot from my mistakes. (until recent years, now I am lucky to have one of the BEST prop benders I know working the plyers)

If it was not for the duplicator I would have literally had a pile of junk props.

The point here is to experiement and learn how to tune the prop to the boat, with the duplicator being one of the tools in the equation.

Norm Doerr

 

[Marty Davis]

Marty,
Please don't get me wrong. I have a utmost respect for your knowledge and ability. What I want everyone to realize is that your "perfect prop" is totally dependant on someone having the ability to put the total package together the same as yourself. That pounding a prop on a tool will not give you the ultimate .20 hydro.

In fact, they should understand that a modified prop can give them as much grief as a way over modified engine. I speak from experience as the first motor I ran in a mono was modified from Ackerman for a hydro. Not a bad motor from the builder, but the wrong application.

I believe for the both of us, it's the love of a tiny engine screaming and producing speeds of the bigger boats that turns our crank. It's just not a class for the not so patient, or less detail oriented hobbiest. Definately not a rookie class. Hope you understand...

Ron

Ron:

Since I put the setup information on RcBoat.com/setup.htm I am making the assumption that people will be smart enough to set their boat up correctly. I didn't say anything about this prop being the best since "sliced bread". I am saying that if you have your boat set up correctly, this will save you a ton of time.

As for your small diameter props, that is your approach. I prefer to have a larger diameter prop to stay hooked up a little better in rough water. Just my way of doing the same thing you are trying to do.

Actually this thread was put out in the open since I had been having a priving discussion about this and wanted to make it public so that others could benefit.

 

[Marty Davis]

Marty,After spending a little time with the pitch guage and a 1450, and going by the comments I've received so far - I'm theorising that I need to try a different line of thought to the original L/E pitch idea.

Reducing blade area on this prop without reducing diameter seems to be the feedback I'm getting so far. Several people have said don't reduce the diameter at all, yet my current hot 1450's have had the diameter reduced to 46 - 48mm, rather than removing substantial leading edge and/or Barr cutting.

I'm planning on doing some direct lap speed comparisons based on full diameter blades with reduced blade area vs. a reduced diameter with similar if not the same load @ the engine and therefore pipelength etc, as soon as my "raw" 1450's arrive. (I was hoping I'd have them for this coming weekend, but not to be unfortunately).

Tim.

Tim:

Good conclusion....

Diameter is great for race water to keep the prop "hooked up". There is a sacrafice in the amount of speed that you can get though, and you nailed the probable cause. I think that the LE pitch is limiting the terminal speed some. I hope that you optimize the prop some using Barr Back Cut and then work on the LE. I think that you will find some additional speed there. It is difficult to make very small changes to the LE (what you have to do) to get it better. Andy is a Master at that and I have not learned to do that very well.

Also don't forget to work on the outer edges to hold the water on the blade so that it exits where the pitch is.

Keep me posted, I am sure that I will learn something from your efforts!

I would strongly urge you to get the duplicators so that you have a great start point as well as the ability to fix poorly bent props You will have a LOT of those if you do a lot of testing.

Prop duplicators...

Maybe we need to move this thread to the "for sale" forum? Props are cheap and by far the best performance advantage over any other mod. I believe in trimming the attitude of the boat with a small easy to turn prop. Then tweak, bend and grind on something more suited to your application. If you're not real good at finishing. Measure what you have created and have Andy do one up for you. A prop from any other boat/set-up is only wishfull thinking.

Ron

Ron:

I take it that you don't like me mentioning something that will help everyone running a 20 hydro. FYI: I have NOTHING to do with Prop Duplicators since I sold the business to Frant Bonanno several years ago. I had him make the dulicators mostly so that I could be sure to have the prop duplicated. I decided that it would be good for anyone wanting to have a great prop for their 20 hydro.

I am sorry that I offended you by offering the information about how to get these duplicators.

I guess I volunteered too much information

Marty,

No offence taken.

I'm sure your intentions are good. However, lets be honest here. Hull, sponson angle, strut adjustment, weight, pipe, cg etc. has as much to do with the overall package as any duplicated prop. You know as well as I do that you can't bolt the best prop in the world onto a bastard boat and expect miracles. Your "great prop" may or may not work for me or anyone else, depending on our application.

This has nothing to do with me liking you "mentioning something that will help everyone running a 20 hydro" because we both know it won't. It's more about the reality that it may only work for a select few. Lets keep it real!

Ron

Thanks for the email addy i been looking for it since i lost it a couple years ago. I have a 1455 dup and like it. Marty have you tried an h-4 or h-7? I know this thread is about 1450 but others are using these with some sucess?

Yes, I use the same duplicators for the H7 and the 50x69. Both work well just a little different blade profile.

 

[Tim_Duggan]

Interesting to note H7 has a diameter of 47.5mm unlike the others which are a 50mm blade. Therefore, a H7 done on the same duplicator would act smaller than a 1450 or 50x69 done on the same duplicator at the same strut depth.... I don't have a 50x69 so am unaware of the blade profile - is it noticably different to the 1450?

Also, a personal note on the duplicator front - I know only too well that something that works on one boat doesn't work on another (and I'm used to that - I've always ran stuff considered far from the usual) but as I've stated earlier in this thread - I'm a rookie at bending props to find more performance - so I view bending with somewhat of an idea is better than bending with no idea in my case. I do appreciate the concern raised though as there are bound to be other forum users who may not be of the same understanding about finding the right combination, and this is a public discussion. After exchange rate conversion from US$ to AUS$ + shipping, it just about kills it for being practical for me at the moment in these difficult economic times. I have to allocate my boating budget wisely and without fuel or glow plugs I can't even turn the prop, let alone measure any performance gain. It's a shame, because I think I could learn a lot from them.

 

[Joe Warren]

How many have ever seen a 83-84 mph 20 hydro W a reduced H-10??

 

[Tim_Duggan]

How many have ever seen a 83-84 mph 20 hydro W a reduced H-10??

I haven't. No such boat exists here in my neck O' the woods. In the spirit of keeping the thread informative, was it reduced in diameter or blade area L/E and T/E?

 

[aaron alberico]

I have, but not in an oval race 21 boat....

 

[Joe Warren]

Bill Mcgraw had one 10 years ago that would run 83-84 mph any time he Desired. We are not talking one or 2 times I`am talking every other weekend. 3lb. Roadrunner Xtreme 21, Frank Orlic .21 Nova Rossi, ops 3280 @ 3 1/4 swinging a reduced & tip pitched Older (tidewater) H10 W/ 70% Nitro Odonnell in the tank. On Stalker Radar Gun 83-84 any time he wanted!! Mcgraw & Ed Lackey had some of the fastest 20 hydro I have ever seen to date!

 

[Chris Wood]

joe.. do you mean a h-7 because octura don't make a h-10?

chris

 

[John Knight]

joe.. do you mean a h-7 because octura don't make a h-10?
chris

Octura doesn't make the H-7 either. ABC makes all of the H series props, H-4, H-7, H-10, etc.