Prop Indexing

[Lennard Cuenco]

thx for the real life example of this principle in action marty...

if i sound like a cynic, its because i have history with prop indexing from a few years back..

derret, if i think he is who i think he is, will be able to confirm this story as well:

derret and i had run boats together for years, during this time i was competing for the championship, my boat was decently fast and handled well...

for the most part, when derret and i ran together, my boat was generally the better running boat of the two...as i recall, derrets boat was a wof boat...looked heavy...not sure if it actually was heavy...lol

one day, after running with his boat for at least two years...he changes something and his performance was like a light switch...it was either on or off the pipe...it went from idle to 70 mph very quickly, passing us like we were goin backwards...needless to say, me and the guys (Alfred Lanza) were all over his pit table...lmao..we were checkin his cooling setup, askin bout his clearance, his fuel...the poor guy was bein run over...

then he lays the "prop indexing" idea on us, and we're scratchin our heads (and other lower body parts) saying "duh-huh?"

i fully understood his explanation, i just couldn't figure out why derret didn't index his props previously...and from what i recall..this was the last time i remember his boat goin faster than all of us...

point is: a boat performing like his did that day, i would guess had little to do with indexing and more to do with his prop/pipe/clearance....

furthermore, the way it was presented to me, "indexing" sounded a bit like voodoo, and the evidence wasnt substantial enough to pay attention to...

derret?/marty?/mr zaker?

 

[Marty Davis]

An example of this indexing that I have stated for MANY years is a true story:

I used it on my 40 SAW boat (20 Crapshooter with 45 K&B on mini-pipe). I would run 80-85 mph in 1979.

Marty,

You said in 1979. Would this have been a hard shaft drive?

Yes it was....

 

[Marty Davis]

thx for the real life example of this principle in action marty...

if i sound like a cynic, its because i have history with prop indexing from a few years back..

derret, if i think he is who i think he is, will be able to confirm this story as well:

derret and i had run boats together for years, during this time i was competing for the championship, my boat was decently fast and handled well...

for the most part, when derret and i ran together, my boat was generally the better running boat of the two...as i recall, derrets boat was a wof boat...looked heavy...not sure if it actually was heavy...lol

one day, after running with his boat for at least two years...he changes something and his performance was like a light switch...it was either on or off the pipe...it went from idle to 70 mph very quickly, passing us like we were goin backwards...needless to say, me and the guys (Alfred Lanza) were all over his pit table...lmao..we were checkin his cooling setup, askin bout his clearance, his fuel...the poor guy was bein run over...

then he lays the "prop indexing" idea on us, and we're scratchin our heads (and other lower body parts) saying "duh-huh?"

i fully understood his explanation, i just couldn't figure out why derret didn't index his props previously...and from what i recall..this was the last time i remember his boat goin faster than all of us...

point is: a boat performing like his did that day, i would guess had little to do with indexing and more to do with his prop/pipe/clearance....

furthermore, the way it was presented to me, "indexing" sounded a bit like voodoo, and the evidence wasnt substantial enough to pay attention to...

derret?/marty?/mr zaker?

I think that the biggest result of indexing will be for props with the largest variance in pitch.

The prop that I gave an example with had a BIG difference in pitch from 1 blade to another.

Don't look for a huge increase in performance with indexing. It is for people who have optimized as much of their boats as possible and this is one small part to increase performance. This will NEVER be dramatic unless it is similar to the example I gave.

 

[nws]

Back when I was racing, control line Eat Race, I used to pitch each side of the prop different.

Turn the prop 180 deg & the plane would go 5mhp faster.

I did that for many years.

It worked, got all of Nat. trophy ,for all the work.

It worked on the hard shaft boats to.

Norris

 

[Derret]

My three cents worth- I've been in boating (both with a long term business & as my hobby) & have seen & done a lot in this neat hobby.

My thinking has always been to try things- for every good idea we get, there has to be hundreds(?) that are just not useful. I have boxes full of stuff like that in my rafters in the shop.

I do know that when I have something working (a winner) I don't mess with or change anything on it till it usually (always?) blows up or breaks. Then I got to start again to get things back in tune.

I had an 3.5 hydro (Hughey) in the early days that was like that. (Held the NAMBA SAW record for three years).

Any real difference in indexing the prop? Can't truely say.....

But...I do know the boat tested better after I used the same setup drill every time I ran the boat...

I know I did get real close to that boat when it ran fast. Almost like it was happy with me on the day?

Maybe I just tricked my thinking it was better?

I believe in perfect practice to be perfect & this seems to lead in the direction of doing things the same (like indexing).

Thanks-

Derret

Derret,

I agree with repeating setup techniques that work over and over...I do the same...

there are many examples in life/this hobby where doing things that have worked in the past will work in the present...

bottomline:

methods that bring value that are measurable...you should continue to do...we can all agree with that...

when you are able to measure the value that "indexing your props" brings...please define it here so we can understand what you did and how it made your situation better.

thanx,

Len

btw derret, if you still have that 7.5 that you were running with me and Alfred a few years back, I'll take it if ur done with it

you talk to gonsel lately?

 

[Joe Warren]

Marty since we are talking about the drive line.. What do you think about Flywheel & Crankchaft Weight?? I know many use to think less flywheel weight? But we are finding a lot of extra Cheap Power in the New Engines that have Added Crankshaft Weight. The boat does not slow down & wet up as quick when you lift on the throttle If it has a higher crank shaft weight. I would have to think this helps launch a Maxed Out Cupped up Prop too for Heat Racing.