weight of the prop ?

**phillnjack** · 11-18-2017, 10:57 AM

Do any of you weigh your props ?
I am obviously talking about stainless steel props not alloy .
Personally I have found that most props in the 13 inch diameter range are around the 9 pound weigh, some a little over and some under.
But today I saw something about prop weights and it got me wondering.
I know that with a merc trophy you can shed 2 pounds off it without even touching the blades by shortening the hub and thinning the hub where its not
having any strain put on it.
I have seen some props like the Ballistic come out very thin on the blades, yet very heavy hub, this was my heaviest prop.

the way I am thinking is having a lighter prop is like having a lighter flywheel, speed up maybe faster but lose on energy once up there.

so what does your prop weigh ?
and any thoughts on losing a bit of weight from the assembly ? good or bad ?

**Dave S** · 11-18-2017, 06:14 PM

You going on the rite thought.....less is better....

**olboatman** · 11-19-2017, 07:56 AM

I have been under the theory that for high rpm the lighter the moving parts the better...then again when it come to performance the less weight of the total machine the better. Looks to me like you got a win-win going here!
Gary

**phillnjack** · 11-19-2017, 08:04 AM

I have notice that so many props have very thick barrels where there is no weight bearing or load bearing on these parts.
the front and the back by the nut for example, can be shaved to take off a lot of weight.

But I would like to know the various weights of props, for example is a mercury trophy a lot heavier than other similar props or lighter etc.

I only have 4 OMC stainless props and 1 Attwood ballistic, the Attwood although having ultra thin blades is the heaviest by around 2 pounds, the barrel of the prop
is very thick and heavily built compared to the omc barrels.
They went for lighter thinner blades for speed, but totally opposite with the barrel !!!!

I dont bother weighing the alloy props, they are already very lightweight.

**olboatman** · 11-19-2017, 08:25 AM

Start machining! I would think that the weight loss would be even more noticeable with lower hp motas like twins and triples. I will look closely at my Yammy props now that you have brought this up.
Gary

**phillnjack** · 11-21-2017, 10:14 PM

I think knocking off a couple of pounds from the prop must help it spin up a touch quicker. it definitely would if not in water.

But I think ive just blown my " theory" right out the water so to speak, as it would mean an alloy prop should be faster to spin up if the same size prop was used.
I dont think it does, I will have to time this as best as possible and see if there is a difference.

prop theory is a wicked witch, just when you think something might work, you have another idea to say why it wont work ha ha
I think the prop is the worst thing to try and get right on a boat, so many variables to mess around with.

**wicheckmate** · 11-21-2017, 10:57 PM

water itself is 784 times more dense than air.... The weight of the prop Maaaaaybe might matter on small lightweight applications Way more important is balancing statically and pitch wise along with blade shape...

**phillnjack** · 11-22-2017, 08:20 AM

yeah I understand what your saying Wicheckmate. the water makes a difference, even the density of salt water and fresh water is so different to run in.

I do balance my props, amazing how far out some new props have been, and how good a real wonky looking prop was.

it only takes a couple of minutes to balance a prop and well worth it if it helps saves the life of a bearing or seal..