Stainless steel prop...?

[fisninfool]

Hi again,

How much difference would a SS prop make for my slightly doggy 680 T w/ 60 merc?

Thx

[Esox_Magnum]

Big difference, buddy ran a 4 blade on his old 2 stroke and was pushing in the low 40's... IMO the 60 is a little underpowered for the 690 and a 90 is by far a better motor.... A 115 is sweet but needs a 90 cowl LOL

[delcecchi]

I recall the tests done by the late lamented bass and walleye boats mag. There really was little difference between aluminum and stainless props.

Here is what they had to say....

Quote:

Q: Are stainless steel propellers really faster than aluminum props?

A: Not really. If you switch from an aluminum prop to a stainless wheel (of the same style and pitch), you probably won’t see a big change in the boat’s performance.

But there’s more to it than that. Although aluminum is light, inexpensive, and relatively easy to repair, it isn’t a very strong material, so the blades on an aluminum propeller are usually fairly thick. Most aluminum propellers are good for general-purpose applications where price (or reparability) are the

primary considerations.

Stainless steel, on the other hand, is about five times stronger than aluminum. Stainless props can be made with thinner blades (and in a wider variety of blade shapes and styles) than is possible with aluminum. Thinner blades and advanced blade geometries equate to better performance and speed. On a fast hull with a very positive power-to-weight ratio, stainless props can be faster than aluminum.

Pitch and maybe rake seem to be the two biggest factors in prop performance.

[Walleye Guy]

Stainless makes a big difference on higher horsepower powers. I think you will be disappointed in the limited gains you would get on your 60 HP if you bought a stainless prop. Unfortunately your boat is underpowered and changing the propeller is not going to correct that fundamental issue.

[JohnMickish]

what 60 horsepower on a heavy boat the gains will be small but there will be gains. if you can get a stainless prop for real cheap I would say go for it if you have to pay retail in the 400 dollar plus range you are not going to be happy.

[fisninfool]

Isn't a 60 Hp the max on a 680?

[highlife4me]

Yes it is. I believe if you had a console it is 90HP. I don't know what pitch your prop is but you may want to consider changing that too.

[fisninfool]

K, thanks guys

[magnum mike]

Stainless props have their place but that place is not on my boats. They are 3 - 5 times the cost of a comparable aluminum screw. There is no argument that SS props do perform better than aluminum. My main objection is that a SS prop will not bend / break when struck and will transfer that energy to the drive train of the motor. I spend $50-$100 every year to tune up aluminum props. Much better than $1000's to re-build a lower unit in my opinion.

[Borch]

Stainless props have their place but that place is not on my boats. They are 3 - 5 times the cost of a comparable aluminum screw. There is no argument that SS props do perform better than aluminum. My main objection is that a SS prop will not bend / break when struck and will transfer that energy to the drive train of the motor. I spend $50-$100 every year to tune up aluminum props. Much better than $1000's to re-build a lower unit in my opinion.

Get a flo torq prop and the issue of lower units are gone as the $30 plastic part takes up the shock Just not an issue anymore if you move to the new stainless prop style.

[magnum mike]

Very interesting tip Borch...

I need to do some investigating.

[delcecchi]

And one other point of reference.... for what it's worth. I used to have an alumacraft classic 16 with a 40 merc (the 2 cylinder 2 stroke). I got tired of wrecking al props on the rocks of lake vermilion so bought a Stainless prop. There was no perceptible difference in performance but it didn't get damaged every time I bumped a rock on the way into the little harbor at the resort. And I never wrecked a lower unit either.

[Whoaru99]

Pitch and maybe rake seem to be the two biggest factors in prop performance.

I agree. Before considering SS for even a second longer the proper pitch of prop should be confirmed as appropriate for the existing setup (runs in the proper RPM range at WOT throttle).

Sorting that out and perhaps making some changes in weight distribution will help more than just going to SS prop. The more I think about it going to a SS prop straight across the more I think that could make it even worse if something with too much cup and rake was chosen.

[BoxMN]

Fishinfool, is your 60 a 2 stroke or 4, and are you looking for better holeshot or top end?

I have a 60 (bigfoot) 4 stroke on pontoon and have one of the new 4 blade Merc alum props on it (can't recall the name) but I gotta say, it has some umph. Obviously I don't have speed with a 22' pontoon (21 gps) but holy cow would it have umph to get out of the hole, and handling, for a boat.