STAINLESS OR NOT

[gbrowne63]

I have a thundercraft firebird 143V (canadian) with a 90hp mercury 3cylinder. The boat weighs 600-700lbs. With a 13.5X21 turning point prop i get 44mph at 5800rpms. With a slightly damaged 13.5X23 turning point prop i get 46mph. should i get a stainless 23p or maybe a 22p stainless. what are your thoughts. thanks

 

[aspeck]

What are your RPMs with the 23p?

 

[gbrowne63]

sorry ,with the 23p 5300 rpm

 

[gbrowne63]

the outboards rpm range is 5000-5500.

 

[airshot]

sorry ,with the 23p 5300 rpm

With any extra weight, it will begin to bog down and slow down your hole shot. If it were mine, I would go with the 22" and keep the rpm up near the max, so when extra weight is added you don't bog down.

 

[aspeck]

Yep, go with the 22

 

[Texasmark]

I have a thundercraft firebird 143V (canadian) with a 90hp mercury 3cylinder. The boat weighs 600-700lbs. With a 13.5X21 turning point prop i get 44mph at 5800rpms. With a slightly damaged 13.5X23 turning point prop i get 46mph. should i get a stainless 23p or maybe a 22p stainless. what are your thoughts. thanks

According to TP, the only difference in props is blade thickness which I doubt would change WOT 100 RPM. I ran a 24 P SS Ballistic on my 17.5' stepped hull alum BB, picture of it in my Avatar kissing 50 at around 5600 RPM. Rev max spec. is 5500 but I don't have a problem running over it.

 

[dingbat]

Thinner, stronger, less flex
Running a SS prop on a 90hp motor is futile

 

[Texasmark]

Thinner, stronger, less flex
Running a SS prop on a 90hp motor is futile

"Running a SS prop on a 90hp motor is futile"

Not so sir. My Ballistic SS had stellar performance on my BB as I indicated above on my 2002 stock Merc. 90 2 stroke when it was around 10 years old. My Avatar speaks for itself.

 

[dingbat]

"Running a SS prop on a 90hp motor is futile"

Not so sir. My Ballistic SS had stellar performance on my BB as I indicated above on my 2002 stock Merc. 90 2 stroke when it was around 10 years old.

Stellar is empirical.
What quantifiable improvements did a $600 SS prop have over a comparable aluminum prop?

 

[aspeck]

Stellar is empirical.
What quantifiable improvements did a $600 SS prop have over a comparable aluminum prop?

I gained 5mph, a much better hole shot, and low speed handling improved when I went stainless on my 16’ Skeeter with a Johnyrude 75 hanging from the back.

 

[Texasmark]

Stellar is empirical.
What quantifiable improvements did a $600 SS prop have over a comparable aluminum prop?

The Ballistic was bought at a decades old marine dealer that had a wall full of props and thrust washers. Paid $200 for it. My TPs all ran just over $100.

 

[gbrowne63]

I plan on going used as well. New props in canada can cost $1200.

 

[gbrowne63]

Thanks for all the input.

 

[JimS123]

Stellar is empirical.
What quantifiable improvements did a $600 SS prop have over a comparable aluminum prop?

"Quantifiable" may also be subjective. Sure, speed improvement is one data point, higher mpg is another. But hole shot, maintenance costs on the sandbar and bow rise are not as easy to determine.

My kickers run aluminum, as do every motor I ever had under 30 HP. All others run SS since 1977 when I discovered a 'Rude SST.

 

[racerone]

In Ontario ---try ----King's propeller repair.----Many used stainless props.

 

[dingbat]

The Ballistic was bought at a decades old marine dealer that had a wall full of props and thrust washers. Paid $200 for it. My TPs all ran just over $100.

Didn’t answer the question….. quantify performance over comparable aluminum prop

 

[gbrowne63]

bought a 13.25X22 ss lazer2 from facebook marketplace for $400. prop is like new.

 

[Texasmark]

"Quantifiable" may also be subjective. Sure, speed improvement is one data point, higher mpg is another. But hole shot, maintenance costs on the sandbar and bow rise are not as easy to determine.

My kickers run aluminum, as do every motor I ever had under 30 HP. All others run SS since 1977 when I discovered a 'Rude SST.

On the "Rude SST" if you missed it.....posted about this somewhere before.

I bought a new rig in 1972, 18' Caravelle with a 125 Johnson. OEM prop was aluminum. The local lake was a fresh fill with lots of saplings. We'd go out on usually Sunday afternoon. Monday during my noon break, I would drive over to the prop shop for a prop repair. This went on all year.

1973......lo and behold OMC came out with the SST. Cost was $185, lots of money for a prop back then but the trips to the prop shop on Mondays ceased and the savings mitigated the cost of the SST. Really a fine performing prop besides being damage resistant.

That was also the year they added PTT to their engines. I had tilt and wanted the PTT function but never got around to adding it.

 

[Texasmark]

"Quantifiable" may also be subjective. Sure, speed improvement is one data point, higher mpg is another. But hole shot, maintenance costs on the sandbar and bow rise are not as easy to determine.

My kickers run aluminum, as do every motor I ever had under 30 HP. All others run SS since 1977 when I discovered a 'Rude SST.

I bought a new 18' Caravelle tri hull in 1972 with a 125 Johnson, factory aluminum prop. In 1973 the SST came out and since I dinged the alum almost every time I took the boat out I spent the $185 for the SST as I previously stated. One of my better decisions in life.

Sometime later our work group at the company had a picnic at a park on a lake. I was alone in the boat and it didn't happen immediately, but I got 5 skiers up with that rig, I think I remember the pitch was 17", top speed alone, no water toys, was 39 indicated. No doubt most if not all the skiers were on 2 and at least a couple were light weight folks. Only stayed up for several hundred yards as one and then two fell off.....forgot how to ski....and we terminated the experiment. But I was amazed at pulling that stunt off.