pressed in hub vs flo torq pre-alpha

[muskyfins]

I have a 93 stingray with a 188/888 from an old cabin cruiser. I always call it a pre-alpha but I guess it's really an MR?

Anyway, spun hub on 3 blade SS 19P prop of unknown brand. Can I press out the old rubber and replace with a flo-torq kit or do I have to take it to a shop. I work in manufacturing and removal shouldn't be a problem, but I'd want a professional to do the install.

 

[Bondo]

Re: pressed in hub vs flo torq pre-alpha

I have a 93 stingray with a 188/888 from an old cabin cruiser. I always call it a pre-alpha but I guess it's really an MR?

Anyway, spun hub on 3 blade SS 19P prop of unknown brand. Can I press out the old rubber and replace with a flo-torq kit or do I have to take it to a shop. I work in manufacturing and removal shouldn't be a problem, but I'd want a professional to do the install.

Nope,... They're completely different systems.... 'n yer drive is an MC-1,... Pre-MR...

 

[Texasmark]

Re: pressed in hub vs flo torq pre-alpha

Clarifying what Bond-0 said that may not be clear, "the prop systems" are completely different.

The rubber hub is round and pressed in relying on friction to lock it to the prop. Prop shops do that for you. The other uses a prop with a molded square (for one) slot that the plastic hub with bronze, splined to match the prop shaft, insert slides into.

When you hit something with the former, the hub slips and locks back in place. On the plastic hub with the brass insert, it has two options: (opinion here but I bet I'm correct) either hold together because the object was not that much of an impact, or the fingers of the brass hub, liken to the blades of an impeller (radial in shape), rip through the plastic molded around them and destroy it's ability to develop thrust.

If you are in harms way, on the windward side of rip rap and a storm is on you, you are dead meat!!!!! To me it's liken to the old OMC days where you had a "drive" (we called it a shear pin as that is what it did at the worst possible time) pin that locked the prop to the shaft and all you had to do was to whack something once, the pin would shear and the prop was no longer hooked to the shaft.....not a fun experience and one reason I quit the badge and went to Phantom black....course back then they were green and silver, later white, and finally Phantom Black Lacquer.

My 2c,
Mark

 

[muskyfins]

Re: pressed in hub vs flo torq pre-alpha

I will have to take a closer look at what's going on with my prop. I've never owned a boat with a pressed in hub before (and I think originally this boat didn't come this way either) All I know, is when trying to take off from a stop or idle speed, if I give it too much throttle the motor spins fast and there's no forward propulsion. if i give it throttle very slowly and eventually get on plane, she runs out no problems at all. (42 mph at 4000 rpms) Spun hub right?

I had the prop off once for about 3 minutes and it sure looked to me to have a square slot like all the other props I've ever owned, but a neighbor was over and said "oh that's a pressed in hub. you'll need to have a new one pressed in." I took his word for it, but maybe I need to get a few more details.

While we're at it-it's the prop that makes the difference in type, not the drive/shaft. Right?

 

[muskyfins]

Re: pressed in hub vs flo torq pre-alpha

good news/bad news....
Closer inspection reveals that I do in fact have a pressed in hub with a round hole in the prop. Prop shop says problem is with rake angle of blades not spun hub. i suppose that should be a different topic so I'll start a different thread for that. But, is it the prop or the drive that determines pressed in versus flo torque?

PS-thanks to everybody for all your help. It has made boating more enjoyable to understand my equipment.

 

[Bondo]

Re: pressed in hub vs flo torq pre-alpha

But, is it the prop or the drive that determines pressed in versus flo torque?

Ayuh,... It's all in the way the prop is built,... The drive don't care,...