will 140 prop work on alpha?

RandyJ

RandyJ

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I've got a nice stainless steel prop that was on a Mercruiser 140. Will it work on an Alpha outdrive with a 3.0L chevy engine? They look the same to me but the one on the Alpha has an insert thingy that I'm not familiar with since all I've ever had was the old 140's and 260's. Time for me to update......
 
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dubs283

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Re: will 140 prop work on alpha?

there should be a part number and pitch/diameter stamped in the prop somewhere, i would say a 19 pitch prop would be a "standard" runabout prop

your true test would be the gear ratio of the drive, should be 1.98:1 for a 3.0L 4 cyl engine

as far as an "insert thingy", it probably has a plastic hub insert common for later model alpha props - as long as you have all the hardware for install you should be good to go
 
RandyJ

RandyJ

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Re: will 140 prop work on alpha?

Not sure if there's any special hardware required. I've got everything that came off the 140 outdrive. It worked great on that old boat when it was running....
 
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fishrdan

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Re: will 140 prop work on alpha?

The prop will work, but use the correct hub kit and/or thrust washer for the prop. You might need to use a thick thrust washer, maybe not...

Clear as mud, eh?

Oh yeah, just because the prop worked great on a 140 doesn't mean it will work the same with a 3.0. Prop selection has more to do with "boat" and load, than engine.
 
RandyJ

RandyJ

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Re: will 140 prop work on alpha?

Thanks. The specs call for a 14.25 x 21.5 or a 14.25 x 19. The ss prop is a 14 x 21 so should be fine. I've got a bucket full of thrust washers. The prop that came with the boat threw me off with that insert thingy I've never seen before. I've got a yard full of old boats so the newer ones (less than 20 or so years old) kind of throw me off.
 
achris

achris

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Re: will 140 prop work on alpha?

RandyJ said:
I've got a nice stainless steel prop that was on a Mercruiser 140. Will it work on an Alpha outdrive with a 3.0L chevy engine? They look the same to me but the one on the Alpha has an insert thingy that I'm not familiar with since all I've ever had was the old 140's and 260's. Time for me to update......
Click to expand...

Sounds like the Flo-torq II hub assembly. As long as you have all the parts, they are the best prop around... They're putting prop shops out of business. That insert thingy is the hub. No more rubber hubs that spin. That insert is user replaceable, which also means if you have a spare insert and the tools to do the job, you can do it at sea. I have done it and it's not easy, but it is doable... I tied rope to EVERYTHING, the prop, the spanners....

Oh, your question... Yes, it will fit on your engine. If you go to buy a new prop now, it will be a Flo-torq II....

There are 6 parts to the prop. The prop, the hub (plastic insert), the brass propshaft (splined) adapter, the forward thrust hub (looks like a big brass (or SS) washer), the prop nut and the prop nut locking tab....

Chris........
 
jimbo_jwc

jimbo_jwc

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Re: will 140 prop work on alpha?

My 87 came with this 48-78118-a40-17p prop its a 3.0 L 130Hp Mercruiser Alpha One outdrive . It pushes a 196 Cuddy Cabin nicely
 
Bondo

Bondo

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Re: will 140 prop work on alpha?

RandyJ said:
I've got a nice stainless steel prop that was on a Mercruiser 140. Will it work on an Alpha outdrive with a 3.0L chevy engine? They look the same to me but the one on the Alpha has an insert thingy that I'm not familiar with since all I've ever had was the old 140's and 260's. Time for me to update......
Click to expand...

Ayuh,.... Any prop that fits any Alpha series drive, will fit any other Alpha series drive....

A 140 motor is the Same motor as the 3.0l....
 
RandyJ

RandyJ

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Re: will 140 prop work on alpha?

Bond-o said:
Ayuh,.... Any prop that fits any Alpha series drive, will fit any other Alpha series drive....

A 140 motor is the Same motor as the 3.0l....
Click to expand...

I don't know all there is to know but the old 140's and 120's were pre-alpha (I think).... I do know they ain't as pretty.... gaskets are pretty much interchangeable tho'.
As for that flo-torq prop tho' ... I don't think the bent prop on that boat is a flo torq. One blade is pretty bent. The insert is not plastic. It's brass with 4 big splines around it which slide over the splined shaft. It also has the rubber hub inside. All the old 140's I've had were made before they started talking metric... before they became known as 3.0L. I've got two bass boats with the old type 140's and a junk 120 on the ground. One has a 165 decal on the hull but I don't have a clue what that refers to because it surely is not a 165 hp. My cuddy is a Volvo penta and tho it's a really good boat & motor & the 170 outdrive seems really tough I sure wish it used the mercruiser props.. LOTS cheaper! The newest boat I've ever had is the 1983 bayliner cuddy cabin
 
Bondo

Bondo

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Re: will 140 prop work on alpha?

RandyJ said:
I don't know all there is to know but the old 140's and 120's were pre-alpha (I think).... I do know they ain't as pretty.... gaskets are pretty much interchangeable tho'.
As for that flo-torq prop tho' ... I don't think the bent prop on that boat is a flo torq. One blade is pretty bent. The insert is not plastic. It's brass with 4 big splines around it which slide over the splined shaft. It also has the rubber hub inside. All the old 140's I've had were made before they started talking metric... before they became known as 3.0L. I've got two bass boats with the old type 140's and a junk 120 on the ground. One has a 165 decal on the hull but I don't have a clue what that refers to because it surely is not a 165 hp. My cuddy is a Volvo penta and tho it's a really good boat & motor & the 170 outdrive seems really tough I sure wish it used the mercruiser props.. LOTS cheaper! The newest boat I've ever had is the 1983 bayliner cuddy cabin
Click to expand...

Ayuh,... Like I said, the 140, 'n the 3.0l are the Same motor, the 2.5l is the Same motor as the 120....
The 165 sticker Did in fact mean a 165hp motor, probably an ole 470, or the I6, 165hp...(it'll also be a different gear ratio)
And,...
Like I said, the Propshafts on ALL the Alpha series drives are the Same shaft, 'n take the Same props....
This includes, All but the very earliest MC-1s, which had a squared shoulder, which went to a tapered shoulder, 'round the very early 70s, or maybe the late 60s....
 
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fishrdan

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Re: will 140 prop work on alpha?

RandyJ said:
The specs call for a 14.25 x 21.5 or a 14.25 x 19. The ss prop is a 14 x 21 so should be fine.
Click to expand...

"The specs" What specs, specs from the boat manufacturer?

The only way to see if it will work is to try it, and make sure the engine will still reach it's WOT RPM. That would be either 4200-4600RPM or 4400-4800RPM, depends on which engine you have. I think that's going to be a lot of prop for a 140HP/3.0L as the 21P SS prop will perform close to a 23P aluminum prop. If you have a "fast hull" with a light load, it would work.

What is the current prop pitch and what is the WOT RPM of the engine running that prop?
 
RandyJ

RandyJ

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Re: will 140 prop work on alpha?

Current prop is a 14.25 x 21.5. I've also got a 14 x 19 ss prop. This is for a bud... not my boat. Late model very nice ski boat (late to me means later than 1990. Very nice used ski boat. And yep, boat manufacturer specs....
 
achris

achris

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Re: will 140 prop work on alpha?

RandyJ said:
...The insert is not plastic.
Click to expand...

Technically it's delrin...

RandyJ said:
It's brass with 4 big splines around it which slide over the splined shaft. It also has the rubber hub inside.
Click to expand...

IT'S NOT RUBBER!!! Once you have that brass sleeve out get a small pin punch and a hammer and knock that insert out (from the back of the prop through to the front of the prop) and have a good look at it....

FLOPRP1.jpg


This is the advertising blurb from Merc -> http://www.mercurymarine.com/propellers/advantage/technologies/flo-torq/

Chris.....
 
smokeonthewater

smokeonthewater

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Re: will 140 prop work on alpha?

Chris, SOME of the new props DO actually have a square rubber insert.... The ones I've had were delrin but not all of em are.
 
achris

achris

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Re: will 140 prop work on alpha?

smokeonthewater said:
Chris, SOME of the new props DO actually have a square rubber insert.... The ones I've had were delrin but not all of em are.
Click to expand...

ok... but the advertising blurb specifically states Delrin... and that's all I've ever seen. Are you sure they are Genuine Merc props? I know some aftermarket still use rubber...
 
smokeonthewater

smokeonthewater

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Re: will 140 prop work on alpha?

No they weren't oem merc.... IIRC they may have been turning point.... not sure tho ....the advertising blurb isn't necessarily relevant to the op's prop.... in fact I didn't even read it..... O/P simply state's that one prop was on a 140 and the other an alpha 3.0

I wasn't trying to argue with ya.... just thought maybe you didn't know......


either way, as you guys said above.... it WILL fit.
 
RandyJ

RandyJ

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Re: will 140 prop work on alpha?

Yep... that pretty much looks like it. I had never seen a 4 splined washer made to insert into the hub. Guess I'm just used to working on old junkers. Sumpin' new with every boat I work on.
 
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