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-   -   450: 3 blade fixed recommendation for 2012 450F? (https://www.cruisersforum.com/forums/f139/3-blade-fixed-recommendation-for-2012-450f-236654.html)

LeeV 07-07-2020 11:33

3 blade fixed recommendation for 2012 450F?
 
We have a 2012 450F with 4JH5E Yanmars and SD50s, and we need to replace the stock 2 blades currently on the boat. I know the max rpms are 3000, the reduction is 1:2.32 and I believe the props rotate counter clockwise. With the 2 blade we needed lots of rpms to manouver. We'd like to install fixed 3 blades as we can use the bit of extra torque docking in current etc....



I've gotten a slew of different answers from prop dealers, so I thought I'd see if anybody here has installed 3 blade fixed on that combination and what size you used and where you found them.


Best regards,

Tin Tin 07-07-2020 18:56

Re: 3 blade fixed recommendation for 2012 450F?
 
Are you assuming the 3 blade is going to make a significant difference? It is a lot of money and hassle and you could well be disappointed with the differential result, if you are considering any long distance cruising I would bite the bullet and get Flexo folds, granted a lot more money, but for just pottering about the Chesapeake I would stick to what you have. I am a bit biased as I hate the thrum that fixed blades make when sailing plus their degradation of sailing performance, that whilst not huge is still a pain. So for example if you can improve 0.5 knots on 6 knots that is a 8% saving - or over 24 hours 2 hours - over 10 days (say sailing to BVI) that is 20 hrs - almost a day. Also when motoring on one engine the drag from the other prop is eliminated, so better fuel consumption, also when motoring through crab pots if you select neutral and glide through a close call, the folded prop will less likely wrap a pot line. Just speaking from experience, sorry to Hijack the thread.


Back on topic, you might find that someone that has upgraded to folding props needs to dispose of their old fixed 3 bladers for a bargain price. Try Lagoon Facebook forum.

LeeV 08-07-2020 03:49

Re: 3 blade fixed recommendation for 2012 450F?
 
I have one prop that we knew was marginal when we bought it, and now needs replacing; they were the originals. The boat is new to us and several systems need replacing or updating, so plunking down 5k just wasn’t on the list; for the next 3 years, $650 isn’t so bad, and then we can splurge before we head out.

Three over the original two is only for the bit of extra torque maneuvering.

A 450 just to putter around the bay? I can’t imagine, unless someone has an enormous family!

Pete7 08-07-2020 04:49

Re: 3 blade fixed recommendation for 2012 450F?
 
Quote:

Originally Posted by LeeV (Post 3181274)
so plunking down 5k just wasn’t on the list; for the next 3 years, $650 isn’t so bad, and then we can splurge before we head out.

That plan would mean you also have a pair of fixed 3 blade props on board as spares when you do head out, should you damage or loose one in some far flung corner of the globe.

Pete

Tin Tin 08-07-2020 05:08

Re: 3 blade fixed recommendation for 2012 450F?
 
Quote:

Originally Posted by Pete7 (Post 3181292)
That plan would mean you also have a pair of fixed 3 blade props on board as spares when you do head out, should you damage or loose one in some far flung corner of the globe.

Pete


Plus the original 2 blades, that makes 4 spares.

Pete7 08-07-2020 05:18

Re: 3 blade fixed recommendation for 2012 450F?
 
Might be worth seeing what a pair of Kiwi props will cost state side:

https://www.cruisersforum.com/forums...?do=file&id=23

j.g.evans 08-07-2020 09:15

Re: 3 blade fixed recommendation for 2012 450F?
 
I once went to 4 propeller outfits and got 4 different , really different, answers. Then I did my own calculations based upon Propeller Handbook by Gerr. Alternatively I have found the propeller calculator at https://www.vicprop.com/displacement_size.php quite good. I recently replaced a folding propeller with a 3 blade feathering propeller by Autostream. It is SS which I like on a SS shaft. Furthermore its pitch can be adjusted under water and even changed from RH to LH.

Thumbs Up 08-07-2020 10:40

Re: 3 blade fixed recommendation for 2012 450F?
 
I was running a 3 blade on one side and a 2 blade (from a Yanmar) on the other and didn't notice much of a difference. A 3 blade aluminum Volvo prop costs around $310. from General Propeller. Volvo and Yanmar saildrive props seem to be interchangable.

a64pilot 08-07-2020 11:17

Re: 3 blade fixed recommendation for 2012 450F?
 
Good idea to have spares on a 450, but also have the other bits required.
I don’t know why, but I have met two 450’s who’s props “fell off”, so if they are prone to falling off, have the other bits too in spares.

CATJAVA 09-07-2020 02:41

Re: 3 blade fixed recommendation for 2012 450F?
 
I Don’t know what a 450F is or the HP of ur engines, but assume it is 45ft cat with bigger engines that I have which are Yanmar 3YM30AE’s. I used the 17x13 Volvo Aluminum props I used to buy from Jimmy’s Prop Shop in FL for a few years. But BEWARE, because the splines on these are VERY slightly undersized for a Yanmar saildrive shaft and thus have a little rotational play, which doesn’t seem like a big deal, but in 3-4 years the splines wear away and you have a free wheeling prop. They were cheap to replace, so I always carried a spare, but this will happen! I never tried to “glue” them on (bad idea to me).

When I got to the Philippines I had a prop foundry make me the same 17z13 prop out of bronze w/ stainless insert for the splines. For $340 each, I couldn’t be happier! Obviously u can’t do this in the USA as cheaply as I did, so can’t tell you where to go.

As an aside, I have always had 3-bladed props because I want positive power at all times in any direction, not that I use marinas much. You will appreciate them! Also, please don’t pay attention to what these armchair sailors have to tell you about the notorious “prop drag” of fixed props while sailing. It is serious BS! When your props are not in use, Yanmar specifies that they are to be freewheeling. Maybe not on a shaft, but on a saildrive, you can spin one easily with your “pinky” finger. So they have very little drag. And not much vibration while sailing or motoring with one engine, which I’ve done across the Pacific Ocean twice. They might hum a bit when sailing over 8-9 kts, but I consider this a plus when I think about encountering whales. If they do provide excessive drag, well all I can say is that I’m still going a lot faster than these other know-it-all YAHOOS! Enuf said.
Evan on JAVA

LeeV 09-07-2020 03:54

Re: 3 blade fixed recommendation for 2012 450F?
 
Quote:

Originally Posted by Tin Tin (Post 3181309)
Plus the original 2 blades, that makes 4 spares.

I may keep them but the stbd side would need to be re-hubbed, if they even do that.

LeeV 09-07-2020 03:56

Re: 3 blade fixed recommendation for 2012 450F?
 
Quote:

Originally Posted by j.g.evans (Post 3181474)
I once went to 4 propeller outfits and got 4 different , really different, answers. Then I did my own calculations based upon Propeller Handbook by Gerr. Alternatively I have found the propeller calculator at https://www.vicprop.com/displacement_size.php quite good. I recently replaced a folding propeller with a 3 blade feathering propeller by Autostream. It is SS which I like on a SS shaft. Furthermore its pitch can be adjusted under water and even changed from RH to LH.

Thanks for the references!

LeeV 09-07-2020 03:59

Re: 3 blade fixed recommendation for 2012 450F?
 
Quote:

Originally Posted by a64pilot (Post 3181582)
Good idea to have spares on a 450, but also have the other bits required.
I don’t know why, but I have met two 450’s who’s props “fell off”, so if they are prone to falling off, have the other bits too in spares.

Correct; there have been several instances of the 3 blades falling off. I was just speaking to somebody who had that happen, and we discussed drilling the shaft to pin the castellated nut.

LeeV 09-07-2020 04:09

Re: 3 blade fixed recommendation for 2012 450F?
 
Quote:

Originally Posted by CATJAVA (Post 3181901)
I Don’t know what a 450F is or the HP of ur engines, but assume it is 45ft cat with bigger engines that I have which are Yanmar 3YM30AE’s. I used the 17x13 Volvo Aluminum props I used to buy from Jimmy’s Prop Shop in FL for a few years. But BEWARE, because the splines on these are VERY slightly undersized for a Yanmar saildrive shaft and thus have a little rotational play, which doesn’t seem like a big deal, but in 3-4 years the splines wear away and you have a free wheeling prop. They were cheap to replace, so I always carried a spare, but this will happen! I never tried to “glue” them on (bad idea to me).

When I got to the Philippines I had a prop foundry make me the same 17z13 prop out of bronze w/ stainless insert for the splines. For $340 each, I couldn’t be happier! Obviously u can’t do this in the USA as cheaply as I did, so can’t tell you where to go.

As an aside, I have always had 3-bladed props because I want positive power at all times in any direction, not that I use marinas much. You will appreciate them! Also, please don’t pay attention to what these armchair sailors have to tell you about the notorious “prop drag” of fixed props while sailing. It is serious BS! When your props are not in use, Yanmar specifies that they are to be freewheeling. Maybe not on a shaft, but on a saildrive, you can spin one easily with your “pinky” finger. So they have very little drag. And not much vibration while sailing or motoring with one engine, which I’ve done across the Pacific Ocean twice. They might hum a bit when sailing over 8-9 kts, but I consider this a plus when I think about encountering whales. If they do provide excessive drag, well all I can say is that I’m still going a lot faster than these other know-it-all YAHOOS! Enuf said.
Evan on JAVA

Sorry, I falsely assumed since I posted in the 450 section of the Lagoon sub directory that everybody knows what a 2012 450F with 4JH5E Yanmars and SD50 is. Lagoon 450 F is the flybridge version of the 45’10” x 25’10” cat. The 4JH5E Yanmars are dual 54hp.

Interestingly enough, Jimmy’s is one of the shops I called. 🙂 I know I want 3 blades; I’ve been on boats with 3 blade props, but never 2 and I can tell the difference. Thanks for the info.

Regards,

gla57 09-07-2020 05:13

Re: 3 blade fixed recommendation for 2012 450F?
 
LeeV, please check your inbox. I sent you a pm.


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