Propellor Shaft Diameter

[Alaskahick]

Got a bit of a problem and need some information to help sort this out. Currently Spirit is sitting in Yakutat, AK due to weather in the Gulf of Alaska. The last three weeks I spent cruising her up from Everett, WA. During my trip from Elfin Cove to Yakutat I hit a piece of wood that set the port propeller to vibrating. I should have put her on the grid and pulled the prop prior to leaving but I had a serious case of get-home-ittis. My boat is a 1979 34 LRC with twin Perkins T6.354 engines and Borg Warner Velvet Drives (I assume 72C). Currently she has 3 blade 20" dia props with a 20 pitch. If she has a 2:1 gear ratio, boatdiesel is recommending 23" diameter 20 pitch prop.

Does anyone know what the standard gear ration was installed into our boats and what the standard propellor shaft diameter is?

 

[long-cours.62]

On the owner book of Perkins

Got a bit of a problem and need some information to help sort this out. Currently Spirit is sitting in Yakutat, AK due to weather in the Gulf of Alaska. The last three weeks I spent cruising her up from Everett, WA. During my trip from Elfin Cove to Yakutat I hit a piece of wood that set the port propeller to vibrating. I should have put her on the grid and pulled the prop prior to leaving but I had a serious case of get-home-ittis. My boat is a 1979 34 LRC with twin Perkins T6.354 engines and Borg Warner Velvet Drives (I assume 72C). Currently she has 3 blade 20" dia props with a 20 pitch. If she has a 2:1 gear ratio, boatdiesel is recommending 23" diameter 20 pitch prop.

Does anyone know what the standard gear ration was installed into our boats and what the standard propellor shaft diameter is?

You have some graph to help you too definite the shaft diameter (page 82 on one wrotte in French ) but now we are on the boat and I am not able to scan it for you .
For example we have the same engine than you and our shaft diameter is 60 mm i will give a sample for shaft in 'mid-steel 44kg/mm2 ' (for that I suppose your engine is 215C model) normes Loyds 65 mm diam norme 'commercials' 60 mm for the shaft
and the maximum between two bearing for this diam . around2700/2800mm
But the graphs are very small and my eyes ....not very young

And gearbox ration is 2,52/1 , we have the 215C models, between two bearing we have around 2,30m, and our proppeller ar 27'X27' '
4 blades.

 

[chc]

I'm not sure that there will be a "standard" shaft diameter; it may vary reference installed engine type & hp. My 1984 34 LRC has 250 hp Detroit's w/1.5 " shafts. Can't quite remember the prop diameter/pitch, but I think it is 22x22 3 bladed. The more ground I discover, the smaller the diameter. Good luck.

 

[Phil Fill]

I would hire a local diver, who can probable take off the damage prop and/or take measurement. Also most diver know where to take prop to be repaired locally. A lot cheaper to have the prop repaired than buying a new on.

 

[Capn Craig]

You didn't say if your engines are 185hp or 200hp. I don't have my engine book with me, but I believe the difference between them is aftercooling. Both are turbo. That said, mine are 200hp Perkins in a 1982 34LRC. The Tranny is a 1.52 ratio. Shafts are 1 1/4" and props are 21x21 3 blade. The 1 1/4" shafts are a bit unusual for 21" props. Normal would be 1 3/8 or 1 1/2". The boat brocure said it came with 21 x 22 3 blades. No mention about shaft size. An interesting feature of mine is that the struts are 2"ID x 5 1/2" long. The only 1 1/4" ID x 2" cutlass bearings I can find are 5"long. 1 1/2"ID cutlass bearings can be had 5 1/2" long. The boat came with 5"long bearings and that is what I replaced them with. The 5" will work fine, But it makes me wonder if the original shafts were replaced. I suspect that Californian varied the tranny retios by horsepower in order to keep prop sizes common accross all engine options, Perkins at least. That is a theory, not confirmed. If that were true, and your engines 185hp, maybe your ratio is slightly higher than 1.52.

 

[Edelweiss]

Got a bit of a problem and need some information to help sort this out. Currently Spirit is sitting in Yakutat, AK due to weather in the Gulf of Alaska. The last three weeks I spent cruising her up from Everett, WA. During my trip from Elfin Cove to Yakutat I hit a piece of wood that set the port propeller to vibrating. I should have put her on the grid and pulled the prop prior to leaving but I had a serious case of get-home-ittis. My boat is a 1979 34 LRC with twin Perkins T6.354 engines and Borg Warner Velvet Drives (I assume 72C). Currently she has 3 blade 20" dia props with a 20 pitch. If she has a 2:1 gear ratio, boatdiesel is recommending 23" diameter 20 pitch prop.

Does anyone know what the standard gear ration was installed into our boats and what the standard propellor shaft diameter is?

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If they are factory stock, should be either 1 3/8" or 1 1/2" shafts, the gearing of your VD trans. is on a plate on top of the tranny and the wheels are anyones guess, but the only way to accurately know what you've got is to pull the prop. A diver would be a good investment.

A 23" diameter sounds a little big and you may not have the proper hull clearance. Don't worry what boatdiesel says, they didn't build the boat. Unless there is some performance issue, leave the props as built.
Larry B

 

[C lectric]

Do not change your propellor based on the Boatdiesel Calculator.

Although it has helped many and is a usefull tool it CANNOT be taken verbatim.

If you wish to pursue a prop change wait untill you are home and STUDY ALL the threads and ARTICLES about props. There is a lot to it and you need to do some serious testing, not necessarily expensive, before any changes are made or you may make an expensive, disappointing mistake.

 

[FlyWright]

Alaskahick,

I'm going through something similar here with our 1977 34 Californian LRC. I hit a couple of logs this winter and have a vibration, so I had a diver pull the props and am having Prop Scan tuning completed today. Tomorrow they go back on the boat.

I know that I have 1 1/4 inch shafts, the Perkins 4.236 85HP engines and 20x18 3-blade props. One is stamped with a 1976 date, so I suspect they are original equipment. My CR2 BW Velvet Drives are 2:1 ratio. Don't know if this helps you with your particular engine/tranny pair, but if Capt. Craig has the same shafts and prop diameter on his 200 HP 1982 Californian, maybe it was a standard shaft size and prop diameter when paired with the Perkins engines.

CHC, are your Detroits original equipment or a retrofit? Yours is a Wellcraft model, so maybe they offered different engine choices than Marshall.

 

[chc]

I am assuming that they are original. The starboard engine has about 4000 hrs; the port was replaced by the PO about 1000 hrs ago. As far as I can tell, I am the 3rd owner. That would work out to about 140 hrs a year. Don't have any logs, so I'm guessing. I put 400 hrs on the boat in 2010, so that skews things a bit as well.

 

[Edelweiss]

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If they are factory stock, should be either 1 3/8" or 1 1/2" shafts, the gearing of your VD trans. is on a plate on top of the tranny and the wheels are anyones guess, but the only way to accurately know what you've got is to pull the prop. A diver would be a good investment.

A 23" diameter sounds a little big and you may not have the proper hull clearance. Don't worry what boatdiesel says, they didn't build the boat. Unless there is some performance issue, leave the props as built.
Larry B

_____________________________________

P.S. Forgot to mention how mine are setup

6.354 na's 130 HP, VD trannys are 1.5 ratio and shafts are 1 3/8", wheels are three blade 21" x 22

 

[FlyWright]

..I put 400 hrs on the boat in 2010...

That's some serious use! I'd LOVE to be able to put on 400 hrs in a year! Maybe next year...

 

[Alaskahick]

Thanks for the info guys. My Perkins have aftercoolers but have been told that they are only 185 hp. The Borg Warner transmissions do not have the plate attached to either one. I'll have to look at them closer in the future to determine exactly what I have.

I have contacted a person in Yakutat to see if there is a diver in town. The problem is, Yakutat is a village of about 700 people and the only access is boat or plane. Not many options. Worst case is I spend $500 on a plane ticket, put the boat on their grid pull the prop myself (like I should have done in the first place) and haul it back to town with me. I am almost positive that no one in town repairs these props.

The vibration varies depending on load. I noticed that by upping the rpms on the starboard engine I can reduce the vibration on port prop. I sure hate to put addition stress on things especially since the run from Yakutat to Seward is 315 nm accross the Gulf of Alaska. No harbors in between. Cordova is out of the question because the channel accross Strawberry is constantly changing.

Best bet is that I find a diver for less that $500.

 

[Edelweiss]

Thanks for the info guys. My Perkins have aftercoolers but have been told that they are only 185 hp. The Borg Warner transmissions do not have the plate attached to either one. I'll have to look at them closer in the future to determine exactly what I have.

I have contacted a person in Yakutat to see if there is a diver in town. The problem is, Yakutat is a village of about 700 people and the only access is boat or plane. Not many options. Worst case is I spend $500 on a plane ticket, put the boat on their grid pull the prop myself (like I should have done in the first place) and haul it back to town with me. I am almost positive that no one in town repairs these props.

The vibration varies depending on load. I noticed that by upping the rpms on the starboard engine I can reduce the vibration on port prop. I sure hate to put addition stress on things especially since the run from Yakutat to Seward is 315 nm accross the Gulf of Alaska. No harbors in between. Cordova is out of the question because the channel accross Strawberry is constantly changing.

Best bet is that I find a diver for less that $500.

_______________________

Too bad you don't know the shaft size for sure, you could pickup another prop and take it with you. Make sure someone has a prop puller or take one with you. They can be a bear to get off sometimes.
Good luck
Larry B.