Prop size question

[Lumpy]

Hello,
I was checking out the underneath of the boat now that it is in the garage for the rest of the season. I found that the prop nuts were finger tight. How tight should they be? Any certain torque or what? Also, I saw on the prop it is an OJ 12x15 and it says cupped on it. Is this a prop normally used for pulling skiers or is it your standard sized 3 blade? I don't ski much any more so I am thinking this prop is killing my top end. This boat is used for cruising and hauling ass. What prop size would you recommend? I am not sure of what gears I have in my v-drive. Thanks......Lumpy

[FlatRat]

Lumpy,
I'm farely new in this but they say that the OJ brass three blade should be a paper weight.I took one off BBC Sanger flat and went from 5,500 to 6,800 rpm's.What a whole shot and top end too.

[missilemud]

Lumpy:
Hello,
I was checking out the underneath of the boat now that it is in the garage for the rest of the season. I found that the prop nuts were finger tight. How tight should they be? Any certain torque or what? Also, I saw on the prop it is an OJ 12x15 and it says cupped on it. Is this a prop normally used for pulling skiers or is it your standard sized 3 blade? I don't ski much any more so I am thinking this prop is killing my top end. This boat is used for cruising and hauling ass. What prop size would you recommend? I am not sure of what gears I have in my v-drive. Thanks......Lumpy

[FlatRat]

Oops,
I went from 12x16 brass three blade to a 12x15 steel two blade.Hallcraft box with 17 over gears.

[missilemud]

oops i mean to write something too .. ok that prop nuts should be balls tight , if there loose then good thing you found it now. i like to put a dab of silly-bone on the shaft before install,only because water gets in there.i use a lock nut on my shafts , with a little blue loc-tight

[126driver]

Lumpy - you need to find out what gear you have in the box. Don't bother tightening up that prop nut. Back it off all the way and pull that brass three-blade off. You're going to want a steel two-blade but you need to tell us what you're running for a motor first.

[Lumpy]

Thanks for the replies guys.....
126Driver,
I bought the boat in June of this year from a 70 year old guy who has had it since new. He said it is a 1969 427. He said when it was rebuilt they put a slightly bigger cam in it but thats about it. It has a single 850 double pumper on an edelbrock intake. I ran the numbers on the heads which is 3964291 and these are the specs....69-70 rectangle ports..closed.. 109cc chamber. I drove the living piss out of it this summer and it ran flawlessly. I was very impressed! I remember hearing how you can determine your gear ratio by counting the shaft rotations. Can someone please tell me exactly what I need to count and line up to figure out what gears I have? Thanks......Lumpy

[CircleJerk]

Lumpy, If that's a Casale split case, the gear ratio is stamped on the aluminum spacer-mount that the two sides bolt to. Look at the very bottom if the v-drive is out of the boat. Pulling the front case for gear inspection is a snap IF you have a top bearing puller. Super Dave sells them. It's always good to check bearings, change the oil, and check for metal fatigue or debri. Now you can remove the gears and read the stamped numbers for ratio identification. Also note if any water, rust, damage has occured. V-drives should have the oil changed every year and you may do so without pulling the cases apart by removing the very bottom bolt on the 5 or 6 bolt shift pod. it drains very slow but you have all winter right? We use Amsoil 2000 90weight gear oil in our race boats gear box and love it!
The bronze prop is for skiing under 5000 rpm so the steel blade is a good investment for speed as well as safety. Remember it's spinning more than engine rpm unless you gear ratio is 1:00. A common ratio is l:15 {fifteen percent}, 1:18, or 1:12 etc. Consequently, you can fling a prop blade and ruin your day! This is what the experts say but I have never seen a prop failure and dont want to!... Just one Jerks opinion.... :eek:PS refer to a thread entitled 'Prop Nut' for more info on that loose nut.
[ November 09, 2002, 01:45 AM: Message edited by: CircleJerk ]

[058]

Yeah... that "prop nut" thread reads like War and Peace. Everything you wanted to know, thought you knew and some things you didn't need to know are covered in that thread. :D

[126driver]

Lumpy,
Pull the gears and check everything out. That way you'll know for sure what's going on with the box. Click on the banner above and email Tom at Menkens. He'll hook you up with a prop. Probably 11.5 x 15 or something like that.

[superdave013]

126driver:
Lumpy,
Pull the gears and check everything out. That way you'll know for sure what's going on with the box. Click on the banner above and email Tom at Menkens. He'll hook you up with a prop. Probably 11.5 x 15 or something like that.Ditto, Tom at Menkens is the guy to talk and the best source of parts for your v-drive. He even sells my bearing puller so you might as well get it through him (same price even).
His props are not cheep but who's prop is these days. If you buy a new prop from him, he will make sure you get the right prop on your boat. Just ask Snowboat how Tom helped him with props.
If I'm guessing I bet a 15% gear and something in the 11.5X15 pitch range.

[Ian]

On my old flatty my prop nut came loose, but that was because the lock nut I was using was worn out, just replace your old nut with a new stainless steel lock nut and a new cotter pin. You really need to pull your v-drive apart to find out what gears you have, it's really easy to get apart, just make sure you have the proper amount of gaskets when you put it back together. As for the prop, it souds like the prop you have now is off a ski boat. A good steel three blade might be what you want, for a mild flatty they perform great. If all out speed is what you want I would go with a two blade 11x16 menkins. You can usually get a nice prop used for between 200-300 bucks, just make sure to have a prop shop check it out before you run it. When props come apart at wide open you would be lucky to stay dry, plus they usually ruin the bottom of the boat. Well now I am rambling so if you have any questions feel free to email me, I don't know much but I am more than happy to lend any knowledge I have

[V-Drive Tom]

Lumpy, You want an 11-3/8 or 11-1/2 x 16.(not 11 inch dia.) That boat of yours is large and heavy, you need the DIA. to get it moving. You will be slippin with 11. You want a 2 blade not 3,because you already established that your not so interested in skiing. (just hot roddin) ANY prop you get for 200or300,SHOULD be checked for cracks and reshaped and balanced. $120.00. The 11 1/2x16 older Stellings props are not a bad runner for the money. TOM.. :)

[Ian]

Hey lumpy if this v-drive Tom is the guy I think he is take his advise, he knows his stuff. I only speak from my own experiences, I like the 11in. prop because I can burn it and get the motor up into its powerband, but we're running a Cole runner bottom with a Norm Grimes power plant, so my own experience may not relate well to yours. You should try and find some v-drive guys close to you that will let you borrow some different props. Anyways take v-drive Tom's advice he seems to know a lot more than me

[Sangster]

058:
Yeah... that "prop nut" thread reads like War and Peace. Everything you wanted to know, thought you knew and some things you didn't need to know are covered in that thread. :D 058...Don't bring the "prop nut" thread back....It would be better if we discussed the difference between Blue & Red Loctite...If ya know what I mean... eek! eek!

[Sangster]

P.S. Listen to TOM........

[126driver]

Now let's see: The blue Locktite is for nuts that get removed all of the time, right? I keep getting that mixed up. And what is up with that Locktite primer? What the hell is that for? :rolleyes:

[Sangster]

126 DRIVER, Now you've oened up a big ole' Can of worms...... :rolleyes: :rolleyes: :rolleyes:

[126driver]

Sangster:
126 DRIVER, Now you've oened up a big ole' Can of worms...... :rolleyes: :rolleyes: :rolleyes: wink

[jechols]

Blue loctite not necessarily for removing 'all the time' but is easier than removing anything with the red loctite. Just put the blue loctite on it that will be fine it won't go any where. As far as 'loctite primer' W.T.F. your not painting a car, don't need it!