• If you log in, the ads disappear in the forum and gallery. If you need help logging in or getting registered, send request to: webmaster@southernairboat.com

350 DD boat

Barefootduck

Well-known member
Got a new hull to start fresh and put my 350 on. Going to start Cleaning up the hull and paint it in the next few weeks. 12ft gililoeo
 

Attachments

  • BC5F0F82-05BB-44A7-836D-A0C7419D3704.jpeg
    BC5F0F82-05BB-44A7-836D-A0C7419D3704.jpeg
    1 MB · Views: 7,724
  • 71DEA4CA-77F3-4990-AA41-889CEAC7D6DF.jpeg
    71DEA4CA-77F3-4990-AA41-889CEAC7D6DF.jpeg
    1.3 MB · Views: 7,724
  • 89321D7F-2D59-4F6F-A7B4-5BFDD8443875.jpeg
    89321D7F-2D59-4F6F-A7B4-5BFDD8443875.jpeg
    1 MB · Views: 7,724
Re cam it with a Mellings CS-711 camshaft, a set of 305 Truck heads or if you can find a set of 267 small block heads even better, a stock 305 egr 4 barrel aluminum intake adapted to a 390 Holley with a secondary metering plate jetted 65 primary and 72 secondary will snap a 72" prop hard.
 
kwanjangnihm said:
BFD did you make any mods to the 350?

No not yet, it has an edelbrock performer Intake. Supposedly a GM performer crate motor. I was going to change the cam and run it see how it does. I have the 305 that I’ve been running so y’all are saying I could use those heads? The 305 is Out of a 85 c10. Have a 72x36 stick prop that I’ll be running so that’s what I’m trying to be able to spin up.
 
Got started on the hull. Removed the old deck because some rot, but forgot to take a picture after the actual wood was removed. Lol the glass was delaminated so bad a cut around and a pulled removed it from the wood. new one cut out, ordered resin and already have the glass. The kickpanel part of the deck is still good. Also glued in some wooden dowel rods into the old rigging holes, and will be running a piece of glass over them. Poly looks to be pretty new.. the old rigging had some homemade stringer jacks, are they worth having them on fiberglass hull? Did some searching on here and either glass or aluminum said it helped on dry, and even in the deeper water. Just curious
 

Attachments

  • C4B82455-2668-4974-B9C5-218BD47C0C15.jpeg
    C4B82455-2668-4974-B9C5-218BD47C0C15.jpeg
    1.1 MB · Views: 7,654
  • 143B4698-EC35-462C-93AC-FE9AC724F6C5.jpeg
    143B4698-EC35-462C-93AC-FE9AC724F6C5.jpeg
    977.2 KB · Views: 7,654
  • 86352ECF-0A22-4064-BE8C-98A723CBBDC7.jpeg
    86352ECF-0A22-4064-BE8C-98A723CBBDC7.jpeg
    1 MB · Views: 7,654
  • 621A76E9-70CD-404C-A465-044BA8D6B33B.jpeg
    621A76E9-70CD-404C-A465-044BA8D6B33B.jpeg
    859.5 KB · Views: 7,654
John Fenner said:
Re cam it with a Mellings CS-711 camshaft, a set of 305 Truck heads or if you can find a set of 267 small block heads even better, a stock 305 egr 4 barrel aluminum intake adapted to a 390 Holley with a secondary metering plate jetted 65 primary and 72 secondary will snap a 72" prop hard.
Is the edelbrock performer aluminum intake similar?
 
The 305 heads have smaller combustion chambers so you get higher compression. Depending on how willing you are to pay for premium fuel, you are looking for 58 cc chambers and flat top (max compression) or dished pistons (a bit lower compression). Doomed pistons will put you into race or Aviation fuel. 305 heads also have smaller runners so you get higher velocity at DD rpm’s.

Pull off the valve covers and find the casting number to look up what you have. Here is one link:
https://outintheshop.com/faq/casting/heads.html

The Edelbrock Performer should work fine, is it a square or QJet pad? Don’t be afraid of an adapter spacer, that will help make torque.

Follow Johns input on carb and cam for max performance. The Q jet you are running on the 305 will also work if tuned right, but it’s a bit big for the application, like you have already learned.

Sounds like you have most of what you need to make a fine motor. Quit being cheap on the prop though. Save your pennies for a carbon fiber prop and make a wall hanger out of that stick, you will be glad you did.
 
airduds said:
Best of luck but you won't run the hill with that combo.

Right on, been running a 305 on a heavier hull turning that prop 2200-2300 so it can only get better lol.
Plan to run this awhile then sell and go reduction or A/C but that will be in the future. Just getting started in this so it is what it is
 
Didn’t get as far as I wanted because I decided to cut out the wood in the kick panel good thing I did the bottom was rotted out underneath the tabbing so made the new wood coated in resin and got the deck coated and layer of glass on the bottom. Next weekend will be the install of kickpanel and deck tabbing and dealing with glass hopefully
 

Attachments

  • 0080F5D3-6358-4939-AFCB-96D71C2A084C.jpeg
    0080F5D3-6358-4939-AFCB-96D71C2A084C.jpeg
    963.6 KB · Views: 7,503
  • 0F85310A-6D7B-4336-BC4D-39E222BEC341.jpeg
    0F85310A-6D7B-4336-BC4D-39E222BEC341.jpeg
    918.3 KB · Views: 7,503
  • 946B92B3-A030-4F75-A4D6-56A83785985F.jpeg
    946B92B3-A030-4F75-A4D6-56A83785985F.jpeg
    847.5 KB · Views: 7,503
  • E9C368A2-4627-44F4-A226-57DBE993D65A.jpeg
    E9C368A2-4627-44F4-A226-57DBE993D65A.jpeg
    1.1 MB · Views: 7,503
What would be the best prop for a SB DIrect drive. I have been reading posts about waterthunders Dd ls and he ran a short three blade carbon? Apparently producing thrust up to 3500 rpm? Anyone have any input of this or know more about it. Now I’m not saying I would be pushing the HP or torque he was but a prop that is safe and still producing thrust over 3k rpm would help in any DD application. I’m just curious to be looking for an alternative when I get the boat going again and want to upgrade from the woody.

Thanks
 
Side note, started glassing in the kick panel maybe this weekend I’ll finish up the deck.
 

Attachments

  • 96B63BBF-8AE8-4711-AE18-62FE0F0946F8.jpeg
    96B63BBF-8AE8-4711-AE18-62FE0F0946F8.jpeg
    904.5 KB · Views: 7,086
First layer of tabbing
 

Attachments

  • D2CB20E2-2775-4BCD-B394-C9CDE7596C86.jpeg
    D2CB20E2-2775-4BCD-B394-C9CDE7596C86.jpeg
    772.5 KB · Views: 7,086
  • 5E702071-A019-46C1-8809-D643F8BDFEC9.jpeg
    5E702071-A019-46C1-8809-D643F8BDFEC9.jpeg
    842.2 KB · Views: 7,086
Looks like you are making some progress with the repairs!

As far as the prop goes there are plenty of guys who have run DD 350s and 305s so search the threads. I suggest a two blade prop like a Q as it will give you the ability to adjust pitch and performs well for push and speed. Don't get hemped up on spinning it higher than what is a safe rpm or it will bite you.

Look up OleMan on here he runs a 305 with a wood prop and it does well for him.
 
SWAMPHUNTER45 said:
Looks like you are making some progress with the repairs!

As far as the prop goes there are plenty of guys who have run DD 350s and 305s so search the threads. I suggest a two blade prop like a Q as it will give you the ability to adjust pitch and performs well for push and speed. Don't get hemped up on spinning it higher than what is a safe rpm or it will bite you.

Look up OleMan on here he runs a 305 with a wood prop and it does well for him.

Yea I wouldn’t spin a prop over the specified rpm. But that’s what I was curious about because I’m sure waterthunder mentioned his turning 3500 rpm. Was somthing like a 66in? My prop says 2700 rpm max on the paperwork when I got it so that’s what I’ll stick too.

Thanks I’ll check it out
 
OneEyeGator has a chart that takes the diameter of the blade and rpm to factor blade speed. Maybe talk with him but anything Dave WT does is going to be high end. He does R&D with Sensenich so my bet is that they got him hooked up with something special.

What prop you have now Duck and why the need to change?
 
The hull jacks help tune the boats bottom so I like having the jacks in place and would keep them. It is not just a dry ground thing actually they can help a boat to stop hopping or get it off it's nose depending on where they are put and how they are applied.
 
SWAMPHUNTER45 said:
OneEyeGator has a chart that takes the diameter of the blade and rpm to factor blade speed. Maybe talk with him but anything Dave WT does is going to be high end. He does R&D with Sensenich so my bet is that they got him hooked up with something special.

What prop you have now Duck and why the need to change?

Yea if I remember right he said it was cut down. Not sure what that entails. Lol. But I have a brand new sensenich 72x36 stick. Got it last December and ran it on my 305 boat only turnin 2200 give or take. Plan was to run a 350 so that’s why i went over propped for the 305. It ran good only turnin 2200.i was just looking for future ideas you know. And yea I’m definitely going to keep the floor jacks in the new hull. Think it’s a great idea. Do you have any experience with where to locate the jacks? And I tried to find oleman on here and didn’t come up with much and nothing about a 305?

That’s the heavy boat I was running the 305 on. Someone poured resin to cover the poly bolts and it’s thick. Real thick. I built the cage and set it up last December.
 

Attachments

  • 999322A8-A3B4-4E14-A597-14791DE69E11.jpeg
    999322A8-A3B4-4E14-A597-14791DE69E11.jpeg
    1,000.1 KB · Views: 7,067
Back
Top