350 DD boat

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Barefootduck
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Re: 350 DD boat

Post by Barefootduck »

SWAMPHUNTER45 wrote:I believe that every engine based on it design and component spec will respond differently.

In testing and real world use I can tell you that in a direct drive application that getting 25 to 35 additional "pound foot" of torque is noticeable on the tachometer. Depending on the prop it can be an additional 40 to 150 rpm so it matters.


You go from a 305 with hours on it to a properly built 383 you will see a gain in push I am sure.

The 350 probably a small gain but more will depend on its condition and tune as the stroke is equal.

In this case 305 vs 350 it is only the additional 45 cubic inches of volume divided by 8 cylinders as the boost. A more powerful explosion but not a longer duration of power transfer.
Interesting, so I’ll see what happens when I run the 350. The 305 was stock besides an edelbrock performer intake. I’m planning on a low end cam and same intake on the 350. So we’ll see how much it improves the rpm. Get some testing going.
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SWAMPHUNTER45
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Re: 350 DD boat

Post by SWAMPHUNTER45 »

A low dual plane intake will probably serve you best. It is also recommended that long tube headers be utilized with standard size tubes. The longer narrow pipe will help to scavenge or "pull" the exhaust gasses out and with a proper cam that can aid in filling the cylinder more efficiently on the intake side of the process.

You may also try to experiment with a 2 inch spacer under the carburetor. On DD generally one with holes in it rather than an open plate. This stupid low cost modification can really help to improve your low end.

Picking a cam will be a key piece of your success. You want your power to be made from idle to 3,100 rpm
Learning to properly degree the cam will also prove to be an asset. The companies don't always grind the timing properly and I have seen cams retarded 4-6 degrees which make for a power loss.

Wish you the best with it

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Barefootduck
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Re: 350 DD boat

Post by Barefootduck »

Thanks for all the info swamp
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Barefootduck
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Re: 350 DD boat

Post by Barefootduck »

Well got the deck glued down. Covered the inside with chop strand to seal it and found out the outer stringer been replaced and they fired fiberglass way past were they had prepped it.. so I have to rip out all that old fiberglass that isn’t bonded and then level out the edge it leaves behind. Anyways happy with the one day progress, getting closer to start rigging it up.
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SWAMPHUNTER45
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Re: 350 DD boat

Post by SWAMPHUNTER45 »

Glad you found it now !

Gary S
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Re: 350 DD boat

Post by Gary S »

Thats what happens when you don't grind all the gelcoat off before you glass it in. Hope that's not how your stringer was put in.

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Barefootduck
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Re: 350 DD boat

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Gary S wrote:Thats what happens when you don't grind all the gelcoat off before you glass it in. Hope that's not how your stringer was put in.
Lol they didn’t even rough it up much less remove it to bare glass. But yea about 6in out from the stringer is correct and bonded. They just went way farther out with the glass for some reason. Maybe it was done after the stringers? I’m not sure but either way stuff that isn’t bonded is coming out
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Barefootduck
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Re: 350 DD boat

Post by Barefootduck »

Any advice on where to locate seats, gas tank, and engine to avoid hopping from the start? I have a basic idea from seeing other boats as well as my other one just barely likes to hop, but then again it only hit just over 30mph In deep water. Also that was rear steer and I want to do front steer for this one. Just don’t want to use a trim tab or have to do a bunch of moving stuff around after the fact. Any input would be great thanks
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Re: 350 DD boat

Post by SWAMPHUNTER45 »

Any chance you could use the fuel cell as a ballast. I have seen guys have the tank mounting where it can slide fore and aft to tune the weight balance? Once they get the sweet spot they bolt it down.

I have heard of using a pipe on the ground to check a boats balance point.

We generally eye it up and tune from there.

I like to have the prop a good beer can from the transom for the prop.

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Barefootduck
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Re: 350 DD boat

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SWAMPHUNTER45 wrote:Any chance you could use the fuel cell as a ballast. I have seen guys have the tank mounting where it can slide fore and aft to tune the weight balance? Once they get the sweet spot they bolt it down.

I have heard of using a pipe on the ground to check a boats balance point.

We generally eye it up and tune from there.

I like to have the prop a good beer can from the transom for the prop.
Yea I can make somthing like that up, how much do you think it would need to be able to move back and forth? A foot? Or a few feet? And supposed to rain this weekend so not sure how much I’ll get done but hope to get the deck completely done besides the lid, and some more of that delaminates glass out. On a side note this was my dads boat when I was a kid, 500 caddy, the hull shape looks like the gilileo I have now
Photo was taken in 2008. Yes I was young and am only 22 now. Lol
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Slidin Gator
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Re: 350 DD boat

Post by Slidin Gator »

Barefootduck wrote:On a side note this was my dads boat when I was a kid, 500 caddy, the hull shape looks like the gilileo I have now
Photo was taken in 2008. Yes I was young and am only 22 now. Lol
Dang Duck, were you driving that boat to Mars back then? Straighten that pic up, it hurts my neck :scratch:

Looking good man.
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Barefootduck
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Re: 350 DD boat

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Slidin Gator wrote:
Barefootduck wrote:On a side note this was my dads boat when I was a kid, 500 caddy, the hull shape looks like the gilileo I have now
Photo was taken in 2008. Yes I was young and am only 22 now. Lol
Dang Duck, were you driving that boat to Mars back then? Straighten that pic up, it hurts my neck :scratch:

Looking good man.
Lol I thought I was
Thanks
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Scotty1
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Re: 350 DD boat

Post by Scotty1 »

:rebel: looks like it says alumitech or something like that on the rear there. :rebel:

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Barefootduck
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Re: 350 DD boat

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Scotty1 wrote::rebel: looks like it says alumitech or something like that on the rear there. :rebel:
Yeah that’s what it said. Did they make fiberglass hulls? Counter intuitive I would think. It does look exactly like my gilileo so maybe someone just put the sticker on it?
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Re: 350 DD boat

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Well the deck is officially done with fiberglass. Going to have to sand it down some and get some color on it. Tabbed deck to kickpanel then second layer of chop strand over the top of deck and thicken resin with chop fibers on the deck supports and the edge of the plywood to totally incapsulate the wood. Glad it’s done. Now all I have To do is get rid of all that delaminated glass out and a few other things before I can start building the rigging.
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Re: 350 DD boat

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Progress being made changing the poly hardware to get rid of the nuts and washers that weren’t stainless and got some color on the front half of the boat. Going to go with a camo so it’s coming along
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Rick McC.
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Re: 350 DD boat

Post by Rick McC. »

Keep the pics,coming, Sir. I’m enjoying seeing your build progress!
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Re: 350 DD boat

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Rick McC. wrote:
Thu Oct 24, 2019 9:52 pm
Keep the pics,coming, Sir. I’m enjoying seeing your build progress!
I will, thanks. Kinda dragging on the fiberglass work but lookin forward you the rigging.
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Re: 350 DD boat

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Got some more poly bolts changed out and started on some of the little patches. Also started playin with the grass rake because it was raining in and out and only half the boat is covered
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Re: 350 DD boat

Post by Barefootduck »

What do you all use for motor mounts with direct drive. I have the bell housing brackets from summit I used on my 305 boat and just solid mounted those and the front. I was thinking of getting the tapered tube and come bushings to use on the rear and getting these mounts for the front? Thoughts?
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Re: 350 DD boat

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Well it’s getting close. Rub rail riveted back on with aluminum rivets. Bow eye, and hull with first coat of paint. Happy with progress. Also got the new stainless hinged riveted to the deck lid and a rubber seal around the opening. Have to get some hardware to mount it to the deck though. Also redid an old patch on the corner
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Re: 350 DD boat

Post by SWAMPHUNTER45 »

Real good to see your progress, wont be long and you can ride!

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Re: 350 DD boat

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Started the rigging got to work tonight though. Doing a shutdown so this is it for today. Rear half of engine stand tacked together, everything is the same angle and looks good to me
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Gary S
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Re: 350 DD boat

Post by Gary S »

Not trying to tell you what to do, but shouldn't you have that hull leveled and blocked solid during your rigging build?

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Re: 350 DD boat

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Gary S wrote:
Sun Nov 17, 2019 6:06 am
Not trying to tell you what to do, but shouldn't you have that hull leveled and blocked solid during your rigging build?
Yeah I hear ya, it’s blocked and doesn’t move and I was using an angle finder to match my angles as if the boat WAS level but I think when I go to build the front engine mounts and level up the engine I will definitely put it on the flat ground leveled all the way around so I’m not going back and forth from the stringers to the rigging remembering the angle that the boat is on. Lol ordered front motor mounts but not gonna be here for this weekend so not exactly sure what I’ll do this weekend on it but I’ll find something
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