350 dd

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jbtn
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350 dd

Post by jbtn »

on a 350 dd what size cfm carb for a 2 bl 350 or 500 and would you run a 2 bl on a 144 blower if i went with that thanks

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Junker
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Re: 350 dd

Post by Junker »

500 holley 2 barrel.........a blower is a waste of money without a gearbox...
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SWAMPHUNTER45
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Re: 350 dd

Post by SWAMPHUNTER45 »

The strongest DD small block that I have seen run was a lightly modified 400 out of a 1973 Caprice Classic. If I were you and wanted to stay with the sbc platform in our application I would hunt for one of those.

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glades cat
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Re: 350 dd

Post by glades cat »

If you're going to put a blower on it you're going to need a boost referenced carb. If you don't, you'll have tuning issues and run lean under boost conditions. The smallest Holley makes is a 600 cfm's 4 bbl. At 3000 rpm, you may not see high boost pressures with the stock pulleys and may have to over drive it to achieve modest pressures.
I say, build it, test it, run it.
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diamondback0320
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Re: 350 dd

Post by diamondback0320 »

My buddy runs a 450cfm 4brl with a elderbrock intake & does pretty good

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Re: 350 dd

Post by diamondback0320 »

That's a Holley 450cfm

Olf Art
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Re: 350 dd

Post by Olf Art »

You could add a belt reduction with a whole lot less grief and expense than a supercharger, keep your existing rigging, and just add a blade to your prop. The direction of rotation wouldn't change. Just a thought.
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jbtn
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Re: 350 dd

Post by jbtn »

Thanks for the help i can get a 144 blower for about 1200 but the cheapest belt box or gear drive ive seen on here is about 2200 but i think reduction is best route thanks

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Re: 350 dd

Post by SWAMPHUNTER45 »

I spent a lot of time looking into the Paxton / Vortec type of Supercharger for a DD Cadillac application. The bottom line is your wasting your money on a blower for DD it is not going to give you a good HP your looking for from boost at sub 3000 rpms.

For $400 you can have nitrous that gives you 125 hp at a push of the button. Not the perfect solution but there when you need the surge to break ground.

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Re: 350 dd

Post by Tw96 »

What is the average cost of building a dd 350?

Olf Art
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Re: 350 dd

Post by Olf Art »

Tw96 wrote:What is the average cost of building a dd 350?
I met a guy once who used 350 DD's for froggin' and fishing. He said that he had several that he'd bought for around $200 bucks apiece out of wrecked cars when he found one, and he said he'd run one until it started being a problem and then he'd hang another one on his old boat. The only 'special' thing he added was just the prop adapter ...... everything else was bone stock. Add things like a better intake manifold, headers, a better carb, and a few other performance items and the cost can go up fast, but a man can go to the river cheap if you don't need to be fancy. :)
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Tw96
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Re: 350 dd

Post by Tw96 »

I want something not too expensive and be able to still go out fishing shallow and ride around.but this is my first airboat build so wish me luck

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Re: 350 dd

Post by Olf Art »

Tw96 wrote:I want something not too expensive and be able to still go out fishing shallow and ride around.but this is my first airboat build so wish me luck
A DD will do all of that for you. The secret is to not let it gat too heavy, so just a couple seats, a single battery, and it'll take you anywhere you need to go on the water. Run good viscosity oil in it too ..... all the load will be against the thrust bearing on your engine's crankshaft. Good luck!
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mojoe
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Re: 350 dd

Post by mojoe »

X2 with everything Olfart said.

I ran a dd350 on a deep sided glass hull for 5 years. Great boat. Went anywhere there was any water. Great to fish and frog and gator hunt. Quiet. Reliable. Great gas mileage.

Eventually I couldn't stand not being able to go anywhere I wanted and switched to an 0-540 on an aluminum hull... But that glass DD boat was a really good boat.

Just keep it light as possible.... Be safe... And HAVE FUN!
Mark 7:9

Olf Art
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Re: 350 dd

Post by Olf Art »

mojoe wrote:
I ran a dd350 on a deep sided glass hull for 5 years. Great boat. Went anywhere there was any water. Great to fish and frog and gator hunt. Quiet. Reliable. Great gas mileage.
Eventually I couldn't stand not being able to go anywhere I wanted and switched to an 0-540 on an aluminum hull... But that glass DD boat was a really good boat.
Just keep it light as possible.... Be safe... And HAVE FUN!
My first airboat was a 350 DD, and like you said, if there's water you can go. I really enjoyed that old boat. It would run a long time on 10 gallons of 87 octane, and it always got me home. It taught me a lot about driving, and about Florida waters. The engine was mounted on an old 13' Gilleo hull so I had to be pretty careful if the water got at all choppy, but it was a speck fishin' machine and it gave me a lot of good memories. 8)

Like Swamphunter45 said above, a GM 400 small block makes a fine DD motor and if you shop around you might be able to find one for not a lot of money. Don't buy one that somebody says they've "rebuilt" ..... they're usually trouble. Pull one out of an old Chevy or Pontiac that's been out of the weather someplace, clean it up, and run it. If the Lord lets me build one more airboat it'll probably be a 400 SBC-DD on a 13' hull. It should do everything I want to do, and I'll be able to buy gas for it at the same store where I fill up my old GMC tow truck. 8)
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