New to me CMB

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Swamp Thang
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New to me CMB

Post by Swamp Thang » Sat Oct 08, 2016 8:31 pm

Finally got my dream boat, No such thing as the perfect boat but this is about as close as it gets for me.... I think :D . It's a 14x8 Diamondback 5 seater - removable front triple, all stainless rigging, 30 inches deep at the rear corners, Century 2 to 1 belt drive, Sensenich 80 inch 3 blade R prop, aluminum trailer. Bought it without an engine, was thinking about a twin turbo LS but after talking to Nevin about the turbo power I have come to my senses and decided to go with a big block. I've been looking at a 632 Dart block, AFR alum. heads, hydraulic roller and forged internals with a low lift cam that makes about 775 ftlbs of torque at 4300 rpms and about the same hp at 5100 or so. Might need to add a blade and a long hub to tame the beast but will have to wait and see? This engine package will definitely put me over budget but I Dam sure don't want you AC motor guys Pointing and Laughing at the Newbie with the overweight/under powered CMB gettin' stuck on some dry ground :stirpot:
The green one is my Kennedy with a GPU 220, it's a great boat but the aluminum CMB will be better for my type of use.
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db9.jpg
db2.jpg
db7.jpg

Swamp Thang
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Re: New to me CMB

Post by Swamp Thang » Sat Oct 08, 2016 8:33 pm

The Kennedy.
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PAINKILLER
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Re: New to me CMB

Post by PAINKILLER » Sat Oct 08, 2016 8:34 pm

:thumbleft: looks good
1st Corinthians 13:4-5 :rebel:

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Re: New to me CMB

Post by SWAMPHUNTER45 » Sun Oct 09, 2016 10:01 am

I would think a 14ft boat would be better served with a LS3 / LS7 platform due to weight. Five people in a 14 with a BBC don't sound to safe or forgiving.

If your set on a BBC and big inch engine, I recently found a new 632 short block assembled by Dart for < $5000 PM if you want the lead.

If you have never run a engine over 502cid your in for a new way of thinking, heads, porting and low lift flow are ultra critical and low rpm torque is like trying to find Bigfoot with some platforms. Big hogged out race heads will fall on their face with low rpm torque. Cam selection is another huge component to match and don't believe all you read on the "majic dyno" a lot of it is bullshizt.

The proof is in the prop!

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Re: New to me CMB

Post by GMAC 76 » Sun Oct 09, 2016 10:05 am

Swamp Thang wrote:The Kennedy.
man that hull sets nice and high in the water............unless its on the bottom???

Swamp Thang
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Re: New to me CMB

Post by Swamp Thang » Sun Oct 09, 2016 7:43 pm

PAINKILLER wrote::thumbleft: looks good
Thanks PK. I can't wait to get it running.

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Re: New to me CMB

Post by Swamp Thang » Sun Oct 09, 2016 8:46 pm

SWAMPHUNTER45 wrote:I would think a 14ft boat would be better served with a LS3 / LS7 platform due to weight. Five people in a 14 with a BBC don't sound to safe or forgiving.

If your set on a BBC and big inch engine, I recently found a new 632 short block assembled by Dart for < $5000 PM if you want the lead.

If you have never run a engine over 502cid your in for a new way of thinking, heads, porting and low lift flow are ultra critical and low rpm torque is like trying to find Bigfoot with some platforms. Big hogged out race heads will fall on their face with low rpm torque. Cam selection is another huge component to match and don't believe all you read on the "majic dyno" a lot of it is bullshizt.

The proof is in the prop!
Thanks SWAMPHUNTER, I hear ya on the weight issue and until recently the plan was an LS but this is a Big 14 foot boat and even though it is a five seater it will rarely have more than two in it. One of the first things I did when I got it home was to remove the front seat, an over weight boat is a pig no matter how much power is on it and that's the main reason for not taking a full load of people most of the time, not that I don't enjoy taking a group but there is nothing better than running a light boat in shallow water :D
The car motor stuff is new to me but I've been doing quite a bit of research and the builder I'm considering is telling me the same things you're saying about the components being very critical for the low rpm torque needed for an airboat, he recommended a "School Bus" cam and a low dual plane intake with the 335 runner heads. I've still got some research to do before the order is placed.
That sounds like a good price on the short block, do you know what internals it has?

PS I didn't think that Safe or Forgiving were in the airboater's vocabulary LOL Looking forward to riding with you guys , I recently bought a water front lot with a ramp about a 1/4 mile north of the Turner camp slide and also do a lot of fishing out of Ozello.

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Re: New to me CMB

Post by Swamp Thang » Sun Oct 09, 2016 9:00 pm

GMAC 76 wrote:
Swamp Thang wrote:The Kennedy.
man that hull sets nice and high in the water............unless its on the bottom???
Yes Greg, it's floating in that pic. I hate to sell it but there's just not enough time for two, it will be missed :cry: If airboating was my only hobby there would definitely be more than one in the yard but fast out board flats boats are hard for me to give up, I've got a 20 foot custom Sleekcraft with a 300 merc. and in the middle of a 23 ft custom Eliminator Daytona project with twin 300's which will also be a flats/pleasure boat.

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Re: New to me CMB

Post by SWAMPHUNTER45 » Sun Oct 09, 2016 9:50 pm

Price just went up to 6k but still hell of a deal

632cid
Bore: 4.600"
Stroke: 4.750"
Block: Dart Big "M" Sportsman
Main Caps: Ductile Iron 4-Bolt (all 5 positions)
Main Cap Bolts: Dart
Crankshaft: Midwest Racing Ind. Billet Steel
Pistons: Howards Racing Components ProMax Forged 2618
Piston Dome Type/Volume: -3cc Flat Top
Compression: 11.4 w/110cc, 10.6 w/119cc, 10.3 w/124cc heads
Connecting Rods: 6.700" Callies CompStar 4340 Steel H-Beam (Bushed)
Connecting Fasteners: ARP L-19 Capscrews
Rings: Howards HRC True Seal Plasma Moly
Crank/productinfo/DRT97366632/#.V_r2SfkrI0Q
Rod Bearings: Clevite (H-Series)
Main Bearings: Clevite (H-Series)
Cam Bearings: Yes (Coated)
Freeze Plugs: Brass
Balanced: Yes (Internal)

Built by DART

http://www.competitionproducts.com/Dart ... _r2SfkrI0Q

Swamp Thang
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Re: New to me CMB

Post by Swamp Thang » Sun Oct 09, 2016 10:52 pm

SWAMPHUNTER45 wrote:Price just went up to 6k but still hell of a deal

632cid
Bore: 4.600"
Stroke: 4.750"
Block: Dart Big "M" Sportsman
Main Caps: Ductile Iron 4-Bolt (all 5 positions)
Main Cap Bolts: Dart
Crankshaft: Midwest Racing Ind. Billet Steel
Pistons: Howards Racing Components ProMax Forged 2618
Piston Dome Type/Volume: -3cc Flat Top
Compression: 11.4 w/110cc, 10.6 w/119cc, 10.3 w/124cc heads
Connecting Rods: 6.700" Callies CompStar 4340 Steel H-Beam (Bushed)
Connecting Fasteners: ARP L-19 Capscrews
Rings: Howards HRC True Seal Plasma Moly
Crank/productinfo/DRT97366632/#.V_r2SfkrI0Q
Rod Bearings: Clevite (H-Series)
Main Bearings: Clevite (H-Series)
Cam Bearings: Yes (Coated)
Freeze Plugs: Brass
Balanced: Yes (Internal)

Built by DART

http://www.competitionproducts.com/Dart ... _r2SfkrI0Q
Thanks, I hadn't seen that site. Looks like a very good deal with those internals, gonna have to give them a call about a complete package price.

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Re: New to me CMB

Post by jeepinocala1111 » Mon Oct 10, 2016 6:59 am

Small block with around 500hp will do great.

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SteveReid
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Re: New to me CMB

Post by SteveReid » Mon Oct 10, 2016 2:57 pm

For the best setup advice for that boat I would talk to Tommy and, or Scooter at Diamondback because with a 2.1 belt drive you may overpower it with a big block. If it was me I would go with a 350 SBC or a 383 stroker. I have a 15x8 Diamondback with a 350 SBC rated at 330 HP and a Ch3 2.38 belt drive with 3 blad 80 R Sensenich Propellers. With 4 seats and I go anywhere I want and need to go. I took 4 big guys gator hunting in the Lake Kissimmee Marsh last month killed 2 gators went across the road crossings with ease. It really depends on whether you want a fast boat or a practical boat. JMO Chech your stand to see what will fit.

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Re: New to me CMB

Post by jeepinocala1111 » Mon Oct 10, 2016 3:04 pm

jeepinocala1111 wrote:Small block with around 500hp will do great.
Like I said :cheers:

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Re: New to me CMB

Post by HuntingBigun » Mon Oct 10, 2016 3:06 pm

welcome to the cm club and DB family, should be a great boat for my 10 cents I run a LS 550hp and up on it, great fuel ecomnomy and plenty hsp, ether way have fun and make sure the build is for a "airboat" engine not car hot rod will not live if not cam right and long runs above 3000 rpm. See ya on the pond :thumbleft:
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Re: New to me CMB

Post by Joe » Mon Oct 10, 2016 6:00 pm

Image

This is my 14x8 DB iron head and block BBC 2.68 and 3 blade S. runs good,stable with 3 - 4 people,5 gets a lil harry.
Compromise is for those that cant get it done!!

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Re: New to me CMB

Post by Swamp Thang » Mon Oct 10, 2016 10:36 pm

jeepinocala1111 wrote:Small block with around 500hp will do great.
Small block/LS is still on my mind, too many choices.

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Re: New to me CMB

Post by Swamp Thang » Mon Oct 10, 2016 11:02 pm

SteveReid wrote:For the best setup advice for that boat I would talk to Tommy and, or Scooter at Diamondback because with a 2.1 belt drive you may overpower it with a big block. If it was me I would go with a 350 SBC or a 383 stroker. I have a 15x8 Diamondback with a 350 SBC rated at 330 HP and a Ch3 2.38 belt drive with 3 blad 80 R Sensenich Propellers. With 4 seats and I go anywhere I want and need to go. I took 4 big guys gator hunting in the Lake Kissimmee Marsh last month killed 2 gators went across the road crossings with ease. It really depends on whether you want a fast boat or a practical boat. JMO Chech your stand to see what will fit.


Steve it will be mostly a play toy in the Citrus swamp along with some backwater type flats fishing on the coast, most of the time there are two guys on the front deck/rake step along with a trolling motor so the weight of the BB would help balance the boat. too light in the stearn and they don't track well using the trolling motor. I don't plan on running a lot of dry but there will be some, mainly getting to some secluded backwater ponds on the winter low tides.
As for the fast or practical.... What, I can't have both? LOL Leaning more toward fast but somewhat practical fuel mileage aside. I'm that guy who thinks too much is just right when it comes to power.
The previous owner had a SC 383 on it first but put a little too much timing in it and Boom so he and a buddy built a 496 with an estimated 600 hp and he liked it slightly better .

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Re: New to me CMB

Post by Swamp Thang » Mon Oct 10, 2016 11:18 pm

[quote="HuntingBigun"]welcome to the cm club and DB family, should be a great boat for my 10 cents I run a LS 550hp and up on it, great fuel ecomnomy and plenty hsp, ether way have fun and make sure the build is for a "airboat" engine not car hot rod will not live if not cam right and long runs above 3000 rpm. See ya on the pond :thumbleft:[/quot

Thanks Wayne, the lighter modern power of the LS is appealing. Fuel economy would no doubt be worse with the BB but if cam and tuning are correct it would be a whole lot of fun with the big torque. Been looking at the FI Tech fuel injection with the self tune but not sure if it will work well for an airboat application, more research necessary. See you in the swamp.

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Re: New to me CMB

Post by Swamp Thang » Mon Oct 10, 2016 11:29 pm

Joe wrote:Image

This is my 14x8 DB iron head and block BBC 2.68 and 3 blade S. runs good,stable with 3 - 4 people,5 gets a lil harry.
Nice ride Joe :thumbleft: Five is too many for sure on any 14 ft boat unless the side seating closer to the center of gravity of the boat is used, weight on the front sucks. My Kennedy bow steers a lot with two in the front seat but if one moves back beside the drivers seat it handles and steers much better.

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Re: New to me CMB

Post by CarMotorBarge » Tue Oct 11, 2016 6:21 am

Swamp Thang wrote:
HuntingBigun wrote:welcome to the cm club and DB family, should be a great boat for my 10 cents I run a LS 550hp and up on it, great fuel ecomnomy and plenty hsp, ether way have fun and make sure the build is for a "airboat" engine not car hot rod will not live if not cam right and long runs above 3000 rpm. See ya on the pond :thumbleft:[/quot

Thanks Wayne, the lighter modern power of the LS is appealing. Fuel economy would no doubt be worse with the BB but if cam and tuning are correct it would be a whole lot of fun with the big torque. Been looking at the FI Tech fuel injection with the self tune but not sure if it will work well for an airboat application, more research necessary. See you in the swamp.
Been using a Holley HP EFI on my airboat. I have an LS3, but the system will work with a BBC. The system self learns the fuel table and you can set the AFR and timing tables. If you can post on SA, you have enough computer skill to use the system. The rest is understanding engines.
14x7.5 Al David hull with 14 inch transom
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SteveReid
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Re: New to me CMB

Post by SteveReid » Tue Oct 11, 2016 7:00 am

Steve it will be mostly a play toy in the Citrus swamp along with some backwater type flats fishing on the coast, most of the time there are two guys on the front deck/rake step along with a trolling motor so the weight of the BB would help balance the boat. too light in the stearn and they don't track well using the trolling motor. I don't plan on running a lot of dry but there will be some, mainly getting to some secluded backwater ponds on the winter low tides.
As for the fast or practical.... What, I can't have both? LOL Leaning more toward fast but somewhat practical fuel mileage aside. I'm that guy who thinks too much is just right when it comes to power.
The previous owner had a SC 383 on it first but put a little too much timing in it and Boom so he and a buddy built a 496 with an estimated 600 hp and he liked it slightly better .[/quote]
When I read what you had my mind was thinking you had a Ch2-2.1!

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Re: New to me CMB

Post by airboat83 » Tue Oct 11, 2016 11:34 am

I am the previous owner and I had a blue print 383 with a blower and didn't work out to well. Then I had an all forged 383 from whites and did very well considering the weight. The bb was a better engine for the boat but ls would do good to I'm sure. That belt is a 2.3 gear not a 2.1. good luck :thumbleft:

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Re: New to me CMB

Post by Swamp Thang » Tue Oct 11, 2016 10:03 pm

CarMotorBarge wrote:
Swamp Thang wrote:
HuntingBigun wrote:welcome to the cm club and DB family, should be a great boat for my 10 cents I run a LS 550hp and up on it, great fuel ecomnomy and plenty hsp, ether way have fun and make sure the build is for a "airboat" engine not car hot rod will not live if not cam right and long runs above 3000 rpm. See ya on the pond :thumbleft:[/quot

Thanks Wayne, the lighter modern power of the LS is appealing. Fuel economy would no doubt be worse with the BB but if cam and tuning are correct it would be a whole lot of fun with the big torque. Been looking at the FI Tech fuel injection with the self tune but not sure if it will work well for an airboat application, more research necessary. See you in the swamp.
Been using a Holley HP EFI on my airboat. I have an LS3, but the system will work with a BBC. The system self learns the fuel table and you can set the AFR and timing tables. If you can post on SA, you have enough computer skill to use the system. The rest is understanding engines.
Thanks CMB, I've heard nothing but good things about the Holley system and FI Tech is getting a good reputation also but still fairly new to the market.
Do you think the fuel mileage is better than a carb or about the same?

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Re: New to me CMB

Post by Swamp Thang » Tue Oct 11, 2016 10:06 pm

SteveReid wrote:Steve it will be mostly a play toy in the Citrus swamp along with some backwater type flats fishing on the coast, most of the time there are two guys on the front deck/rake step along with a trolling motor so the weight of the BB would help balance the boat. too light in the stearn and they don't track well using the trolling motor. I don't plan on running a lot of dry but there will be some, mainly getting to some secluded backwater ponds on the winter low tides.
As for the fast or practical.... What, I can't have both? LOL Leaning more toward fast but somewhat practical fuel mileage aside. I'm that guy who thinks too much is just right when it comes to power.
The previous owner had a SC 383 on it first but put a little too much timing in it and Boom so he and a buddy built a 496 with an estimated 600 hp and he liked it slightly better .
When I read what you had my mind was thinking you had a Ch2-2.1![/quote]

Sorry Steve , it is a CH3 2.3. Had a brain fart when typing the info

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Re: New to me CMB

Post by Swamp Thang » Tue Oct 11, 2016 10:15 pm

airboat83 wrote:I am the previous owner and I had a blue print 383 with a blower and didn't work out to well. Then I had an all forged 383 from whites and did very well considering the weight. The bb was a better engine for the boat but ls would do good to I'm sure. That belt is a 2.3 gear not a 2.1. good luck :thumbleft:
Thanks Jeff :D I'm very happy with the boat, hope your new one is going well. Very nice doing business with you :thumbleft:

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