Merc 454 Intake

klawton55

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Feb 23, 2011
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Hi, I have a 89 Sea Ray 24' with a 454. I have owned it going on the third year. It currently runs good, but the previous owner ran it in salt water and the intake is starting to look poor. I would like to replace it with an aluminum intake but wanted to get an opinion if the aluminum intake would be better or cause reliability issues.

Also if I go aluminum can I use an intake off of a automobile, or is there differences? Thanks for any help.
 

achris

More fish than mountain goat
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May 19, 2004
Messages
27,468
Re: Merc 454 Intake

If you're in freshwater, then use an aluminuim intake by all means, but if you ever put in salt water.... Go cast iron.

Off a car engine? Would be better a truck engine. Car engines tend to be tuned more towards top-end where as truck engine tune is much closer to a boat engine, nice flat torque curve without the nasty peaky bits...

Chris..........
 

RogersJetboat454

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Jul 9, 2010
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Re: Merc 454 Intake

A dual plane with long runners would suit you well. Just make sure you match the intake to the style of intake ports the heads on your engine has (either oval port which it most likely is, or square port).
 

klawton55

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Feb 23, 2011
Messages
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Re: Merc 454 Intake

Thanks for the help. After looking at different intake setups I assume that I would not want a high rise as that will push the torque curve past the rpm range of a boat. Is that correct?

I have posted a picture of the intake. I believe that my intake is square but thought I would make sure.20121227_155641.jpg
 

klawton55

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Re: Merc 454 Intake

Thanks for all of the information and help! KL
 

klawton55

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Feb 23, 2011
Messages
116
Re: Merc 454 Intake

I like the intake that the link goes to. But I am unsure if how much choke would mount on the new intake. I have added a picture of my intake. Would my choke mount on the new intake or is there something else that I can do?


image.jpg
 

Bondo

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Re: Merc 454 Intake

I like the intake that the link goes to. But I am unsure if how much choke would mount on the new intake. I have added a picture of my intake. Would my choke mount on the new intake or is there something else that I can do?


View attachment 178492

Ayuh,.... You'll have to convert the carb to an Electric Choke, insteada a stove choke...
 

klawton55

Petty Officer 2nd Class
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Feb 23, 2011
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116
Re: Merc 454 Intake

What exectly does that require? Is the power wire straight from the batt? And how would the choke mount to the carb?
 

Bondo

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Re: Merc 454 Intake

What exectly does that require? Is the power wire straight from the batt? And how would the choke mount to the carb?

Donno,.... ya didn't say which carb ya got.... probably an ole Quadra-jet...

It's old enough,... I'd just buy a matchin Edlebrock, with an electric choke, for yer new intake,....

Electric chokes are usually wired into the ignition circuit...
 

Speakrdude

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Feb 25, 2004
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942
Re: Merc 454 Intake

(It's the unused purple wire thats laying there all wire tied up with a connector on the end)
 

klawton55

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Feb 23, 2011
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Re: Merc 454 Intake

I believe that it is a carter. I had it rebuilt last year and had thought it was a guadrajet but he said it was a carter. By that sounds of it it's not too involved. I am excited to start buying parts. I have boatin fever!
 

RogersJetboat454

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Re: Merc 454 Intake

I believe that it is a carter. I had it rebuilt last year and had thought it was a guadrajet but he said it was a carter. By that sounds of it it's not too involved. I am excited to start buying parts. I have boatin fever!

Post a picture.
Carter built some Quadrajets under contract with Rochester.
 
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