7.4l 330 hp needs a new carb what do you guys suggest
#1
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From: okotoks ab
Hey guys
so i got a 1994 baja islander with the 7.4l (454) 330 hp engine with the bravo 1. i also have captins choise exhaust on it as well. i was out this weekend and the carb has a few issues with wore out parts......Long story short i am just going to put a new carb on (plus i just want to). what do you guys suggest? Now i also have just "came" across a set of 049 heads that were rebuilt but have been sitting for awhile. I my train of thinking is that if i do the carb how about a new intake and if i am doing a intake why not throw the heads on and if i have the heads off why not throw in a cam as well. i know this a a cast engine and should not be reved past 5k and its not worth spending money on and that i should just buy something better but i cannot leave this alone and don't have time to do a full engine swap. I don't mind used parts and want to spend around 2k if it blows then it blows. what do you guys think? Any suggestions on the heads,cam,intake,carb? sorry for the long a$$ post with a few to many questions. Also i live around 3500 feet if that makes a diffrents
Thanks for the time Ryan
so i got a 1994 baja islander with the 7.4l (454) 330 hp engine with the bravo 1. i also have captins choise exhaust on it as well. i was out this weekend and the carb has a few issues with wore out parts......Long story short i am just going to put a new carb on (plus i just want to). what do you guys suggest? Now i also have just "came" across a set of 049 heads that were rebuilt but have been sitting for awhile. I my train of thinking is that if i do the carb how about a new intake and if i am doing a intake why not throw the heads on and if i have the heads off why not throw in a cam as well. i know this a a cast engine and should not be reved past 5k and its not worth spending money on and that i should just buy something better but i cannot leave this alone and don't have time to do a full engine swap. I don't mind used parts and want to spend around 2k if it blows then it blows. what do you guys think? Any suggestions on the heads,cam,intake,carb? sorry for the long a$$ post with a few to many questions. Also i live around 3500 feet if that makes a diffrents
Thanks for the time Ryan
Last edited by demax990; 05-20-2014 at 12:32 AM.
#3
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Ryan, a lot of OSO members were in your position at one time, including myself. All I can tell you is that it is a very slippery slope. Once you dive into this thing you can easily find yourself dropping $8K - $10K into it. I call it the "might as well syndrome". If I'm going to get a new carb, might as well get a new intake for it too. Well, might as well install those better flowing heads too. Oh yeah, in order to take advantage of the heads, might as well install a more aggressive cam too. Oops, my stock exhaust won't work with that nasty cam, time for some headers or performance manifolds. Cha-ching! You can get there before you know it.
A lighter boat will respond to minor increases in power more readily than something big and heavy, but you are still going to be hard pressed to realize any major gains without also spending some coin on some decent exhaust. The 049 heads can be made to flow pretty well with the installation of the larger valves and some work in the valve bowl areas, but here comes that "might as well sydrome" again!
How do you plan to use the boat? Balls out WFO throttle runs all the time, or just cruising around the lake and slinging the kids on a tube? If the latter, there is a lot to be said for leaving it stock, putting the hatch down, drinking a cold beverage, and enjoying the boat for what it is.
A lighter boat will respond to minor increases in power more readily than something big and heavy, but you are still going to be hard pressed to realize any major gains without also spending some coin on some decent exhaust. The 049 heads can be made to flow pretty well with the installation of the larger valves and some work in the valve bowl areas, but here comes that "might as well sydrome" again!
How do you plan to use the boat? Balls out WFO throttle runs all the time, or just cruising around the lake and slinging the kids on a tube? If the latter, there is a lot to be said for leaving it stock, putting the hatch down, drinking a cold beverage, and enjoying the boat for what it is.
#4
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What kind of carb is on it now - Q-jet or Weber? Once set up properly on a relatively stock 7.4L, the Q-jets are pretty much trouble-free and bullet proof. If you just have to have a new carb, a smaller Holley in the 750cfm range would be appropriate. Best to find the marine version to make sure you are USCG (and insurance) compliant.
#5
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How much does the guy want for the heads, and what kind of work do they need? The 049's have at least 119cc chambers. A good set of 820 casting heads would get you some more compression with their 114cc (I think) chambers.
#6
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From: okotoks ab
Thanks Budman, I do believe that the carb is a weber it is def not a q-jet. maybe I will put a new carb on and a new intake to match it. what do you guys like to use for carbs? demon? holley? and how about intake
#7
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I have a 715cfm Holley marine carb that would probably be appropriately sized for your setup, but it needs a rebuild. I can pull it off the shelf and look at it and see what kind of work it needs if you are at all interested. It might not need anything more than a basic rebuild kit with new gaskets, which I can handle easily.
#9
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From: AZ
It's funny because I can completely relate to what Budman is saying. I started with a 7.4 330 and figured I would just put a new carb on it. Yeah right. New carb turned into exhaust, then an intake, then a cam..... After the first cam choice, decided I was selling it short and contacted Bob Madara.... About 4 iterations later we are now solid on the final build which I'm assembling this week if time allows (625-650hp 496 stroker with callies bottom end and a fairly snotty hyd roller cam, HOLLEY HP MPFI, dry eickert headers......)
It is indeed a slippery slope. There is something to be said for a stock 330. They run forever as long as the exhaust manifolds don't spring a leak. If that's good enough, I would say leave it. Now if you have the time and money to make it into something faster that you might enjoy that much more,by all means research and find the best way to achieve your goals. I came from a drag racing and automotive restoration background prior to really getting into boats. It truly is 3 times as expensive... Good luck!
It is indeed a slippery slope. There is something to be said for a stock 330. They run forever as long as the exhaust manifolds don't spring a leak. If that's good enough, I would say leave it. Now if you have the time and money to make it into something faster that you might enjoy that much more,by all means research and find the best way to achieve your goals. I came from a drag racing and automotive restoration background prior to really getting into boats. It truly is 3 times as expensive... Good luck!
Last edited by Borgie; 05-21-2014 at 09:41 AM.
#10
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From: Fox Island, WA
The Carburetor Shop in Ontario California is a great place to get your carb rebuilt.
If you want to go faster it might make more sense to find another boat that
performs to your satisfaction. I chased 5 m.p.h. in another boat with twin SBC
in the past. As BORGIE stated above, EXPENSIVE! This time I picked a top speed
that was more than enough to satisfy and shopped for a boat that performed at that level.
If you want to go faster it might make more sense to find another boat that
performs to your satisfaction. I chased 5 m.p.h. in another boat with twin SBC
in the past. As BORGIE stated above, EXPENSIVE! This time I picked a top speed
that was more than enough to satisfy and shopped for a boat that performed at that level.


