Supercharger, would you?

f_inscreenname

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For the people who know me here know I have done everything possible to my I/O motor (Mopar 360ci) to suck out every HP I could get. But now I am at kind of a “wall”. There isn't much else I can do short of yanking the whole thing out and starting over with a big block. If I do buy a big block I will also have to look for a place to live (the wife know how much $$$ I have in the 360 small block now). Then I started looking into superchargers. The kind that bolts to the front of the motor and runs off a pulley and belt (not the roots style) and has a 3” hose from it to the carb. Anyone run one of these in a boat? Any reason not to?? Thanks
 

Scaaty

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Re: Supercharger, would you?

I'd do it...simple. No extra weight. Plenty of room? Would think you just need to fatten the head gasket for a lower C/R..sounds cheaper than a new wife too! Look into Summit or Jegs, or, since we aint used to it yet (or just forget) google it.
 

f_inscreenname

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Re: Supercharger, would you?

Hey DD;<br /> A little big for what I need. This is more on the line I am looking for http://www.thesuperchargerstore.com/products.html <br />Seems like you just bolt on and go. With no real experience with superchargers I thought I would run it past my friends at iboat’s before find one and put out the cash. The saddest thing about all this was I could have bought a roots style blower when I first bought my boat 4 years ago. Get this, the total price for the whole kit shipped to my door, $400.00. I have been kicking myself everyday for missing that one. You can never find one for a Mopar small block and if you do you will pay for it and I mean PAY.
 

Bondo

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Re: Supercharger, would you?

Most of the blowers like your talking about, that I've seen are for EFI........<br /><br />The Problem you're going to have is, You'll need a Carb Box to blow thru........<br /><br />You can't just hook it to the carb intake,<br />It'll Blow gas out of the carb..... No Vacuum for the carb to work off.....<br /><br />In other words, You have to pressurize the Whole Carb..... <br />Not saying it Can't work, But it's Much More Complicated with a carb.....
 

vrod2002

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Sep 17, 2004
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Re: Supercharger, would you?

Hey Mark sounds like you got 2mph itis! Remember what brownie told you? Your maxed out for speed unless you change your lower unit! Volvos,early 270'although excellent drives just cant push past 65mph.Thats what i'll be happy with when i'm done!<br />Every thing is a trade off. Your boat is unique,handles extremely well for a 19ft in rough water and has great sound!My harley buddys down here have the same problem.<br />theve got there motors up to 131inch(stock 80-95inch), and those little weedeater-crotchrockets just eat them alive! :mad: I've got a yamaha gp1200 two seater for sale with afters on it if your interested!You can drag it behind that classic for under 3 grand!<br />Your buddy<br />Barry
 

f_inscreenname

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Re: Supercharger, would you?

Hummmmmm.. EFI means a computer, right? Dam.....looks like I'm back to the roots style. Dam,dam,dam,should have bought the one for 400 bucks, dam, dam, dam..........
 

vrod2002

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Sep 17, 2004
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Re: Supercharger, would you?

Hey what kind of prop are you runnin! You got the horseys to run a stainless. Alot of times alum props flex at top end reducing pitch by up to 1!Couple hundred on ebay for a stainless might gain you 2mph without building a bomb.
 

jimmythekid

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Sep 21, 2004
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Re: Supercharger, would you?

centrifugal supercharger is nothing more than a belt driven turbocharger, works MUCH better on EFI, but will work on carb engines that are set up right.<br />Roots type will work EASIER less complicated on a carbed engine (especially V8)due to the fact that the fuel/air mixture is mixed BEFORE boost. IE creates boost downstream from carb, turbos(centrifugal superchargers) create boost upstream. You can buy a carb designed for this however. It all boils down to how fast can you afford to go? regardless, they ALL require you to be good at tuning, which inevitably requires a computer of some sort or another to tune the setup for max HP. While carbs are known to make more MAX HP, EFI RULES IMHO, from a maintanance point of view as well as everyday drivability, turnkey starts, and fuel mileage, but from you post I get the feeling you dont care about fuel mileage. Also carb would need to be rejetted/reconfigured for use with a supercharger and you also have to consider that you have made a bunch of mods to your engine already, geared towards normal aspiration, if you have a relatively high compression already, you may not be able to use one in the current configuration. Also the cetrifugal superchargers originally were designed for added performance to an engine with no mods at all they run on bone stock engines. IMHO if you already have a performance engine adding one of those is fruitless, they are for guys that have stock engines, and want them to perform like the one you have now, without going thru all the work you already have done. Sound like you want a better holeshot while retaining top speed ability as well, ever thought about nitrous oxide?I would stay away from the cetrigugal one, but if i had the money Id have a roots type in the time it takes to stop a heartbeat. Yes I am a Mopar fan myself and I love nitrous oxide!! :) Peace
 

f_inscreenname

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Re: Supercharger, would you?

Hey Barry; <br /> Had a Honda 750 for a few years. The roads and drivers around here are just plain unsafe to be on with a bike. Let it go a couple years ago just to make sure I made it to my 30th birthday. <br />“Hey Mark sounds like you got 2mph itis!” I know, I know. Football is over for us, Nascar doesn't start for 6 weeks, boat will be put away for another 8 weeks, even the message boards I hang on are kind of dead and now for my business has hit its slow season. I’M BOARD!!!!! I have a list of stuff I want to do this spring (CD player to working on the trailer) but its starting to look like for the first time I will not have any motor performance upgrades. I would love to do a full inboard like in the picture I sent you but if I did that I would have to start all over. I would have to even change the trailer. Just really tired of being run over by those dam water flees.
 

Don S

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Re: Supercharger, would you?

I just typed in "Marine Superchargers" into google.com and found lots of info on them.<br />I especially liked the first one.<br /> http://www.procharger.com/marine.shtml <br />Lots of info at google you might find helpful.
 

vrod2002

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Re: Supercharger, would you?

Mark i remember you told me you were running a alum prop.Even if you upgrade, more hp, Your going to have to spin more rpm's or prop up to achieve higher top speed.What rpm's are you turning now?What pitch? I'm tellin ya a high perf. stainless is worth looking into.We call those"fleas"power rangers down here.There outfits usually match there graphics.
 

f_inscreenname

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Re: Supercharger, would you?

Barry;<br />I run a left 15 1/2 X 21 cupped (probably to a 23) bronze ocean racing prop. Looks like a prop that inboards uses but it has teeth inside the hub (the hub is solid) for the 270 shaft. A e-bay find for $110.00. I would think you will need a left and a right hand prop’s for the twins (you know the counter rotation thing).<br />Jimmy; <br /> Thanks for rationalizing it for me. I have thought about nitrous but I don't like the fact of a quick shot then back to normal. That's cool for a 1/4 mile but the bottles run out fast especially with the heavy thumb like I have. I was just looking for a more permanent solution but then again Barry had a good point (volvo 270 only good up to 65mph). I guess I will wait till the day I find a whole 454ci with a Mercruiser drive set up that I can afford to buy and swap out.<br /> With Barry having twin 302’s and the only other one I have ever saw (on -e-bay) having been converted to a big *** outboard I would hate to have the slowest Allmand / SuperNova in the country. It wasn't to long ago (before Barry found me and Merc found the one on e-bay) I was the fastest. That is one season I have gone from first to worst. Maybe I will have to look into those marine turbines I saw on the Mother of all maritime links http://www.boat-links.com/boatlink.html <br /> That place is pure evil to someone who has to much time on his hands.
 

vrod2002

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Sep 17, 2004
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Re: Supercharger, would you?

Okay Mark here we go! Start sanding that power robbing anti fouling paint.Repaint.Wax. Surfboard wax on 270. PROP PROP PROP! horsepower to weight ratio to WETTED SURFACE! 2 maybe 5 mph who knows?
 

vrod2002

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Re: Supercharger, would you?

Twins will get me out of the hole faster but not neccessarly top speed.My hp/WEIGHT is worse than yours! That why i want alum logs,alum intake,ect.
 

vrod2002

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Re: Supercharger, would you?

Hey Mark wanna trade! Shannons got your digits if anything would happen to me! Sorry about the prop thing i could have swore you were running alum.
 

f_inscreenname

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Re: Supercharger, would you?

Barry;<br />Ha, ha, ha. I know, I know. Not everyone has a 20 ton lift in there shop. A little hard to paint the bottom sitting on a trailer. The last boat I went through the hell of painting the bottom after a year or so the paint started coming off. Also my boat sat in the water for some of its life time and after someone got all the growth off of it didn't leave the smoothest bottom. The only way to fix it would be to flip the boat over and strip it and rejel-coat it. Not in this backyarder lifetime. I really need a garage with a 20 ton lift. <br />I can put on my right hand prop and get another 5mph (it make it steer like a tank) I like the left I use now because it steers like it has power steering. The prop I use now is right for what I have (I had a prop master around here tweak it out). <br /> Don S <br /> I’m checking them out but like most I do not see a small block Mopar. I am sure it is available but I would rather keep my arm and leg. Putting another 3 grand in this set up would not be worth it. I am looking at stuff on e-bay and places like that. But again unless I find the roots style I don't think it will work with out major modifications. I was thinking I could adapt the newer Magnum motor superchargers to my motor but without a efi I am stuck unless I find the kind that boxes the carb. <br /> But again I am limited by my Volvo 270 outdrive. If I am going to change that (I will also have to replace a solid transom) I might as well go with a big block. If I could just get the winning power ball ticket.<br />There is a money making idea. Design a older Volvo to a mercruiser transom shield adapter. All it is, is a single cast piece of metal so people do not have to install transoms in boats that have been cut to big for the newer drives. I am sure it would not be that hard and there would be plenty of buyers
 

mercrewser

Petty Officer 1st Class
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Dec 4, 2003
Messages
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Re: Supercharger, would you?

Who is the guy "Brownie" that Barry is referring too? If you guys are getting info on other boards about your boats, could you tell me where, I'd like to see. Thanks Mercrewser@aol.com
 

vrod2002

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Sep 17, 2004
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Re: Supercharger, would you?

Brownie would be Allen "brownie" brown just some punk that was building and rigging boats when my mother was wiping my nose.Not only did he design the supernova he has designed a "few" classics, ever heard of Donzi? www.donzi.net if you would like to look up some of his archive threads. Dont feel bad i've only known about him for about three weeks, but I'll take his word as the bible when it comes to classic boat setups.
 
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