Supercharger, would you?

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Supercharger, would you?

hello<br />one of the shops I work with is repowering some 4 year old 7.4 mercs to 8.1's. I know 1 engine is perfect the other has a problem but I dont think they have 1000 hours on them. volvo makes an adapter for using the out style transome to the later style with minor triming. I also have a 340hp chysler marine 460 with a 2-1 clutch I am going to unload, you just have to take the 26 ft wood hull with it :)yes this is a 460 ford marinized by chysler with a q jet carb :) <br />I also have the 460 ford cobra bell housing
 

Scaaty

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May 31, 2004
Messages
5,180
Re: Supercharger, would you?

Originally posted by Bondo:<br /> The Problem you're going to have is, You'll need a Carb Box to blow thru........
They sell carburated plenum boxes with the kits
 

f_inscreenname

Commander
Joined
Aug 23, 2001
Messages
2,591
Re: Supercharger, would you?

Hey Rodbolt<br />The problem with the adaptor is they start around 800 bucks. A little out of my price range. Add a drive to that and .......I would love to have one of your motor/drive set ups but unless you are into charity work I don't think I will be able to afford it this year. It is a shame to because some time before the 4th of July I have to get to South of the Border for a few things. ;-) <br /> Robby <br />True they do but I haven't seen any on e-bay or on any cars from the factory that I could scavenge off a junk yard car. The real question was if people in boats use them. No one really answered it but the over all feeling I get is yes but on the way to this conclusion a few other issues have come up where I think I will be wasting my time and money to buy a new custom kit. If I found one cheap enough I may give it a try but for two grand to start even this gear head cant justify it for a small block with 30 year old technology.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
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20,066
Re: Supercharger, would you?

hello<br /> I have no idea what the 7.4's will resell for. the shop does not like resells and usually does so cheap. some years ago most transoms for the sx,sxdp and merc and the omc cobra all went to the same cutout. <br /> merc used the b&m blower on some of its high performance big blocks for years.<br /> volvo has used a belt driven centrifical blower for many years on its diesels. I personally like suck through systems over blow through do to the fact its more simple and easy to start rich and lean out without valve or piston replacements between jettings:). the main reason for not running superchargers is at WOT for extended periods of time at boost requires some bottom end mods that can get expensive and the assy gets rather tall. but the 340 460 I have is complete although I have not run it in a year or so. but the 270 will puke with a big block. but after last years hurricanes I see a lot of junk boats for sale cheap with 290 drives.<br /> look online at some of the insurance auctions.<br /> when I was in ft worth and working around the eagle mountain lake area there were a lot of supercharged mercruiser go fast boats. usually they stayed less than 5 pounds of boost. much more and you get into bottom end block mods and oringing cyl heads.<br />+look up or call gale banks. the have many blow through systems both turbine and centrifical. if you have the compressor and mounting systems all you will need is the carb and the plumbing and wiring. the kad42 volvo used a system that the blower turned on at about 1500 and off at 2800 with a 3300 or so redline. the boost was kinda lagging at hole shot but once the pressure came up it was very responsive. that is why most used positive displacement types over centrifical or turbine.
 

f_inscreenname

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Aug 23, 2001
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Re: Supercharger, would you?

Rod; I have been keeping my eye out for a 290. I really think “trim” would be one of the best improvements overall. Not that the boat has any problems now but you have to set the “outdrives pin” in a middle of the road setting and are not able to change that setting unless you stop and get out of the boat. I also like to run in rivers where the water may be a little shallow (not skinny water) to get back to that fishing hole. It would be nice for that also.<br /> Like I said, I think I would try one (supercharger) if the price was right but buying a custom kit, for the money, is just not worth it. <br /> Oh well. That is why I posted it here first before I tried it. With all the evidence so far I think it works out like this. A lot of money for a custom kit. In most all cases (with either style blower) I would have to make lots of changes to a great, hi pro, strong motor. My 270, I think could handle some more power but design limits will hold me back no matter how hard I push. Pushing boat motors/drives hard all the time is not good. I have to remember this is a 360 small block. Sure you can get 500hp out of one but how long will that last? Not long. The bottom line is to be happy with what I have (most people would be) till I find a “complete drive set up” and in a perfect world it would be a big block with a Volvo 290 drive with trim at a price this backyarder can afford and can float pass the wife. Like most here who rebuild boats know getting a different full set up is just the beginning of the journey and the money that goes with it. If I had a dollar for every time I looked at something and said that will be a easy swap just to find myself at home depot, pep-boys, US boat or the hundred other suppliers 20 times a day so I could complete the “easy swap” I would be rich. Now that I think about it I would have to move and build new motor mounts and would have to change some wiring and and, and............... It all adds up. I kept a list of my expenses for the first two years of my restore religiously. I had to stop. That was a number that could not become public knowledge if you know what I mean. Especially when I started replacing things I had all ready done with upgrades. Those numbers will never see the light of day. “Yea Honey, those seats were always gray. What’s that? That gage looks new??? Yea it cleaned up real well....Why is the UPS man stopping in front of our house? Hummmmm.... I don't know.” :D
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Supercharger, would you?

hello<br /> yep I know the "reto" money thang :) :) . keep your eyes out on the auctions for a sunk hurricane boat with a dp drive. grab the shield and all.<br /> if I see another sunk one ill post it.<br />a dp with trim would help ya alot more than a huffer.
 

ae708

Chief Petty Officer
Joined
Jun 17, 2002
Messages
591
Re: Supercharger, would you?

Put a nitrous system on it... supercharger in a bottle... use as needed.
 

f_inscreenname

Commander
Joined
Aug 23, 2001
Messages
2,591
Re: Supercharger, would you?

Nitrous is great for cars but for boats it doesn't last long enough. That and spinning a motor 8 grand that is built to run a 4.8 grand is not very good for the motor. Then there is the prop issue. Spinning a prop I use every day with out nitrous that fast is totally inefficient. I am thinking more like for a poker run not for 10 seconds running up the channel. Thanks anyway.
 

Bondo

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Apr 17, 2002
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71,310
Re: Supercharger, would you?

Ayuh,..... <br />The Dynamics of Water, Vs the Road........<br /><br />Nitrous is a No Win Situation, in most boats............... ;) <br /><br />Turbos,........... Now That's Another Matter.......... :D
 
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