I dont think she can take it captain |
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coreytread
Senior Member Joined: October-05-2005 Location: United States Status: Offline Points: 184 |
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Posted: June-23-2006 at 6:25pm |
Im almost finished with my restoration of the 77 SN. So Im planning the 2nd stage engine and gelcoat. The motor Im using is a 351w with electronic conversion a basically stock motor. It came from an 81 SN oh yeah its also reverse rotation the tranny is a velvet drive 1:1 my question is can I get 350 horses out of that motor or atleast 325. I will be sking a decent amount but mainly the boat is for late night cruising. Im going to allow for about 3 grand for the enigne rebuild. the tranny has about 900 hours on it but I have another one Im getting rebuilt. Im sure somebody in our CCFAN community has got some goodies under the hood let me know what to do or if Im nuts for wanting that much power. MORE POWER=MORE PROBLEMS, MORE POWER=BIGGER
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DrCC
Grand Poobah Joined: April-12-2004 Location: at home Status: Offline Points: 2867 |
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Corey, Keep it stock!!! Big bucks and big HP= porpoise big. (only my opinion)
Did you get the AWSA decals? AT PS take a look at my post "255 pretty ponies" all stock,except for the aluminum intake, valve covers and coil. |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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Corey, its pretty easy to get 325 hp out of a 351w. The right combo of heads, intake and cam should get you there. There are several people here who have modified their motors and shared their results, so I'd try searching this site first and read everything you can.
The 351w is capable of making quite a bit of power by just making it breath better. Replacing the restrictive stock parts with superior aftermarket ones shouldnt make the motor any less reliable. The first thing you should replace is the prop (if you havent already). A $300 Acme will improve the feel and performance of the boat almost as much as $1000 in engine modifications. |
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Bradley950
Senior Member Joined: February-07-2005 Location: United States Status: Offline Points: 168 |
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I am making around 300hp and this was done with a cam and intake kit, some head work and a hot ignition. Just letting it breath.
http://www.performancedistributors.com I rebuilt my engine two summers ago, I went with a Eagle Balanced Rotating assembly but all the numbers are stock, bore & stroke. You can easily! make 300hp with a stock bottom end. Like TRBenj said the biggest thing is my acme prop!!! |
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Brad Miller
bradley950@yahoo.com |
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hotfish172
Groupie Joined: June-11-2006 Location: United States Status: Offline Points: 42 |
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I am repowering my Fish Nautique and had some great comments from other owners. check out all the comments on the "repowering" inquiry under general topics. I had a 351 just like yours and it would appear that everyone thought that building a stroker motor was the best way to get more horses out of a 351. I am now having an stroker engine built that should come in at near 400 h.p.
For me, the most important upgrade was an electronic fuel injection system. ALWAYS STARTS are my two favorite words. Besides, an EFI system vastly improves fuel economy and longevity of the motor. Good luck. BTW... If you will go to the links section, you can find a pretty good upgrade package but you can save some serious bucks by shopping around for the same stuff. |
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MarkNConnie
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
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corey the stroker boy is going to have more problems later, he just doesn't know it yet, Tim's a little over optimistic on the gains from the heads alone. There are several things to do to get to the low 300HP, doing all the head work and staying with the stock PCM exhaust doesn't make much since to me, you buget is going to run out very quickly, but to start, intake and cam, balance the motor, electronic distributor, doesn't have to be the HEI unit, they have just bought into a sale's pitch that the advance curve is going to be better, when it's not anything you cann't do yourself, and it's atleast 100 bucks more. Heads are the next thing GT40's are nice, easy cheap upgrade but not top dog when it comes to heads, there are other options that cost a little less.
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hotfish172
Groupie Joined: June-11-2006 Location: United States Status: Offline Points: 42 |
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BC, What kind of problems do you think I'll have with a stroker motor? I certainly don't want to be left stranded out in blue water with a dead engine (been there, done that, got the t-shirt). Fish Nautique owners like me need the ability to slow troll for hours and good power in the mid-range to get back home. I have no desire to try and beat the guys with triple outboards. If you have a better suggestion, I'm all ears. I have many options available to me right now as the engine builder is a close friend of mine and he'll build whatever I want. He's been building marine application engines for many years and he's quite sure I need an EFI package. Other than that, I'm wide open for suggestions.
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MarkNConnie
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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79, I said 325 horsepower can be had by upgrading heads, intake and cam- not the heads alone. PCM claims 45 horsepower from the GT40 heads (240 vs 285 hp) so the intake and cam should get pretty close to 325. Wouldnt it make more sense for Corey to do the heads and intake first, then select a cam based on chosen parts? Obviously any electronic distributor is going to be a big improvement. Its expensive, but I think the money spent on a DUI is well worth it. I picked up 200 RPM on the top end from that alone. Upgrading the exhaust manifolds should gain some decent power, its too bad there arent many options for the 351w. Ill probably do some port work on the stock pieces until I have the funds saved up for the $1700 HiTeks. |
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coreytread
Senior Member Joined: October-05-2005 Location: United States Status: Offline Points: 184 |
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Im going to balance the motor add some spark, port and polish my heads new intake manifold and research the hell out of camshafts. where can I get better exhuast manifolds? can I have custom headers built that would be cool?
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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Corey, are you planning on doing the port/polish on the heads yourself? If youre paying to have it done, I would start with some better heads. Decent gains can be seen with GT40 or GT40p's, and they can be found used for pretty cheap.
Several members have posted here sharing the specs for cams they have used. I also got great info from a company called Cam Research that only does Fords- their tech knew more about my specific application than CompCams did. You will need to know what other parts youre working with to get a good recommendation on the cam. Like I alluded to above, performance exhaust manifolds for 351w marine motors are rare. HiTek makes some nice looking pieces for ~$1700 but thats pretty much it. If thats not in the budget, Ive heard that some gains can be had from porting the stock manifolds. Custom headers would be difficult and expensive- better to go with the HiTeks at that point. |
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coreytread
Senior Member Joined: October-05-2005 Location: United States Status: Offline Points: 184 |
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Yeah I figured custom headers would be expensive. Im still going to have them priced. I have done a little engine work myself but wouldnt know how to port and polish anything. I will be on the look out for a set of GT40 heads. I might go ahead and get an intake does everyone agree on the edlebrock performer or performer rpm. I had a performer but it was stolen out of the back of my truck at wally world luckily my carb wasnt mounted on it.
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coreytread
Senior Member Joined: October-05-2005 Location: United States Status: Offline Points: 184 |
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just checked out HiTeks those will be on the boat within the year but what about clearance those things are as high up as the carb.
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JoeinNY
Grand Poobah Joined: October-19-2005 Location: United States Status: Offline Points: 5698 |
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Here is where I got my GT40p's
The price has gone back up to $550 but still not a bad deal considering the modifcations for the larger valves and the all new components... Tristate Cylinder Heads |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
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you shouldn't have a clearance problem with the HiTek exhaust they are not suppose to be any higher than the current PCM center risers
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coreytread
Senior Member Joined: October-05-2005 Location: United States Status: Offline Points: 184 |
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Im wanting to order those things bad, today I got a offer on a house I own. If this guy is serious I will have the money for alot of new goodies. I read alot about the HiTeks last night they are actualy smaller. and alot lighter.
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MaddMarxx
Platinum Member Joined: June-29-2006 Location: United States Status: Offline Points: 1741 |
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my new motor has about 325 to 340hp you have to start with forged flatops and work your up.
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coreytread
Senior Member Joined: October-05-2005 Location: United States Status: Offline Points: 184 |
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I have always been a chevy man and have pushed 475 with a chevy 350, Im scared of fords they dont seem to be as good of engines. Flat tops are a great upgrade, Im more used to a deep lope and a hydraulic cam Ive spent alot on engines in the past but have sold all my race cars and 4x4s Im trying to make the boat a lake rod, I would be more comfortable with a chevy though.
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MaddMarxx
Platinum Member Joined: June-29-2006 Location: United States Status: Offline Points: 1741 |
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The 351w is a strong motor i would rather have chevy 350 too but we have what we have.
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