1994 Four Winns 190 horizin 5.0 cobra engine swap & upgrade

[jj50cal]

ok, son is getting tired of continuous problems with the 5.0 that is in the boat. we have at our disposal a complete 5.0 H.O. completely overhauled from a 2001 mercury mountaineer, 4 bolt main fuel injected, he wants to swap engines put a larger marine camshaft in and run ceramic headers out the side of the boat. Arkansas rules state that the exhaust has to be wet, with the addition of the headers what is the best way to do this? the wife loves the boat she calls it her (happy place), and i am concerned that the old 5.0 just isn't what we were told it was when we bought it, i believe it has a few more hours on it. and it's just tarred. any ideas as to what cam will go good with the fuel injection? i'm an old car guy and not too up on the boat werld, but i'm tryin'...

 

[Bondo]

and run ceramic headers out the side of the boat.

Ayuh,.... Sounds like yer tryin' to build a Bomb, rather than a boat,.....

While the long block motors maybe the same,....
Everything related to electrical, fuel, 'n the exhaust must be Marine rated,.... to prevent Explosions,....

 

[Lou C]

Of course you have to stick with all marine electrical, fuel and exhaust system parts. If the 5.0 is a Ford, you might think of taking this opportunity to swap to a GM 5.7 if you don't have to change the rear transom plate. You probably will have to use a different bell housing, maybe the coupler and not sure if the present Y pipe will match up to the GM exhaust. If you can look through the OMC parts catalog, see if they used both the GM and Ford engines in the same year and if those part #s are the same or different. One good way to tell. Using a GM marine engine will make your life a lot simpler, there was nothing wrong with the Ford engines other than the fact that they have not been supported for years. I did like the front mounted oil filter & distributor though!

 

[Maclin]

In the Marine world, what the boy wants to do is noble, but that would not be the best method. Especially with the headers, mainly because that will basically destroy the happy place Many times you dive down a rabbit hole, what with the non-marine Fuel injection and wiring problems and other things you find out along the way why it was like it was before, and can end up with a non-runner.

Have you done a compression check on it lately? If some holes are low, then do a leakdown to see if maybe all it needs is a valve job.

Best tack is to work with what is in there now, and be on the lookout for another boat that has more better stuff for what you need. Or even a donor boat of same Vintage OMC and engine, just better engine. But see what you have first by way of that compression check.

My son has 3 dang Camaros now and each one in various stages of dis-repair and/or hotrodding plans, and a non-running truck and a car that goes but no A/C (in Texas), drives me nuts, I'm like PICK ONE AND FINISH IT already...sigh.

Good Luck!

 

[Bondo]

My son has 3 dang Camaros now and each one in various stages of dis-repair and/or hotrodding plans, and a non-running truck and a car that goes but no A/C (in Texas), drives me nuts, I'm like PICK ONE AND FINISH IT already...sigh.

Hmmmmmm,........................ Dad,..??..??..??..??

 

[Maclin]

Youth is wasted on the young!

 

[Efini Motorsport]

I'm in the process of doing almost exactly the same thing right now in my 195 freedom. Original engine was a carb'd 4.3 chevy, I'm swapping in a fuel injected 4.3 vortec from an 03 Blazer. I didn't do it as much for the power as I did because it was cheaper than a rebuild which I would have needed. I don't know if Ford's are the same but the Chevy's have used the same bolt pattern for the bellhousing forever and since they'r both 4.3 everything pretty much lined up. Dry open headers would be a bad idea from a noise and heat stand point. I know there's wet headers available for chevy's but not sure about the Ford's. I also know they're not cheap. You may be able to get away with the stock marine manifold assuming the bolt pattern and mounts are the same.
As far as "building a bomb" it is a pretty common response. My boss's boat mechanic was at the shop a few weeks ago and I showed him what I was doing. As soon as he saw the automotive alternator and starter he said the same thing. Along with "it's your life, it's your passengers lives". I asked him what made the automotive and marine parts different and he said he didn't know. He suggested I call the place he uses that rebuilds both automotive and marine starters and alternators and has also been around a long time to ask them. I called them the next day and told them exactly what I was doing and they said don't worry about it. 203-30 years ago it was an issue. It used to be that the marine alternators had the brushes and commutators sealed to prevent sparks and the automotive didn't. A long time ago the automotive figure out that if they sealed them for automotive use the parts would last longer because it kept dirt and water out. The starters are not only sealed but because most starters now are gear reduction type the motor is mounted deep in the case so also better isolated from fumes, as well as being sealed. One good response I got on my post, which I was't aware of, is coast guard regulations require the fuel pump the be within 12" of the engine, measured in a straight line. By dumb luck my fuel tank is about 6-8 inches away from the engine. I am also using an in tank pump as it's one less thing to worry about. I am using the stock computer with all the truck emissions, a/c, transmission, etc stuff removed and tuned out. I am also using the stock (new style) manifolds, risers and elbows with silicone hoses. GM uses sealed weatherpack connector for all the sensors which are way better than the stock clamp on connectors that were originally on my engine too.
Most of it just comes down to use common sense when you're doing it. Keep fuel lines well routed and away from hot stuff, run your blower, etc. When I was trying to get a straight answer on what actually makes something "marine" (aside from a 3x price increase and black paint) I did a google search for news articles of boats actually blowing up. I couldn't find any that blew up because someone used car parts and most of what I did find was people just got gas and didn't realize they pumped 4-5 gallons of gas into the bilge because they did something stupid.
If you want to check out more of my build here it is.
https://forums.iboats.com/forum/eng...es/10562245-thought-i-d-show-off-my-new-build.
I've been building custom cars for 20+ years so I do have experience with this type of stuff. It's not the hardest thing in the world but you definitely do need to know what you're doing. I have a lot of resources most people don't so it's a huge help.

 

[Bondo]

It used to be that the marine alternators had the brushes and commutators sealed to prevent sparks and the automotive didn't. A long time ago the automotive figure out that if they sealed them for automotive use the parts would last longer because it kept dirt and water out.

Ayuh,..... Alternators build heat, 'n are not only heavily vented, but have the fan at the pulley,....
A Marine alternator has screens on the vents to trap sparks,.....
Automotive alternators, do Not,..... 'n can, 'n will cause an explosion if gas fumes are present,.....

While it's true that a gear reduction starter is naturally spark shielded, most new style starters are Not gear reduction, but are permanent magnet motors, which are Not spark sealed,.....
Two very different things, that came about at nearly the same time, 'n are confused by many,......

Is yer "In-tank" fuel pump, wired through an oil pressure switch,..??
If not, what shuts it off when the motor ain't runnin',..??
How did ya modify the tank to accept the fuel pump,..?? That sounds scary enough, by itself,....

Gas fumes are heavier than air, 'n sink,.....
They dissipate under a car, but build to explosive levels in a boat bilge,.....
Better to be Safe, that mourned by those ya leave behind,.....

 

[Maclin]

Efini Motorsport While having the actual fuel pump within the CG recommended distance, it seems the length of fuel hose was what the CG was concerned with as well. Having the fuel pump within specified distance of 12" in a straight line, yet having some 30+ inches of rubber, just sayin', seems like a bad interpretation of what is allowed. That hose, as you described it's use, is on the pressurized side of the pump, kind of a "wow" to me when the length is taken into account, just my opinion.

 

[Efini Motorsport]

If the fuel lines were ridiculously long I could see that being an issue also. The coast guard doesn't seem to have any regulations about fuel hose length but again you need to use common sense. The statues specifically says "in a straight line from pump to engine not following the lines." If they are that close it's hard to get crazy with the amount of fuel line.
My fuel pump is an in tank but does not run through an oil pressure switch on purpose. The engine computer controls the pump and kills power to it any time the engine shuts down for any reason. The pump is made to mount in a plastic fuel cell (which is what I have) and has a threaded lock ring that goes in the tank and sandwiches the tank, gasket and pump flange together. They are made for racing environments with the potential likely hood of being subjected to high g loads in a crash. If I had an aluminum tank I would have welded in a flange ( and yes I know the tank needs to be purged for welding so I wouldn't be making a bomb there either.
I don't know about all "marine" alternators but many of the new ones I've seen have the same vented case design as what I'm using. I do know they used to use screens which everyone knows a porous mesh is the best thing to keep fumes out. In conversations with the electric motor rebuilders and an electrical engineer with decades of marine experience I feel pretty confident in using the automotive parts. I can't even find one case in online searching and in talking with any of the dozens of marine shops we deal with of anyone actually blowing up from using automotive parts.
I did a quick search for marine alternators and came up with this Balmar alternator (part # 260757) which lists for $962 from defender. This is what most of the new alternators look like, with a very open case design and internal cooling fan. There are no screens anywhere on it. If gas fumes are present they will get inside the alternator screens or not. The only way to make them marine is to seal the things that could spark, the brushes and commutators. I've never even found a good explanation as to how a screen is going to stop gas fumes except for potentially grounding sparks before they could ignite fumes OUTSIDE the alternator. If fumes INSIDE the alternator get ignited a screen isn't going to prevent the flame from traveling out and igniting any fumes present outside.

 

[Efini Motorsport]

The permanent magnet motors are gear reduction starters. Here's a good write up on them
http://what-when-how.com/automobile/permanent-magnet-starter-motor-automobile/

 

[Maclin]

Ok, sounds closer to safe then! Let's not give the original poster's son ideas though, they may not have a NASCAR tech available

 

[Efini Motorsport]

Fair enough. Assuming he used the marine starter, alternator, exhaust and a carb swap it is relatively straight forward. swapping to fuel injection adds a whole other level of complexity.

 

[jj50cal]

thank you guys for your knowledge, i ' m sorry for creating a war between car and boat guys, i too am an old head when it comes to my hot rods, i still own my '68 chevelle with 420hp 327 turbo 400 tranny, had it since 1980. and bought it from a retired elem school teacher. anywho. the compression on the omc ford 50ho cobra is for the sake of rounding off 135 across the board, give or take 4foot lbs, the biggest problem has always been slow out of the gate, changed the prop 5 different times trying to spped up the hole shot, but then momma said it was too slow, so went back up to a 17 3 blade. the motor originally had a 4bbl holley on it, but when it was taken back to dealer with the original owner who fergot to winterize it and cracked the block dealer installed (new) engine but replaced carb with a 2bbl. i've been playin with it ever since to get it back right. and now son has been putting his time into it, and thinks bigger is better. and yes i HAVE been keeping it all MARINE grade. i have to bite my finger sometimes but do it anyway,( it keeps momma happy), but now i finall started thing maybe my son has something, since he has friends with speed boats, and he has been taking notes from them. we did change the bilge somewhat, to get more air into it and put a stronger blower in it even have one up front (just-n-case).

 

[jj50cal]

admiral maclin, is there really a difference in the marine, and automotive fuel injection? i thought both were a closed system?

 

[jj50cal]

oh, let me please add, we um he IS using the marine alternator that is already on the boat, (simple swap), starter, and fuel pump, those are good, he was mostly wanting to use the fuel rail, all braided lines (factory), and much stronger 50 ho motor, but change the camshaft to either a marine cam which is made for all low end torque, or put towing grade camshaft into it for good lowend, and mid-range. so momma can go more than 35 miles per hour...

 

[Efini Motorsport]

They are both closed systems though they operate at much higher pressure. usually 45-60psi vs 4-5 psi for a carb. One definition of a carb is a metered fuel leak. Because they've been around so much longer and are (usually) completely mechanical they are much easier to implement.

 

[jj50cal]

Efini ok, you think i should continue using the holley 600cfm 4bbl, oh yeah, we did swap that out last year along with the cast iron 2bbl intake that was installed, it now has an aluminum edelbrock marine intake with an additional 1inch drop. it werks much better on top end, but not so much on low-end. i'm trying to find out if the omc 5.0 which is suppose to be (H.O.?) because one of the biggest reason for the swap was to get to use what we know is a 4bolt main 5.0 H.O engine with fuel injection, suppose to up the HP, from supposedly 190 up to 215 stock. then putting the larger cam in, ?who knows.

 

[Efini Motorsport]

I prefer fuel injection personally. It comes down to your skill level and how much work you're willing to put in.If you want to PM me I can try and help out with any questions you have.

 

[jj50cal]

Efini Motorsport, ok great, i have no experience with the fuel injection systems, my son loves them but has limited experience also, like i said earlier, i am an old skool gasser, mouse motor (327) holley 750 dbl pump with comp cam with 520 lift, and 480 duration, pullin around 420hp in front of a turbo 400 tranny, and 411 gears all wrapped in a 68 chevelle body. thats where my experience lies. i have or we have several boats that we manage to keep afloat and running most of the time. everything from kawasaki 900 and 1100 jet ski's, 1986 mark twain w/ 140hp chevy mercruiser 4cyl, an 85' chris craft w/ same set up, just a lucky coincidence, and the famous 94 four winns. the biggest trouble we have with the four winns is that the motor seems to always be draggin during start up, as if trying to use a 6 volt battery to crank with. we normally change out the starter because of the dragging twice during the year, my rebuilder probably thinks i'm bring in cores and having him build them under warranty, lol.. if i didn't know him i might be suspicious of his wermanship, but i know him well and he knows i wouldn't do that to him. i have even tried a brand new starter that i purchased from the boat dealership here in memphis that carries omc parts, with the same results. hence why we are starting to think the motor is just tired. We were tossing the idea of just swapping the heads out with the mercury 5.0 mainly so we can actually change spark plugs without pulling the exhaust manifolds off to get to them. the person who designed that should be drawn and quartered and hung upside down. anyway, it was my suggestion that if we go to the trouble of head swapping to just go ahead swap it all, since we have to pull the engine anyway. easier to do it on a bench than humped over.