So I've been thinking

[Efini Motorsport]

A few months ago I picked up a 90 Four Winns Freedom 195. I got the boat and trailer for $450 with an extra engine, 4 sets of heads, extra outdrive and a bunch of other parts. The interior is shot but the floors and everything structural is in great shape. I've already cut all new seating and panels. I'm converting from dual back to back with jump seats to a helm/jump seat starboard and a back to back/ lounge seat port side. I've gone through the wiring and everything that I didn't rip out is intact. I will be rewiring for all the new accessories, lighting, stereo, etc. Got some good ideas for that stuff too.
Where I'm hung up right now is what to do about the engine. The one in the boat is all there but full of water and at minimum needs to be torn down, inspected and rebuilt. The "extra" engine is already torn down and seems to be in good shape. Between them I have more than enough parts to build one good engine. I'm not sure if that's the route I want to go though. I've been building custom cars for almost 20 years and can handle any of the mechanical or electrical aspects no matter which route I take. I prefer to do things different than most though.
Option 1: Rebuild engine basically as stock using the best of the the pieces I have and replace what needs to be replaced. It will basically be an entirely stock motor with a holley 500cfm 2 barrel carb. Functional but rather boring.
Option 2: Rebuild and upgrade. It would be new stock internals with vortec heads, custom cam and the same holley carb. I'm looking at about another $600-700 over a stock rebuild. A little more fun but doesn't say custom enough to me.
Option 3: Pull a fuel injected 4.3 vortec from a newer truck and drop it in, fuel injection and all. This is actually the cheapest route but a little more work. I know I'll need an electric fuel pump, swirl tank or bladder for fuel tank and some rewiring and tuning. All things I can handle. If nothing else I could carb swap the motor. I actually found someone who did an FI setup on almost the same boat http:/tm/home.hiwaay.net/~davida1/boat.htm.
So what route should I go? The whole interior will be custom, all the electronics will be new with plenty of sound and LED lighting and the engine will be detailed out (yeah I know, I have a bad habit of double assing everything). Time aside it seems the new FI vortec would give me the most bang for the buck plus the cool factor.
My last questions is about the bat wing manifolds. I've got two sets that seem to be in pretty good shape, I had them sandblasted and will check them for leaks but for now I'm going to run the best pair of the two. I know most people say stay away from them but I think I've figured out a cheap temporary fix. I was thinking of using brass 1/4 turn valves on the drains of both manifolds. I keep them open until the engine is running then close them. I can open them back up before I shut the engine down to drain the jackets. That way the only time they're "wet" is when the engine is running so unless it's a huge leak it shouldn't be enough to hydrolock the engine.

 

[Scott Danforth]

welcome aboard

option 3 wont work. you cant use the automotive EFI, starter, alternator, water pump or head gaskets. in a boat, they call that a bomb. you need to use marine rated electrics, the marine circulating pump, marine head gaskets, brass or stainless core plugs. the automotive EFI throttle body does not have the extras needed for a marine environment.

if you want an EFI marine motor, buy an EFI marine motor.

you can use the short block and heads from a truck motor, swap over to brass core plugs and marine head gaskets. then add all the marine accessories, brackets, pulleys, etc.

as for option 2, you should price out a custom cam for the 4.3. its like the forged crank that is available for them. not anything cheap.

you really dont understand the theory of marine exhaust manifolds do you? throw away the bat-wings and get good new manifolds. you cant run them without water, you will thermal shock them and they will grenade, not to mention you now have 900 degree exhaust hitting your rubber flapper and rubber hose. either acetone test the manifolds if you want to be cheap and you want to gamble your motor, or buy the updated volvo style manifolds and elbows.

BTW, welcome to one of the most expensive hobbies on the planet. more expensive than auto racing and almost as expensive as owning an air plane.

if you are going to change from a non-balance shaft motor to a balance shaft motor, you also need new motor mounts.

here is a bit of reading on the 4.3 https://forums.iboats.com/forum/eng...history-of-the-4-3-liter-with-casting-numbers

 

[Lou C]

What I'd do is use the Vortec heads, get a cast iron Vortec 4-bbl intake, a Holley 4160 calibrated for the V6 engine (Holley already sells them set up this way, just look on their website) and get the Barr aftermarket Volvo center riser style exhaust.​

You can still get the fuel line made for the mechanical fuel pump (from BRP) for​

the Holley, because it was used on all the OMC and Volvo V6s after they stopped using the Q-Jet. You will need an adaptor to fit the Holley (square bore) to the spread bore manifold, Holley and Mr Gasket sell them on the Holley website). You will need the Volvo 90* exhaust elbow that connects the 4" riser hose to the 3.5" Y pipe. This is the same exact set up the 91 and up OMC Cobras had and all the joint venture and newer 94 and up Volvos had with the 4.3. I had 3 sets of batwings on my 4.3 in the salt pond. I changed them at 5-6 years of use and never had water in the engine, ever. When they became NLA I started researching the center riser conversion. I found that the Barr manifolds/risers and the Volvo 4" riser hose, 90* elbow and 3.5" hose from the Volvo elbow to the OMC Y pipe fit perfect.

Note: that Volvo part is expensive, there is a cheaper GLM copy of it available, but because my boating is 100% in salt water, I didn't want corrosion issues.

 

[Efini Motorsport]

This isn't my first boat and I'm pretty good making things work on a budget. I work at an upholstery shop now so the interior is going to cost me a couple hundred $. I'm doing all the work except the machining o f the engine if I do rebuild. My engine builder has built a few of these 4.3's for marine use and has a custom cam grind he uses and it's about $300 for it. As far as thermal shocking the manifolds I see what you're saying but not sure it's going to be an issue. The engine would be shut off within seconds of the valves being opened to drain the manifolds. That setup is my plan b as I have two sets of manifolds. I do plan on changing them out to the newer style but if I can get a season out of them I'm OK with that. I will be doing the acetone test on them but may run the valves anyway to be able to keep some of the salt water out of them between use. I will be using the boat on salt and fresh water.
I know the freeze plugs, water pump, alternator and starter need to be marine parts. What is the difference between automotive and marine head gaskets? The Throttle body is sealed and I would be using a marine spark arrestor on it. Thanks for letting me know about the engine mounts, I didn't know they were different. Is it the part that bolts to the engine, the part that bolts to the boat or both?
I know I'll get a little more out of the 650cfm 4 barrel carb but I already have the 500cfm 2 barrel and manifold for it.

 

[Scott Danforth]

If you run your manifolds the way you state, you will burn up your flappers and you will burn up your marine hose. both need water running on them to prevent burning. also, a running engine with a cracked manifold will still ingest water during the cam-overlap cycle, so not sure what you are trying to gain.

marine MLS head gaskets are stainless to deal with water/salt water, etc. most automotive head gaskets are steel because they have glycol running in the block. only in the last few years has the automotive world started using stainless MLS gaskets

the electronics to the throttle body have not been spark suppressed. the throttle shaft on an automotive application does not have the additional sealing o-rings. if fuel leaks in a car, it leaks on the ground. if fuel leaks in the bilge, it leaks into the bilge and the boat blows up.

water pump on a marine motor has brass impeller and stainless back plate

non-balance shaft motors are squishy to allow the motor to rock around and not break the fiberglass due to fatigue. the balance shaft motors share the same mounts with the V8's

your manifold must match the heads. early manifold wont match vortec heads and visa-versa

 

[Efini Motorsport]

I was going to run the drain on the manifold so that when the engine isn't running (between use or whatever) I can easily open the valves and drain the saltwater out. That way if I don't use the boat for a week or two they're not soaking in salt water.
I forgot about manifold bolts being different on the vortec and non vortec. Most of the headgaskets I've dealt with aren't MLS because you need a much smoother finish on the mating surfaces. Most are paper or some similar material. They suck to clean off when you pull the heads.

 

[Scott Danforth]

Still need marine head gaskets. Head and block surface finish is the same for MLS as it is with cored gaskets. 60-100ra for steel heads, 50-60ra for aluminum.

A fresh water flust after every use is highly recommended for the manifolds and block. Simply draining salt water and exposing to air will cause rust about 10x faster than simply leaving salt water in there

 

[Lou C]

In the end running the manifolds that way probably will not extend the life of them, unless you can rig up something similar to Volvo's neutral salt system. In salt water, its 5/7 years of use and you replace with new. I did this and never had an exhaust system caused problem on my 88 4.3 that was moored in salt water every year since 2002 except last year (top end engine overhaul) and 2006 (deck replacement).

 

[Efini Motorsport]

I can go with flushing. The boat will be on the trailer almost all the time except for possibly a few overnights

 

[Scott Danforth]

I use salt away and muffs. I also flushed the old trailer with salt away which is how i got 5 years from a steel trailer in salt water

 

[jimmbo]

The Holley 500cfm 2bbl(378cfm when flow rated like a 4bbl) has more airflow than the engine really needs. If you want a 4bbl, a Holley 390cfm will be plenty for a 4.3 turning 5000 rpm. As mentioned earlier, only USCG certified fuel and electrical on a Marine Engine