new engine convert to fresh/salt water cool ibfo

bolo78910

Chief Petty Officer
Joined
Jun 25, 2006
Messages
503
as yall know i recently got my reman block from rapido.

i am thinking of making it into a freswater cool by adding a heat exchanger ect, now my mechanic say that is a waste of money on his part, he said if i go raw water cool the engine will runs cooler and by the time the engine gets all rusty in the block i will be longtime sell the boat ect.

my ??? what does the fresh water have over the raw water,??

apart from the block will have antifreeze wich would keep rust and sand out, what else does it do, also i know the manifold will last a few years longer too,.

your thought guys.
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: new engine convert to fresh/salt water cool ibfo

A closed cooled engine will last far longer......
My 302 Ford with closed cooling is 35 years old & still runs good.....
Try that in salt water with standard cooling.....
I will never own a standard cooled engine as long as I live anywhere near salt water....;)
 

starsnstripers

Lieutenant
Joined
Nov 30, 2007
Messages
1,330
Re: new engine convert to fresh/salt water cool ibfo

I agree with Haut, I'm putting in an eng. and going to closed system. If I can sneak a ? in here which may help in this discussion do you have to have an expantion/resevoir with that system or can it be done without it?
 

bolo78910

Chief Petty Officer
Joined
Jun 25, 2006
Messages
503
Re: new engine convert to fresh/salt water cool ibfo

my friend has the same boat as me, he has the heat exchanger, and the overflow tank. he gets his cooling water from a belt driven water pump, now here is my big ? can my alpha one drive supply enough water to do the job or i have to convert to the belt driven pump to suck the water from the ocean???
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: new engine convert to fresh/salt water cool ibfo

Your alpha pump in the drive may be able to, as long as you don't try to run antifreeze in the manifolds. At that point, the Alpha pump in the drive is just too small. Then you need an engine driven pump and a thru hull pickup. Now things are really going to get expensive and complicated.
If you just stick with what is known as a half system and only cools the block and not the manifolds, your engine will last, but the manifolds will have a life expentancy of 5 to 8 years before needing replaced when used in salt water.
You know your boat, and how long you plan on keeping it. Raw water cooled, the engine will still outlast the manifolds and risers. And don't forget about resale value of a boat used in salt water With and Without a closed cooling system.
 

bolo78910

Chief Petty Officer
Joined
Jun 25, 2006
Messages
503
Re: new engine convert to fresh/salt water cool ibfo

thanks don s ok that cool i wil only do the block with antifreeze cool this coming season, but not the manifolds , as long as the drive impeller will do the job. thanks. don do you have a drawing or pic on how the hose routing with the half system???
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: new engine convert to fresh/salt water cool ibfo

When you buy the freshwater cooling kit, it will have all the preformed hoses, thermostat housing, heat exchanger, brackets, clamps, bolts, etc. and instructions for the system you get.
Look in the OEM service manual and it will give you a general idea of how it's plumbed.
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: new engine convert to fresh/salt water cool ibfo

my friend has the same boat as me, he has the heat exchanger, and the overflow tank. he gets his cooling water from a belt driven water pump, now here is my big ? can my alpha one drive supply enough water to do the job or i have to convert to the belt driven pump to suck the water from the ocean???

My 888 (302 Ford) is closed cooling with the block & manifolds on the closed side.....
The exchanger is cooled solely by water supplied by the Alpha 1 impeller......
It works for me, but your mileage may vary......:)
 

peejcj8

Petty Officer 2nd Class
Joined
Jan 8, 2006
Messages
102
Re: new engine convert to fresh/salt water cool ibfo

For what its worth,

I have a 79 Albemarle with the original engine, seawater cooled. 2500 hours.
 

bolo78910

Chief Petty Officer
Joined
Jun 25, 2006
Messages
503
Re: new engine convert to fresh/salt water cool ibfo

up date here guys after thinking, i had just install a freash water flush after each use, wil that help some to keep the engine from rust out.

this is how i did the plumming work.

at the back og the engine, i cut the raw water inlet hose , now this is where i use the same size copper tubing i made up a t this t has three shut off valve at three angles, after a day of fishing as soon as i got back to the dock i will connect my garden hose to one inlet i will open that valve, now i will close the other valve for the raw water inlet, the other valve going towards the stering cooler will allways stay open , now i will start the boat turn the fresh water hose on and let the boat runs for a while to get that salter water out,

after the engine gets flush i will clost the shut valve for the fresh water inlet and just open the valve for the inlet seawater and we finish. i wish i have a camera to show you guys some pic, with this set up you dont need to take the boat from the water to get it flush.

i saw this setup on the net selling for goog bucks i just hack it and made my own, all you need is a propane torch and some copper tubing, and use the right valve for saltwater use.

maybe next apter one season i will install the close cooling system.

let me hear your thought guy, last the garden hose in let connector is bolted on the outside transom for easy screw on with the right piece perchase at the marine store. so you see even when your boat is haul out and the drive is off you can still run your engine with the garden hose connect, or you can send antifreeze down to the engine with the propper container with the hose fitting,

thats all i hope you guys finds this info helpfull.
 

j_cizzo

Cadet
Joined
Nov 13, 2007
Messages
22
Re: new engine convert to fresh/salt water cool ibfo

there is absolutely no down-side to freshwater cooling an engine. not only will it last longer, but also it'll make more power (not noticible, but it will be more efficient) and it will also stand being rebuilt in the future (all engines DO wear out eventually).

as far as your alpha pump, you should be fine, the alpha might not pump that much water, but you're not making much power if you're running an alpha! so i'm certain you'll have plenty of capacity. you don't need to start going the route of another pump until you up the power big time, even then, putting a thru-hull fitting in to a pick up is a very easy thing to do and i wouldn't worry about it. even if you have it done for you, just putting the thru-hull in will only take a mechanic (if you don't do it yourself) half an hour tops maybe?

stick with what you have, you'll be fine... oh, and even if you include the manifolds in the loop, it's nothing more because the thermostat is actually mounted to the heat exchanger itself (on that type of system)... so the coolant goes from the engine, to the manifolds, to the thermostat, thru the heat exchanger, back to the engine. essentially, the temp of the water coming off the manifolds will dictate the functioning of the thermostat, so if you put a 180 degree thermostat in there, the engine could run a bit cooler... it's still the best way to go though.

i've done this a lot, so i tend to ramble...
 
Top