? Raw Water Cooling in the Salt ?

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PNWAlan
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? Raw Water Cooling in the Salt ?

Post by PNWAlan » Thu Aug 03, 2017 12:23 pm

I hope I'm not being too much of a pain with all my questions.

Still on the search for an F-25/26. I'm seeing some very nice lake boats. Are there any folks here who run a raw water system in the salt? What do you do as a flushing routine? If I am anal about flushing (no pun intended ) what kind of life span could I expect from a salt water cooled block?

Tried to find a conversion kit but came up empty. Kits available for every marine Chevy, Ford, Mercruiser, OMC ever produced but nothing for the Chryslers. It doesn't seem like it would be all that hard to piece together a conversion. Searched this forum and others and found the question a few times. Didn't find any answers about what exactly would be involved in a DIY conversion.

I should add that I am at ground level in dry stack storage. So with a little cooling system modification or the right adapter, flushing should be about as easy as what I do now with an outboard

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Re: ? Raw Water Cooling in the Salt ?

Post by The Dog House » Thu Aug 03, 2017 5:47 pm

If you add a safety seacock converter you can flush the engine by attaching a garden hose ( http://www.discountmarinesupplies.com/V ... gLlnfD_BwE ). My F26 had one stock from the factory, so the boat you buy may already have one. If not, they are easy to add.

If you are running in salt water but using dry stack storage and flushing every time, you should be fine.
1971 Trojan F26 with Chrysler 318, Paragon PV31R V Drive, and 15 x 11 Bronze Prop
1979 Starcraft 14' Rowboat with 2011 Mercury 9.9 hp Outboard

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oil&water
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Re: ? Raw Water Cooling in the Salt ?

Post by oil&water » Thu Aug 03, 2017 7:14 pm

Depending on your flushing routine, you can easily get 30 years out of a block. Expect to replace your manifolds every five to ten years depending on your use. When they start getting clogged up, you can clean them once or twice, then expect replacement. Buy quality manifolds and risers. They last longer.

Before I get flamed by others, I am basing these numbers on first hand experience on the Chesapeake Bay and in-shore Atlantic usage that I have experienced first hand.
1980 Trojan F32 / 323 (sans lower helm - wet bar in its place)
Twin Chrysler M360 / Onan 6.5

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WayWeGo
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Re: ? Raw Water Cooling in the Salt ?

Post by WayWeGo » Thu Aug 03, 2017 10:55 pm

Our engines are fresh water cooled, but I still flush the heat exchangers and exhaust.

Sen-Dure made fresh water cooling kits for Chryslers and you might be able to find out some info on how they did your particular engine. Heat exchangers are readily available and the rest of the kit would have been hoses and plumbing fittings and possibly an engine driven pump.

I have been told that the 440s were difficult to cool, and that is why the engine circulation pump was removed from our engines and replaced with a dual chamber belt driven one. With a small block, that probably would not have been necessary.
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Re: ? Raw Water Cooling in the Salt ?

Post by oldboat1 » Sun Aug 06, 2017 6:36 pm

add that an adjustable inboard flusher is available. Think of a toilet plunger with a hose fitting.

If you have ground level storage, one of these flushers might be all you need. Not as elegant as the plumbed- in style, but effective and convenient.
Motors should run. People -- not so much.

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PNWAlan
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Re: ? Raw Water Cooling in the Salt ?

Post by PNWAlan » Mon Aug 07, 2017 2:30 pm

oil&water wrote:Depending on your flushing routine, you can easily get 30 years out of a block. Expect to replace your manifolds every five to ten years depending on your use. When they start getting clogged up, you can clean them once or twice, then expect replacement. Buy quality manifolds and risers. They last longer.
That's the kind of real world experience I was looking for, thanks. I had a Searay I/O that had a closed half system and owned several outboards but never a raw water inboard. I did see some posts from a few years back about the Fake-a-Lake. Will have to look into that. Sounds like something I could rig up with some hardware store bits and pieces.

I did check out Sen-Dure. Might pursue that once I actually have a boat.

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Re: ? Raw Water Cooling in the Salt ?

Post by oldboat1 » Wed Aug 09, 2017 3:23 pm

I ran a Chris Craft 251 Catalina Express in the Chesapeake (brackish creek off the bay -- salinity varied). The Sen-dure tank on my '79 system began to leak, and I took it to a radiator shop for repair. Fix consisted of pressure testing, soldering, retesting. System seemed to function well. If you pick up a boat with the Sen-dure closed cooling, you might consider just pulling off the tank and having it pressure tested and repaired/prepped.

When the tide was right in my shallow slip, I used to use a flusher while in the slip, running fresh water from the hose at the dock. On the Sen-dure system, there is a pencil zinc in the cooling tank for added protection.
Motors should run. People -- not so much.

1980 F26, Mercruiser 305
1979 14' Starcraft, 1957 18 hp Evinrude and '57 3hp Evinrude kicker

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Misty
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Re: ? Raw Water Cooling in the Salt ?

Post by Misty » Sat Aug 26, 2017 1:06 pm

Alan I think San Juan Mfg makes aftermarket cooling for Chrysler? But don't go with a flusher or RWC here in the NW unless you moor upriver and come home on the outgoing tide. It's just easier to get the right boat the first time and avoid headaches. Remember nothing ever dries here and hot marinas are the norm. PS Don't fall in love with hookers or boats while boat shopping. :wink:

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Re: ? Raw Water Cooling in the Salt ?

Post by Bear » Sat Aug 26, 2017 6:33 pm

I would never buy a salt water cooled engine again mine was converted over to fresh water anti freeze system a year later the engine started overheated white smoke sweet smell of anti freeze lost compression in one cylinder took heads off they were paper thin breached through the gasket found a ton rust in the block it was so bad it was packed in between the cylinders clogged holes no wonder it was overheating, probably not much block left I flushed it out what a mess got new heads just put them on still have to put the rest together hoping this will work to get me through the season looking at new engines long blocks these are 1986 crusader 350 guess it's time now thanks to salt water cooled engines stay away
Jim Bear Shut up & reel II ( life is short go fish)

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PNWAlan
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Re: ? Raw Water Cooling in the Salt ?

Post by PNWAlan » Mon Aug 28, 2017 12:39 am

Well, I thought I had found a solution. I was working a deal for an F-26 with the Mercruiser Chevy. Fresh water conversion kits are readily available for those. Unfortunately real bids for shipping came in about 30% higher than Uship's "free estimate". So I had to back out of the deal. :cry: Living here I am not on any snowbird migration routes so it's hard to catch a deal on shipping no matter how flexible I am on dates.

If I do find a boat with a raw water cooled 318 my own conversion should be doable. Looks like the raw water pump and thermostat housing could be the problem areas, heat exchangers are easy to find. Not going to spend a lot of time engineering until I actually have my name on a boat title. :)

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Re: ? Raw Water Cooling in the Salt ?

Post by cappy » Fri Oct 27, 2017 11:07 pm

A caution...

When an engine has been Raw Water cooled for a while, the coolant chambers end up coated with rust. This layer of rust, unless removed during an acid bath of the block and heads during a rebuild, acts as "insulation", and a barrier to heat from the engine being transferred to the coolant and on to the heat exchanger.

So a "converted to closed cooling" engine may run hot ....

Dave

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Re: ? Raw Water Cooling in the Salt ?

Post by K4282 » Wed Dec 06, 2017 6:58 pm

I have raw water cooled 318's in my F32 and run in salt, I don't flush them, just tie the boat off when im done and leave. Ive heard bad things converting a salt/raw cooled motor to fresh water cooled, building loosening up and clogging the system and so on, Im not about to reengineer the wheel.

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Re: ? Raw Water Cooling in the Salt ?

Post by bjanakos » Fri Dec 22, 2017 7:50 am

I added flush valves to my raw water cooled boat. I just hook up a garden hose and run the motors for about 5 minutes.

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