How to Switch to Antifreeze Cooled Engine

[scatgo]

It could be a 302 with a bent connecting rod

Glad to see we have a smart azz aboard to keep us entertained. That is funny lol.

 

[scatgo]

Ok here is the update i was hoping to get a lot sooner. The boat is a 1982 Sea Ray with a 5.7 Chevy. The owner said it is the newer version of the 350. Not sure what he means by newer version but thats the boat i plan on buying. Sorry for any bad info but i got ahead of myself as usual and it turns out the owner of the boat is deaf so communication was bad

 

[scatgo]

I doubt this is any Pontiac 301 engine, very unlikely to be ever used in a boat, if its a Ford/Merc I/O It could be a Ford 302, if an OMC same thing both used Ford engines then, in addition to GM, which could be a 302 (5 liter).
As far as putting a closed cooling system on a salt run inboard, you can't really understand how much corrosion there will be until you've run boats in salt. Fresh water you will never see this. Just an example, this is new vs 5.5 seasons exhaust elbow section of my old OMC manifolds....next is my old cyl heads with 15 seasons on them....

Looking at the pictures of your exhaust elbows after less than six years of use is making me lean towards doing what everyone suggests i dont do. A very quick look came up with close to 200.00 for one elbow. Does the salt water pass through the manifold too? If dose that would mean about a grand in new exhaust parts about every six years.

 

[tpenfield]

So, we are talking about a 1982 Sea Ray w/ new(er) 5.7L engine ~ 50 hours.

You may not really know if the engine is still a viable candidate for closed cooling conversion until after you make a commitment to buy it (or have bought it). You *could* take off the thermostat housing of the engine for a look inside the housing and into the water passage of the intake manifold to get an idea of the amount of rust scale that may exist. Additionally, you could do the same sort of thing by removing the recirculating pump and getting a peak at the cylinder walls.

Then you may have to make a judgement call as to proceed with closed cooling . . . or not.

There is not much more pre-sales guidance that folks could reasonably offer beyond what has already been stated IMO.

Roll of the dice and a judgement call.

 

[tpenfield]

If you do a 'FULL' closed cooling system, the engine block AND exhaust manifolds will be isolated from raw water (sea water) and just the risers will get the salt. If you get a 'HALF' closed cooling system, it is just the engine block and you would be replacing the full exhaust every 5-7 years.

 

[Lou C]

Looking at the pictures of your exhaust elbows after less than six years of use is making me lean towards doing what everyone suggests i dont do. A very quick look came up with close to 200.00 for one elbow. Does the salt water pass through the manifold too? If dose that would mean about a grand in new exhaust parts about every six years.

If you are going to run a raw water cooled inboard in salt water, the exhaust replacement every 5-7 years is standard maintenance. If you go with full closed cooling, then you won't have to replace the manifolds only the exhaust elbow. Keep in mind that for full closed cooling you may have to upgrade the raw water system, your drive mounted raw water pump may not flow enough raw water to cool the engine & exhaust manifolds. If your raw water impeller won't flow enough volume to cool the engine & exhaust manifolds then the best you can do is a half system that protects the block.
If you don't want to worry about all this then forget using an I/O boat in salt water and buy a LATE MODEL outboard boat.

BTW, 20 years in salt water, I am on my third exhaust system, first 2 were the OE OMC one piece units like the picture, the last was a 2 piece conversion using OMC/Volvo exhaust parts. I used Barr aftermarket manifolds and elbows and Volvo 90* exhaust pipes & hoses. Total parts cost for the conversion was about $1200, when the time comes I can replace just the manifolds/elbows for about $725.
I have not seen what drive system this boat has. Is it Mercruiser or OMC? If its an OMC Stringer system I strongly suggest you DO NOT buy it. No matter how good it looks or what the seller says.

 

[Scott06]

Looking at the pictures of your exhaust elbows after less than six years of use is making me lean towards doing what everyone suggests i dont do. A very quick look came up with close to 200.00 for one elbow. Does the salt water pass through the manifold too? If dose that would mean about a grand in new exhaust parts about every six years.

A Barr kit with both elbows and manifolds is about $750. Barr is considered same quality as OEM as they do a lot of OEM castings.

Yes the cooling water goes through manifolds to and they suffer the same corrosions, blockage, and engine damaging leak potential.

 

[scatgo]

If you are going to run a raw water cooled inboard in salt water, the exhaust replacement every 5-7 years is standard maintenance. If you go with full closed cooling, then you won't have to replace the manifolds only the exhaust elbow. Keep in mind that for full closed cooling you may have to upgrade the raw water system, your drive mounted raw water pump may not flow enough raw water to cool the engine & exhaust manifolds. If your raw water impeller won't flow enough volume to cool the engine & exhaust manifolds then the best you can do is a half system that protects the block.
If you don't want to worry about all this then forget using an I/O boat in salt water and buy a LATE MODEL outboard boat.

BTW, 20 years in salt water, I am on my third exhaust system, first 2 were the OE OMC one piece units like the picture, the last was a 2 piece conversion using OMC/Volvo exhaust parts. I used Barr aftermarket manifolds and elbows and Volvo 90* exhaust pipes & hoses. Total parts cost for the conversion was about $1200, when the time comes I can replace just the manifolds/elbows for about $725.
I have not seen what drive system this boat has. Is it Mercruiser or OMC? If its an OMC Stringer system I strongly suggest you DO NOT buy it. No matter how good it looks or what the seller says.

From my limited experience i would say its a alph 1. Are the omc stringers the outdrives that used a gear and electric motor to raise the outdrive? And maybe electric shift?

 

[76SeaRay]

Yes, the old OMC stringer drives used an electric motor and gear to raise and lower. Alpha's use hydraulic ram pistons to raise and lower.

Keep in mind that exhaust elbows typically come in either 7 degree or 14 degree down angle so consider that along with my earlier comment on the exhaust pipes when buying or upgrading parts. I ran into this issue on getting a full closed system installed on my 5.7L with Mercruiser Alpha One. I can't address exhaust hookup on an OMC as mine was an OMC but I took it out and rebuilt my transom for a Mercruiser Alpha One to go back in due to obsolescence of the OMC drive.

 

[scatgo]

If the engine has been operated in any salt water during the last 50something years, you would be very ill-advised to fit a heat exchanger. Salt has already leached int the metal of the engine block, head and manifold. A heat exchanger will have more problems than it's worth.

I just checked the salinity of Long Island Sound (27-32g/L), same as most other part of the world. You'll be fine.

Chris.......

Can you please explain to me why you would be testing the salinity of the water? And welcome to the USA and NY.

 

[Lou C]

From my limited experience i would say its a alph 1. Are the omc stringers the outdrives that used a gear and electric motor to raise the outdrive? And maybe electric shift?

you want to REALLY make sure it's a Merc Alpha and not an OMC Stringer. I have a later Cobra and there are very few places who will work on them, and parts you have to search for. DO NOT buy if it's an old OMC drive!
and far as the salt water discussion, you just get used to the extra maintenance of salt water use. A closed cooling system is ideal but if you can't fit one due to internal corrosion, then you can compensate for that in other ways, by fresh water flushing when you can, and when you winterize, fill it with the best propylene glycol antifreeze with corrosion inhibitors. I've done this every year and I am still using the original intake manifold and cylinder block. I could probably get more than 5 seasons out of my new style manifolds but will still replace the elbows then because they get the worst of the corrosion, due to hot exhaust gases and salt water mixing at the outlet.

 

[scatgo]

Thanks for the heads up on the OMC outdrive. Right now I am 95% sure its a alpha and not a cobra. I just looked at a of pics of cobra ODs and you would have to be half blind not to be able to pick up difference between the two. Just for the sake of asking. How much of a nightmare would it be if someone had a cobra that **** on them and the wanted to switch up to a alph? Major work and money would be my guess. I had to pull the out drive off of a boat I had many years ago and from what i recall it was no big deal.

 

[Scott Danforth]

look at it from our confusion

post #1, you are calling it a 1960's something SeaRay with a 301

I just took a fast look at a 19sixtysomthing Sea Ray boat in great condition. It has a new 301 engine with very low hours. Unfortunately the water in Long Island Sound is like battery acid so I would like to switch it over so the seawater never sees the inside of my engine. I know I will need a heat exchanger and maybe different exhaust manifolds but clueless for the most part. any help on how to deal with this would be extremely appreciated. Thank You.

Then in post number 22 its a 1982 boat with a 5.7

Ok here is the update i was hoping to get a lot sooner. The boat is a 1982 Sea Ray with a 5.7 Chevy. The owner said it is the newer version of the 350. Not sure what he means by newer version but thats the boat i plan on buying. Sorry for any bad info but i got ahead of myself as usual and it turns out the owner of the boat is deaf so communication was bad

since the owner is deaf, my guess also original owner making him well above retirement age.

that new motor with only 50 hours on it could have been installed in 1985 or 1995 or 2005 or 2015

if those hours are only freshwater, you need to pull the motor out and pull the heads to clean the water passages in the block. no way around it

if any of those hours are in salt water. nothing you do to the motor will allow a heat exchanger not to get fouled short of a brand new block and heads.

Just for the sake of asking. How much of a nightmare would it be if someone had a cobra that **** on them and the wanted to switch up to a alph? Major work and money would be my guess. I had to pull the out drive off of a boat I had many years ago and from what i recall it was no big deal.

SEI makes a conversion kit to go from a cobra drive to a mercruiser clone.

If you love the boat, just buy it and use it. when the motor and drive go, get a 1996 or newer 5.7 and Alpha 1 gen 2 and drop in at that point. however most likely you will have suffered twofootitis and bought another boat.

 

[achris]

Can you please explain to me why you would be testing the salinity of the water? And welcome to the USA and NY.

ROV pilot... 'Nough said? (buoyancy)

 

[MagKarl]

Looking forward to seeing the pictures. My boat is similar, 81 Searay with a Mercruiser and SBC.

 

[scatgo]

Looking forward to seeing the pictures. My boat is similar, 81 Searay with a Mercruiser and SBC.

I am going to give the the guy iam buying it from a deposit on Friday. If its not snowing like they say it's going to be i plan on taking the tarp off of it and taking some pics. How long did you have your boat?

 

[achris]

I am going to give the the guy iam buying it from a deposit on Friday. If its not snowing like they say it's going to be i plan on taking the tarp off of it and taking some pics. How long did you have your boat?

Have you test driven the boat? Check the engine WHILE RUNNING? If the answer is 'No', DO NOT pay a deposit. SO MANY people come to iboats because they bought a boat without test driving it (would you buy a car without a test drive?) only to find out that the seller lied their teeth out and the whole thing is a pile of dog poo.

Check the boat floats. Check the engine isn't cracked and filling up with seawater, check the trailer bearings and winch, CHECK EVERYTHING!

TEST DRIVE THE BOAT before parting with your money!

 

[Scott Danforth]

What Chris said ^ + 10000

read this https://forums.iboats.com/threads/f...help-buying-a-boat-a-buyers-checklist.612841/

check everything

take boat for a sea trial.

 

[tpenfield]

Yes, what these guys ^^^^ said . . .

Don't be the "I was told . . . " guy.

 

[scatgo]

Got it. Any one know what the compression should be on a 350?