302 marine engine?

[73stallion]

got a friend who has a 302 out of a boat. i have no idea if it was run in fresh or salt water, but it does have some corrosion in the cooling system. it was a running engine when removed. i can get the whole engine with stand for $50, then i'd tear it down and build it. over time i'd like to build it into a 331 stroker.

my question is how bad could the cooling system be if it was run in salt water?

 

[mustangtoby]

I don't know for sure, but I don't think the salt would hurt the cast iron too bad. If your gonna rebuild it, have it boiled and I bet you would be fine. If your too worried have the block sonic checked and it would tell you if there is any thin spots.

 

[Viuhkola]

Most marine motors have heat exchangers.(Like a water radiator) the sea water would go through the heat exchanger and normal fresh water/ antifreeze would circulate through the motor. You should be fine, the corrosion is probabaly the normal cooling system corrosion. Also most marine motors I deal with are 30+ years old and still running.

 

[Broncobowsher]

Corrosion will rot out head gaskets and freeze plugs a couple times before the block is too shot to use. But do let the machine shop know so they can dip/boil/tank/whatever they like to clean out all the crudies inside. A good shop will know what to do and if you give them a heads up they will fix it up right.

 

[conseated T]

how old is the motor? most Volvos and Mercs now have GM motors the 5.0 is a 305 more than likely it was fresh water cooled and if it was winterized correctly ( filled with antifreeze and not just drained) it should only have minimal rust

 

[73stallion]

it's a mercury engine according to the valve covers. i was thinking about having it boiled, but didn't know if that'd do it. my other concern was if it's reverse rotation, but i'm not worried about it since i'll be changing the crank and cam anyway.

 

[canrel]

Had a guy , friend of the boss, bring in a boat with the same motor. He had not run it for 8-10 years and could not get it to run. He had someone do some work on it before it got to me. I started with the basics, fuel, spark .... It didn't sound like it had much compression so I did a compression check on all the cylinders. I had the valve covers off to make sure the valves were not staying open. that's when I noticed the valves were opening in the wrong order. The cam was set up for reverse rotation and the guy that had worked on it had replaced the starter with an automotive one, which turned the wrong way. If you get the starter and it is set up for reverse rotation, don't use it as a core. Sell it on e-bay or something, it is very expensive. The crank should be the same.

 

[bax]

stay away from a salt water motor. Even if it ran heat exchangers it still ran salt water thru the exhaust.

 

[bmc69]

stay away from a salt water motor. Even if it ran heat exchangers it still ran salt water thru the exhaust.

What Bax said. And its clearly an 'old' engine too..since Ford stopped delivering engines to Mercury (and everyone else in marine propulsion too, for that matter) quite a while back. Further, very few of the Ford/Mercs were fresh-water (closed system with HX) cooled. Same was true for the OMC/Ford 'Cobra' series and the OMC/Fords were the last Ford marine engines..in the 80s.

As for whether its reverse rotation or not...it would not be unless it was the starboard engine out of a twin-engined vessel.

 

[Scrapper_MV]

If the engine was raw water cooled it will most likely have a very low temp thermostat. Like 150-160 degree. If it was fresh water cooled (heat exchangers) it would have a normal temp range thermostat. Yes the raw water on a 50/50 set up with heat exchangers does exit the raw water through the exhaust, this should not be a problem because I highly doubt you're going to use the marine exhaust manifolds. Now the engine could be damaged from sucking exhaust water into the cylinders, but you said it was running when pulled, right?

Do you know what kind of boat it came out of? If it was a bigger boat with twin engines then it could be a reverse rotation engine. Might want to check that out.

I say get it and tear it down check out the cooling jackets. If it looks good then build it. You can't go wrong for $50, the stand is worth that.

 

[bmc69]

I say get it and tear it down check out the cooling jackets. If it looks good then build it. You can't go wrong for $50, the stand is worth that.

'course thats true too. And raw water cooled engines typically run only 140-degree stats, while fresh-water cooled engiens run 160 (most common) or 180. Again, all that applies to 'old' engines..of the vintage that 302 would be. Today's marine engines (all chebby) are a whole different animal with EFI, always fresh-cooled and running much higher jacket temps.

 

[ep67bro]

Take a look at the heads even if the cooling system was a closed loop the exhaust was salt water cooled and a little bit of salt water in the exhaust can do a real job on the heads. Also check and see if the motor has been bored out. If it is bored 60 over and was cooled with salt water I would pass on it. The water jacket around the cylinders can get pretty thin on a motor like that.

 

[Broncobowsher]

Doesn't matter about the manifolds. Never seen anyone adapt water cooled exhaust manifolds to a Bronco. Who cares if an unused part has corrosion.

Engine ran cool all it's life? It was designed to. Wear, probably has some. You are rebuilding it right?

Reverse rotation, yea there are some parts that are wrong, but swap them out during the rebuild.

$50 for a core engine, from a boat, reverse rotation, any cooling system. Fair deal. go for it.

 

[73stallion]

think i'll take the plunge. worst case i have to buy a set of heads, which i know where there's a fresh set of '88 302 heads for $250.00.

 

[73azbronco]

Maybe a cam, the marine cam is made to make the power above 4500 rpm i think.

 

[Broncobowsher]

Maybe a cam, the marine cam is made to make the power above 4500 rpm i think.

Marine cam is more like power under 4500 RPM. They try and keep the redlines on marine engines a bit low.

Trivia bit, the original 302 HO engine from '82 to '84 used a marine cam. Execs wanted something to add a little power to the 302 mustang of the day and bring back the GT name. They took a trip to the engine lab and asked what they could do. One of the workers said they already have the part and handed them a marine cam (standard roatation). It was the cheapest engine program Ford ever ran

 

[73azbronco]

I knew it was something, thansk for correcting me.

 

[67ster]

I've had my hands in several 302-351 marine engines from a pair of daycruisers that "mysteriously" swamped out at Lake Mead . The insurance adjusters felt that perhaps the payment book and insurance policys had somehow chafed together and caused the sinkings.We were called in to remove and tear down the engines and in one case we found a starboard 351 W had a broken crank and couldn't possibly have been in operation , the other was fine except for a bit of water damage. A friend then bought the salvage from the adjuster after fraud was proven . The reverse rotation engine was replaced with a factory longblock and everthing seemed to be OK . I've often wondered what effect the piston pin offset would make if a standard rotation engine were run backwards.

 

[73stallion]

well i'll find out in the next few weeks. he's gonna let me take it and tear it down, then make a decision. if it's good i'll give him the $50 for it. if not i'll scrap it.