I'm sure this has come up before somewhere, but has anybody have experiences with salvaging marinized engines for cars? Repower take-outs can be had pretty cheap sometimes and some feature better performance parts as standard compared to their automotive cousins. I salvaged a late 302 a number of years ago and it had the 'good' D0 351 heads on it with screw-in studs and guideplates from the factory, plus a few other interesting goodies like a three-bolt 50 oz damper. Unfortunately, the block was cracked.... My main concern would be rust if it had a 'open' cooling system and around here that likely means salt water cooled. Had bad does the rust have to get before it's beyond the point of saving? What's the best method of cleaning one out?
Yes, raw water cooled engines have the potential to have thin cylinder walls. More so in salt water. But not always. About all you can do it buy it right, have it hot tanked, and after it clean have the cylinders thickness tested. I would look for a heat exchanger cooled engine.
100% if you live by the coast and saltwater pass on raw water cooled mercruisers. I wood only look at engines with "from the factory" heat exchangers. Also cheap skates will overhaul a marine engine and use the cheapest Chinese ebay automotive gasket set possible. Then the head gasket goes and you have salt water in the cylinders. Let the boat sit in the back yard 3 or 4 years. Then put it up for sale "running when last used". Honestly you can't get rid of the salt. It always comes back. Had a friend in the 80's rebuild a raw water 454 from a shrimp skiff that blew a head gasket. He had it tanked twice and a Mercruiser dealer did the rebuild with new heads. He installed a heat exchanger. The block put out so much rust scale it plugged the exchanger 2 times the first season. He had to pull the thermostat twice a week to clean the crap out and ended up taking it out. The second season it made a chunk of scale large enough to plug up a port in one head and blow a head gasket. The flakes were up to the size and thickness of a penny.
I'm a boat guy, and have played with some pretty cool engines. I agree with skipping anything that's been in salt water, 100%. Closed cooling systems are pretty rare in anything that's not pretty new. I've got this cool Chris Craft Hercules MBL tri-carb to rebuild right now. Not something to drop in a car, but these herc str8 6's sound amazing. Sneak Pic of the boat too...
I picked up a 454 block from an off shore boat in Ga. I had it hot tanked and sonic tested. It took a .060 over bore with no issues. I put a set of 12 to 1 pistons and put over 500 passes on it and then sold it to another racer who ran it 2 more seasons in Super Pro and Super Gas in his Chevy 2. The oval port heads also came from a boat. I paid 50 bucks for the block and 50 for the heads. I have seen salt water big blocks with rust holes in the bores and in the combustion chamber. Our marine patrol training boats were always getting new power plants due to corrosion.
Not if it's a saltwater engine. I don't think that there is an engine rebuilder on Long Island that will touch a cast iron engine that has it's inside eaten away with salt water. Have you ever seen the insides of an engine cooled by saltwater?
Kind of depends where you come from. You're not that far from me. A lot of the ski boats mainly see fresh water in the lakes. Run hard, but fresh water. Only if you know the history. I grew up on boats, and Dad was real careful to idle in slowly in salt water, and cool everything down. We normally moored in Lake Washington, so they got a good rinse after coming back thru the locks. Same with "fresh water cooled" with a heat exchanger. Since the engine ran with a pressure cap, the minute you lost coolant you looked for a bad heat exchanger as it was leaking the salt side into the engine side. But it's a crap shoot unless you know the history. All the engines had "wet" exhaust, heat exchanger or not. Had to keep the pipes cool to exit thru the transom. We never had anything with exhaust out the top.
I once brought a rejected 351W salt water cooled block from the machine shop I worked at to a local community college as a practice block. They skimmed the decks nice and shiny, but the next day the deck surface had numerous little rust patches sprouting. It appears to be evidence that cast iron truly is a bit porous and will absorb the salt water right into the metal.
Back in the '80s it was commonly stated that the small block Ford HO engine used the "marine cam". I have no idea if it was true, or marketing mumbo jumbo.
I have a new one that I pulled out of a B-58 Windsor short block.... I went with an X-303 roller cam instead.....
Unless they are reverse rotation they are ground for low end torque A prop is always grabbing not like a loose converter or spinning the tires to get it in it's RPM range. If you have a standard trans car with a big cam try letting the clutch out at an idle in high gear and standing on it and see how fast it is.
Here in Louisiana a lot of shrimpers used big block Chevy motors in shrimp skiffs. The ones that used sea water to cool the motor almost always had a rust out around the intake or exhaust valve in the combustion chamber. I was out with a buddy in his skiff one afternoon when the cadence of the motor suddenly changed its tone. A few moments later it sputtered and died. The motor was locked up solid. When we pulled it down one cylinder was loaded with water. I thought it had blown a head gasket. A mechanic shrimper told us to look at the heads closely. Upon examination a small dark spot was spotted at the edge of the valve seat. When probed with a screwdriver I was able to push the tool completely into the head opening up a hole as large as a dime. Heat exchanged motors seldom had such issues. I used 455 Olds motors in my skiff also salt water cooled. The Olds must have had heavier castings. I never had any internal rust issues. Now most shrimpers run diesels for the obvious advantages of torque, longevity and such. Not to mention the clandestine advantage of trading a basket of fresh caught shrimp for a charge of diesel fuel to a passing tug or crew boat. Most shrimp guys carry a 12 volt high volume fuel pump and a long section of transfer hose for just such encounters! Life on the Louisiana bayou can be quite eventful at times.
My brother bought a 350 chevy out of a ski boat for his 68 chevelle we proceded to rebuild it bored it 60 thou over after running it for less than 30 mins coolant seeped through a fine crack in one of the cylinders caused by corroded water jackets during its previous life. That was our initiation to stay away from boat engines. What made it worse we ended up finding a beautiful virgin block that had water jackets that looked like they were brand new my brother ended up re-boring that block 60 thou over to fit the parts from his previous engine. Also another point boat engines live a rough life and always under maximum load that means everything in the motor would have been stressed so if you are going to rebuild i would replace all fasteners as well as other parts
Couple of years ago when scrap steel was going for 3 cents a pound, I was in a scrap yard in Chattanooga unloading and a guy pulled in next to me with eight 454 marine engines, some with the outdrives still attached. I questioned him about where they came from. He said they were all local engines from work boats on the Tennessee river. I could have bought the whole lot for 10 cents a pound. There had to be a lot of usable parts in that group. I just didn't need 8 Chevy motors cluttering up my place. Had they been Fords, the story might have been different
I put a reverse rotation 426 Mopar short block in my '40, first time around. Had a rear main oil leak. Turns out the seal journal also had reverse knurling. It was helping push the oil out. Polished the knurling off. Stayed a little wet at the seal area, but didn't leak. Don't know if all manufacturers do this, but seen it on a couple of Chrysler cranks. Gene.
What about the 4cyl Mercruiser engines some guys like to run in their A's? Do they suffer as bad as the V8's from rust, or is it less due to it just being a smaller engine? Interesting thread, bringing up things I haven't thought about....
Some rebuilders won't take a marine block as a core, that should tell you something. I do have a marine 270 baby hemi I will be experimenting on soon though.
Don't know much about these but we did buy a couple of 409 motors from boat shops in the 70's that had been run in drag boats. No problems with those.
If your referring to the aluminum block 470 that uses a BB ford head they were all closed cooling systems. If the riser failed then you could get raw water in the cylinders and have problems. I owned a machine shop on Long Island and over the years used marine engines in all kinds of racing/ street stuff. But as said only blocks that had closed cooling systems. Any thing that was raw water cooled got scrapped. There are many changes that were done depending on the manufacture. As mentioned the Chrysler stuff had the knurl on the crank done in the opposite direction for reverse rotation and that needs to be ground off. Chevy engines just used a different seal. On some of Hemi engines they used a gear drive for the cam and the crank won’t except a standard timing chain sprocket. Sent from my iPhone using H.A.M.B.
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