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Osterkraut wrote:curtis73 wrote:The only real concern with the marine part is that it may give you fits if it ever had saltwater in it. There is never any way to get all the salt out of the pores and salt + glycol coolants = green jello.
How is this a problem in a closed-loop cooling system?
If it's cooled with raw water it will be full of salt.
Osterkraut wrote:curtis73 wrote:The only real concern with the marine part is that it may give you fits if it ever had saltwater in it. There is never any way to get all the salt out of the pores and salt + glycol coolants = green jello.
How is this a problem in a closed-loop cooling system?
That's why I said salt "in it." It wouldn't be a problem on a closed-loop cooling system. I shoulda been more clear 
carguy123 wrote:This boat has never seen salt water.
But are you certain its was not a rebuilt block that had been used in saltwater?
chaparral wrote:Osterkraut wrote:curtis73 wrote:The only real concern with the marine part is that it may give you fits if it ever had saltwater in it. There is never any way to get all the salt out of the pores and salt + glycol coolants = green jello.
How is this a problem in a closed-loop cooling system?
If it's cooled with raw water it will be full of salt.
I know it's standard op for outboards, but are there inboards out there that really have an open coolant system? Did the British come up with that?
curtis73 wrote:carguy123 wrote:This boat has never seen salt water.
But are you certain its was not a rebuilt block that had been used in saltwater?
100% positive I was there when it was bought and have been on it many times since. I know the complete history of the boat.
100% positive I was there when it was bought and have been on it many times since. I know the complete history of the boat.
Great, then no worries on the glycol.
I know its not easy to get to it, but when you get a chance, post the block casting number (above the bellhousing flange behind the intake) and the block stamp (on the 1/2" flat pad in front of the starboard head) and the head casting (remove valve covers.)
With that information I can narrow it down to who assembled it and what color his pubic hair was. Ok, not really, but I can narrow it down a lot.
Osterkraut wrote:chaparral wrote:Osterkraut wrote:curtis73 wrote:The only real concern with the marine part is that it may give you fits if it ever had saltwater in it. There is never any way to get all the salt out of the pores and salt + glycol coolants = green jello.
How is this a problem in a closed-loop cooling system?
If it's cooled with raw water it will be full of salt.
I know it's standard op for outboards, but are there inboards out there that really have an open coolant system? Did the British come up with that?
When's the last time you saw a radiator in a boat with an inboard engine?
Most boats suck the water right out of the lake/river/etc. It's great for running water to air intercoolers also.
Osterkraut wrote:chaparral wrote:Osterkraut wrote:curtis73 wrote:The only real concern with the marine part is that it may give you fits if it ever had saltwater in it. There is never any way to get all the salt out of the pores and salt + glycol coolants = green jello.
How is this a problem in a closed-loop cooling system?
If it's cooled with raw water it will be full of salt.
I know it's standard op for outboards, but are there inboards out there that really have an open coolant system? Did the British come up with that?
I worked at a chesapeake marina for 3 years and never saw a closed system except on utility/commercial boats. That is mostly because fresh-water systems are cheap and usually outlast the rest of the drivetrain.
In my experience, closed systems are for A) boats that are big enough that the extra weight penalty isn't a problem, and B) for boats that are already expensive enough that the buyer can afford it.
Closed systems require a teeny bit extra maintenance which most boat owners think is far beyond their talents. Closed systems are therefore only used sparingly for marketing purposes. Cheap boats with easy maintenance sell like hotcakes. Most of those buyers use their boats three times a year. Once galvanic corrosion turns the engine into powder its out of warranty. Then when the disgruntled owner gets on boat forums and tries to start a class-action suit, everyone just says; "dude... you should have flushed it."
theenico wrote:Both inboard engined, offshore fishing boats I've been on had closed loop/fresh water cooling systems. Always figured it was the norm, because, you know, highly corrosive salt water. The guys that owned them made a lot of money, probably makes sense they'd purchase higher-end equipment.Osterkraut wrote:chaparral wrote:Osterkraut wrote:curtis73 wrote:The only real concern with the marine part is that it may give you fits if it ever had saltwater in it. There is never any way to get all the salt out of the pores and salt + glycol coolants = green jello.
How is this a problem in a closed-loop cooling system?
If it's cooled with raw water it will be full of salt.
I know it's standard op for outboards, but are there inboards out there that really have an open coolant system? Did the British come up with that?
When's the last time you saw a radiator in a boat with an inboard engine?
Most boats suck the water right out of the lake/river/etc. It's great for running water to air intercoolers also.
novaderrik wrote:bravenrace wrote:Marine engines are designed to be efficient in a narrower RPM band, since they spend most of their time at one RPM. So cam and ignition tuning is different, and the heads "may" be also.
a lot of the GM crate motors are just repurposed marine engines and as such come with marine cams in them and they do just fine in street car/truck applications.
That doesn't mean they aren't different. At least they should be. If a marine engine makes a good street engine, then it wasn't that great of a marine engine.
Any engine is designed and tuned for it's intended application. If done right, a marine engine and a street engine would necessarily have to be different.
Marine engines are designed to be efficient in a narrower RPM band, since they spend most of their time at one RPM. So cam and ignition tuning is different, and the heads "may" be also
Disagree... marine engines have to be tuned to work over the entire RPM range. Low end torque is incredibly important, especially where it peaks in the RPM range. You can build a 500-hp 350 for an I/O, but it may never get on plane since the torque peak is higher than the "flash stall" of the proper prop.
That doesn't mean they aren't different. At least they should be. If a marine engine makes a good street engine, then it wasn't that great of a marine engine.
Any engine is designed and tuned for it's intended application. If done right, a marine engine and a street engine would necessarily have to be different.
I think you might be surprised. A great I/O engine would be hard to distinguish from a street motor. From the factory, a 350 vortec Mercruiser engine came with 9:1 compression, factory heads, intake, cast crank, stock rods and hypereutectic pistons. Cam specs out to 194/204@.050" with a lift of .457" with a 112 LSA.
Ignition curves are very similar on the mechanical side, but marine engines don't use vacuum advance.
bravenrace wrote:novaderrik wrote:bravenrace wrote:Marine engines are designed to be efficient in a narrower RPM band, since they spend most of their time at one RPM. So cam and ignition tuning is different, and the heads "may" be also.
a lot of the GM crate motors are just repurposed marine engines and as such come with marine cams in them and they do just fine in street car/truck applications.
That doesn't mean they aren't different. At least they should be. If a marine engine makes a good street engine, then it wasn't that great of a marine engine.
Any engine is designed and tuned for it's intended application. If done right, a marine engine and a street engine would necessarily have to be different.
GM doesn't even try to hide the fact that a lot of their crate motors are marine engines with different oil pans on them. the fuel injected Ramjet 350 and 502 engines are taken directly from the marine department.
GM doesn't even try to hide the fact that a lot of their crate motors are marine engines with different oil pans on them. the fuel injected Ramjet 350 and 502 engines are taken directly from the marine department.
Exactly. Even the ZZ4 intake carries the same casting number as the marine intake. Heads are the same, except most marine builders now use Inconel exhaust valves.
In reply to Osterkraut:
Most inboard/outboard setups will be open loop, with the exception of some really big or saltwater specific setups, or if it's a Volvo Penta out drive. A lot of those were closed loop even in small pleasure craft applications. Once you get into something that might be called a "yacht" the closed loop systems are more the norm. Almost always if there is a diesel engine aboard
Strizzo wrote:In reply to Osterkraut:
Most inboard/outboard setups will be open loop, with the exception of some really big or saltwater specific setups, or if it's a Volvo Penta out drive. A lot of those were closed loop even in small pleasure craft applications. Once you get into something that might be called a "yacht" the closed loop systems are more the norm. Almost always if there is a diesel engine aboard
Well now, they both were exclusively saltwater fishing boats, and because I remember at a young age being convinced Volvo Pentas were the best (Mercruiser second), you're probably on to something.
As it was explained to me on a boating engineering forum: Buying a closed-loop system for a boat is like buying a water-cooler cruiser motorcycle. One isn't better than the other, just different strokes for different folks.
I'm a fresh-water cooling kinda guy. You can seriously push the limits of compression and timing when your coolant is an endless supply of 70-degree water. The few times I do hit saltwater, I just flush later.
