LSA Engine Open Cooling?
11-20-2018 | 11:55 AM
#22
"Unregistered Gun"
Joined: Dec 2005
Posts: 1,423
Likes: 225
From: Paducah, Ky
You need a closed system for many reason and for longevity. Electric water pumps basically are short duration and how does it adjust for the ever wide changing RPMs that a marine engine goes thru for hours on end ? Yes they are great for drag racing and so forth but thats blast off and shut the engine off in 10 seconds -- no hours of on and off the throttles for a jist to see water flow spikes / volumes and water temp drops & spikes. Plus has any one done YEARS of testing for duration with electric water pumps in the complete marine enviroment on open water cooling systems ??
Closed system is what he would need, I think he might be talking about the electric pump that GM used in the ZL1 and CTS-V that circulated the coolant from the intercooler brick in the supercharger lid to the heat exchanger/radiator on the front of the car. That pump had one speed and circulated as much coolant as it could to keep the IAT's down, I had a ZL1 that I built and loved it. You could use a three stage sea water pump (if they make one), I know Hardin offers a two stage pump for the LS platforms. But stage 1 & 2 could circulate freshwater through the Heat exchanger for the engine and heat exchanger for the SC coolant, then use the third stage to circulate the coolant from the SC through the heat exchanger. Just a thought, but LS Swap the world lol
11-20-2018 | 12:29 PM
#23
Banned
Joined: Jul 2011
Posts: 9,594
Likes: 45
From: Ft. Worth TX
Im extremely experience with marine closed cooling since I prob worked on more 496's than one can count plus the many HP 525's along with a ton of inboards.Also new marine inboards and I/Os are closed cooled especially all LS and LSA based engines since their intro into the marine market with the cats = emission controlled engines.
Closed cooling is the way to go regardless of engine especially for MPI engines. It keeps better constant steady engine temps thru out all rpms. This also helps with AFR's as well. That provides better engine temp control for a jist of it.
Also less air and steam pockets, aerated water in the cooling system by far. Also less thermo shock internally - very cold water - vs heat soaked engine. Heads and block upon start up. And this is not even talking about the longevity factor of internals being closed cooled.
Closed cooling is the way to go regardless of engine especially for MPI engines. It keeps better constant steady engine temps thru out all rpms. This also helps with AFR's as well. That provides better engine temp control for a jist of it.
Also less air and steam pockets, aerated water in the cooling system by far. Also less thermo shock internally - very cold water - vs heat soaked engine. Heads and block upon start up. And this is not even talking about the longevity factor of internals being closed cooled.
Last edited by BUP; 11-20-2018 at 12:32 PM.
11-20-2018 | 12:48 PM
#24
Registered
Joined: Oct 2013
Posts: 2,888
Likes: 148
From: SF Bay Area
I’ve always wondered why more boats don’t come with closed cooling for the reasons BUP mentioned. Once you get into big power, sure, but why not the cookie cutter 502 etc? At the factory level it doesn’t seem to be a huge expense on a 100k+ boat.
11-20-2018 | 01:29 PM
#25
Registered
Joined: Jun 2007
Posts: 7,311
Likes: 1,817
From: Merritt Island, FL
Im extremely experience with marine closed cooling since I prob worked on more 496's than one can count plus the many HP 525's along with a ton of inboards.Also new marine inboards and I/Os are closed cooled especially all LS and LSA based engines since their intro into the marine market with the cats = emission controlled engines.
Closed cooling is the way to go regardless of engine especially for MPI engines. It keeps better constant steady engine temps thru out all rpms. This also helps with AFR's as well. That provides better engine temp control for a jist of it.
Also less air and steam pockets, aerated water in the cooling system by far. Also less thermo shock internally - very cold water - vs heat soaked engine. Heads and block upon start up. And this is not even talking about the longevity factor of internals being closed cooled.
Closed cooling is the way to go regardless of engine especially for MPI engines. It keeps better constant steady engine temps thru out all rpms. This also helps with AFR's as well. That provides better engine temp control for a jist of it.
Also less air and steam pockets, aerated water in the cooling system by far. Also less thermo shock internally - very cold water - vs heat soaked engine. Heads and block upon start up. And this is not even talking about the longevity factor of internals being closed cooled.
12-01-2018 | 11:19 AM
#26
Registered
Joined: Jul 2004
Posts: 24
Likes: 1
My opinion about aluminum in a boat is different than most people (and I may get flamed for it), but it is based on my own real world experience.
I use to run a SBC jet drive and the jet, impeller, intake and exhaust were aluminum. The jet was powder coated, but the rest was raw aluminum and after 20yrs of running fresh, salt and brackish water nothing showed any signs of corrosion. I know it sounds like BS, but it's not. I always flushed the motor asap after salt use, but didn't always flush after fresh use.
So based on my experience, I don't worry much about aluminum in a boat. I know there are tons of horror stories out there about aluminum, but I've seen cast iron rot out in short order too.
I've never been able to wrap my head around why there is so much fear about aluminum when aluminum trailers are used instead of steel for salt water use. What am I missing here?
I also don't worry much about using car motors either. I personally don't see any difference, save for the cam and accessories. I'm currently replacing my "marine" engine with a GM crate LS. Yes, I am going closed cooling, which is counter to what I just said, but that is only because I have all the parts from my 496HO to use and I plan to be in salt a lot more than fresh. If I was fresh only, I wasn't going to put it on.
All that being said, BUP makes some good points. Temperature control may be more critical on these engines than the old SB's I used in the past.
And as always, my advice is worth exactly what you paid for it.
I use to run a SBC jet drive and the jet, impeller, intake and exhaust were aluminum. The jet was powder coated, but the rest was raw aluminum and after 20yrs of running fresh, salt and brackish water nothing showed any signs of corrosion. I know it sounds like BS, but it's not. I always flushed the motor asap after salt use, but didn't always flush after fresh use.
So based on my experience, I don't worry much about aluminum in a boat. I know there are tons of horror stories out there about aluminum, but I've seen cast iron rot out in short order too.
I've never been able to wrap my head around why there is so much fear about aluminum when aluminum trailers are used instead of steel for salt water use. What am I missing here?
I also don't worry much about using car motors either. I personally don't see any difference, save for the cam and accessories. I'm currently replacing my "marine" engine with a GM crate LS. Yes, I am going closed cooling, which is counter to what I just said, but that is only because I have all the parts from my 496HO to use and I plan to be in salt a lot more than fresh. If I was fresh only, I wasn't going to put it on.
All that being said, BUP makes some good points. Temperature control may be more critical on these engines than the old SB's I used in the past.
And as always, my advice is worth exactly what you paid for it.
Last edited by yeller; 12-01-2018 at 11:27 AM.
