Anyone have any experinece on using Closed Cooling Systems? Application will be on staggerd twin 540's in salt water environment. Justification (in my thinking) is this would allow me to use Aluminum heads without the worry of corrosion from the salt water, more stable engine temps and less corrosion on block internals. By using a "full" closed cooling system, dry joint aluminum exhaust manifolds or dry joint stainless headers would also last longer as the coolant flows from the block thru manifold then thru exhaust manifolds/headers then returning to the heat exchanger with the raw water that cools the heat exchanger exiting thru the risers/tails. With the staggerd engine arrangement there should not be a fitment and congestion issue of the added heat exhanger. All inputs welcomed.

I have a 406 sbc that is freshwater cooled. the benefits I have found is that I can run a 14lb pressure cap for better cooling, as my block is a siameze block(water does not circulate between the cylinders) to eliminate hotspots,no winterizing needed for the block I run 160 thermostat for better ring seal.could actually run 180 but I'm running a 177 supercharger at 6psi so I worry about detonation. and just for fun I have cooling lines and a cabin heater for the Clearlake boat parade in December just say'n

Benefit - the insides of your engine will not look ten thousand years old. Your running temps will be more consistent, assuming your heat exchanger is large enough. Your warmup time in cooler temperatures will be much shorter. Winterization is a much abbreviated task.

Cons: Is heavier. Takes up more room. Costs more money.

And in a salt environment, the insides of your aluminum heads will look good, but the outside of them will look ten thousand years old in short order unless you keep them away from salt spray and mist.


Adding the exhaust manifolds to the closed loop will dramatically increase the size requirements of your heat exchanger.

I have been running closed cooling for years now. I would never have another engine without it.

As you mentioned cooling your exhaust keep what Mcollinstn said in mind-you will have to have a signifigant cooling system to remove heat from a high performance motor's headers. I put closed cooling on my old jet boat (to keep sand out of motor and to run a concstant temp after seeing what the cold water did to motors) and the exchanger I used was average size, I think it was meant for a mild 454. I tried cooling more than just the engine block itself and even with 35 + psi of cooling water it would over heat the motor so size your exchanger for what you really want from it so you aren't buying another one later, Smitty

Hope I am not Hijacking the thread. For those of you using closed systems, are you mounting the heat exchanger up top in front or somewhere remote? Seems like our engines wind up so unique (especially us with old engines) than an off-the-shelf wouldn't fit up exactly.

Thanks, Randy