Closed cooling upgrade?

[gtfireftr]

Re-powering both engines..... 4.3 Vortec 4 barrel... Alpha 1 gen 2....
My question is it worth doing a closed cooling upgrade considering I am installing new manifolds, risers, and new engines?
Not sure if the outdrives have an effect on closed cooling.... Never had closed cooling, but if I am going to change I think now is the time...
Any advice is greatly appreciated.

 

[tank1949]

If you use it in salt water, then YES! If fresh water boat, I wouldn't wast the money. BUT, you will have to install a crank pump and water thru-hull pick up to supply water to motors for Alphas. Others have stated that Alphas may draw enough water to cool motors but not exhaust manifolds. I have 100% closed system MC Bravo 1s. Antifreez cools block and exhaust manifolds. Sea water goes through HXs and risers. Water still comes in from OD but main pump is a crankshaft mounted pump. No pullies/mounts. I don't know how you would set up to use both OD pump and crank pump. You might have to remove ODs pump?

 

[achris]

If the water temp doesn't exceed 26C (79F), then you DO NOT need an engine driven pump, the Alpha pump is man enough for the job, even with closed cooled exhaust manifolds.

 

[Scott Danforth]

factory heat exchanger on the 4.3 is a half system (block and heads only). there is a dealer installed option for full cooling. it mounts a bravo raw water pump. the pump in the leg is left, the water is discharged

there are about a doxen aftermarket kits that cool both the block/heads and the exhaust manifolds. these have less restrictions than the factory heat exchanger. as achris mentioned, the pump in the alpha drive would work.

with full cooling the risers are cooled by discharged water from the heat exchanger.

if I was repowering, I would install a closed cooling system. However I would use a half system and get a set of EMI or IMCO manifolds or even a set of HiTek vs factory cast iron manifolds and risers.

 

[achris]

factory heat exchanger on the 4.3 is a half system (block and heads only). there is a dealer installed option for full cooling. it mounts a bravo raw water pump. the pump in the leg is left, the water is discharged.....

I had a factory FULL system on my previous V6 (1994 4.3LX) that still used the Alpha One Gen II pump. Never had an overheat, even in water a few degrees warmer than maximum recommended. At that time the factory systems were only full (includes exhaust manifolds). And as far as I know, they still are. Only a/m have half systems available.

Chris...........

 

[gtfireftr]

Sounds great thanks....
Another question regarding this topic......? Monitor system, or San Juan system.... there is a bit of price difference, and I don't know why...
The Monitor system is 1/3 less $$..
TIA

 

[HT32BSX115]

About 11 years ago, I bought a San Juan system from http://oceaneastmarine.com/freshwater.html

I don't remember if they had systems other than San Juan & Seakamp. I have run my 7.4L (full system) in 85 degree water with no overheats.

I'll never have a boat with open cooling again.

Cheers,

Rick

 

[gtfireftr]

I just pulled the trigger on upgrading to fresh water cooling system on my repower....
I ordered from Monitor... anyone have any experience with installation or use of these kits...
Full system with alpha outdrives..... any advice is appreciated....