Closed cooling system

[M&T]

I am concidering installing a closed cooling system on my 350 5.7 I/O. Will there be a loss in HP or perfomance, and will the benifits justify the cost?

 

[ponyman460]

Re: Closed cooling system

interesting...I would like to know as well.

 

[Bondo]

Re: Closed cooling system

Will there be a loss in HP or perfomance, and will the benifits justify the cost?

Ayuh,... If anything, you can run it Hotter for better efficency...

 

[M&T]

Re: Closed cooling system

My research on this system is very limited. I noticed on some of the descriptions it reads cooling for block only. Will I have to have a seperate system for my exhaust manifolds or change them? I am currently running stock exhaust.

Bond-O would you recommend changing to this type of system over the stock set up? If so are most of them equal or would you recommend one over the others. I am rebuilding a chevy 350 5.7 Gen II engine all stock with a GM RV cam. for my power. I have an Alpha I out drive.

 

[Don S]

Re: Closed cooling system

There is going to be very little, if any noticable change in how your engine. more like you will think things are better, but nothing you will feel.
You will only be raising the temp about 20?. The main reason for the lower temp is to keep salt build up at the higher temps. Do you even boat in salt or brackish water?

If you want to do a full system, you are going to be needing an engine mounted raw water pump for more cooling. The Alpha pumps will not handle the extra heat.
Mercruiser has the raw water pump kits along with pulleys and brackets needed to change over to the Bravo type pump.

 

[M&T]

Re: Closed cooling system

To answer your question, I will be boating in freshwater only; no salt or brackish water.

Adding the MerCruiser raw water pump sounds like a much better system than the Alpha I. This brings up a few more questions.

1. With the new system (raw pump) in place do I still need the Alpha I impellers or do I remove them?

2. Do I have to have a closed cooling system to run the raw pump system?
(I think the answer is no for obvious reasons but wanted to ask)

3. If running a 1/2 system vs. a full is there a problem with water back flowing into the exhaust ports?

4. Can my stock exhaust handle not being cooled?



I have found a few links but nothing I feel has any real meat to it. Can anyone recommend a book or link that can help me understand this system better before I attempt to put it on?

 

[bruceb58]

Re: Closed cooling system

To answer your question, I will be boating in freshwater only; no salt or brackish water.

Then its not worth it at all.

 

[JoLin]

Re: Closed cooling system

Then its not worth it at all.

Ditto- no point to it. Lot of work and expense for virtually zero benefit.

 

[M&T]

Re: Closed cooling system

Thanks for everyones advise and opinions. It has all been helpful and saved me some cash which is always a plus.

 

[Black Snow Slide]

Re: Closed cooling system

I have a VP 5.7 with a sealed cooling system. Performance difference? There is none. Reasons for a sealed system:

1. Anything to keep salt out of the block, hot water heater, water circulating pump, and fuel pump means better reliability.
2.Will set your boat apart from everyone else when its time to cure the inevitable 2 footittis.
3. No need to drain the block and such when its time to put her to sleep for the winter.

My motor runs at 180 degrees under all circumstances and loads. I had a computer reprogram for the different temp the motor runs at. If I was a strictly fresh water craft I would not spend the $1100.00 for the conversion. If your in the salt I would say go for it.

 

[Bondo]

Re: Closed cooling system

3. No need to drain the block and such when its time to put her to sleep for the winter.

Ayuh,... That's a fallacy,... You Still have a raw water side that needs Drainin'...