Anyone converted to a closed loop cooling system?
 

I am putting serious consideration into converting to a closed loop cooling system that uses a heat exchanger instead of pumping raw water thjrough my engines. No need to winterize my engines, and would suspect that coolant would be nicer to my engine internals... Any thoughts on the matter or recommendations would be appreciated.

You would still need to winterize to a certain extent. You need to run AF through anywhere that water runs through. I just don't see a need for it in this area.

Was going to do the same until
I heard the A F could loosen scale
up inside the motor and clog the
exchanger up. Decided not to do it

I have. Used the kit from monitor marine. It works great! 540 alum heads. The idle is so much better with more heat in the engine.
Steve

Nice site. www.monitorpro.com

I converted mine to closed cooling but I am in salt water. Yes AF is slightly acidic and released scale and rust, but since you are in fresh water you probably don't have much. Another benefit is that I could run a higher temp (160deg) thermostat instead of the 143 and the engine will run more efficiently. Maybe in fresh water you can run a 160 with raw water though. Also, the potential for shock cooling (say after raw water pickup clog is cleared) is eliminated as the exchanger acts as a buffer.

The decision for salt water use is easy, for fresh water it's a toss up IMO.

I run 160* stats in my fresh water cooled engines.

All Mercruiser black EFI/MPI engines run 160* tstats also.

I have been running a 400 sbc in my boat for years, I added closed cooling because of hot spots in my rear cylinders because of the cooling patterns with siamezed block and I run salt water also. I found that i can run a 15lb pressure cap and 160 degree thermostat, which took care of my circulation issues and also improved my idle with a hostile cam also intake manifold corrosion issues. I do recomend the change upon rebuild wich eliminates the issue of loosening up of scale left over from raw water cooling.

We design and build closed water cooling systems and would be willing to help with a complete system or simply advice. You can call us at 866-726-COOL. We're an advertiser as well on OSO. But the bottom line is that if you are going to spend a ton rebuilding your engines, it just doesn't make sense not to install the FWC system. All the flexibility the guys talk about above...it's all possible. Gather the information about your engines and call Jim or myself. We'd be happy to help!


Mr. Cool
www.mrcool.us

I see you guys are local, we are doing a 525 efi upgrade to a whipple charged 509 setup, what would you recomend in regards to upgrading the stock coolers ?

Give me your total HP expectations when done (ballpark) because I have to work backwards from that heat amount to determine the cooler size. Also confirm 1/2 system (nearly certain of that). Also let me know what the size of your current cooler is for the 525 as is and the current hp. Your stock cooler should be a 849952. Just get me the diameter and overall length if you can't confirm part number. Confirm water flow gpm and, if changed from stock, the current fluid flow (gmp) of the oil circuit. if you want, call me tomorrow after 4pm. We're at the Miami boat show and reception is not so good.

We have a standard 525 kit but you're tricking it out and need more cooling capacity. Since you're close and I wouldn't mind seeing your boat I'll probably shoot down to check it out. Lake Erie still got ice? :-). For all not in MI, we got 8 inches of snow yesterday hehe. Now you know why we're so darn cool.

You can email to at [email protected] or leave the information here and I'll get it.

Mr. Cool talk to us about adding a system to a "old" motor? What are the issues that can come up and what are the ways to remedy these things?

This is based on a single cooler, not a tandem cooler setup.

As a start: remember that you may already have thin walls on your block to start off with depending upon the number of years you've been mistreating your 500hp metal mistress by raw water cooling her -- and you may have bigger fish to fry. So you should check that first. Then you have to be concerned with knowing what your fluid flows are coming from your water and oil pump. You have wear and corrosion issues to consider. The coolers are designed to transfer heat with a certain amount of fluid flow through both circuits. So if you have corrosion decreasing the oil and water output because of wear and possibly corrosion in the water circuit itself, you'll have trouble with your heat transfer because of reduction in flow. Wear is wear. The corrosion is, of course, time and use dependent and is a saltwater thing. Not a lot of corrosion in the great lakes.

Cooling is physics. So GIGO. The greatest cooler design receiving incorrect fluid flow inputs provides poor cooling on the output. So...my first suggestion: Define what your real inputs are (fluid flows and engine condition) to determine the scope of your project. Are you adding a cooler, or a water pump, oil pump and kit, -- do you need a block? Should you punt and call Eddie from Young Performance? :-).

If you really want to do it right, the fluid flows are a critical input to the cooler design. Doubling your water flow can sometimes double the cooling just because you've finally gotten past the knee of the cooling coefficient's curve (reynolds # for the engineers out there). Flow is critical.

I just read all of that. I don't know if I went too far with the information provided. I'll enhance some of the other pitfalls tomorrow if you like. I want to see if others have input to this thread and see if I've said something that has a hole in it. There's a ton of knowledge on this board and I respect it.

What all of this says is Step 1: Define your current fluid flows.

I considered starting an engine cooling thread for general questions like this. If the questions keep coming and it seems like it's useful to do so, I'd be happy to field those questions as with this one.

I was with Keith Eickert (the man, not the company) Thursday and he had this exact setup (and it looked so sweet). So I have a pretty good idea of what you want to do. I'm chatting with him tomorrow as well and going over that engine so if you have specifics, email them to me at [email protected] and leave your phone number so I can call.

I passed your information on to my Engine Builder and he will be in touch with you, Thank you for the response.