full or half cooling system better?
 

do you use full cooling systems (including the headers) or half system (engine block without exhaust)?

i heard that the full system i installed will let my 454 mag engines get to warm. i have a seakamp heat exchanger which cools block and exhaust manifolds.

thanks for answers and help

chris

Only Ski boats with exposed engines should ever run an uncooled exhaust, even then they'll usually inject water directly into the headers. No boat with an enclosed engine should go without water cooled exhaust manigfolds and risers at the least.

You may find some exhaust that are 'Dry' as in, although still water cooled, the water never mixes with the exhaust, it's just plumbed through a jacket around the exhaust. Most you will find though have water cooled manifolds which the water is plumbed to, then on to the risers (or elbows) then the water enters the exhaust at the end of the risers and out the back she goes. Do not run a boat without water cooled exhaust if the engine is enclosed EVER. Bad Ju-Ju if you do!

If your current setup does cool the exhaust, but you are looking for more power, simply consider upgrading the exhaust to a higher flowing manifold / riser combo.

Good luck!

thanks ghostrider, but i am not talking about uncooled exhaust. at the full system the exhaust manifolds are cooled with fresh water, only the risers are cooled by raw water. at the half system the complete exhaust is cooled by raw water.

the thing is, if the manifolds are connected to the inner circle of cooling than it could happen, that the cooling water gets hotter and hotter. if the exhaust is cooled by sea water, the water runs through the heat exchangers and leaves the engines through the exh. manifolds and risers.

chris

Ah okay, that makes sense. Scared me for a minute there!
I see what you mean though, but I'd worry about running raw water over my exhaust without pre heating it through the engine. Would that cause problems? I run raw water throughout so I don't know about the half closed system. Man, there is so many differences in terminology here. So you mean the closed cooling system with the exhaust only cooled by raw (open) cooling right? So does the water get warm enough running just through the heat exchanger? I suppose it should, being called the 'Heat' exchanger and all!

That would make sense but I'd worry about too cool sea water hitting the exhaust.

Just my 2cents. Sorry for the confusion!

i do not think that the water could be to cool, even to hot. at the closed half system raw water runs through the heat exchanger and leaves the boat through the exhaust manifolds and the risers. at the closed full system the water goes through the heat exchanger and leaves just through the risers. i do not know if it is a problem that in this case the coolant circulates through the engine, the exhaust manifolds and the heat exchanger. the manifolds could make the coolant to hot. in case of the half system the inner circle does not pass the manifold and this makes a huge difference.

chris

I think its just a preference thing or how much salt water you run in .... the half system might be simpler ....

Merc close loops the engine, and raw water cools the exhaust. I think you would need a much larger heat exchanger to cool the exhaust manifolds.

My 600sci has no problem heating up the motor with antifreeze running through the block and raw water running thru the headers and innercooler.

Chris

Chris-Jack:

SeaKamp is a competitor of ours but builds a fine product. You shouldn't have any problems with a full system unless your heat exchanger wasn't sized for the full system or you've pumped the hp an insane amount.

Tell me the hp your running, OD and length of the heat exchanger and I can give you an idea as to whether you're at risk.

mr cool!
the exchanger is sold for use as a full system. it has a diameter of 5" and a lenght of 22". in the middle it is 2" higher.
i am running 454 mags with 365 hp.

thanx

chris

Mr Cool ... how bout some more information on your product ? .....

Hi Guys:
www.mrcool.us

Mr. Cool is owned by Jim Swanson previously with Peninsular Diesel and Russ Cromer (me) a fuel systems guy from way back. We are building a distributing engine cooling products. Tube and shell and plate for the marine industry primarily.
We are in the middle of a web page rebuild to go ecommerce which will be up 5/1. The old pdf on the website is still reasonably accurate.

We supply nearly anything Mercury, Marine Power, Indmar, Westerbeke, Kohler, Crusader/PC, Volvo and more.

We have a rebuild program...send us your old and tired and we'll send you a new one.

We can engineer for hi performance as well. Tell us what you need and we can build to suit. We have Engineers, PhDs in heat transfer (yup, seriously) and PEs with 35 years of heat transfer experience that we use when things get tough.

We've been in the business for 30 years, but opened this business 3 years ago.

I got on this site to meet you guys and hopefully sell a little (I might as well be honest) and learn a bunch. I figure if I help you guys out, maybe you can help me out a little here and there.

I'd like to tell everyone here we are ready to help, just don't know how to get the word out....or did I just do that? :-)

Russ

Chris:

That rise in the middle is probably the surge tank. It captures the fluid in motion when you shut down from full throttle and prepares it to re-enter the cooling stream upon the next demand.

Recheck that diameter and make sure it's a 5 (5.125 to 5.25). If you're running a 4" (appx 4.125 to 4.25 OD), you're going to be in trouble.

If it is a 5X22 (one for each engine of course) and you have the right amount of seawater pushing through it (should be in the literature provided) you should be fine. If the seawater volume is low, cooling drops exponentially.

its exactly this kit: http://www.ebasicpower.com/downloads/SEASK4823.pdf


chris

Yup. Looked it over. This system is based on no change in the standard sea water pump. You should be fine!