Engine Cooling

Am Building A 37` Steel Keeler And Was Thinking Of Installing Cooling On Hull. Does Anyone Know How To Work Out Area Required For 50hp Motor?

 

Look at the heat rejected for the engine and the flow and then get out Mark's Handbook of Mechanical Engineering.

 

I have similar questions, for a faster boat, also in the 50 hp range.

I have come across the following:

http://forums.boatdesign.net/showthread.php?t=4256&page=1&pp=15 - lots of discussion

http://www.ybw.com/forums/showflat.php/Cat/0/Board/pbo/Number/597847/an/0/view/expanded/ indicates 20 sq inches per hp.

http://www.metalboatsociety.com/phpBB2/viewtopic.php?t=115&sid=db7e363dbfacfc1ee60f24eb64d068c8 suggests 30 sq inches per hp.

So I'm thinking of using 1"x4" channel in place of a couple stringers, figure about 20'. 20'*4*12=960 sq inches. Maybe set it up so that some of the channel can be bypassed, in case this is too much capacity. Also, maybe a Y valve to re-route a varying amount of coolant into floorboards in the cabin area, for cold days. Since I'm using a pickup truck diesel, perhaps the heater controls/valves could be used, as is?

Sal's Dad

 

Imagine

The man behind the user name of MikeJohns is an engineer in Australia, he worked out the area for me but needed some manufactureres data for the engine before he gave me the area . You could try raising him. It works a charm. I lost his email but you can find it under users somewhere.
I'll send you that bottle of whisky one day Mike............

Cheers
Jim

 

Jim
Thanks for your message.

I am a bit busy at present to offer free services , but there is a good publication put out by John Deere on marine cooling "Engine application guidlines" Publication AG-24.

You can get this faxed from your John Deere agent. I don't think they have it in an email format.

You will also need your engine specifications particualrly Engine heat rejection.

 

HI Imagine. I live here in S. central Louisiana (Cajun country). I see keel coolers on boats here that exit thru-hull fittings, (threaded, for replacement I'm guessing, not welded) 2 1/2" pipe on one side, run about 10' to the stern, cross over and return back along the keel to return to another thru-hull fitting. A inside valve regulates the amount of flow so the engines run at full heat specs. These are diesel engines & most boats are aluminium (ie, the pipes). The heat transfer is greater. Engines are traded & replaced, so it must work over a range of HPs. These guys are'nt rocket builders but they know what works in their world.