Raw-Water-Cooled Engine - SailNet Community
 
LinkBack Thread Tools
post #1 of 1 Old 12-26-2001 Thread Starter
Contributing Authors
 
Join Date: Jan 2000
Posts: 244
Thanks: 0
Thanked 9 Times in 5 Posts
Rep Power: 16
 
Raw-Water-Cooled Engine

What are the worries of buying a boat with a raw-water-cooled engine?

Mark Matthews responds:
A lot of older engines are raw-water-cooled. I myself happen to own one—one that's now 31 years old. Let me begin by saying that there is no shortage of potential problems with raw-water-cooled engines. For starters, because the engine takes water from the outside to cool itself, small twigs, sticks, marine life, and other flotsam can lodge into the strainer, clogging it, and causing the engine to overheat. Scale is also a concern. Ocean water, which is corrosive by nature, will build up mineral deposits over time inside the water jackets and other water passages that are crucial to keeping the engine from overheating.

The biggest problem though has to do with regulating the engine temperature. As the water temperature varies, so does its effectiveness to cool the engine. And many raw-water-cooled engines lack a way of governing the flow of water. Those that do have such devices are prone to fouling due to scale and other contaminents.

We have got some good miles out of our Volvo MD2B; we sailed from San Francisco,CA, to Charleston, SC, and used it a lot. Sure there was a blown head gasket, an errant oil temperature light that came on while we transited the Panama Canal, and more hand-cranking than I care to remember; and there was also the leaky water pump, which eventually leaked into the oil and made life miserable for a bit. But several engine gurus we met along the way told us d that we'd be hard-pressed to find a new engine today that will last this long. Today's engines are easier to start, but operate at higher rpms, which in the long run may mean they won't last as long. With the right maintenance, a raw-water-cooled engine may serve you well.

Oil changes are key as is regular service of the fuel filters for these beasts. You can send an oil sample away for analysis, which will tell you a lot about what's going on inside the engine. In any event, if you're unfamiliar with engines, it's a good idea to get the engine looked at by pros. You can then query them on whether the engine will be giving you headaches in the future.

Additionally, if yours is the same model as mine, I should tell you that along the way we learned that the engine is relatively simple to disassemble and reassemble, should you be inclined to take off the exhaust manifold and inspect for scale—it's a relatively straightforward procedure given some patience, time, and determination. I'm hoping, mine will run forever.


To demystify the process, I'd refer you to either Don Casey's This Old Boat or Nigel Calder's Boatowner's Mechanical and Electrical Manual.

 

Mark Matthews is offline  
Closed Thread

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is Off
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome