no engine coolant over winter OK? heat exchanger removed

[kerk fisher]

Had a great two months sailing. Love this boat!

When I couldn't get the pencil zinc off I decided to undertake a thorough checking of  the heat exchanger, so proceeded to take it off and have it cleaned over the winter. This is what I did.  A few days ago I winterized the engine with "the pink stuff" through the freshwater cooling system. THEN I took off the Heat Exhanger. I the process, of course , I lost some of the "pink stuff" and much (all?) of the coolant (the green stuff). I left the engine in that state in Midland, Canada (cold) and have the heat exchanger here with me in KY over the winter>(Rushing back to work after two months sailing. Then I had second thoughts.  Will the engine be OK over the winter without coolant and all the pink antifreeze? One diesal mechanic here says OK but I need to check you all who know more about the specifics of our 35M. Do I need to go back up (800 miles!) and finish the job or will it be alright?

Also, what are the specifics of putting it back? Check the hoses for replacement, connect the hoses, fill the engine with coolant.  Do I need to do any bleeding of air from the coolant or pink stuff/water system?or does that take care of itself--unlike air in the fuel lines.  If so how do I do it? 

Much of the time I feel I am way over my head with these projects, but with this great website I am gaining courage to wade in....... Thanks, Kerk

[Ted Pounds]

Your mechanic is right.  She'll be OK.  The important thing is not to have any plain water in the cooling systems.  That'll do damage when it freezes.  In fact after I winterize with the pink stuff I drain the muffler and some of the hoses (when I remove the impeller).  After you top up the green coolant in the closed part of the system you probably will need to beed some air out.  Do a search on this board for info on how to do that.

[Ron Hill]

Kerk : You're engine should be OK after you ran winterizing coolant thru the "raw water" system. 
Don't worry about the loss of "internal coolant" until you reconnect the heat xchngr next spring.  Then you'll need to refill the internal coolant back up and bleed the air out of that system.  Easily done by sucking air/coolant out of the heater return line to the engine thermostat until you get ALL coolant.  Reconnect that hose and you should be good to go.
Read about this topic on our site and you engine owners manual.   

[kerk fisher]

Thanks. Whew! How do I "suck" the air/coolant through the return?

[Ron Hill]

Kirk : "How do I bleed the air out of the internal coolant system" has been written up many times!!! 
Take a small suction pump and attach it to the upper inlet hose that goes into the thermostat.  Then suck out the fluid and air until all of the air is out of that line. 
It's written in FAQs and projects.  It's also addressed in your engine owners manual. 
Send air fare and $300/day per diem and I'll come up and do that 15 minute job for you!!   

[kerk fisher]

Ron, I was looking in the heat exchanger search rather than the internal coolant. Hadn't gotten that far yet. Got it. Your discussion on the Jabsco pump. I'm a gettin' one. A great way to do the transmission fluid. The turkey baster I"ve been using the last two seasons is not a happy scene.    You do mention in one of your discussions that you do a reserve overflow tank to avoid oxygen caused by low fluid, oxygen being one of the prime ingediants in rust. With no coolant in the system will I have a dangerous rust situation?  Anyway, I don't need to pay you to come (Thanks for the offer), BUT if you've never been in these waters, you should come up. I"d be glad to show you around. It's magnificent!  (By the way, when I finally got the pencil sinc out it was totally gone!!  Thanks for your help.  AND, is there really any such thing as a 15 minute job? Maybe because I am new at all of this, everything is taking longer than expected--a scene I'm familiar with from working on old houses.  Kerk

[kerk fisher]

Another question: the heat exchanger tubes run from one side to the other. It looks as if the internal coolant and the raw water would mix. Somehow I think not. HOw does it work?  Kerk

[Stu Jackson]

1.  It's empty, what's gonna rust?

2.  It's called a shell & tube HX.  One liquid goes through the tubes inside the shell.

As previously suggested, I think, Kerk, please buy Calder's book: "Boatowner's Manual for Mechanical and Electrical Systems."  They just came out with a new third edition, so you should be able to buy the 2nd edition on ebay or B&N for a lot less than $50.  The 2nd edition is great for older boats.  The new edition doesn't add much new that's applicable for our boats.

[Ron Hill]

Kerk : Stu nailed it - it's empty so it won't rust in that next 6/8 months.

Look at where you took the zinc from in the HX, you'll see that the raw water flows on the outside of the tubes and the 50% Prestone coolant mix flows thru the inside of the tubes.  The scale and crud builds up on the outside of the tubes/inside HX cylinder wall.  It's that calcium and crud build up that prevents the maximum transfer of heat from the 50% engine coolant to the raw water.

Just did the Lime-a-Way cleaning (Mainsheet tech notes this month) on my HX yesterday.  It had started to run at 180 degrees.  After the L-a-W, it's back down to just under 160 degrees!!   

[kerk fisher]

Ron, Stu, Ted. Thanks. Ron,your last info on the flow pattern (in and out) was the clincher!! Thank You!! Calder's book will be great winter reading. And what great timing to have the Mainsheet article on HX maintenance waiting for me. I had not gotten to the stack of mail before entering into this forum discussion but dug it out immediately. Kerk