heat exchanger cleaning

[bigbill]

hey guys, i'm cleaning heat exchangers on 8v92s, i need to know what to clean them in. also i'm having trouble getting one exchanger out of the tank,does anyone have a solution to the stuck core ? thanks, bigbill

[Capt. Tobb]

hey Billy, I did not want you to feel all alone here....I can tell you how not to remove a core a week before a tournament....ha ha

[fixin-to-cruise]

My DD V-71 manual Section 5.5 says:

"Immerse the heat exchanger core in a scale solvent consisting of one-third (1/3) muriatic acid and two-thirds (2/3) water to which one-half (1/2) pound of oxalic acid has been added to each two and one-half (2-1/2) gallons of solution. Remove the core when foaming and bubbling stops. This ususally takes thirty to sixty seconds. Flush the core thoroughly with clean hot water under pressure.

To prevent drying and hardening of accumulated foreigh substances, the heat exchanger core must be cleaned as soon as possible after removing it from service."

There's nothing in the manual about getting the core out, but maybe you could use some of this solution. Be careful if the acid is too agressive on the tank!

[fastblast]

I can't help you with your core removal as my engines are 8v53's . However i do have a story about cleaning them yourself . I bought my 41C seven years ago and one of the first things i did was to pull and clean the heat exchangers. Good thing to, the two inch inlets and outlets were down to about 3/4 of an inch! After reading about cleaning them yourself by dipping them in muriatic acid thats what i did. They came out brite and shinny as new. Two years later i decided to pull and check them agan so i could get an idea about future cleaning intervals. They were in pretty good shape, so i dipped them in acid again ( mine fit perfectly into a five gallon bucket ) ,neutralized them with baking soda and reinstalled them. Two mounths later while doing my prestart checks i found zero water in the starbord engines holding tank!! All the implications seemed bad, blown head , lost season, lots of lost money. So for the first and so far only time i called in a pro. His first check was to put a pressure gage on the radiator cap. The tank pressure was way high. He said the heat exchanger was clogged, no way i just did them! He convinced me that it was the the logical place to start.So i told him to have at it. I thought this was just the first spin of the big money wheel. Well, he was wright, it seems muriatic acid only cleans the salt water side and does nothing for the fresh water stde. those tubes were totally blocked. That was a $400.00 lesson learned. Take them to a radiator shop and let them boil them in their solution. I pay $75.00 each and now they really do come out brite and shinny as new.

[Rickysa]

Bill,

Check out Genesis' post on the subject in the FAQ section:

http://www.samsmarine.com/forums/showthread.php?t=1483

Rick