Electrolysis in 7.3 Engine Block
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Electrolysis in 7.3 Engine Block
My machinist found a void/hole/crack in my 7.3 diesel engine block. The cylinder in question was the back left. He bored it out and put a sleeve in.
The interesting part is that he indicated that this may have resulted from a void in the casting ... but more likely he felt it could have resulted from electrolysis caused by old anti-freeze. Just wondered if some of the more knowledgable out there find this plausible?
If this is a problem .... should the entire block be considered suspect?
The interesting part is that he indicated that this may have resulted from a void in the casting ... but more likely he felt it could have resulted from electrolysis caused by old anti-freeze. Just wondered if some of the more knowledgable out there find this plausible?
If this is a problem .... should the entire block be considered suspect?
Posting Guru
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From: Northeastern Pa - USA
Sounds more like cavitation erosion ... it happens to all diesel engines. Seems during the process of burning the fuel there is some molecular degeneration of the block and this causes a tiny hole in the cylinder wall. There is an additive that will slow it down considerably. Caterpillar uses it, International uses it, Detroit uses it and Mack uses it. I dont know how bad the rest of your block might be, but it seems that the 7.3 engines had the problem with the rear cylinders. You can only try it and see if it is still drawing coolant into the cylinders that are affected. I dont know of any "quick fix" that will repair the damage already done. Good luck on your endeavor.
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Electrolysis VS Cavitation
I had just that thought ... a sacrificial anode that would take the beating rather than the block.
What I don't understand is the use of the word "cavitation" ... seems like that would mean that air was somehow swirling around in there ... as opposed to a chemical reaction.
What I don't understand is the use of the word "cavitation" ... seems like that would mean that air was somehow swirling around in there ... as opposed to a chemical reaction.
Post Fiend
Joined: Nov 2003
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From: Nutter Fort, WV
It is air that causes cavitation. And detonation vibration of the cylinder wall is the source of the air bubbles. The erosion is from bubbles forming and collapsing not swirling around.
The SCA DCA 4 deposits a sacraficial layer over the cylinder walls to save the block from cavitation much as a sacrificial anode would on a boat outdrive.
The SCA DCA 4 deposits a sacraficial layer over the cylinder walls to save the block from cavitation much as a sacrificial anode would on a boat outdrive.
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Joined: Jan 2005
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From: Norfolk, VA
search function is down right now or i'd link, but Dave spelled it out. when you can, read up (and don't proscrastinate!)
not to undermine you at all, dave - here's an excerpt from an article on cavitation written by a trusted old goat:
Supplemental Coolant Additives are a must - especially for the 7.3s.
(Dave, please check PM)
not to undermine you at all, dave - here's an excerpt from an article on cavitation written by a trusted old goat:
So what happens is the cylinder expands at a high rate of speed during the power stroke, this forces the coolant away from the cylinder liner, but then on the exhaust stroke the cylinder wall returns to it’s normal state, which snaps back at a high rate of speed. The speed is too fast for the coolant to react so a vacuum is created at this moment in time. The coolant finally slams back into the side of the cylinder when it does this it chips away a small microscopic piece of the metal. Now over time these small microscopic pieces will add up to larger areas. Over a long period of time it can and will create a hole leading to combustion chamber. This is the nature of the beast.
(Dave, please check PM)
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Post Fiend
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From: Manitoba
Oskiford
If I was you I would have all cylinder holes sleeved while your machinist is at it. You then can get on with life without further worry. Cylinders prone to cavitation are 6, 7 and 8 usually........ but who wants too gamble........
Anybody who does not use SCAs in a 7.3 is fool...... especially if you do not do regular coolant replacement with SCAs added and tested regularly. Due to this site and many others the use of SCAs is becoming part of the info people want to know when purchasing used trucks. Purchasers in the know even carry test strips now for their own protection.
If I was you I would have all cylinder holes sleeved while your machinist is at it. You then can get on with life without further worry. Cylinders prone to cavitation are 6, 7 and 8 usually........ but who wants too gamble........
Anybody who does not use SCAs in a 7.3 is fool...... especially if you do not do regular coolant replacement with SCAs added and tested regularly. Due to this site and many others the use of SCAs is becoming part of the info people want to know when purchasing used trucks. Purchasers in the know even carry test strips now for their own protection.
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Running a 7.3 IDI without SCAs is not a good idea you will have a expensive problem on your hands when cavitation strikes you. The original engine in my truck before I bought it died from cavitation and I know 3 other IDIs in this area died from cavitation.
Its a common problem with the 7.3s but it affects all diesel engines some worse than others. The big problem was back in the early years Ford didn't put it in the owners manual that you were supposed to add the additive to the coolant.
The common cylinder togo is number 8 but if you are sleeving the engine do all 8 and it will never happen again. I think its around 100 dollars a hole to sleeve but its worth it if you plan on keeping the truck for a long time.
Its a common problem with the 7.3s but it affects all diesel engines some worse than others. The big problem was back in the early years Ford didn't put it in the owners manual that you were supposed to add the additive to the coolant.
The common cylinder togo is number 8 but if you are sleeving the engine do all 8 and it will never happen again. I think its around 100 dollars a hole to sleeve but its worth it if you plan on keeping the truck for a long time.
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Hi Roy here I have A 88 7.3 IDI I use Evans coolent in mine you do not have to worry about Cav. using it. Also will not boil or freeze check there web sit I think it is Evans.com this stuff is great I have had it in my truck for 5 Yr. now with A new Engine at that time Also dont need A presure cap on system. I know sounds crazy "what ever" I know it works Roy G
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