Corrosion, ever ate through a cylinder wall?

[nathanhooper]

I am having some corrosion issues with my 79' I-6. I also am having some water intrusion into cylinder(s). I have another post going with that, because I am hoping it is the lower crank seal and not related to the extreme corrosion I found when pulling the powerhead to replace the seals.

In the first photo you can see a small crack, that pretty much just flaked off when I touched it, the aluminum was very, very thin. I then decided to take off the exhaust cover to look in it and found even more corrosion. It also ate through the inner jacket cover, but in the water passage area, not the exhaust side. Hopefully you can tell what I am talking about from the pics.

This has really got me stumped because the motor was very clean looking. It is not a saltwater motor that I know of, but looking at the corrosion issue I cannot see how fresh water would do this to one. Anybody have some comments or pictures of extreme corrosion caused by fresh water?

I am going to pull off the head cover to take a look in there. Is there a chance that I could have corrosion eating through the cylinders? I did a compression check on it when I first got it. No signs of any weakness, but I did have it running and am wondering if it running managed to stress it enough to cause a crack to form.

This never crossed my mind or else I would have already done another compression check, I will be doing that tonight. I just thought I would get some insight from the helpful folks on here today while I mull over my options on this motor. Like, at what point does corrosion become too bad and is a risk of breaking through and causing serious problems while out on the water?

Hopefully you can see the extent of the wear it has caused. There are quite a few places where it feels/sounds like I could take the tip of a screwdriver and with minor force punch through the metal.

 

[nathanhooper]

Re: Corrosion, ever ate through a cylinder wall?

Here are some more pictures...the first couple are of the hole ate through the inner cover and the corrosion that has just completely thinned out the aluminum as far as I can tell. Unless it is supposed to be that thin.

The last photo is a spot on the outer cover that I noticed before taking off the cover(s) to examine the inside. I scratched the paint with my fingernail and it just powdered off. It has a very thin/hollow sound when you tap it with your fingernail as if it would just break through. I am not sure just how much of a concern this all is.

Would just replacing the covers do me any good? Is it probable that the block itself is just too worn to be corrected? Advice is needed here.

 

[Chris1956]

Re: Corrosion, ever ate through a cylinder wall?

That sure looks to be a motor that has seen some salt water, or some real polluted water.

I have seen damage on the baffle, water jacket cover and inner cover, like you have seen. However, I have never seen any significant damage to the block or liners, however, I suppose it would be possible if the motor was exposed long enough.

 

[nathanhooper]

Re: Corrosion, ever ate through a cylinder wall?

Yea, so now it would be anyones guess if I could find the covers or not. Or if it would even be worth it. I am pulling the head/water jacket cover off tonight if I get a chance. Then I can see how bad the corrosion is inside of there.

 

[Dave1027]

Re: Corrosion, ever ate through a cylinder wall?

Wow. The further you dig, the worse it gets. I think the thing is toast.

I'm curious about the history of the motor with you being in landlocked Arkansas and all.

 

[nathanhooper]

Re: Corrosion, ever ate through a cylinder wall?

yea, me too. I think someone could "fix" the water intake chamber on bottom of block with some welding and such. The inner and outer cover would need replaced though, they are way chewed up and could potentially fail at any time I think, but then again I am not an expert. I am curious as to what the head water jacket cover looks like and what the outside of the cylinders look like. I really had high hopes for this motor because of the look of the outside of it, but looks can be deceiving it seems.

I know the guy I got it from had it sitting out in his field for 5-6 years. Before that it came from a retirement community not too far from here. Most people have moved from up north to here, but I would not be surprised if it came from someone that moved from the gulf or something up here. Who knows for sure.

I would love to know if there is anyway possible that this kind of corrosion could be caused by fresh water though. It would be interesting if there is someone else out there that knows exactly where their motor has been and had the same kind of damage to the inside as this does. But for all it seems this has to be salt water damage. I have another motor that has seen some really hard running days and the corrosion on the inside of it doesn't even hold a candle to this.

maybe it is fixable, but it seems like it wouldn't be worth the hassle. I attached some pictures of what it looks like on the outside. It was this clean after sitting for years. All except it was covered in dirt dabber nests. There is no sign of a new paint job, everything looks factory. But as I was up loading the pics I got to thinking that if it was indeed salt water driven you would think that the grounding straps would be toast on the motor. But, I guess if a guy was taking care of it the best he knew how, he would have taken care of all the external stuff not realizing what was happening on the inside.

I doubt if I will ever know for sure. What a waste.

 

[Chris1956]

Re: Corrosion, ever ate through a cylinder wall?

Well, it sure looks better on the outside then the inside. it does look factory-fresh.

 

[Chris1956]

Re: Corrosion, ever ate through a cylinder wall?

Those cable ties on the fuel lines are factory. it appears that the fuel lines are all factory, but the fuel pump may have been taken off, possibly for rebuild, hence the ss hose clamps. It doesn't allear the carbs were ever serviced.

I guess the PO hosed the block off every time it was used, but never flushed the salt out of it....

 

[nathanhooper]

Re: Corrosion, ever ate through a cylinder wall?

Well, I replaced the fuel lines when I cleaned the carbs. I went back with cable ties and hose clamps. Hose clamps on the fuel pump because it seemed as if the hose was a little loose with ties and I did not want leaks.

Update is that I did take the cover off and no sign of wear through on the cylinders from the outside in. It is very corroded, but I think it will clean up. Checked compression also and it is the same as before when it ran.

I got more pictures and details on the thread of 79' powerhead removal.