Aluminum heads and salt?

[jkh04200]

Didn't want to jack a thread. In another head several ppl. posted aluminum heads won't stand up in salt water, Why?

[BrendellaJet]

The saltwater eats the aluminum, I think...It is very corrosive.

[jkh04200]

Not to argue with anybody. But, someone correct me if I'm wrong here. All outboards are made of aluminun. Millions of em running the salt everyday. My buddies Chapparal has a 6.2 all aluminum motor. Nowhere does the mfg say not to put it in salt.

[ghittner]

First, let's say it's safe to say we are talking about an open raw water cooling system here?
I would like to know this as well. We all use automotive aluminum intake manifolds as I do and.....no problems. Stainless marine manifolds (aluminum), no problem, outdrives, no problem. Why heads? I've been running in salt and fresh for 20 + years and have never seen the salt ghoulies in a motor unless someone does not maitntain their engines, flushing regularly. That was b4 salt away, now the corrosion risk is even less!

[jkh04200]

This is a sore subject for me. My buddy loves to boat but he wont put his in salt. It almost like he feels he puts it in salt and within a year it will be a rust bucket, exaggerating ofcourse. I do both and have for the past 5 years. You could not tell mine has ever been in the salt. I wonder why people limit themselves. There is so much to see out there.

[jkh04200]

I really feel alot of people don't have common sense. They were raised being told that salt enviroment is terrible. I'm not a fan of the beach at all. I can remeber going to Galveston as a kid and seeing how ate up the vehicles were. Thats a totally diffrent deal there.

[jbone]

No expert here, but salt will attack the weekest metal. Alum heads will most likely be the weekest metal on a BBC. As far as outboards being aluminum, they all have multiple zinc plates to allow the elocrosis to attack them instead of the aluminum.
If I could flush the engine with salt away, or similar product, I would put my boat in salt water. I can't flush my jet, so it never gets in the salt.
Again, I'm no expert, and I haven't stayed at a Holiday Inn Express lately.
J

[Havasu Hangin']

Aluminum corrodes and iron rusts, so pick your poison.
Unless you are leaving the salt in the engine for extended periods, neither will be affected.

[LeE ss13]

Not to argue with anybody. But, someone correct me if I'm wrong here. All outboards are made of aluminun. Millions of em running the salt everyday. My buddies Chapparal has a 6.2 all aluminum motor. Nowhere does the mfg say not to put it in salt.
Exactly .... the real bad deal is that a pair of Aluminum heads bolted to a cast iron block, mix in some salt water and you have a battery !!! To prove it, all you need is a volt meter and put one end on the engine and the other in the salt water coolant. That is also a good way to test your cars coolant. When it gets to .5 volts, it is time to change. The non ferrous metals will start to dissolve and plate to the iron. My $.02

[Boostedballs]

I'm no expert on this either BUT- most ouboards have some sort of consumable anode, like zinc or magnesium, that allows the electrolysis to be concentrated in that location. It greatly slows the electrolysis on other metal parts exposed to the salt water. I would think that you could get away with having a zinc anode near the water pickup for the engine cooling to "charge" the incoming water a bit so it will have less corroding power in the engine. If you made your incoming water port out of magnesium or zinc, I would have some sort of stainless shielding or rubber so when the magnesium gets eaten away, you won't bust a hole in it and have your engine bay fill up with water as your engine runs dry. An anode mounted anywhere underwater that has engine ground will slow your internal engine corrosion. -Even mounted on the outside of the pump as long as the pump is grounded. The more surface area that the sacrificial anode has, the less corrosion your engine will have.
ZINC is common for salt water, MAGNESIUM for fresh water. (I don't know if you can call lakes in AZ freshwater though! HAHA (I lived in HAvasu for 3 years)
If you use zinc in freshwater, it will coat up the anode with some sort of oxide that will need to be wire brushed a little to be usefull again in salt water.

[ghittner]

Aluminum corrodes and iron rusts, so pick your poison.
Unless you are leaving the salt in the engine for extended periods, neither will be affected.
Agreed...

[jkh04200]

Okay, the the battery, thanks, I didn't know that. As mentioned mine has the anodes on e the outdrive. I must have a good ground system on theboat because they start to pitt about every 2 years. I've changed then twice since I've had the boat. What else can be done. I'm wnating to install a aluminum intake. Would running a ground from the intake to the block help?
The salt doesn't do much too the cast Iron. All the big ocean going ships have hundred and hundreds of valves on them. 90% fo them are cast iron. I sale em everyday. From what I've been told is cast iron does not rust. Carbon is what rust and cast iron has very little carbon in it. It will flake/wither sp.? away but its a very slow process. Thats whay there used so much in the ship industry.
I hve seen so much by boat its amazing. Down here you can cruise from daylight to dark and nnever see the same thing twice.

[Boostedballs]

As long as you can read continuity from your engine to the sacrificial anode, you are good to go. I would still bring a little stainless brush with me to scuff up the anode every time I drop the boat in the salt water. Replace it at about 50%.
The anode won't do anything for the water that will sit inside the block when the boat is on the trailor until the next time you run it so, flush with fresh water every time you take the boat out of the salt for at least a minute or two.
sounds like you have some nice boating there!

[ghittner]

PS: I drain my heads and block after each use.......

[jkh04200]

I tink we have some cool places to go. I took one trip down the intercoastal, it is slick calm all the time. We cruiesd at 30 mph, had some adult beveages, ended up at a neat restaurant/bar. Listen to some good music, looked at some bad ass boats. Then headed back to the ramp. That was over 120 miles in one day. Planning another one heading the other way down the intercoastal but this time I have found some rooms right on the water. We'll play on the water all day and end up at the rooms. They have great fishing at night off the pier under lights. I do it all in my boat and it turns heads everywhere I go. Thats the whole reason for this thread mu buddies are missing out on so much because of the salt. I flush/salt away and in 30 mins she's washed and shining like new.