Timing chain cover
Thread Starter
|
New User
Joined: Nov 2002
Posts: 7
Likes: 0
From: central point usa
Timing chain cover
Im hoping someone can answer this question? I noticed while working on my 78 f350 with a 460. that the water pump is routed thru the timing chain cover, now this cover is alum. and is seated against a cast block wont this cause electralisis being of dissimalar metals? Any way it did to mine its all eatin away near the inlet water port to the block and ill have to replace the timing chain cover.The question is should I put some "nolocks" or other similar corrosion resistant material between the block and timing cover, has any one else had this problem? Help!!!!
Senior User
Joined: Apr 2002
Posts: 482
Likes: 0
From: lake ariel usa
Timing chain cover
There is a gasket between the 2. The contents of the coolant system is what eats away the metal. Aluminum to cast iron is a very common thing most newer vehicles have alum heads and a cast block. The only major problem is the 2 metals cool at different rates.
Senior User
Joined: May 2002
Posts: 484
Likes: 1
From: Garden Grove USA
Timing chain cover
[updated:LAST EDITED ON 20-Nov-02 AT 06:55 PM (EST)]Theoretically, yes, there is some electrolisis (SP?) when ever there is a differenct density in metals and are in contact with the same fluid. With the relatively small amount of fluid though, it generally is not a problem in vehicles. This is why you see these engines several decades old with no noticable effects from electrolisis. A different gasket will not make any different whatsoever. The electrolisis is because of the common fluid, not the connected metals.
In boats, you will see significant problems since the engine is using the same water that the softer (bronze) rudders or (aluminum) propellors are in when they may not be on contact with each other at all. The large area and large amounts of fluid transmit much more electrolisis than the limited amount of fluid found only in an engine. In fact, boats with a closed cooling system, generally do not see a corrosion problem with the engines, but still will with the exhaust manifolds, as they still have the open sea water flowing though them. I have seen open system engines in boats completely destroyed by electrolisis if there is no sacrificial (zinc) metals to take the corrosion.
This sacraifial zinc can be dangled into the water on a rope from the dock, and will take away the corrosion from the more dense metals.
It is also worth noting that most of the electrolisis suffered in the marine industry is due to stray electrical current from other boats, poor wiring on the docks, etc...Most corrosion in car and truck engines is due to poor quality coolant, and stuff just rusts away.
In boats, you will see significant problems since the engine is using the same water that the softer (bronze) rudders or (aluminum) propellors are in when they may not be on contact with each other at all. The large area and large amounts of fluid transmit much more electrolisis than the limited amount of fluid found only in an engine. In fact, boats with a closed cooling system, generally do not see a corrosion problem with the engines, but still will with the exhaust manifolds, as they still have the open sea water flowing though them. I have seen open system engines in boats completely destroyed by electrolisis if there is no sacrificial (zinc) metals to take the corrosion.
This sacraifial zinc can be dangled into the water on a rope from the dock, and will take away the corrosion from the more dense metals.
It is also worth noting that most of the electrolisis suffered in the marine industry is due to stray electrical current from other boats, poor wiring on the docks, etc...Most corrosion in car and truck engines is due to poor quality coolant, and stuff just rusts away.
