Karbokane

There was some info on this in the 928 threads. I was wondering if any one else knows about this?

Performance sells these for 25. Im sure you could make your own as one of the 928 guys did.


All water-cooled aluminum and iron engines experience electrolysis--anywhere from 2 to 7 volts. This charge actually pulls molecules away from aluminum, eating at cylinder heads, engine covers, water pumps, radiators and heater cores. It's a leading cause of mechanical breakdowns. The solution is a magnesium anode built into the Radiator Cap. It draws current away from expensive aluminum components. The anode is sacrificed to prevent expensive repairs. (Your home water heater uses a similar anode for the same reasons.) Nothing will eliminate all electrolysis voltage in the system, but this Radiator Cap with anode will add years of life to your cooling system. When the anodehas been used up, about every year or two, you'll need a new Rad Cap. It''s an inexpensive alternative to a new water pump or cylinder head.

TonyG

There's no iron in either the block or head of the 928 or 944 engines.

Karbokane

yes but they are made out of aluminum

cpt_koolbeenz

Must have two different metals for electrolysis... Those two metals (usu. copper and iron are the best). Seems like our cars would be okay to me...
Not sure?

Tony- did you get my phone messages, email, or pm?
Is your turbo still for sale?

Bengt Sweden

I haven't seen any alu corrosion at all in the 10-15 year old blocks I have teared down.
I have heard about some metal catalyst that you can throw in the fuel tank and increase milage...

TurboCab

I do see corroded cylinder heads. Mine as well, and I always have fresh coolant. Seem to me that this device can help.

87Porsche951

Karbokane , You copied all that info word for word from the Performance Products Catalog. I know of the electrolysis issue but it is onlya problem if your motor has significant wear/damage. Most that stuff is mostly sells talk. It can happen but not likely unless you abuse the motor. ie no proper maintanance.

P.S. Only aluminum has the electrolysis issue, iron does not.

Chris White

There are a couple pieces of ferrous metal in the engine – the water pump impeller is one!
Interesting that this is a common failure point!
I have taken quite a few 944 engines and I have seen some very clean engines and some with a pretty high level of corrosion. This can be the cause of head gasket failure – the area around the metal part of the head gasket can become pitted and cause a failure under load.
The general moral of the story is to use a good coolant and keep the coolant passages as clean as possible.

Chris White

www.944enhancement.com

Ben Z.

Aluminum molecules?? Also 2 to 7 volts is way too high of a potential.

Dave951M

Isn't the turbo ferrous as well? Water does flow through it.

Ahmet

Yeah, my headgasket was "blown" through around the coolant passages from the corrosion on the head.
Ahmet

Jaak Lepson

Chris ... don't the WP's come with a plastic impeller now for last two years now? Mine did.

Jaak Lepson

P.S. Do you have any good air box's in stock yet?

Chris White

The couple of ‘new’ Porsche supplied water pumps that I bought this year have not been plastic – just the typical casting.

Chris

PS – nope – I haven’t seen a really good air box in ages!

KuHL 951

Finally something a newcomer like me can reply to. There will always be dissimilar metals even in all aluminum engines. All castings are designed for optimum function such as strength, heat characteristics, corrosion resistance, etc. Aluminum will corrode and form a hard passive oxide film preventing further corrosion until something removes it such as velocity, chemicals, abrasion, etc. In the case of the advertised magnesium anode there are some real concerns over what the literature states. Yes, magnesium would be anodic to most aluminum alloys (-1.5v to -1.72v (magnesium) to -.9v to -1.0v cast aluminum) Unfortunately the mag anode would do nothing to protect anything attached to a radiator cap on a non-metallic reservoir such as ours. There must be a metallic return conductor to complete the circuit. Even with a return conductor (i.e. hard wire) the anode wouldn't see any of the intended cathode (aluminum) and all it's current output would be in self consumption. Picture a light bulb as the anode, what it can see will receive current; is this case the plastic tank would shield any benefit. If installed directly into an aluminum radiator it might provide limited protection to a small area in the top of the tank only. It will do absolutely nothing for the remainder of the engine. In addition if the magnesium is the high-potential type (-1.72v) it can actually accelerate corrosion to the aluminum by raising it past -1.2v which then breaks down the desirable protective oxide film that makes aluminum so corrosion resistant in the first place.

The best bet is to use a superior phosphate free coolant with distilled water and change it every year. My favorites myths are the cathodic protection systems sold for cars (JC Whitney), corrosion/scale magnets, and the various rust "converters" hawked everywhere.

Rust Never Sleeps; I've spent the last 28 years just trying to get it to take a nap!

Steve

TonyG

Ahmet


I would bet money that corrosion didn't cause your head gasket problem.

Post a pic of the head gasket.