I installed an aluminum Z head on my 25 paupers coupe (I never went to medical school) last night and am wondering about the magnesium block sold to reduce corrosion. Any body use them? Do they seem to work? The one I have doesn't go down the radiator neck---should I file it down until it fits or just forget about it? Also, do I now have to put a fresh coat of anti-sieze on my plugs every time I pull them out? I haven't had time to drive it yet but I'm anxious to see if it improves performance significantly.
John
I have no experience with the Z head and corrosion but I do have a Texas T water pump made of aluminum.
I realize that different aluminum alloys have different corrosion resistance, but if the Z head is anywhere near similar I would definitely use the block.
The aluminum on the water pump was severely corroded to the point of pinhole leaks.
I think any kind of sacrificial anode when using aluminum on a T engine is an excellent idea!
schuh
Use 50/50 (or slightly less) antifreeze/rain water mix in your cooling system - it'll inhibit corrosion. Many modern cars has aluminum heads on cast iron blocks without much of a corrosion problem - as long as the antifreeze mix is fresh. No modern car that I know of use any sacrificial anode inside the cooling system. Boats in salt water may use them to protect the hull, but that's quite another type of application.
Mine has been on for about 4+ years, copper head gasket, no corrosion noted. I use quality antifreeze mixed with only distilled water in the cooling system.
I've had aluminum heads on Model T's for many years. I always use a mixture of anti freeze and water appropriate for the climate I live in, having lived in California, Texas, Kentucky, Virginia, and Arizona in the past 15 years. I've not had any corrosion problems in my cars cylinder block, radiator, or cylinder head.
Using a block of magnesium in your home hot water heater makes sense. The magnesium corrodes rapidly, and the resulting magnesium oxide goes down the drain every time you take a shower, wash dishes, or drain your bath tub.
In your radiator, a very bad idea, because now you have corrosive magnesium oxide circulating and being deposited in your radiator and block. This is a bozo no - no. Who ever thought of this gimmick does not give a crap about you, your water pump or your cylinder head. They just want to make a quick buck.
I used antifreeze and tap water. I guess I could sacrifice the antifreeze once I'm sure I have no leaks, flush it with distilled water and go back with antifreeze and distilled water mix. I think I will use the anode as well. Thanks everybody!!
I posted before I read your input, Royce. What you are saying makes sense. I'll have to research it further. Thanks
I can't speak to the Mg, but can attest that the Z-head will greatly improve your performance. Mine was installed over ten years ago by a prior owner and I recently had to have the head milled due to normal corrosion an warpage that was about .003.
I've been seriously thinking about a Z head for my '24 Touring car and was wondering about this anode thing too. Can any one explain the proposed theory behind the magnesium block? I understand what Royce says and it makes sense. But I'm curious as to how this little block supposedly prevents corrosion of the head. It does smell like snake oil, but I'm always open to learn new things.
Look up galvanic corrosion.
Doug - thanks. Just did some reading on Wiki, I got the concept now.
I've been reading too but I can't resolve for myself the issue Royce brought up---what happens to the compound formed by the dissolution of the magnesium? What is it, where does it go and what, if any, negative effects does it have?
John, any bare metal will be coated by the magnesium, if you have a clean radiator it will get a gray coating after several months as the magnesium tries to protect the bare surfaces.
Rick
Thanks Rick---appreciate the input.
I used one of those magnesium blocks when I first installed an aluminum head. After a few months it was eaten almost entirely away, leading me to believe it was doing some good. There was some discussion going on here (similar to this one) about the time I noticed that, so I removed it. I drove the car for many years and many thousands of miles after that with no noticeable erosion of the aluminum. I always use a 50-50 mix of antifreeze and distilled water, so apparently that is sufficient protection to prevent the corrosion.
Disclaimer: I am not a chemist or metallurgist. I'm just reporting my experience with my car.
The magnesium does not "protect the bare surface". It attaches and creates a haven for corrosion to fester.
I have an aluminum head and use ordinary green antifreeze mixed about 50:50 with distilled water. I figure distilled water won't leave mineral deposits and what the heck, it's only about a buck a gallon. Having seen the slimy crust that tap water leaves on my house's furnace-humidifier, I've decided against ever using it in my car. So far, no galvanic corrosion problems.
I just bought 3 gallons of distilled water from Wally World yesterday. It was 88 cents per gallon. If you have a good electrical meter that will measure millivolts you can see if you are in danger. Place one lead in the water in your radiator and the other to your aluminum head. If there is any reading then you are seeing galvanic corrosion.
I should have said "Place one lead in the water in your radiator without allowing it to touch any metal...."
I find Z head corrosion is a complete non issue. But have heard stories of this being a problem mostly by guys who have never run a Z head. Was going to try one of those mag blocks but forgot. I run just plain old tap water and have run my car for 8 years now and have never had problems with the head or corrosion. After 8 years and almost 3 sets of tires it would not bother me if the head broke in half. Money well spent.
Well I never expected to get so many responses to this post--thanks everyone! Based on everything so far, I think I am going to simply go with the distilled water and antifreeze. I drove it around the neighborhood last night and found it to be noticeably more powerful. It seems to pull much better and I'm anxious to get out onto the open road. Maybe later today!!
I have had my Z head on for 11 years with no problems and nearly 15,000 miles. I would make certain that the lower end of the engine is in good condition like bearings, rods, etc. I have experienced bearing problems due to the extra compression on another engine that was a little loose. Ran good but worked a little on the bearings.
Tom -- I had a similar experience the first time I installed a high-compression head (Reeder, not Z). It had been quite a while since anyone had adjusted the bearings, but the engine was still quiet until I upped the C.R. It began talking to me, so I tightened up the rods and center main a bit and all was well.
My engine seems to be in good shape. I had changed the head gasket twice and it still leaked by the back exhaust side. I figured the head must be the problem and decided to try a new head and why not step up to the Z. No unusual noises or leaks yet so maybe I did the right thing.
It's a good idea to check / retorque the head bolts after it's been hot at least once.
Still leaks but found the problem---freeze plug!! See new thread.
I don't have any actual experience with an aluminum head or water pump, but this thread has brought up a question. Could the "corrosion" with the aluminum waterpumps be caused by cavitation? I have had some experience with pumps in a past life, and I know that cavitation can cause problems that look much like corrosion. Just a thought. Dave