Water Jacket Help needed

[Diastole]

Water Jacket Rust Scale

I am in the process of changing my head gasket and head to a 5.5 compression variant.

Reason: leaking head gasket (likely from weakened and galled studs) and engine eating water.

Everything looks good, cylinders’s ridge almost in-perceivable, valves clean and seat well, block's deck's flatness (0.002”), no cracks, no issues my club’s advisors can see except …

The problem is, peering into the water jacket, there is a moderate amount of rust and rust scale. See photos

What do I do?
Now is the best time to do something big.

Thinking through my options:
1. Pipe brushes, solvent, and elbow grease
2. EvapoRust (I have one gallon of the liquid, but not familiar with its use)
3. Metal stripping acid like phosphoric acid

The engine is in the car still.

The little bit of copper (it is not rust) on the engine deck is after test fitting the 509C gasket with the copper spray.

Thanks, in advance, for all the advice and guidance.

Diastole in the Smoky Mountains

[Kurt in NJ]

In my opinion the valve seats have be cut too deep especially the #4 exhaust and looking at the block deck surface there is a lot of pitting from rust ,the block deck should be resurfaced after having valve seats replaced .
the heads of some of the valves look rust pitted too.
I would suspect some of the valves are not seating as good as they should due to rust pitting on the valves an seats.
getting the valve seats back to the proper height will improve performance— it did wonders for my car.
It may not what you wanted to hear and just lapping the valves may make some improvements but the heads of the valves should be above the deck surface.
I would take a coathanger and go poking around to break loose as much scale as possible and use a drill bit to clean the small “steam holes “ to their full size too.

[Bob Bidonde]

Ditto Kurt's comments about the valves. I also suggest you heed the attached slides.

[Diastole]

Kurt,
Your comments are welcomed. Our plan was to do that very thing. But, ...

The engine has been rebuilt by a PO. Over-bored 0.060". There is little wear on the cylinders with minimal to no ridge at top of cylinders. Piston to Cylinder gap is 0.002" Deck is flat at 0.002" lengthwise and 0.0015" cross wise except between #2 and #3 where it is 0.0025". All the valves sit proud with the lowest being valves #3, #4 and #7 at 0.003".
All the valves seat. Compressions were 62-64 psi and all hold kerosene with the head off. There is pitting on combustion chamber side of the valves 1, 2, 3, 6, 7. But that is old and there was no rust nor pitting on the undersurface and seats. The seats were inspected and since they had good compression, held kerosene, and the engine ran well the mechanic advised leaving them. They are the original valves so some pitting is expected.

The combustion gasses in the water jacket has caused the rust. Any thoughts of the the water jacket rust and scale while the engine is in the car.

DitSM

[Diastole]

Bob,
All head studs/nuts changed to chome-molybdenum, grade 8. All threaded holes in block cleaned and held liquid brake cleaner all night. And, none of original threads had rust, therefore I doubt any enter into water jacket.
Will torque to 55 ft lbs following the stepped sequence and through 5 heat cycles retorque.
Plan to use your pop-out cable clamp modification.
Any thoughts on thoughts on the rust in the water jacket?

Diastole

[Big hammer]

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Put it together, fix anything that shows up, go for a drive ! stop by your local parts store and pickup some cooling system cleaner , I’ve used Prestone cleaner , follow the instructions

One of my modern’s had 270,000 miles 10 years all original cooling system, it started running hotter than normal. I used the prestone flush and after it was running way to cool 150*F . I thought maybe the thermostat was stuck open, I put antifreeze back in and after a week of driving it was back to the normal temperature 194*F

[Gene F]

I agree #6 Don't over think it. Change your studs, head gasket, and clean up a little while apart. Then run it. Put something in to clean the water jacket as a maintenance task. Drain it for winter. In the spring water, then let cool, and drain it. Then refill next time you use the car, and add something like water pump lubricant, or something to keep the rust down. I think Rislone makes something, and probably available at NAPA or Advance Auto Parts.

Yopu likely have a good car, and no sense in tearing it into a zillion pieces.

[JayJay]

I've seen far worse water jackets than those. I don't see any large scale flaking that would indicate to me that you have a major problem. You could take off the lower gooseneck and scrape/blow out the water jackets from above. You can also run a rod or appropriate sized drill bit down the cooling water holes in the block, but don't remove any metal, just clean out the crud. Keep blowing from both directions, it's surprising what will come out - flakes, dust, small children, etc.

If it makes you feel better you could have your head boiled out (to clean the water jackets) and surfaced (to make sure there's no warp leading to leaks).

Rust-911 may be a more economical alternative if you really want to clean out that rust. You'll want to reinstall the head for this. Drain your coolant (looks like you already have), fill with Rust-911 solution (1 cup concentrate per gallon of water, or whatever the label says), run it for a bit to get the bubbles out, sit for a day or two. Drain (it should come out black) and flush with water. Repeat if you feel up to it. Flush with water until it comes out clean. Then be sure to use either antifreeze or a rust inhibitor when you refill.

In my experience the cooling system cleaners you get at the auto parts stores do a far better job on smudge from oil in the cooling jacket and radiator than they do on rust.

[Chuck Sea/Tac]

Buy a length of 3/8” cable, cut a 12” or so piece of put one end in a drill and go at the water jackets. Blow it out.

[nkaminar]

I second what JayJay said about seeing water jackets that were in much worse shape. You could put it back together without doing anything to the water jacket. But if you want it spotless use the EvapoRust, since you already have it. It will dissolve the rust but not touch the cast iron. It is not toxic and non polluting so it can be dumped on the grass. Block the drain and let it sit overnight or 24 hours then flush with a garden hose. The acid has a chance of eating some of the cast iron that is not rusted.

A perfectionist (OCD) would redo the valves but if the engine was running fine except for the water leakage I would be inclined to put it back together as is. Use the copper spray gasket sealer but use the Best brand graphite gasket. Follow the torque specification and re torque as recommended. I use anti seize on the studs and just hand tighten them after cleaning up the threads in the block. If any are leaking use a gasket sealer like the non-hardening Permatex.

[Synchro909]

You guys have different products available to you from what we have so talking brands is a waste of time. There are chemicals available that will dissolve that rust and you just drain it away. I'm sure someone will help with a name or two for what's available over there.

[Bigsnapper43]

I use a peice of lawnmower throttle cable conduit in an electric drill to run in and around each cylinder. Especially around the back of #4. Then lots of air and flushing with water. I have found many different size particels after the conduit is used.

[pavilla]

With the head off, one trick I stumbled upon was using a telescoping magnet to poke down into the water jacket in the corner near the #4 cyl. You would not believe the pile of rusty crud I pulled out of that area. Just keep poking the magnet down around the corner and end of the engine block until it stops bringing up rust boogers. The rust and scale sticks to the magnet like glue. You can get a similar magnet at HF. Then do your flushing.

[nkaminar]

A great idea. I wonder if a strong magnet in the cooling system, like the coolant outlet "goose neck" would trap a lot of tramp iron and rust.

[Klattu1929]

I used rust-911, did the usual roto rooting and flushed 5 times until cleaner stopped coming out black. I installed a new head and I didn't want to add rust to my head. So I flushed without the head installed. Made plugs to seal the cylinders, and plugged the head stud holes. Built a dam around the top of block, bit of work but my car was torn apart and i had the crank, rods and pistons removed. Worked great.