Nail head head and block flushing questions

[buick man]

I am about to flush my 364 nail head cooling system. Before I do this I have removed the radiator, water pump and cooling/thermostat manifold to determine the extent of sludge/solidification etc since the car has not run since the late seventies or so.

In so doing, I found that some dampness still existed in the inner heads cooling jacket though it has the usual film of rust butter from sitting. The rest of the cooling system is dry. The cheap aluminum replacement water pump and thermostat goose neck is garbage from electrolysis.

I do not plan to pull the engine at this time unless completely necessary. I would prefer to set up a flush system that would adequately flush the system out. I want to use a flush gun with air/water combo to do the job but have some questions due to some observations I have made.

Now when removing the water manifold I realized that there appears to be only one route for the cooing water to enter the heads from the water pump below. Via this water manifold. But upon further examination I can find no exit route for the heated water to take out of the heads unless I am missing something here. So if I flush the system how will I be able to get good water flushing flow through the heads without removing the water jacket head freeze plugs on the direct opposite rear of the heads against the firewall? Also, where can I buy a water and air controlled flush gun from? Did searches and came up with some very limited and expensive sources.

Any knowledgeable comments or suggestions would be appreciated.

[Bob Engle]

My method of flushiong engines is to remove the radiator and thermostat. Using a pump from a hot tub, I set up for a reverse flush. Put a hose on the suction side of the water pump and put it into a 5 gallon bucket. Run the suction side of the hot tub pump into the 5 gallon bucket and the pump discharge into the thermstat housing connection. Using 200 degree water and a chemical flush; run the pump for 15 minutes. The hot tub pumps give plenty of volume and low pressure. Run as many batches of water and flush chemicals until the water is clean. If the system is really cruddy, I sometimes alternate the flush direction on each cleaning cycle. This system works good on flushing radiators also.

Bob

[bhclark]

Last time I flushed a system, I used the cheap FLAPS preston in-line kit. I'm sure I didn't do an extra good job, but it did get out a lot of gunk.

the problem was, I ended up with a 55 gallon drum of antifreeze tainted water.

Just in case the EPA is listening, I won't tell where I disposed of it, but using your process, how much waste water do you generate and what do you do with it?

I need to flush the system on my '58 super, but i'm sure it would be cheaper to pay someone to do it than risk getting caught dumping the dirty solution....although there's no guarantee that the pro shop will do a great job either...

[buick man]

Sounds like a great flush system Bob. The trick would be to let it just run and run until clean. I would filter the batch each time with a vacuum filter. I think I will do this after I air/water psi flush the system for initial cleaning and debunking. I would want to find an outfit that would take my spoiled water though first.

However the question still remains, upon re-examining the heads, there is no separate water exit. Probably one if not the main reason for the heating problems with the nail head under prolonged torque situations. My conclusion is the water goes into the head and stays there until thermo gradient action moves the heat out conducting the heat via the water as a transfer mechanism instead of just flushing a constant current pass the internals as a means to carry away/transfer heat. This also would allow for a more stable heat condition for the valve guides as well.

However, for getting the crap out of my heads this one-way-street design is a definite concern for flow flushing. Maybe someone can elaborate on this point to be sure. Looks to me just attempting force or flow water into either the top of the water manifold or through the bottom water pump inlet hose, either way the heads will fill with water then via internal pressure will resist direct flushing and flow route will be just through the pump and some of the block. If you examine the water pump design it perks water through slits into the block area via indirect tight meandering routes through the water pump itself and the block orifices. I bet when one attempts a block flush not much flow will go Through the heads! The cure would be to remove the aft head plugs. You would then get flow. Unfortunately head removal would be needed. Otherwise, I see where I may have to fabricate a dual inlet/outlet fitting and bolt it directly to the head orifice where the water manifold would normally bolt onto. Then apply high water psi and keep it going for a while so as to force the water to flow into and through the heads.

[buick man]

Here is what I did. I took the water manifold and the water pump off. I left the timing chain cover on for the moment. I then decgeased the water manifold and then the water pump. Then I soaked them both in a deep bath of phosphoric acid solution to remove rust and scale. I did this repeatedly. Note: If you want to keep the metal part from etching white from the crystallization of the converted phosphoric acid crystals, then just wipe the part dry quickly with a clean cotton cloth/rag and rub. It will turn a deep charcoal tan color and not white out and blotch on you.

The water passages on the nail head have one going into the front top of each bank where the water manifold bolts to. Behind the timing chain cover if you were to remove it are two inlet/outlets for the block. I left the timing chain cover on but one could take it off and expose these block ports but you would have to rig up a inlet adapter to fit over these holes to do what I did.

I then temporally reinstalled the cleaned water pump and water manifold without the thermostat and just bolted on the cleaned goose neck thermostat housing. I had previously removed my radiator so it was not in the picture. I used just a paper gasket for these mountings and leakage was of no real concern. I then filled a 5 gallon bucket with phosphoric acid solution. You can use any brand that is out there for this as long as it is just that, a phosphoric acid solution for rust conversion and removal.

I then got a cheap sealed bearing pump. I used a boat bilge pump I had laying around. Before I used the phosphoric acid rust remover, I first flushed the entire block out with hot clean water from my water heater as best I could going both with the regular flow via the bottom inlet of the water pump, and then reversing the flow using by going into the water manifold via the goose neck. I also at this time removed all the brass engine water drain cocks from the block. Removed not just opened. I reinstalled them for the acid wash treatment detailed below.

After repeated flushings, I then hooked the bildge pump ( high volume/low pressure pump) to my phosphoric acid solution 5-gallon bucket. I had the return hose coming back to this bucket so I could keep a continuous flow going and then turned on the pump. I let it run flushing the acid solution thru the entire cooling flow circuit ie heads and block for an hour. Then I reversed the flow and repeated. Then I would reverse the flow and repeat. I continued this for about 3 hours. I had installed a filter canister on the return hose back into my bucket so I had to stop often and clean it out. Then I proceeded and continued on.

The result was a rust and crap free block and heads. I then removed the water manifold and water pump and reinstalled new brass engine block pep cocks. I have yet to install the new water pump but the water manifold after the acid wash looks like new inside. I then removed the timing chain cover and cleaned, degreased and acid washed this as well. I will be installing a new timing chain and gear set along with a new modern type crankshaft oil seal.

When all is said and done I hope to have a clean cool running engine. I have had the radiator cleaned at a shop but they reported that although the flow was adequate there had been repairs to leaks made in the past and that a new core should be sourced if I want to drive it out of town on a long trip and to run a 7 lb cap instead customary 15 lb radiator cap to keep the pressue down. I have found that to get it recored properly and cosmetically correct for show, it will run around $ 800 dollars or so.

Just thought I would share what I did. I will post pictures of the steps to what I did when I can get around to that.

David

I found keeping everything bolted on allowed me to just use adapter hoses to manage the flow.