Engine

[les]

Well I’m reluctant to do that but recognise they could be an issue, so maybe I will. What would you say is the best sealant to use ?

[philthehill]

Lers
The problem is that you cannot see the back side of the core plug and the citric acid may be just the thing to finish off the core plug. When I did my 948cc block the core plugs looked good from the outside but were eaten away on the inside and had to be replaced. To me better safe than sorry.
Just take care with those pan shaped core plugs as they can be knocked right through and near impossible to retrieve.
As regards sealant - I use Loctite Loc & Seal on the pan shaped core plugs.
Phil

[les]

Drained acid after one week, completely refilled for two more. Sample of first week.

IMG_4347.jpeg (1.71 MiB) Viewed 428 times

[59Elva]

Les/Phil,
What concentration of citric acid should be used? After draining and flushing with tap water do you neutralize with a base solution, baking soda or something or maybe flush with distilled water? I have an aluminum water pump, the one that was solidly plugged with green crystals. I’ve not had the 1275 apart other than the pump so know nothing about the internals.
I bought a gallon of “Zerex Original Green “ coolant. It’s low silicate IAT. Temperature fell into the 30’s last night. I had to turn on the furnace and I covered the plumeria outside but I don’t think we had actual frost. They will have to come in soon if this weather pattern continues. I don’t expect sub freezing weather for a while but don’t want to be “caught in the cold”.
Thanks,
Bill B

[les]

Bill, my procedure was as follows——— I flushed the system via the water pump and out the drain exit and back the other way a few times until clear water was seen. Then filled with citric acid, 6 tablespoons per litre of hot water, I found 1 1/2 litres was enough.
I drained it out after a week, it was dark brown, I then filled it again and will drain in a couple more weeks or so.
I then intend to flush out again with water until clear. My aluminium water pump was in the same state as yours. Phil advised me that aluminium can be damaged by the acid and suggested that I used an old pump for the procedure.
When up and running I like to use distilled water with antifreeze.

[philthehill]

The concentration of 6 tablespoons per litre is right. It does not need to be any stronger.

[59Elva]

Thank you gentlemen. Do I need to ask if that is a metric, imperial, ISO , or US tablespoon?