Page 1 of 2

blocked engine drain tap

Posted: Sun Jul 19, 2020 6:47 pm
by jeff-d
hi, i have the engine out of the car and and i am reconditioning most parts, but i unscrewed the engine coolant tap on the side and found it full of solid rust, i dug it out for about 6-7 inches but how do i clean out the rest of it cheers

Re: blocked engine drain tap

Posted: Sun Jul 19, 2020 6:52 pm
by philthehill
You have reached the limit of penetration from the block drain plug.
All you can do is remove all of the core plugs and have a good poke around. Alternatively fill the block with food grade citric acid and let it stand for a week - then flush. Mix the citric acid at 6 tablespoons to 1 ltr of hot water.

Re: blocked engine drain tap

Posted: Sun Jul 19, 2020 8:06 pm
by JOWETTJAVELIN
That was a good tip Phil I used on mine, one water jacket drop later it's still coming out black. But I first went through what Jeff is going through. Just shows the importance of regular maintenance and using SOFT water.

Re: blocked engine drain tap

Posted: Mon Jul 27, 2020 7:48 am
by Andyhereford
Would the above citric acid tip be a way of giving the engine block a good clean out while it is in situ in the car or would it have a detrimental effect on the radiator and hoses. Presumably giving the system a flush in the conventional way does not remove the accumulations of rust.

Re: blocked engine drain tap

Posted: Mon Jul 27, 2020 8:39 am
by philthehill
The hoses will be ok. The risk is with the radiator and heater cores. What you can do is isolate the heater and radiator and then use the citric acid.

Re: blocked engine drain tap

Posted: Mon Jul 27, 2020 9:25 am
by Andyhereford
Thanks I will give it a go then. I suppose that the easiest way to isolate the radiator and heater would be to simply disconnect / block off the hoses. No effect on the water pump or thermostat?

Re: blocked engine drain tap

Posted: Mon Jul 27, 2020 9:50 am
by philthehill
I have seen no effect to the water pump or thermostat on those engines I have used the citric acid to de-scale/de-rust the engine blocks.
Phil

Re: blocked engine drain tap

Posted: Mon Jul 27, 2020 1:51 pm
by newagetraveller
I use a suitable drill bit to clean them out as much as possible. The largest one that will fit in the hole.

Re: blocked engine drain tap

Posted: Mon Jul 27, 2020 2:06 pm
by philthehill
I have just prepared a 948cc block for soaking with citric acid.
It is really rusty in the water jacket.
I took the old core plugs out to see how bad it was and it was bad. They have now been replaced with new core plugs.
Water jacket 1.JPG
Water jacket 1.JPG (2.41 MiB) Viewed 481 times
Water jacket 3.JPG
Water jacket 3.JPG (1.44 MiB) Viewed 481 times
Water jacket 4 (2).JPG
Water jacket 4 (2).JPG (1.15 MiB) Viewed 466 times
If the other 948cc block de-rusting outcome is anything to go by this block will come up as good as new.
I will post some after soak photos in a while. I will leave this block to soak for at least four weeks as it is just a spare block but is well worth the effort in bringing it back to serviceable condition as the bores are reasonable.

Whilst a drill can be used to clean up and de-scale the water ways there is much more to the water jacket than can be seen. The citric acid gets to all those awkward corners and does the job nicely.
The block is filled just short of the top face with citric acid. It has now been pushed into a corner and left for the citric acid to do its work.

Re: blocked engine drain tap

Posted: Mon Jul 27, 2020 3:39 pm
by philthehill
Water jacket 8 (2).JPG
Water jacket 8 (2).JPG (1.45 MiB) Viewed 462 times
The citric acid is mixed at 6 table spoons per ltr of hot water.

Re: blocked engine drain tap

Posted: Mon Jul 27, 2020 11:20 pm
by jagnut66
Be interesting to see some comparison pictures when the four weeks are up Phil.
Best wishes,
Mike.

Re: blocked engine drain tap

Posted: Wed Jul 29, 2020 1:44 pm
by philthehill
Just drawn some citric acid mixture out of the 948cc block and you can see that the citric acid is already doing its job. :D

See photo below:-
Citric acid 1.jpg
Citric acid 1.jpg (543.4 KiB) Viewed 393 times
That was clean water 24 hours ago, now discolored with rust.

Re: blocked engine drain tap

Posted: Wed Jul 29, 2020 5:12 pm
by Edward1949
I read somewhere that fresh water does its worst to the innards of the block and then becomes effectively neutral. In other words, fresh water is the enemy and breeds rust; old, used water is good. It was suggested that old coolant water should be retained when draining the system for maintenance, and put back in. Older cars like the Minor, with no overflow header tank, will always lose a bit of water if filled right up. Enthusiastic owners over the decades constantly topping up to the filler neck have been doing the wrong thing! My Minor's level happily remains at about one inch below the filler neck.

Re: blocked engine drain tap

Posted: Wed Jul 29, 2020 6:39 pm
by philthehill
Old coolant/antifreeze looses its ability to protect against rust so you do need to replace the coolant every few years. Best if you use a hydrometer to check the strength of the coolant/antifreeze.
Distilled water is best for use in the coolant system as it does not have the nasties that tap and to a lesser degree rain water has.
You can buy additives to put in the cooling system to help prevent rust.

Re: blocked engine drain tap

Posted: Wed Jul 29, 2020 9:24 pm
by alanworland
What about the 'water less' product that lasts indefinitely!
Can't think of the name at the moment but when I looked into it I think I was looking at about £45?
But if it lasts forever?

Alan

Re: blocked engine drain tap

Posted: Wed Jul 29, 2020 10:38 pm
by philthehill

Re: blocked engine drain tap

Posted: Wed Jul 29, 2020 11:28 pm
by jagnut66
My engine and heater are completely drained at present, so I'm giving serious consideration to the Evans prep and Power Cool 180 waterless coolant.
So long as it is okay to drop it when I need to work on the engine and then put it back in again after.........
It has a claimed life of over 20 years.
Best wishes,
Mike.

Re: blocked engine drain tap

Posted: Thu Jul 30, 2020 8:33 am
by Matt
I can't remember exactly who/where but I have read that the waterless coolant isn't really suitable for the A series engines, and that some builders (peter burgess maybe?) won't provide warrantee on engines that have been run with it

Re: blocked engine drain tap

Posted: Thu Jul 30, 2020 8:33 am
by Matt
I can't remember exactly who/where but I have read that the waterless coolant isn't really suitable for the A series engines, and that some builders (peter burgess maybe?) won't provide warrantee on engines that have been run with it

Re: blocked engine drain tap

Posted: Thu Jul 30, 2020 9:41 am
by alanworland
Sounds like the way to go on a clean, dry new build? Cheaper than I remembered as well.

Alan