Classic cars forum & vehicle restoration.

Miken · Joined: 24 Dec 2012 Posts: 577

I've just done an oil change on my Austin and it has reminded me of a tip I would like to pass on.
Over the years i have rebuilt the odd car or old motorcycle engine.
Older vehicles (like my Austin) often have rather primitive or even no oil filtration.
Whenever possible I try to fit a magnetic sump or oil tank drain plug.
The first time you do an oil change in your rebuilt engine, especially if it has been rebored, you will be shocked/ surprised/alarmed at the ferrous sludge that comes out, stuck to the end of the plug. These emotions will rapidly be replaced with a feeling of satisfaction as you realize that your sump plug has done it's job well.
Mag sump plugs are usually easy to make. A lot of sump plugs have the threaded part drilled hollow. Very strong magnets are readily available cheaply from eBay in various diameters and lenghts.
Purchase a suitable magnet, push it in the hole and that's it. It won't come out even if you want it to. Brass plugs can have the magnet glued or pressed in.
If your plug is solid and you own a lathe then its easy to sort.
Mike

Miken · Joined: 24 Dec 2012 Posts: 577

Also,
Many years ago I was sent on a course to SKF bearings.
We were told by the bearing bloke that if manufacturers fitted magnetic drain plugs to gearboxes from new then the rolling element bearings would last many times longer before they fail. I can't remember now how many times longer but it made an impression on me at the time which is why I always try to do it when I can.

Bitumen Boy · Posted: Thu Dec 16, 2021 10:27 pm Post subject:

peter scott · Joined: 18 Dec 2007 Posts: 7214 Location: Edinburgh

lowdrag · Joined: 10 Apr 2009 Posts: 1600 Location: Le Mans

misterbridger · Joined: 09 Oct 2015 Posts: 46

I fitted a NOS gearbox to my Mini engine a few years ago (which doubles as the sump, obviously). At the first oil change a steel pop rivet shank came out attached to the magnet, which must have been dropped in the box when it was on the shelf. I dread to think what damage that could have caused if the magnetic sump plug hadn't done it's job!

Ray White · Joined: 02 Dec 2014 Posts: 7106 Location: Derby

Mog · Joined: 30 Dec 2007 Posts: 663 Location: Sydney

If you have a steel sump , you can get a magnet out of a loud speaker and put it on the outside . It will stop the steel particles from circulating .

MrWhite · Joined: 09 May 2017 Posts: 105

I was considering these, think it's a great idea but I was warned against cheaper varieties as the magnets are sometimes poorly glued in and later detach themselves, causing a major problem, the one they are supposed to solve i.e. loose bits of metal lying around in your engine.
Our campervan is due a service, so the idea came up again and they are some cheaper ones on E.Bay that look good. I contacted one of the companies but I wasn't happy with the response, couldn't tell me anything about the company, the manufacturing process or quality control but "they do sell lots", unimpressed Mad

So by this time I was tempted by a kit I had seen that would give me an Oil-filter and genuine steel sump plug. So I had the idea of buying the standard one and magnetising it and that is what I am currently doing in the Garage. Has anyone done this, will it work? I guess temp changes and loss of magnetism over time as mentioned above will me an issue but I could just leave the magnet on the outside when I fit it?

Ray White · Joined: 02 Dec 2014 Posts: 7106 Location: Derby

The way I see it, if your sump is steel then it wouldn't matter if the magnet came unstuck as it wouldn't go anywhere. Again, with a steel sump it could go on the outside as has been suggested.

Some sump plugs are hollow and tend to collect sediment so fitting a magnet down in there may not be such a good idea?

Bitumen Boy · Posted: Wed Feb 09, 2022 3:10 am Post subject:

Ray White · Joined: 02 Dec 2014 Posts: 7106 Location: Derby

The previous owner of my TC ran the engine with the original 1950s disposable oil filter still in place.!!

I have replaced it with a modern spin on type that is indistinguishable in appearance from the original.

The aluminium sump has a new plug with a built in magnet. I am trusting that it will stay put but I can see how if it came off it could attach itself to the steel intake pipe and maybe block the oil supply!

I can't spend my whole life worrying about what might happen or I will get a complex! Shocked

MrWhite · Joined: 09 May 2017 Posts: 105

So much for magnetising, didn't work! I have been doing odd screwdrivers and so on and it's always worked fine but for some reason, I guess he type of metal, it just didn't work. The magnet still attaches to the plug like yo would expect but nothing has transferred. So it's a leave the magnet on once the plug is back in case and that's exactly what I did.