Today I opened the drain at the bottom of the radiator ( 1914 round tube brass radiator) and it didn't flow. So I used some of the brass sediment bulb screen material and created a sort of filter in my funnel. I pushed a wood q-tip through to get the drain running and after a couple seconds, the funnel stopped running! So long story short, after capturing gobs of black crap, I put a magnet over it and it is magnetic.
Any idea where this metal could be coming from? The radiator was completely cored and refurbished by brassworks, and I think it is mostly brass so it shouldn't be magnetic.
Is this normal for a new engine as it breaks in?
Has anyone ever put a magnet in the top tank to catch metal filings before they cause rust or clogging?
Appreciate any information.
Could it be possible that the block was not cleaned up after the machine work was done? Perhaps the metal filings came from boring cylinders and honing them and from grinding the valve seats or decking the top of the block. What I do when I work on an engine is to clean out as much as I can and blow out with compressed air. Then after I get the head on, before I connect the hoses, I run water through the head and block to wash out any sediment or filings which might be missed before.
Also if you are using a water pump, some of the metal could be coming from it. Anyway, clean out as best you can and after you drive around a while check again.
It could be rust from inside the water jackets, or from the radiator inlet / outlet. A good mix of antifreeze and water will prevent further rust.
Thanks guys. It's all flushed and refilled with 50/50 so I'll put a hundred or so miles on it and check again.
Even with a new rad and block and head cleaned out, you are still going to get rust flakes and other gunk that will easily plug that tiny petcock hole. One poke with your Q-tip stick will clear it every time. I find it best to regularly drain into a couple of one gallon jugs, let them settle for a day and pour them back in, stopping just as the crud at the bottom appears.
A Tefba filter will catch the flakes although I don't know how it would go with a thermosiphon system.
The drain petcock will catch the flakes, rust, and whatever else is in there. Just drain it regularly. JMHO. Dave