Radiator Cap

A good while back i was needing a radiator for my Commer that had a UD5 engine sitting in it not finished & at the time it was suggested to put the largest radiator I could find in it because these engines tended to get a little warm. A mate offered a radiator from down in his lower shed that came out of a Mack. This radiator was fitted & ended up having a water capacity of 30 litres. Problem is the radiator never had a cap. I have been driving this unit around & getting it warmish 180 f/h without a cap but thought I should get one. I cant find one so maybe someone on here can help. The first pick is the radiator neck & the 2nd is a fuel cap that fits.

Maybe think of soldering on a modern neck so that you are able choose what pressure it releases at

With that big radiator you more than likely need no pressure, just something to stop the water slopping out. Motor vehicles did their first 20 or 30 years with no pressure quite OK and every car can run without pressure so long as you do not reach 100/212 degrees.

If you run at your 180/190 degrees you will never have a problem. Pressure does not stop overheating, all it does is raise the boiling point allowing the water to get hotter before turning to steam. Modern cars with higher running temperatures and water additives need pressure to keep the water liquid but your old vehicles can soldier on nicely.

I would put money on your fuel cap in the photo doing just nicely.

Just an aside. Putting additives, particularly anti-freeze, in a radiator reduces the cooling ability by as much as 20% (one of the reasons modern cars need higher temperatures and high pressure caps). Nothing is as good as pure water. If you are going to put stuff in, only use anti-corrosion brew, not glycol anti-freeze which is totally unnecessary here in Australia.

Copper transfers heat from the water to the air much better than aluminium. This is why you may need an extra core in a replacement aluminium radiator on an older vehicle radiator conversion.

If you can find the TRIDON site they will have a cap to fit - they have hundreds of sizes. I will look for the address.

Lang

Lang, plenty of locations in Aus that require anti freeze if being parked overnight in the open. Probably get away with a -8 frost in a closed shed.

Steve

Plenty of places get below zero but for an engine block to freeze solid would take a lot more time and lower temperature than we get. The engine/oil/radiator combination and surrounding structure is a huge cold soak for such marginally sub-zero temperatures to have an effect. If you parked it covered in snow at Falls Creek certainly a risk but bloody unlucky to have a problem in your neck of the woods.

Nobody in Australia even thought about anti-freeze until the modern light weight alloy engine vehicles came in and that was because it was combined with anti-corrosive. You can now get the anti-corrosive without the glycol.

I know you can tell of a mate who had his tractor parked out in Guyra one winters night frozen solid but I would guess millions of car/nights have passed in New England or even Victoria-NSW high country without protection or damage. If you are going skiing and leaving the car outside overnight it might ease your mind to have anti-freeze but I would be interested to know the Thredbo NRMA call outs for exploded blocks or radiators.

Just an "Is it really necessary" discussion. As the brew with glycol is much the same price as the anti-corrosive alone, although it makes your cooling less efficient, you may as well put it in if you live in cold places to sleep well at night.

Lang

Lang if Allora heritage weekend is ever held in winter you better pray or put in some antifreeze if you’re coming we live just up the road and I could show you what happens to a WC allis block and an Austin head and we would be a fair bit warmer then a lot of places

Cheers Bluey

I allways run an anti freeze in the toys that will spend time out in the open over night no matter where we are. Is cheper than finding out the hard way that a theory doesn't work.

I'd just go to Mack and ask about a radiator cap, Mrs Mack needed a new one last year after 40 years, didnt get hot but when I backed off the revs she would let a little go all over the wind screen

Im with Lang, I cant see frozen water happening in Australia been a issue, after all when I knock a bullock on the head and bung him in the deep freeze it takes a week for the freezer to freeze all the way thru, even if he is chilled in a cool room prior to said bunging in the freezer

Just saying

Paul

I remember as a kid growing up out of Jindabyne that we didn't put anything in our paddock bashers & they servived. Most problems were when driving along the air flow through the radiator would cause the freezing. Have seen split pipes off the water pump on standing vehicles at times though.

Doesn't happen every year, but I have household water pump freeze up every now and then (3 times this past year.) And have had exposed copper pipe to HWS burst on one occasion whilst I was absent, then when things thawed out, pumped out a full 22,500 litre tank all over the ground. Luckily I run with only one tank connected to pump at a time.

Always have kettles & jug full every night before bed. Just in case.

If frozen next morning, boil 'em up and have a coffee, pour rest over pump body and exposed connecting pipework, and all is good again - till the next morning. If it happens once, likely to happen again next day!

I have had diesel in tractor wax up badly too although I run Winter mix most of the year and Alpine mix in winter, and I'm not at a high elevation - Alpine foothills, but at only 250 metres AHD !!!!
Some years back, 2003 (I think it was) I had a LandRover wax up on New Year's Eve whilst camping at Craigs Hut.