Radiator swirl pot

[Andy8421]

The 26R style tank is very interesting. It has a straight through pipe but with rather large holes in it. The box surrounds the holy part. I think what is going on is the water flows almost unimpeded with low turbulence through the pipe, and any air then gets trapped in the box. The exiting water is then even smoother and unaerated for the rad. I could be wrong. I'm just imagining what must be happening in there. And of course it does provide a high fill point.

John

That is interesting. The 26R part isn't a 'swirl pot' in the usual sense. Swirl pots (as the name suggests) really should be round and operate rather like a Dyson vacuum cleaner generating a vortex where the bubbles of air come out into the centre of the vortex and steam bubbles recombine. If everything is working well, then de-aerated water should come out the bottom and air out the top. The 26R pot seems to be more of a header tank than a swirl pot, particularly it has a straight through pipe inside and no vent.

[jasper2347]

Started something here haven't I. Our thing has not arrived yet, so can't comment on the results. We have never, even with the standard recovery bottle and correct cap, been able to take off the top hose when cold at the thermostat housing end and have any coolant come out. We had the same trouble on our hill-climb TR7 many years ago, radiator is lower than the engine. We did a similar mod to that with great results and no more problems. The post worrying about a steam explosion, the high pressure cap is to replace the original one on the radiator to save messing around sealing it off. We will move the original cap, which will release long before the other one, to the new filler along with the expansion tank hose into the original tank. Our main problem is sitting around at start lines and no air cooling the rad. We do have a fan over-ride switch to turn the fans on early if it's a warm day. Thanks for all your input. Will let you know what the outcome is next week when we get it fitted and running. Rob

[gus]

You do not want a high pressure cap, you want a no pressure cap, if you have a second cap on the reservoir


IF you fill the radiator cold and start it with the cap off, coolant will come out of the filler as the coolant expands when it gets warm

While my +2 is not pushing anything but stock horsepower, with the fan on in any weather it will idle without overheating until it runs out of gas. Small radiator. Aftermarket modern fan

[jasper2347]

Thought about a sealer or no release cap, but that would mean sealing off the overflow pipe. Easier to just use the pressure cap. Suppose this would be a secondary blow off if the top cap failed for some reason, at least it would let go at it's own rated pressure. Have also kept the original top hose, so can revert to standard if any problems arise. Our little monster is a 1760cc full race motor, so runs a bit hotter anyway, usually around 90c. We aren't allowed anti-freeze or coolant liquids these days on certain tracks, so no cooling assistance from the anti-freeze. Never had any overheating issues, just don't like the thing being what I see as low on coolant. Motor was a bit 'spensive, so no failures are permitted. Looking forward to Harewood next month. As the car is road legal we can drive it there to give it good test run before the competitive runs start.

[jasper2347]

Got the filler on the car and it works great. Had a test run and very happy with the results. Even though the weather was quite warm this afternoon, the car ran cooler than it ever has. Thanks for all your thoughts and input.

[vstibbard]

Best way to do it is how new cars are filled at the factory, they apply a vacuum to the cooling system, until the hoses are squeezed down, then open tap and allow the vacuum to pull the water through.
Guaranteed to be no air in the system.

Cheers

V

[jasper2347]

Thought you may like a pic or two of our machine.

[tonyabacus]

A method we have used successfully in the past when filling for the first time is to pour about half the normal capacity of water into the radiator, open the heater valve and start the engine. Then slowly start to add the remainder of the water. The water pump will start to move the water throughout then system and with it any airlocks.

By filling the whole system cold on some cars it creates an airlock and especially in the heater if the valve is closed, by using the above method it helps prevent the airlocks from being formed in the first place, as the water is gradually filling the system. It can help sometimes to squeeze the top hose as you get towards the last of the filling water, also switch on the heater fan and check the temperature of the water and compare it to the rad hoses. If the heater continues to run cold then you know there is an airlock.

An alternative method is to remove the heater hose at the valve on the head and fill the pipe with water and blow the water through constantly filling the hose as you go until the heater circuit is full. You can tell by squeezing the other heater hose and feel the water coming through. alternatively you can pull the other heather hose off its connection at the front of the engine and watch for the steady flow of water as you are filling into the top hose.

The pipes that fill the heater on an Elan go through the bulkhead from the engine but then have to turn through 90 degrees to fit to the heater and it is here that the airlocks can start. When draining the cooling system initially often the water in the heater cannot drain fully so when you start to refill the system the airlock often already exists. Blowing the water through ensures there is no airlock in that part of the system.
Tony

[Bits]

Hi,
I've just taken delivery of a Coolex rad fan and thermostat housing for my S4 Elan.
The rad does not have a filler - it is on the thermostat housing.
I'm looking to position the rad just behind the air intake as I have dispensed with the pop-up headlights and air filter.

I'll need to make some brackets for the rad and source some longer hoses.

Regards,

Mark.

[mbell]

I have similar filler neck, make sure to drill a hole in the thermostat or air can escape or you can get an air lock.

[Bits]

Is that "so" air can escape?

Does the air get trapped on the engine side of the thermostat, so the hole in the thermostat disk releases the air into the filler cap side?
The thermostat housing has a tube for the expansion/air release.

Regards,

Mark.

[mbell]

Yes. Water goes in on top of the thermostat and then runs into radiator fine the top host. So the engine fills from the lower hose, so you need away for air to escape from the top of the engine or you get a big air lock.

Standard setup that fills from radiator has the same issue but also has problem filling the top host as since if it is advice the filler neck on the radiator.

[Bigbaldybloke]

Don’t most thermostats have a breather hole as standard with what I call a “jiggle pin “ in it to keep it clear?