I am beggining to worry a bit about the size of my....... radiator!

Now i have come to plumbing in my coolant sysytem I'm worried it won't cope with the demands of my engine.

The radiator i am using is slightly smaller than a micra unit and will be tilted back in the nose cone at a 45 degree angle.

There will be an aluminium cowling to stop the air passing anywhere but through the radiator.

Apparently mounting the radiator at an angle increases its effective area.

The radiator i have seems to have quite small inlet/outlets (1". Is this the same as a micra rad that people commonly use?

To give the rad a helping hand I am going to use a large header tank to increase the systems capacity.

Has any one got any other tips to keep it cooler?

Has anyone ever had a over heating problem with their high powered locost?

Many thanks,

Doug.

well,

i think that a bigger headertank doesn't affect the temperature much..

because of the fact that on the moment of all the water has passed the rad/engine the temperature will be the same, also

the system is in that way that on a cold engine it uses all you bottle water when thermostat opens it uses it only for more room for the water..untherstand??

soow plenty of bottle water will take time to heat//larger warm engine time..

a normal rad @ 45degrees wil not help you because the ribs of the rad will go with the 45degrees you need to force the air to pas thrue the rad..

soow if i was you place the rad like it was designed to be! or just a small angle..

regards

TKS

I've asked my lady and she says fit a Polo rad...

It might help to know what your rad is off and what engine you are using.
One of the most important factors in raddiator selection is not the overall physical size of the package but the number of fins. For example a Cortina rad is much bigger than the original Mini unit but the old style Mini rad had more fins per inch -- so much so I suspect a 1275 Mini rad has a much bigger cooling capacity than the Cortina unit. The downside is the Mini unit wil clog up more easily both on the air and water sides.

As for cooling requirements the cooling load on the rad depends a lot on the engines combustion efficiency, older engines tended to reject more heat to the coolant. The 2 situations where most heat is rejected to the coolant are at idle speed and pulling hard from low rpm at higher rpm more of the waste heat goes to the exhaust.
Over retarded or over advanced timing has avery big impact on the ammount of heat going to the coolant.

Angling the rad will have little effect either way.



[Edited on 24/1/05 by britishtrident]

Sorry, but I fail to see how angling the radiator increases its effective area.

Surely angling the rad deacreases the effective area as you 'see' less of the radiator. (see dodgy pic).

David
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and I would agree, flakmonkey!

me too!

erm.. I think what was meant is that you can fit in a taller rad if you put it on a slant

I spose that would then give better cooling because of the increased capacity of the cooling system...but the radiator is actually less efficient...

Red Line Water Wetter, it does what it says on the can! works by breaking down the surface tension of the coolant which somehow makes it more effiecient. Believe it is used by formula one teams. Used it in a tow car which used to get a bit warm, dropped the temperature by a good 20 degrees . hope this helps .Rusty

Old mid 70s March single seaters had a rather strange idea of angle rads but it worked just fine -- the rad used was a Golf http://www.marchives.com/March_77B_2.JPG

[Edited on 24/1/05 by britishtrident]

the frontal area still stays the same, but the air speed into the duct will be higher , and because the frontal area of the radiator is bigger than the opening , the air pressure is lower across the radiator, hence forcing it through , this can be used to create downforce

You can always fit a heater which will increase the water capacity, keep you warmish in winter and cook you in the summer but the engine will like it!

The way i look at it, getting good airflow through the radiator (all of it) is just as important, if not more so, than the size of the rad.

I'm using a pretty tiny rad but this allows me to fit it slanting out slightly at the top (opposite to most rads in 7s). This in turn will allow me to duct the air from the back of the rad out through the top of the nosecone/bonnet. I can't see much point ducting air into the rad if it then has nowhere to go afterwards. This will create higher pressure after the rad (not conducive to getting air through it) as well as drag on the vehicle.

Despite the relatively small area, my rad is about 2" thick and twin core, so probably has more water pipe and fin area than a micra rad or whatever. Oh and it's black which might help a bit.

The only source of concern is that it's from a tiny engined fiat 126 and i want it to cool a large V6 (eventually turbocharged). Hopefully it'll be OK. Production cars tend to have massive radiators even for small engines probably because they must get awful airflow through them - through a small restrictive opening then straight into an engine. I guess the plus side to the large-rad-crap-airflow approach is that it is presumably less sensitive to speed than a small rad with good airflow. I might need a bitchin fan to keep me cool if i'm ever stuck in traffic.

F1 cars also have tiny rads (there's one on ebay) and Caterham are doing the same as me on their new CSR, which is reassuring.

LIam
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Just fir two