Radiator help please...

[travellinbob]

:god  Ok so there is htis guy who is trying to put a 12a into a morris minor and it just wont go in easily because...well it just wont.
 So the current problem I face is that even the skinniest of radiators wont fit in front of the engine and beforer the grill. So can someone please explain how they size up the correct size of rad to go with their car? As in I have an engine and want a different to stock rad so therefore I will go with .........
   Is there a basic rule of thumb that says if an engine can produce 150 horse power then it must have a certain sized rad. If yes then this would help me to choose the new rads size.
 anyone understand this coz as usual I seem to be almost confusing myself. :evillaugh  :rolleyes:
 cheers, michael.

[travellinbob]

Ok so a different question....what psi does a usual rotary water system pressurise to?

[Martiny]

mm dont know bud, but I do know that the Mazda Radiators are very efficient for a Rotary, and so therefore, if you find a radiator from another car that will fit that space, it wont be good enough.

We might need you to get one custom made, with the correct "heat transfer capacity" or whatever a radiator is measured in !

[Martiny]

mmm FD manual says to test for leaks at 20 PSI !

1st gen manual says cap opens at 13 lb/in2

[travellinbob]

Cheers martin. I have a few wack ideas going through me scone at the minute. I am worried about the standard 12a water pump being able to pump the water through something like a twin rad setup. Both rads would be in the engine bay though. So I figured that with 2 smaller rads and extra piping the volume would be the same. All I would have to be clever about would be airflow but I think I can do that.
 cheers and thanks, michael.

[nikp]

hmm....20 PSI. I don\'t quite understand. The rad cap for an FD is 0.9 bar. Plus the atmospheric 1 bar of pressure, makes 1.9 bar: this equates to 29.9PSI.

Can anyone explain that?

[MillSpeed]

The coolant system runs at 0.9 bar or ~13 psi. Why are you adding on atmospheric pressure?

[MikeLMR]

you will always test over the required limit I suppose Mazda decided 20Psi was enough to show up any faults.

You shouldn\'t need to add atmospheric on as most of the time people will quote guage pressure and not absolute pressure.

[nikp]

Well, overall, for calculating the temperature that the coolant boils at you would use the absolute pressure. I consider the coolant system to run at 1.9 bar, as then it makes the calculation for boiling coolant easier to work out.

[MillSpeed]

There we go then, test for leaks at 20 psi gauge pressure or ~34.7 psi absolute pressure.

[oldone]

Bob,Bob..Bob...you are a stress princess my dear friend.Measure the available space for the rad,go to the breakers and find one that fits.Have the pipe attachments moved to suite the ROTOR setup i.e.both pipes on one side of rad.Fit radiator and electric fan...Its diff to explain without getting to tech,the size of the rad dictates the angle of the installation which dictates the size of the fan.The rotary water pump is very efficient and can pump loads vast distances so that must not be a worry............pressure testing and all that is a minor worry for you and not worth the pain. :cheers

[antnicuk]

Ok so a different question....what psi does a usual rotary water system pressurise to?

the stock cap pressure is 0.9 bar

[MikeLMR]

what rad is the VW bloke running in his beetle ? surely that same setup would fit in the moggy ? tried and tested too ?

[antnicuk]

hmm....20 PSI. I don\'t quite understand. The rad cap for an FD is 0.9 bar. Plus the atmospheric 1 bar of pressure, makes 1.9 bar: this equates to 29.9PSI.

Can anyone explain that?

you dont need to add atmos pressure as it is cancelled out because the same pressure is on the outside of the pipe also

[oldone]

you dont need to add atmos pressure as it is cancelled out because the same pressure is on the outside of the pipe also

Somebody with common sense...............thanx Ant