Cooling System question.

quote:

Originally posted by David_Nunn:
Peter,

The very first thing to do, is make sure every part of your cooling system is correct and working properly. The first thing I'd do is make sure you have the correct 351C thermostat. Also, make sure the engine temp sensor is mounted in the engine block and not in the pressure tank. Then, make sure your cooling system is properly bled (of air).

Finally, make sure your fans are both working and blowing though the radiator, not running backwards; blowing air away from the radiator. A dollar bill (sorry, I see you're in the UK - use a £5 note!) placed against the back of the rad, with the fans running, should get blown away from the rad, towards the back of the car. If the fans are wired backwards, the dollar bill will get sucked towards the radiator. This assumes you have OE style fans mounted in front of the rad.

If you've done all these things and it still overheats, you'll need to look deeper. Does your Pantera overheat when you're idling in traffic or when you're driving? If it only overheats when you're idling in traffic, you have an airflow through the radiator issue. If it overheats when you're driving, it could be a number of things including a rad problem, water pump problem, lean mixture or even a spun timing ring on the crank damper that caused your timing to be set way off.

quote:

Originally posted by Belgiumbarry:
Peter,
without baffles the water can take all the tubes across the radiator.So from the in-collector to the out collector.(In heat exchanger terms that's called cross-flow.)
Now for better heat exchange, as for example,more water velocity inside those tubes, one can use baffles ( dividing plates ) to force the water trough some tubes and returning in another number.For example a 2 pass , which has 1 baffle in the in-collector , water takes 1/2 amount tubes , returns in the opposite collector trough the other 1/2 amount and out the same side as "in".

Design depends on the water flow ( water pump) and section of radiator tubes .As the air to fins heat exchange is more determing , the water velocity isn't that important , so from a optimum design it will give only more and more unessecery pressure drop ( which the water pump has to deliver )without really gaining heat exchange.

Now cross flow , 1,2,3 etc passes can be much better made in view of heat exchange, by passes in counterflow with the air. So the hottest water sees the hottest air in 1 row, returning in de second row were the cooler water sees the coolest air. That makes the "average temperature difference" between air and water better , which is a direct factor in the heat capacity .

Again this is only important if the temperatures are close(r) to each other, when the radiator cools water from 90 to 80 °C and the air is from 20 to 25 °C it won't make much difference.It would when the air flow was heated up 60°C . Then counterflow would improve alot, ofcourse a minimum counterflow radiator is at least a 2 pass.
Regardless of design , venting remains important, were air is inside , there's no heat exchange , as a part of the radiator that's not working !

quote:

Originally posted by George P:
You may want to pick-up a copy of the TSB Booklet one of these days. Good information.

-G

quote:

Originally posted by Peter Fenlon:

Do you know if I can modify my original Radiator and if so where can I get the drawings/ diagrams to perform the operation correctly?

quote:

Originally posted by JFB #05177:

Where?

quote:

Originally posted by George P:
Technical Service Bulletin (TSB) #8, pages 4 & 5.

The TSB's are gathered together into a booklet, I could use this as a plug for selling you a copy. But instead I'll scan a copy of the two pages & post them for you. I can't do that immediately, I've got a few other things to attend to. But I'll get to it.

If somebody else beats me to it, that's cool too.

You may want to pick-up a copy of the TSB Booklet one of these days. Good information.

-G