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radiator opinion
Posted: Tue Feb 08, 2011 9:11 pm
by poo slinger
i am looking for a radiator in my mk1 escort and have found this, i know there is not much info on it, but car will be running a fast road 3.9 rover v8 (220bhp ish)
i think they are about 400 x 450mm in size,
opinions if this will be up to the job?
http://cgi.ebay.co.uk/Ford-escort-rs200 ... 4cee62e7fb
Posted: Wed Feb 09, 2011 10:44 am
by richardpope50
Answering your question another way, general guidelines are:
1. Maximum cooling is gained by slowing down the air supply in front of the radiator. On a Se7en type car, to do this, add ducting from nose cone to the radiator surface. The reason is that the nose cone’s cross-sectional area is smaller than radiator surface area so by adding ducting to direct all air through the nose cone to radiator’s surface without gaps, air is slowed down. I.e. Fast air through cone is now slowed as the ducting increases cross-sectional area. (Same logic as a aeroplane wing.)
Slow air takes much more heat from core than fast flowing air as it has more time to heat up (unless too slow and does not move, I guess).
2. Fans should be sucking and not blowing because you do not want airflow turbulence, you want smooth airflow at low speed. A blowing fan not only gets in the way of airflow but will blow air in all directions and what goes through the radiator core will go through with significant turbulence. A sucking fan will suck air through the core smoothly.
You should also have plenty of room for the hot air after the radiator (and sucking fan) to escape the engine area. Flared side panels are a good idea.
3. Put your fan temp sensor on the output side of the radiator, not inlet as then the fan only comes on if the radiator cannot cool enough. If the radiator is cooling enough, the fan will not come on.
4. Within the radiator you need to force the water through furthest cooling distance. An inlet in the centre top and the outlet at centre bottom will mean that the water will take the shortest route and be cooled by a small section of the core. I had internal ducting put in the header and bottom tanks so the water took the furthest route. Some radiators have a barrier across the centre so the water has to spread throughout each radiator – if you like two radiators on top of each other with a connection opposite to the inlet / outlets.
5. A thick core allows air to take the maximum heat out as the flowing air stays in contact with core longer.
Posted: Wed Feb 09, 2011 10:44 am
by kiwicar
Hi
I would think it should stand a pretty good chance, It looks well over spec for a 2 litre pinto anyway, only thing is if it is brass cored it will be heavy.
Best regards
Mike
Posted: Wed Feb 09, 2011 10:43 pm
by poo slinger
as far as i am aware the brass radiators offer much better cooling after about a year compared to ally ones.
if its up to the job i will buy it then
RV8 Temperatures
Posted: Mon Feb 14, 2011 8:01 pm
by MendipWursel
I think the radiator you are considering may struggle to keep an RV8 cool. The radiator is not that large and only a 2 core. As an example in my Lotus 7 type kitcar with an RV8 I use this radiator (see link below).
http://www.westfield-sportscars.co.uk/s ... &PT_ID=all
This is a 4 core radiator of similar size which just about keeps the engine cool in the summer. I have a main fan and two motorcyle auxilary fans which click on when it gets really hot (so 3no fans in total). I would not want any less cooling and when I had the single fan I was struggling to keep the temperature down. As we all know with the RV8 the cooler the better, especially with the 3.9 which is prone to cracked blocks.
Posted: Wed Feb 16, 2011 10:22 am
by richardpope50
My Dax Rush rad for V8 based on above spec of mine.

Posted: Wed Feb 16, 2011 12:45 pm
by Ian Anderson
On the GT40 radiator is 300 * 600mm
The engine gets no airflow when starionary in traffic (it's behing me) so no additional colling ther compared to you "fronties"
It is a 4 core (about 2 inch deep unit)
It runs twin 11 inch high volume fans moving 1100cfm each - it is the flow of air that will remove the heat so make sure you have enough airflow - making sure all air from the car movement goes through the rad makes a lot of sense.
And the spec said it would cope for engine up to 600hp
IAn
Posted: Wed Feb 16, 2011 1:33 pm
by kiwicar
As a rough guide, each extra core does about half the amount of heat transfer of the previous one n the air stream. So to compare a 2 core and a 4 core of the same frontal area you will get about 37% more cooling from a 4 core rad. To use Ian's radiator as a referance, it has the same frontal area as the one on the listing, said to be good for about 600 bhp so the one listed should handle cooling for about 375 bhp. this would be consistant with the one I had for the chevy in the Mclaren, 4 core but 13"x 20", slightly less area but again said to be good for about 600 to 650 BHP.
The real issue, as said above is to get air passing through it, you will need good ducting and somewhere for the air to get out (remember if you stop all the air passing under the car with an air dam It won't be pulling air out from the bottom of the engine bay) this is the bit everyone tends to overlook (ok not Ian) and can make the differance between a kettle and a funtioning cooling system.
Best regards
Mike
Posted: Wed Feb 16, 2011 1:40 pm
by Ian Anderson
Another rule of thumb
The Grill needs to be at least 1/3 the area of the radiator cores
and behind you should have about 2/3 of the area free for the hot air to escape!
Ian
Posted: Wed Feb 16, 2011 2:02 pm
by kiwicar
And a final one rule of thumb ,
If you make the inlet side of any ducting to the radiator more than 2/3 of the core area you gain nothing for your trouble (provided in so doing you don't actually block off the core area!).
Hence if you have a 12"x 24" duct ideally you can put in an 18" x 24" radiator at an angle and the overall set up will be pretty well as efficient as it can be (ok you could taper the duct out after the rad but you won't gain very much), likewise you can drop the inlet side of the duct to 50% rad area and loose a very few percent in efficiency, have a look at any single seater side pod arrangment.
Best regards
Mike
Posted: Wed Feb 16, 2011 11:49 pm
by poo slinger
well i got a radiator similar, cot me £120 and they made it for me in under an hour.
about the fan,
best just to get the biggest possible that will fit??
reccomendations?
i need a fan infront of the radiator (slim 1)
core is 450mm x 500mm
Posted: Thu Feb 17, 2011 10:07 am
by kiwicar
Hi
Yes biggest one you can fit, It will probably be tricky but the longer you can make any shroud between the rad and the fan the better, and flair it out to the shape of the Rad coreeven an inch will help alot, the more core you can blow air through the better.
Best regards
Mike
Posted: Sat Feb 19, 2011 12:23 am
by Robrover
For a fan controller, many people (including me) swear by the DCController used on many a US musclecar.
http://www.dccontrol.com/introf0.htm
Brian Baskin (who makes these in his spare time) doesn't deliver real fast usually, but his products are top quality. It feels real good knowing the controller WILL work when it's hot outside (and it gets to 44C here in the shade in the summer).
Advantages
Pulse Width Modulation: Allows the fan to be ramped up in speed so the fan only spins as fast as is necessary to cool then rad/engine. Instead of being turned on full speed.
Temp settings: Allow you to configure/tune the temp that the controller comes on.
Full Speed on switch: Allows you to wire a switch to turn the fan on full speed when you want it to.
A/C integration: Allows you to wire the DCC controler into the AC compressor power line to kick the efan on when the AC system is turned and the A/C condenser is dumping more heat into the front of the radiator.
Posted: Sat Feb 19, 2011 7:43 pm
by mgbv8
You can buy a new RV8 MGB rad from the owners club for £132.00
this was originaly for the 3500. But I used mine for 2 years on the road with the 4.6 and its still the same rad that I use on the car for racing now. OK!
Its only 1/4 mile sprints. but I stick a lot of heat into that rad and it recovers really fast after a race.
Posted: Sat Feb 19, 2011 8:06 pm
by poo slinger
well i got a radiator now,
what fan should i go for tho? has to go infront of radiator but i aint got alot of money, the ebay cheap stuff tends to be rubbish i think,
fan can be 16"