Just something I have picked up and I thought I might bore you all with.

I have read around that after installing an a14, a gemini radiator or an exel alloy radiator will help with cooling. perhaps it is not necessary.

After installing a worked a14 before the summer of last year in my 1200 I realised I had to be very carefull of over heating whilst siting in traffic (quickly climbing above 190f). I had removed the fan and installed a thermo fan which could not cope with siting in traffic , so I would have to cut the engine every time I stoped.

The first hillclimb in dec the engine temp rose to about 190f after 65 sec. The same happend for the rest of the summer series.

Come march and the short sprint of Barbagello the temp got upto 205f before I let off to let it cool down (1 warm up 3 hot 1 cool down lap by the second lap it was hot). I was putting off a bigger radiator for money reasons.

I didn't worry to much as was now coming into winter so instead I bought a bottle of water wetter, not much noticable difference. I then did a tuning day (on a cool day) at wanneroo and still the temp climbed to 210f before I let off. time to sort it out.

I spent some time reserching and found that the engine bay needs a lower preasure than outside to draw through the radiator. Looking at my engine bay there were two great big holes 100mm square either side of the radiator and a 30mm to 40mm gap the between the bonet and the radiator suport the whole length of the bonet. time to seal these up to force air through not around and try and create a lower preasure (air it seems will take the easiest route).

I sealed up the 100mm holes with some sheet metal and the bonet gap with two lots of 15mm plumbers aeroflex insulation cut and glued with silicone so the gap was completly sealed.

Two weeks later I had a long sprint around wanneoo and the temp did not get above 185f. For less then $10 I seem to have fixed a rather big problem. Much rather fix what I have than the spend money on a bigger radiator and have extra wieght up front.



Quite happy with myself.

My friend, you get the YAY for the day from me. You addressed the cause of the problem in this case instead of trying to bludgeon the symptoms.
I presume that you knew that the whole cooling system was in serviceable condition beforehand.

There is also a filler piece between the chassis & the sump at the front of the engine, sometimes incorrectly refered to as a 'bash plate'. This apparently helps also & removing it is NOT a performance modification.

Interestingly, lowering the front of the car more than the rear, or adding an air dam also helps by reducing the volume of air going under the front & as a result, reducing the air pressure under the engine.
By now you understand the wonderfull nature of 'pressure differential' & how it can produce the effect we want, well apparently this helps too.

As you are now well aware, using your head first instead of adopting the 'bigger hammer' mentality can produce the desired result without needless cost & effort.

Score 10/10.

and where does some one get this insulation? is it that high density foam stuff you see on fridge pipes etc or similar?

I like this mod as i have always thought air has been going around (not that theres much room for it to) my radiator and not all the way through since upgrading to the n13 version.

well done jeffroy and Dodgy,i fully concur.We found 15 degrees in the old circuit car(doing 15 or more laps)by closing off these areas and giving the air flow no choice but to go where it was told.
I must admit i was put onto it by a motor racing engineer and his reasoning seemed perfectly logical,after all look closely at a Supercar or even any new production car with a pissey little radiator...theres plastic shrouds and venturi's everywhere to direct flow to required areas.

Some nicely polished .5 aluminium plate riveted on for the big holes,and rubber strip about 5mm between the radiator and support panel and down the sides...and put the "bash plate" back on if you have it.

bash plates on, car is lower at front than rear currently and the radiator takes up heaps of room (all the nose cone between the chasis rails).

Making a top shroud slowly, so anything will help in the hot summer expected.

When I installed aircon in my humble 200B years ago, I checked the parts book to see just what parts were involved.

One of the parts that the factory thought was necessary enough to produce was a rubber strip that sealed the gap between the bonnet/hood & the top of the radiator support panel.

I knew full well that if the factory could save 5 yen per vehicle by leaving it out & still have the aircon & the cooling system perform as advertised, then they would leave it out in a heartbeat, so clearly it was regarded as important & I found one in a wreck & fitted it.

Those Datsun engineers were not known for being stupid so I figured if it was good for them, ................................

this can't possibly have solved the overheating while sitting still problem you mentioned. Assuming the cooling system is in good condition, you really need a bigger radiator if it can't maintain temperature at idle sitting still! otherwise you are just treating the symptom rather than the problem.

but it is always a good idea to block off any unneccesary holes in the radiator support panel. I did this after having temp creep issues after a few laps at QR last summer with my coupe - the previous owner pretty much had the whole radiator support panel cut out with massive gaps either side of the radiator and a big intercooler (including its end tanks) stuck right in front of the radiator core. I bought a different intercooler and have mounted it lower to clear the radiator. Its under the bumper in a front spoiler (which are a big help with cooling on a track), and with the radiator support panel now closed off up to the radiator core I'm not expecting any more problems.

Perhaps i should have put in a note,obviously standing still makes no differance whats so ever,it's only on the move at moderate to high speed.

I was replying to jeffroj comment that it had fixed the problem. If he didn't have the overheating problem sitting in traffic, I'd agree the problem was fixed.

either way, its definitely a good idea to do this. Also a good idea to fit a front spoiler for track cars - preventing all that air rushing under the front end gets rid of the high pressure area under the engine bay with 2 results:
1) improved cooling - hot air in the engine bay now has a free path to exit under the car AND a greater volume of air is forced to pass through the coolers.
2) reduced front end lift at high speed = better stability and handling on high speed corners

my old L18 powered coupe used to overheat on the track if I took the spoiler off.