Radiator to angle or not to angle

[pneall]

Mike M and myself have been discussing the merits of angling the radiator back so we can get a straight air intake into the throttle body. The way I see it is that if you angle the radiator you in effect increase the resistance through the radiator and as such slow the air down which should mean it picks up more heat. This is probably countered as less air will get through the radiator for a given speed.

We are both running alloy radiators , mine being a two row unit.

Any thoughts please on relative merits of angling the radiator versus vertical mount??

Thanks,

Phil

[Leeroy]

By placing on an angle you effectively reduce the surface area of the radiator and therefore reduce the cooling efficency of the radiator. I am using the standard VN radiator which I have mounted vertically but you guys are using high efficency radiators with 2 rows and probably more surface area than a VN. I wish I had the space between top of radiator and body to give a nice open clean air intake which you would be able to get when you mount yours on an angle. To answer you question "who knows".

[cameron02]

My local radiator bloke said it would not make too munch difference. Thermo fans must work pretty good. When you look at a lot of modern cars, they have bugger all air flow but seem to stay cool with no problems. I'm sure I could leave the engine running on my stationary Magna all day in 40 degree heat and it would not be a problem.

If your going to be racing it then I suppose air flow would be more important.

[Aussie Mike]

I'm going to bore a 4" hole right through the middle of the radiator and run the intake pipe through there.

Cheers

[Rick Parker]

I recall reading a book by the late Carroll Smith who was well respected in the metalurgy and fastener industry about race car preparation. Read it cover to cover a minimum of 2 times, it is a technical bible, titled "Prepare to Win" In it he stated that if possible the radiator should be inclined at a 30 degree angle. The idea was to present more fin surface area to the incoming air supply, and to reduce/lower the overall height of the opening to the radiator thereby reducing drag. I believe he originally worked in some capacity with Shelby during the original design of the Cobra, hence the layed back radiator.

Rick

[pneall]

Rick,

I just purchased (but havent read) all of Carroll Smiths books there is some good info in the ones I have read.. I will look up that section.

Thanks,

Phil

[cameron02]

Wow Mike,
That's really "outside the square thinking" or should I say "through the square thinking".

I guess you have already thought about this but I'll state the bleeding obvious anyway. I think you will have to do something to stop the heat getting from your radiator to the intake tube, otherwise your cold air intake will be a warm air intake.

[pneall]

Mike,

Stay calm. There must be a better way.

Phil.

ps. Upholstery is finished. IT comes home tomorrow.

[Aussie Mike]

I've got the hole saw ready to go. Not sure what I'm going to do about the coolant leaks?

I'm thinking leaning the radiator back is definitely the go. I hadn't built my upper mounts as I was still deciding which way to go. there is certainly no shortage of room behind the radiator to lean it back.

with the intake tube running straight over the top of the radiator and into the grill opening area there should be quite a bit of positive air pressure at speed. Might even get a ram air effect out of it. Also since the throttle body is on the front of the manifold it will be a very straight shot from the air cleaner to the manifold. I'll make sure there is some heat shielding between the top of the radiator and the intake pipe.

Good news on the interior Phil!

Cheers

[NASSTY]

Mike, why don't you just ditch the rad alltogether and be air cooled like a VW Beatle

You'ld have to travel pretty fast to keep it cool though

Cheers

[PCC]

Don't mock Al.

When in the UK recently, I came across a Porsche 914 powered Cobra (pretty good space for luggage at the front end).

The same guy also had a Rover V8 Cobra - lucky guy.

[boxhead]

I personally would have thought that since we arent trying to lower the frontal area of the car then there wouldnt really be a great benefit in laying the radiator down?

Congradulations on the progress Phil, dont forget to show us all the pics.

[NASSTY]

Originally posted by PCC


When in the UK recently, I came across a Porsche 914 powered Cobra (pretty good space for luggage at the front end).

That doesn't surprise me. I often buy UK Which Kit?. Full of interesting stuff. I'm often amazed at what our UK cousins get up to. Makes the kit industry here in Oz comparatively small

My RCM has the radiator on an angle as well. I've seen some Cobras with sheeting either all around the rad or just above and below it to direct the airflow. People have told me that a Cobra's footwells can get pretty hot if you cover completely around the radiator so I'll just cover the top & bottom.

As for cold air intake, I'm planning on running the intake tube around the rad by running it through the inside of a wheel arch
as there aint really enough room b/w the rad and the wheel arch.


Cheers

[PCC]

Al, thats how my intake runs.

Makes for plenty of space between the block and radiator.

The only problem I find is that the airflow meter is pretty close to the bonnet and when accelerating it does rub against the bonnet.

Also makes room a little tight for changing plugs etc.

Otherwise, am happy with it.

[Rebel1]

Radiator to angle or not to angle ??

Hiya Phil...Next time you're driving in freezin Melbourne, stick your hand out the window with ya palm horizontal.

Then...slightly angle ya palm up or down .. notice any difference in temperature??.

Dont do it for long tho cuz ya hand will freeze solid.

Cheers

[REPTYL]

Hi Reb'

3-month expiry period up on your new years resolution?

[Rebel1]

Hiya Jas

Well mate..life just wasn't the same without some form of interstate rivalry. I was suffering withdrawal symptoms and some were wondering if I was ill and were sending " get well cards"

Re the thread subject tho...my answer is correct. A slight incline actually increases the cooling effect. Specially if one uses the new dimpled radiator tubes which break up the laminar flow across the tubes.

Its just that the effects of the experiment are more obvious in southern states.

Anyways...what are you doing up this early. Did ya wet the bed or get kicked out?

[pneall]

Les,

I am going for the angle. gotta get that 4" inlet to the TB somehow.

Get to drive my Cobra for real this weekend. Yahoo.

Then its back into the garage to fit alloy fuel tank, sidepipes and 4" inlet to TB. Got some pin drives coming also.

Really happy with interior. Any colour as long as its black.

Photos soon.

Regards,

Phil.

[PCC]

Phil,

At least you get to drive yours this weekend.

Mine's at the Upholsterers getting decked out in leather (not black, but pretty dark charcoal grey).

Supposed to collect today, but the job's been slowed up. Can't even drive it as is as no seats!

Anyway, gives me an excuse to get some house reno work done.

And I have a chrome fire extinguisher getting delivered today - cheap frills!

Enjoy your drive!

[pneall]

Peter,

Grey on blue should look good

I ve been looking for chrome extinguisher in Sydney but only find red. Your vehicle is looking good in the gallery.

Is it as low as it looks. Whats the lowest point.

Mine sump is modified to 8.5 litres plus gates and baffles and is lowest part of car. I have madeup 6mm chq plate to protect it.

Iam trying to keep 100mm under lowest point so I can drive over house bricks (thrown by people not impresed with noise).

Regards,

Phil