Engine bay cooling mods... options/ideas

I'm sure I've seen impreza's with a water mist cooling thingymabob. If you're going to go for it you press a button. Its sets engine water cooler spraying and then you can really go for it.

What about these chaps:
http://www.aquamist.co.uk/




Might not work as think its for turbo setups but might be worth a look. Or get down to B&Q Get a plant sprayer with a nozzle, rig it up to a mini air compressor with a switch and you can have the same effect for about £15.00 Might be a bit loud though.

Hi
why not just rap your exhaust

helsbyman wrote: Hi
why not just rap your exhaust

Thats a very good point.. Was origionally warned off wrapping a stainless manifold.. due to cracking etc.. But may call Janspeed and ask them.. see what they say..

Wrapping would be easy as its currently on the lounge floor :bust:

Let us know what they say. Camcoat quoted £160+vat to do the manifolds just outside. That spray stuff doesnt look particularly great. I wouldnt be too fussed myself if i knew it wouldnt start flaking off. Maybe it might be good under wrap?

Diesel Destroyer wrote: One idea I had early on was to remove the rear brake light (centre one) and vent out the rear of the boot lid..

But in all honesty.. air ducts under the car (a pair) will (reads should) scoop air up into the engine bay whilst moving.. This will result in the warmer air rising.. and should naturally exit the enlarged holes in my boot lid..

The bigger problem is when the cars stationary.. Hence the extra fans Im going to fit.. to 'force' the air through the engine bay to shift some heat out...

Looked at having 4-2-1 ceramic coated.. but its £400+ :omg:

The space where the rear brake centre light for the F was situated was originally designed as the hot air escape for the engine bay. I think the idea was the grilles let air IN and then that shot out backwards caused by low pressure at the rear of the car and sucked the engine hot air out!

helsbyman wrote: Hi
why not just rap your exhaust

Aparently wrapping the exhaust on a K Series causes far too much heat to transfer to the head - and this risks it warping it. So I've heard!

adamelphick wrote:

helsbyman wrote: Hi
why not just rap your exhaust

Aparently wrapping the exhaust on a K Series causes far too much heat to transfer to the head - and this risks it warping it. So I've heard!

Im currently looking at this kit.. The silicone spray is added on top of the wrap to keep out moisture..

Used with thermal gaskets to eliminate/reduce heat soak.. it could be good

http://www.nimbusmotorsport.com/ProdShop2.asp?id=8383

Gaskets here

http://www.ferriday.co.uk/gaskets/gaskets.shtml

Diesel Destroyer wrote:

adamelphick wrote:

helsbyman wrote: Hi
why not just rap your exhaust

Aparently wrapping the exhaust on a K Series causes far too much heat to transfer to the head - and this risks it warping it. So I've heard!

Im currently looking at this kit.. The silicone spray is added on top of the wrap to keep out moisture..

Used with thermal gaskets to eliminate/reduce heat soak.. it could be good

http://www.nimbusmotorsport.com/ProdShop2.asp?id=8383

If the transferrence of heat can be stopped (or reduced) then this woudl be a great addition to the reduction in engine bay heat!

This is from a forum in 2008 about mgb's...
Reducing temperatures inside of the engine compartment is beneficial for power output, as well as presenting less potential for detonation. Although most carburetors do not have a ‘brain’ or sensor to measure temperature, all carburetors function similarly in that it is pressure drop across a venturi that is the mechanism that pulls fuel into the venturi. The pressure drop itself is a function of air density. Air temperature also plays into the equation. In operation, carburetors are quite effective at adapting within the limited range of operating conditions that we subject them to. Without cold air induction, a carburetor must accommodate a significantly wider range of air temperatures than if you supplied air from outside the engine compartment. For every 3o Celsius (5.4o Fahrenheit) decrease in temperature that the air ingested by the engine is lowered by, power output is raised by 1%. In view of this scientific fact, although wrapping the exhaust manifold in insulating tape (sometimes called “‘lagging”) may seem to be a good idea in principle, it is a very bad idea in practice. Peter Burgess mentions this problem in his book “How to Power Tune MGB 4-Cylinder Engines.” Why is it a bad idea? Heat from the exhaust gases still being conducted into the cast iron, the insulation factor will be such that heat cannot escape from a wrapped cast iron exhaust manifold and both the cylinder head and the exhaust manifold will consequently run hotter. The heat will just build up and up, far beyond what the factory engineers designed the exhaust manifold to handle, with the result that the exhaust manifold will warp, often resulting in a leak at the manifold gasket. In addition, the additional heat collected in the iron of the exhaust manifold will also be transferred into the cylinder head, heating the walls of the intake ports and thus reducing the density of the incoming fuel / air charge. Even worse, the coolant passages in the cylinder head were not designed to remove such an excessive amount of heat, thus preignition of the fuel / air charge can become a problem and valve seat life can be shortened. In extreme cases, due to the fact that the exhaust valves for the middle two cylinders share the same central exhaust port, the cylinder head can actually warp between #2 and #3 cylinders, resulting in a coolant leak or a blown cylinder head gasket. In the case of tubular steel exhaust manifolds, the metal will become so hot that it will often spall and form flakes that will eventually disintegrate to form a hole in the area where the heat accumulation is greatest, usually at the junction of the runners. The lagging tape also becomes a moisture trap, accelerating the rusting process that can plague cast iron exhaust manifolds.

Instead of wrapping the exhaust manifold, get it Jet-Hot coated. Jet-Hot coating is a ceramic coating that can be applied to coat both the interior of the exhaust manifold as well as the exterior. The heat will have nowhere to go except out through the exhaust system, thus it will greatly reduce underhood temperatures. This is a significant factor as exhaust manifolds often reach temperatures above 400 degrees Fahrenheit (204.4 degrees Celsius). Thus, the cooler air being inhaled into the engine being denser, more fuel can be mixed with it to result in a more powerful fuel / air charge. Another benefit is that the setting of heat-sensitive 1½” SU HIF4 Series carburetors can remain more consistent. At the same time, it decreases deceleration of the exhaust gases, the sustained gas inertia thus enhancing the pulsed-vacuum effect, resulting in more effective scavenging of cylinders. The increased velocity of exhaust gases produced by higher exit inertia not only clears each cylinder more quickly; the improved vacuum effect inside of the combustion chamber draws in the next fuel / air charge more efficiently. Jet-Hot coating does not contribute to hydrogen embrittlement, a condition associated with chrome plating and other coatings in which microscopic cracking can lead to premature part failure. One word of warning to those considering Jet-Hot coating or any other type of ceramic coating: Be sure that the entire surface of the exhaust manifold, both the interior as well as the exterior, and that of the flanges is coated so that the heat of the exhaust gases will pass on through the system instead of being absorbed and trapped in the metal of the exhaust manifold, otherwise the absorbed heat will create the same problems as in the case of lagging the exhaust manifold with insulating wrap. Warping of the exhaust manifold would become something to be expected, and warping of the cylinder head would also become a distinct possibility. Jet-Hot has a website that can be found at http://www.jet-hot.com/ .

Should you decide to use a tubular exhaust manifold that is not Jet-Hot coated, be sure to use a synthetic rubber gasket (Moss Motors Part # 296-375) and the later rear tappet chest cover as cork gaskets used in this location tend to fail under prolonged exposure to the extreme heat radiated by such exhaust manifolds. Use of the more warpage-resistant rear tappet chest cover from the 18V-883-AE-L, 18V-884-AE-L, 18V-890-AE-L and 18V-891-AE-L engines will assist in this as well. Always use the thin cork gasket on the front cover - it lays flat and is actually the right size. Both the synthetic rubber gaskets and the thick cork gaskets are too small to fit well.

I did a fair bit of research on the tinterweb yesterday.. Most racers prefer wrap that's then silicone sprayed over ceramic coating..

Had an e mail chat with Gary at Merlin yesterday and he reckons they've had no issues with the Janspeed 4-2-1 wrapped and siliconed sprayed to keep moisture out when used on the Elise/Exige

This reply from Janspeed:

Dear Allan

Many thanks for your enquiry to Janspeed.

We don't recommend the use of wraps on the manifold as there is a slight chance of it cracking or stressing the stainless steel.
If you were to use it and it were to damage the manifold, the part would not be eligible for our manufacturer's warranty because of it, and the warranty will be voided.

Kind Regards

Niki Ashford
Development and Sales
Janspeed Limited