Heat elimination---engine bay``
Discussion
What would you guys say gives the most heat in the engine bay, the engine or the exhaust?
My thoughts are the exhaust. Now I know the exhaust system is a real nice bit of kit, especially in S/S but has anyone ever wrapped their silencers up in the strapping used for exhaust manifolds ala Rally Cars e.t.c.
My local Rally guy swears by this strapping on his cars, it comes from the States and is made of some special stuff and actually does what it states it does, i.e. reduces engine bay heat by up to 70%. The exhaust system is beautiful, but with so many posts about heat soak into the cabin and if the flow and return water pipes were lagged in it as well, surely this would significantly reduce heat entry into the cabin. I like the idea of fitting fans to the engine bay as well, as I believe Javier has and further cold air ducts into the cabin from the front.
Would it be possible to fit extractor fans inside the cabin as well, near the footwells and then hopefully the aircon system would cope and just logically thinking about it, if the only venting in the cabin is the small helicopter vents in the windows, then if heat could be sucked out, surely this would reduce heat penetration and help throw out hot air as well.
Any thoughts?
Dave
My thoughts are the exhaust. Now I know the exhaust system is a real nice bit of kit, especially in S/S but has anyone ever wrapped their silencers up in the strapping used for exhaust manifolds ala Rally Cars e.t.c.
My local Rally guy swears by this strapping on his cars, it comes from the States and is made of some special stuff and actually does what it states it does, i.e. reduces engine bay heat by up to 70%. The exhaust system is beautiful, but with so many posts about heat soak into the cabin and if the flow and return water pipes were lagged in it as well, surely this would significantly reduce heat entry into the cabin. I like the idea of fitting fans to the engine bay as well, as I believe Javier has and further cold air ducts into the cabin from the front.
Would it be possible to fit extractor fans inside the cabin as well, near the footwells and then hopefully the aircon system would cope and just logically thinking about it, if the only venting in the cabin is the small helicopter vents in the windows, then if heat could be sucked out, surely this would reduce heat penetration and help throw out hot air as well.
Any thoughts?
Dave
Hi Dave,
The heat can be dealt with, but I'm very surprised to never have seen the factory show many examples of this. In regards to the cockpit, I think Javier posted an excellent solution. That is to vent the hot air out of the cockpit. What he did was run vents into the cockpit from ducted air that he got from the front of the car. This allows outside air to enter. He may have even ducted it into a fan or blower inside the car with vents that hit his face. He also drilled 4 holes into the rear of the side screens to allow the hot air to escape. Its an excellent concept, and I think it has a lot of potential. This is somewhat similar to a paint spray booth that creates positive pressure inside the booth. They use it to eliminate dust inside the booth. A negative pressure booth would suck dust in. We definitely don't want to suck heat in from the engine bay. Your idea of cockpit fans could perform the same "positive pressure" task, but I think you would want to take air into the cockpit from in front of the radiator. This would be a source of a high pressure air. Then vent the hot cabin air out the back of the cockpit. I really like Javier's idea. Also, Stig has shown an excellent example of insulating the coolant pipes.
In regards to the engine bay heat, I think you are correct. The headers and exhaust generate a lot of heat. In fact, the rear bonnet will be too hot to touch if you don't insulate this panel. I've insulated it, and recently insulated my fuel tanks. I've also insulated the two removable rear braces. The exhaust heats these up. The cylinder heads also generate a lot of heat, and are pretty close to the rear bulkhead. Also, the swirl pot is mounted onto the rear bulkhead. My rear bulkhead gets very hot. I have not used the exhaust header wrap, but most people I've spoken to tell me it lowers temps more than ceramic exhaust coatings. You'll want to coat the exhaust with something if your going to wrap it, b/c it can rust holes in the exhaust. Unless your going SS route. I think one of the companies sell a spray that is applied over the wraps to keep out moisture. My next step is to completely insulate the rear bulkhead (on the engine bay side) with a heat reflective material. One friend of mine runs two fans, similar to the rad fans, in the engine bay and blows air out the back. Its helped lower his engine bay temperatures.
The bottom line is...all of this can be dealt with.
Cheers!
-Mack
The heat can be dealt with, but I'm very surprised to never have seen the factory show many examples of this. In regards to the cockpit, I think Javier posted an excellent solution. That is to vent the hot air out of the cockpit. What he did was run vents into the cockpit from ducted air that he got from the front of the car. This allows outside air to enter. He may have even ducted it into a fan or blower inside the car with vents that hit his face. He also drilled 4 holes into the rear of the side screens to allow the hot air to escape. Its an excellent concept, and I think it has a lot of potential. This is somewhat similar to a paint spray booth that creates positive pressure inside the booth. They use it to eliminate dust inside the booth. A negative pressure booth would suck dust in. We definitely don't want to suck heat in from the engine bay. Your idea of cockpit fans could perform the same "positive pressure" task, but I think you would want to take air into the cockpit from in front of the radiator. This would be a source of a high pressure air. Then vent the hot cabin air out the back of the cockpit. I really like Javier's idea. Also, Stig has shown an excellent example of insulating the coolant pipes.
In regards to the engine bay heat, I think you are correct. The headers and exhaust generate a lot of heat. In fact, the rear bonnet will be too hot to touch if you don't insulate this panel. I've insulated it, and recently insulated my fuel tanks. I've also insulated the two removable rear braces. The exhaust heats these up. The cylinder heads also generate a lot of heat, and are pretty close to the rear bulkhead. Also, the swirl pot is mounted onto the rear bulkhead. My rear bulkhead gets very hot. I have not used the exhaust header wrap, but most people I've spoken to tell me it lowers temps more than ceramic exhaust coatings. You'll want to coat the exhaust with something if your going to wrap it, b/c it can rust holes in the exhaust. Unless your going SS route. I think one of the companies sell a spray that is applied over the wraps to keep out moisture. My next step is to completely insulate the rear bulkhead (on the engine bay side) with a heat reflective material. One friend of mine runs two fans, similar to the rad fans, in the engine bay and blows air out the back. Its helped lower his engine bay temperatures.
The bottom line is...all of this can be dealt with.
Cheers!
-Mack
I am going to ceramic spray my exhaust system using www.techlinecoatings.com which comes in a number of colours (Ali, Black, Cast iron)in this way I can reduce the heat output and save £528 by not buying a stainless system.
Edit.
I have double skinned and sound insulated the whole of my rear bulkhead right up to the rollbar. It has 'Barrier Matt' (3mm almost solid rubber foam) on the cockpit skin and 2 layers of 1/2" felt between that and the engine bay skin. I will also apply ali foil glass fibre to the engine side.
I also intend to bring fresh air into the footwell and vent it out low down on the side wall just in front of the rear bulkhead.
>> Edited by Steve_D on Friday 10th January 14:58
Edit.
I have double skinned and sound insulated the whole of my rear bulkhead right up to the rollbar. It has 'Barrier Matt' (3mm almost solid rubber foam) on the cockpit skin and 2 layers of 1/2" felt between that and the engine bay skin. I will also apply ali foil glass fibre to the engine side.
I also intend to bring fresh air into the footwell and vent it out low down on the side wall just in front of the rear bulkhead.
>> Edited by Steve_D on Friday 10th January 14:58
Just got back from the autosport show and this was my pet subject.
The factory demostrator runs a camcoat Cermakrome finish which looks like chrome - Ted said it works
www.camcoat.u-net.com/Exhausts.htm
Those "spooks" at "harwell research" ( atomic research technology )
now called zircotec do something for major race teams www.zircotec.com/index2.html
The factory demostrator runs a camcoat Cermakrome finish which looks like chrome - Ted said it works
www.camcoat.u-net.com/Exhausts.htm
Those "spooks" at "harwell research" ( atomic research technology )
now called zircotec do something for major race teams www.zircotec.com/index2.html Gassing Station | Ultima | Top of Page | What's New | My Stuff