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remove heat wrap on exhaust?
- Thread starter labboy
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Steve_S
Yoda
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Most people will argue that heat wrap prevents the manifold from heating up the engine bay and especialy the carbs, which will aid economy.
I have read information that led me to join the other camp, who believe that wrapping the exhaust will prevent heat from dissipating throught the metal as designed, and therefore increase cylinder head temperatures and cause performance issues.
I have read information that led me to join the other camp, who believe that wrapping the exhaust will prevent heat from dissipating throught the metal as designed, and therefore increase cylinder head temperatures and cause performance issues.
dklawson
Yoda
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I've never heard of wrapping the entire exhaust system. Header wrap and header ceramic coatings are fairly common and I too have seen this discussed pro and con. I have my header on the Mini wrapped.
Steve, can you direct me to some of the sources that made you decide to go "natural". I haven't read the information that suggests higher cylinder head temperatures. I'd like to take a look at that. Thanks.
Steve, can you direct me to some of the sources that made you decide to go "natural". I haven't read the information that suggests higher cylinder head temperatures. I'd like to take a look at that. Thanks.
Steve_S
Yoda
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I wish I could remember where I read it but it was a couple years ago. I believe it was a post on one of the MG forums. The geltleman was prepping a race car, MG I believe, and his results were cooler head temperatures when he removed the manifold wrap. Unfortunately I don't remember any specifics beyond this but if I do find it I'll post here.
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[ QUOTE ]
I just read an article that said you should not have heat wrap on your exhaust, it causes a heat build up.
I just purchased my first MGB '78 and it has the entire exhaust system wrapped.
Any help from folks smarted than I would be nice.
Gary
Red Wing, MN
[/ QUOTE ]
Hi Gary,
There are several considerations for exhaust insulation.
Wrapped headers & pipes obviously reduce radiated heat to the engine compartment & passenger compartment. This definitely makes the cars much more comfortable.
An insulated exhaust system will actually increase engine efficiency & power. Hotter exhaust gasses have more velocity & will exit quicker. Reducing engine compartment heat will also increase the density of the intake charge & increase power.
The down side is that tightly wrapped & therefore much hotter pipes will oxidize (burn out) more quickly & shorten the life of the metal.
A good compromise would be to loosely wrap the components so that there could still be some air circulation around them but deflect it away from critical places. The NASCAR cars are using various ceramic blanket materials to keep the heat out of critical places. On headers, they are using "half wrap" insulation to deflect heat & still permit some cooling of the metal.
Note the heat shields used on modern cars to accomplish much this same purpose.
If an exhaust system is too cool, the water, which is a byproduct of combustion, will not vaporize & collects in the system, mainly the muffler, to cause inside out rust. Cars with catalytic converters put so much heat into the exhaust that rust is seldom a problem now days.
In your specific case, unless you are running the car very hard for long periods of time, the insulation will likely help quite a bit & still give acceptably long life to the exhaust system components. I seriously doubt that the hotter cylinder head is an issue unless you are all out racing.
D
I just read an article that said you should not have heat wrap on your exhaust, it causes a heat build up.
I just purchased my first MGB '78 and it has the entire exhaust system wrapped.
Any help from folks smarted than I would be nice.
Gary
Red Wing, MN
[/ QUOTE ]
Hi Gary,
There are several considerations for exhaust insulation.
Wrapped headers & pipes obviously reduce radiated heat to the engine compartment & passenger compartment. This definitely makes the cars much more comfortable.
An insulated exhaust system will actually increase engine efficiency & power. Hotter exhaust gasses have more velocity & will exit quicker. Reducing engine compartment heat will also increase the density of the intake charge & increase power.
The down side is that tightly wrapped & therefore much hotter pipes will oxidize (burn out) more quickly & shorten the life of the metal.
A good compromise would be to loosely wrap the components so that there could still be some air circulation around them but deflect it away from critical places. The NASCAR cars are using various ceramic blanket materials to keep the heat out of critical places. On headers, they are using "half wrap" insulation to deflect heat & still permit some cooling of the metal.
Note the heat shields used on modern cars to accomplish much this same purpose.
If an exhaust system is too cool, the water, which is a byproduct of combustion, will not vaporize & collects in the system, mainly the muffler, to cause inside out rust. Cars with catalytic converters put so much heat into the exhaust that rust is seldom a problem now days.
In your specific case, unless you are running the car very hard for long periods of time, the insulation will likely help quite a bit & still give acceptably long life to the exhaust system components. I seriously doubt that the hotter cylinder head is an issue unless you are all out racing.
D