Coating the underside of the intake manifold to reduce heatsoak?
03-20-2007, 03:16 PM
#16
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03-20-2007, 03:33 PM
#18
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Flaking off is a risk but a very low risk. This epoxy is hard and tight and does not flake. My intake manifolds have had this coating for about 6 years now.
But apply at your own risk.
Karl
But apply at your own risk.
Karl
03-20-2007, 05:12 PM
#19
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I still think it's a good idea to mount your fire extinguisher inside so that the nozzel hits the intake manifold and just before you get on it, hit it with the extinguisher thus cooling the and the content therein thereby providing cooler air enriched with oxygen resulting in at least 100 additional RWHP.
03-20-2007, 05:14 PM
#20
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I still think it's a good idea to mount your fire extinguisher inside so that the nozzel hits the intake manifold and just before you get on it, hit it with the extinguisher thus cooling the and the content therein thereby providing cooler air enriched with oxygen resulting in at least 100 additional RWHP.
03-20-2007, 06:09 PM
#23
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Since the 20-3300 is a resistive thermal barrier, it's resistance to heat transfer, and thus thermal effectiveness, depends on thickness. Thus a thick coat would be nececessary to significantly change heat transfer to the air charge.
No offense to the originator, but to me, improving .15 sec is pretty hard to believe based only on the increased thermal resistance of a thin, brushed on layer. I don't know how much air density needs to increase to improve that much, but somebody familiar with correcting for DA can probably tell us. A thermocouple in the airstream in one of the intake ports during before/after testing would be more conclusive relative to the thermal improvement. If anybody here is going to try this, that's what I suggest as 'convincing evidence'.
Maybe the reduction in surface roughness helps, too.
No offense to the originator, but to me, improving .15 sec is pretty hard to believe based only on the increased thermal resistance of a thin, brushed on layer. I don't know how much air density needs to increase to improve that much, but somebody familiar with correcting for DA can probably tell us. A thermocouple in the airstream in one of the intake ports during before/after testing would be more conclusive relative to the thermal improvement. If anybody here is going to try this, that's what I suggest as 'convincing evidence'.
Maybe the reduction in surface roughness helps, too.
03-20-2007, 07:12 PM
#24
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Location: Lexington Park, Maryland, USA
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Stoney would not take offence. He's a cool dude. I contend that even a thin layer of epoxy reduces heat transfer to the incomming air significantly.
I won't spend the money to prove it though. Stone actually did some calory to horsepower calculations and the amount "saved" was eye opening.
Karl
I won't spend the money to prove it though. Stone actually did some calory to horsepower calculations and the amount "saved" was eye opening.
Karl
Since the 20-3300 is a resistive thermal barrier, it's resistance to heat transfer, and thus thermal effectiveness, depends on thickness. Thus a thick coat would be nececessary to significantly change heat transfer to the air charge.
No offense to the originator, but to me, improving .15 sec is pretty hard to believe based only on the increased thermal resistance of a thin, brushed on layer. I don't know how much air density needs to increase to improve that much, but somebody familiar with correcting for DA can probably tell us. A thermocouple in the airstream in one of the intake ports during before/after testing would be more conclusive relative to the thermal improvement. If anybody here is going to try this, that's what I suggest as 'convincing evidence'.
Maybe the reduction in surface roughness helps, too.
No offense to the originator, but to me, improving .15 sec is pretty hard to believe based only on the increased thermal resistance of a thin, brushed on layer. I don't know how much air density needs to increase to improve that much, but somebody familiar with correcting for DA can probably tell us. A thermocouple in the airstream in one of the intake ports during before/after testing would be more conclusive relative to the thermal improvement. If anybody here is going to try this, that's what I suggest as 'convincing evidence'.
Maybe the reduction in surface roughness helps, too.
03-20-2007, 07:17 PM
#25
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Join Date: Jul 2005
Location: Baton Rouge, LA
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Stoney would not take offence. He's a cool dude. I contend that even a thin layer of epoxy reduces heat transfer to the incomming air significantly.
I won't spend the money to prove it though. Stone actually did some calory to horsepower calculations and the amount "saved" was eye opening.
Karl
I won't spend the money to prove it though. Stone actually did some calory to horsepower calculations and the amount "saved" was eye opening.
Karl
03-21-2007, 12:40 AM
#29
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Location: Rochester Hills, MI
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That's a cool idea for a test, I agree.
IR temperature sensing is affected by emissivity, which put simply is the 'radiating effectiveness' (mostly finish and color) of the surface. When our thermal techs do an underhood IR temperarure survey, they spray a uniform coating on all the parts to 'equalize' their emissivity. Shiny/light colored surfaces have relatively low emissivity, black is higher. That's one reason bright coated and polished headers radiate less heat. A 'Black Body' has the highest emissivity. Emissivity variation can trick the infrared thermometer - different emissivities at the same temperature read differently. Similar effect occurs on the heat absorbing side. I think painting a coat of HT flat paint on both sides of the sheet metal after putting the epoxie on would go a long way toward equalizing the emissivity.
Anytime I would ask for an IR temp A-B test, the techs would make a big deal about how the results were meaningless unless the emissivity of both parts was the same.
I have never measured this effect, and I don't have a feel for how significant it is. To find out, another interesting test would be to put a shiny metal block, and an identical flat black painted one, in the oven until they are the same temperature. Then measure both with an IR thermometer. But I don't have an IR thermometer. Hint
IR temperature sensing is affected by emissivity, which put simply is the 'radiating effectiveness' (mostly finish and color) of the surface. When our thermal techs do an underhood IR temperarure survey, they spray a uniform coating on all the parts to 'equalize' their emissivity. Shiny/light colored surfaces have relatively low emissivity, black is higher. That's one reason bright coated and polished headers radiate less heat. A 'Black Body' has the highest emissivity. Emissivity variation can trick the infrared thermometer - different emissivities at the same temperature read differently. Similar effect occurs on the heat absorbing side. I think painting a coat of HT flat paint on both sides of the sheet metal after putting the epoxie on would go a long way toward equalizing the emissivity.
Anytime I would ask for an IR temp A-B test, the techs would make a big deal about how the results were meaningless unless the emissivity of both parts was the same.
I have never measured this effect, and I don't have a feel for how significant it is. To find out, another interesting test would be to put a shiny metal block, and an identical flat black painted one, in the oven until they are the same temperature. Then measure both with an IR thermometer. But I don't have an IR thermometer. Hint
03-21-2007, 12:54 AM
#30
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Join Date: Jul 2005
Location: Baton Rouge, LA
Posts: 747
That's a cool idea for a test, I agree.
IR temperature sensing is affected by emissivity, which put simply is the 'radiating effectiveness' (mostly finish and color) of the surface. When our thermal techs do an underhood IR temperarure survey, they spray a uniform coating on all the parts to 'equalize' their emissivity. Shiny/light colored surfaces have relatively low emissivity, black is higher. That's one reason bright coated and polished headers radiate less heat. A 'Black Body' has the highest emissivity. Emissivity variation can trick the infrared thermometer - different emissivities at the same temperature read differently. Similar effect occurs on the heat absorbing side. I think painting a coat of HT flat paint on both sides of the sheet metal after putting the epoxie on would go a long way toward equalizing the emissivity.
Anytime I would ask for an IR temp A-B test, the techs would make a big deal about how the results were meaningless unless the emissivity of both parts was the same.
I have never measured this effect, and I don't have a feel for how significant it is. To find out, another interesting test would be to put a shiny metal block, and an identical flat black painted one, in the oven until they are the same temperature. Then measure both with an IR thermometer. But I don't have an IR thermometer. Hint
IR temperature sensing is affected by emissivity, which put simply is the 'radiating effectiveness' (mostly finish and color) of the surface. When our thermal techs do an underhood IR temperarure survey, they spray a uniform coating on all the parts to 'equalize' their emissivity. Shiny/light colored surfaces have relatively low emissivity, black is higher. That's one reason bright coated and polished headers radiate less heat. A 'Black Body' has the highest emissivity. Emissivity variation can trick the infrared thermometer - different emissivities at the same temperature read differently. Similar effect occurs on the heat absorbing side. I think painting a coat of HT flat paint on both sides of the sheet metal after putting the epoxie on would go a long way toward equalizing the emissivity.
Anytime I would ask for an IR temp A-B test, the techs would make a big deal about how the results were meaningless unless the emissivity of both parts was the same.
I have never measured this effect, and I don't have a feel for how significant it is. To find out, another interesting test would be to put a shiny metal block, and an identical flat black painted one, in the oven until they are the same temperature. Then measure both with an IR thermometer. But I don't have an IR thermometer. Hint