Header temps and such
Thread Starter
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Header temps and such
OK, several folks claim the underhood temps are much higher with headers than with say stock cast iron rams horm exhaust....
I can't see it really , as headers would cool much quicker than cast iron, and that hottest part of the cast iron..say the 'collector' would be highest temp, and radiate longer....I know my O2 sensor lit off quicker on that rams horn install than the header collectors...for instance...so much so I run a heated O2 sensor now...
but I feel the heat given off is about the same, and the energy stored heat due to MASS is much greater in the iron system....that I think is worse for the other plastic components...like relays/wiring/and such....
NOW is there any direct evidence of the sustained underhood temperatures with headers of identical style between bare steel and ceramic coated???
GENE
I can't see it really , as headers would cool much quicker than cast iron, and that hottest part of the cast iron..say the 'collector' would be highest temp, and radiate longer....I know my O2 sensor lit off quicker on that rams horn install than the header collectors...for instance...so much so I run a heated O2 sensor now...
but I feel the heat given off is about the same, and the energy stored heat due to MASS is much greater in the iron system....that I think is worse for the other plastic components...like relays/wiring/and such....
NOW is there any direct evidence of the sustained underhood temperatures with headers of identical style between bare steel and ceramic coated???
GENE
Drifting
Joined: Nov 2000
Posts: 1,428
Likes: 0
Re: Header temps and such (mrvette)
All I know is that within 10 minutes of shutting off my motor on any length of trip I can HOLD my hand anywhere on my ceramic headers. I wouldn't try that on a bet on anything else. Further, a gallon (or whatever) of gasoline is going to generate a certain number of BTU"S no matter how it is burned and exhausted or whatever....Its just the nature of things......My $.02 :cheers:
Melting Slicks
Joined: Jun 2001
Posts: 2,429
Likes: 14
From: CA
Re: Header temps and such (mrvette)
I agree :yesnod: My headers cool off quickly (even more so now since I got them Jet-Hot coated)
Cast exhaust manifolds stay hot forever. Like a cast iron stove.
What stays hot the longest on my motor is the oil - even after the block has cooled.
Cast exhaust manifolds stay hot forever. Like a cast iron stove.
What stays hot the longest on my motor is the oil - even after the block has cooled.
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Re: Header temps and such (mrvette)
Gene,
I think it's all about surface area.
While the car is running headers would transfer more heat to the engine compartment than ram horns.
But yes I areee. Headers don't have much heat capacity, so they should cool off faster.
But on second thought, do headers actually weigh less than cast iron manifolds? If not then they have basically the same heat capacity, but more surface area, hmmmm
I think it's all about surface area.
While the car is running headers would transfer more heat to the engine compartment than ram horns.
But yes I areee. Headers don't have much heat capacity, so they should cool off faster.
But on second thought, do headers actually weigh less than cast iron manifolds? If not then they have basically the same heat capacity, but more surface area, hmmmm
Drifting
Joined: Nov 2000
Posts: 1,428
Likes: 0
Re: Header temps and such (427V8)
And I say again gentlemen: BTU's is the issue here......the sooner we rid them from the engine compartment, via the radiator or the exhaust or free wind movement the cooler the engine compartment is going to be. And also "Free Air" Intakes will help the motor receive cooler air but will not make the engine compartment any cooler since the same amount of gas is being burned.....external temperatures being the same of course......
Thread Starter
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Header temps and such (tnt76vette)
Well, I guess really my question revolves around the affect of ceramic coating on engine compartment temps, and therefore pass compartment temps...will it really make any significant differance?? and does anyone have any direct comparison experience on their car?? or a direct compare to say a friend's car vs. theirs....with one of them having ceramic coating and the other NOT???
GENE
GENE
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Re: Header temps and such (427V8)
Ditto 427 - headers have 3 or 4 times the surface area inside the engine bay to radiate heat from. It's the same principal of steam radiators used in older commercial buildings - more surface area means quicker heat dissipation.
