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Should I wrap my headers?


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Thought of two other comments related to HP:


1) Talk about how the headers refract at Daytona or what NASCAR saw!   Well, header temp is directly related to HP and if you have a NASCAR engine that is melting headers, you cannot directly relate that to an engine that is making 1/2 to 1/4 the HP per tube diameter.  If you want to make comparisons, you have to relate similar applications. 


2) One reason for wrapping is if you don't have the room for the tube diameter you need to be running.  But again, this is really an extreme case for a true racing engine. 


3) As far as HP gains (and loses), boat racers are direct geared to their props but have 2 events they must tune for:  Top Speed and Getting the Hull Out of the Water.  The latter occurs at a mid-range rpm and in many cases, the engine at this reduced HP output does not have enough HP to get the hull up which means the boat will not go any raster.  So what do they do?  They spray water on the header tubes which creates a substantial torque increase and hence HP and gets the hull up!  So it is clear that header temp is a way to make a "variable size header."

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i can say my headers on my jet boat are water injected...... many run a lighteingn header that are actually water jacketed..... never seen it sprayed on a header just in......


i dont know where u read or regurgitated that number 3 point ... but that's ridiculous

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I worked with a guy that raced boats, but that was now almost 20 years ago.  Maybe he did say they spray inside the header.  Frankly that would be the place to do it.  It would have dramatic effect internally.  I just don't remember anything more about that conversation.  I'm pretty sure that was when I was planning to wrap my headers on the 427 truck.


I know we talked about spraying the headers and I thought it was on the outside - probably because I was thinking how they spray down air cooled radial engines and the Reno Air Races.  Even the water cooled Mustangs - they spray "spray bar coolant" on the outside of the engine.


If you do wrap your headers, but sure you get a knitted wrap that stretch some.  Some brands don't and if you get one of them, your job will be impossible and look like crap.

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Its a lot of work but there are 2 advantages:




it will reduce under hood temp which is probably the most practical reason for doing it.




I coated my wrap with a ceramic "plaster" which turned the wrap into a cast.  Then I wrapped it with aluminum foil duct tape.  That resulted in my headers looking like the day they were made after over 10 years of use.  (But I confess, I drove only a few thousand miles a year.)




And NEVER wrap within 6" of the exhaust manifold to head gasket - especially if there is a bend right at the flange.  Yep, I refracted mine into slag and blew a chunk out right where the exhaust flow hit the bend.

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I may not have been paying attention, but is it for a turbo setup?


That is really difficult because like its been said here, those headers will be glowing all the way to the turbo if wrapped.


But keeping that heat contained puts more energy into the turbo.  That is much more significant than a normally aspirated header wrap - just a way to get a "bigger" header if you will.


What about sending them out to Jet Hot?

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The recap should be if done correctly then do it if not then expect damage. I'm not even going to contribute to these threads anymore, people cant be bothered to read our responses anyway. 

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