I did some research on headers but haven't really found answers to my questions. This is not a thread to talk about which header is the best. I have considered NWOR, LCE and Downey. When that time comes I will most likely choose a header from Downey due to their writeup.

My first question...Is there any evidence to support headers lowering cylinder head temps?

I've seen claims from other members saying headers increase engine bay temps. I have a 91 22RE. Is there anything/other parts inside the engine bay that I should be worried about if this is actually true?

Downey specifically states on their website in the header section "Do not wrap Header with insulation wrapping or heat shields". Would the stock heat sheild still be usuable and is this what they are refering too?

Any installation tips/secrets you can share?

Anybody with a downey on their 22RE please speak up. All opinions welcomed, even if you don't like downey.

 

I run a Downey and would again on another truck. It's got a nice thick flange and the O2 sensor sits right where the factory one did and it fit like a glove! Downey also provides a nice thick gasket too. It's ceramic and I don't think you can reuse the OEM heat shield anyways. It actually cools down pretty fast after shut off. I'm not sure about the under hood temps though. I'm also running a flex-a-lite fan and hood louvers if that matters.

 

I don't know anything about the under-hood temps with the header so can't comment there.
As far as using your existing heat shield- won't work so....
And the reason you don't want to wrap the headers is because that trapping the heat in the header piping will weaken it and accelerates internal rust causing it to fail prematurely. You can also opt for ceramic coatings to be applied to the header such as Jet-Hot and get the benefits of wrapping without the down sides but expect 200+ dollars for that type of aftermarket service.

 

anyone else?

 

Downey...