Anyone hear of these

http://www.kijiji.ca/v-boat-parts-tr...ationFlag=true

They have been discussed here already.
Use the "search" feature and read all about them.

They won't call you back

Ordered mine last week. I will post on how they perform.

You may already be aware of it, but I thought it was worth noting that the headers listed in the add are water injected.. Not water jacketed.. Like I said you may already know that and it may not even be an issue for you since I have no idea what these would be going on, but just incase I thought it was worth a heads up.. ;-)

The ones I ordered are water jacketed, like Stelling, CMI, or Hardin....

What's the diff

Not water jacketed like CMIs they are water injected . meaning they are not a tube in a tube with water insulating and cooling the inside tube that carries the hot ehaust gases. They are for open engine compartment like are on flatbottom jetboats .

You put them on an engine in a closed compartment and they will get so hot they will start the boat on fire.

Search in Google even brought the long thread here in OSO:

http://www.offshoreonly.com/forums/g...r-headers.html

As tommymonza said the primary tubes (your 4 individual tubes per side) on a jacketed header are double walled (tube inside of a tube) meaning the water circulates around the tubes and does not enter into the path of the exhaust gasses.. Where as an injected header shoots a stream of water directly into the primary tubes themselves.. And as monza explained the water injected headers are not designed to be ran in a closed engine compartment because they get Very hot, as in burn your azz hot versus a jacketed header will be Drasticly cooler to the touch... Not to mention the water reversion problems with an injected header..