cobra heater

[keane]

Hi guys Dave in Uk, I have been down this road before but need to confirm before commiting to pipe runs etc, I have a spitfire heater mounted behind the dash, could someone confirm the waterflow regarding the pump? the pipework will come off the water pump through the heater, and then into the front of the Perf Rpm? via 5/8" hose or whatever size it needs? should work? thanks Dave

[ByronRACE]

There's a lot of ways to do this. You just want something that works, or are you trying to be vintage/ac cobra correct?

All you have to do is plumb the core between a high pressure part of the system to a lower pressure part. And, my recommendation would be to install a restrictor in the line before the core to keep core pressure and flow down unless you're really trying to create a LOT of heat. A chunk of delrin with a 1/4"-3/8" hole in it inserted in the tube works well. Dropping core pressure will make the core last a lot longer.

[keane]

Thanks Byron, not concerned about being cobra correct, just need a heater that has a defrost facility due to the SVA test that has to be done prior to getting the car registered, so off the top of the pump and back into the front of the manifold will be ok? and point taken re pressure. Dave

[ByronRACE]

If the heater isn't going to be really functional, why not just install a 12V muffin fan under the dash. I doubt they're going to hang around long enough to check for hot air. Just an idea.

Aside from that, I'd take the water either from the factory water pump nipple provided or from the back of the heads (drill/tap your intake manifold). I'd return the water to just below the thermostat; there should be a provision for this.

Taking the water from the back of the heads will do 2 things. 1. It will purge air that tends to get trapped back there in a cobra. 2. It will naturally drop the pressure and flow the core sees. It's not as convenient, however. Don't feel you have to do it this way; it's just a suggestion.

Incidentally, you might laugh if you saw what I'm using for defrost air. My cobra is supercharged and the bypass valve is constantly pumping vast amounts of slightly warm air out to atmosphere. Connect a hose from that to the heater/defroster and you've got one serious defrost system.

Byron
pictures on my site; project ludicrous speed.
www.racesystems.com

[keane]

Thanks Byron, over here in UK we have to put the cars (kit) through a SVA(single vehicle approval) test, so a lot of things we have to fit such as heaters would probably not be used anyway!! I have a 528 ci bigblock to keep me warm! the heater has to be able to defrost the screen, when my friend put his through the tester placed a piece of paper on over the outlet and because it didn't blow it off failed the car! that is just one small aspect so it is a pain in the a**e to get everything compliant. Still nobody says building one of these is a breeze anyway! will look at your suggestions and when its all over and on the road I'll be posting the results on here and the BBF forum. Thanks as always. Dave