Long EZ N110EZ Heater
After years of occasional effort and several false starts I have finally produced a working Long EZ heater. Although the exhaust heat muff and blower system might have worked I had a bad exhaust leak experience with my '67 VW that I didn't want to repeat.
I started out with an oil cooler mounted high on the firewall. A tee in each oil cooler line feeds the front cooler. The front cooler (heater core) is hung under the canard with a fan on top.
I agonized over trying to eliminate the rear cooler altogether but just couldn't summon the ambition. (To eliminate the rear cooler you need all those heater controls that your car has. You need to be able to select outside air or re-circulate cabin air as well as selecting whether you dump heated air on your feet or overboard. Any air you dump overboard creates separated airflow and may also interfere with the NACA scoop etc… ad nauseaum).
Valves on the inlet side of each cooler let me select front, rear, and both or neither cooler. A Shcraeder valve with a high pressure cap just down stream of the front cooler control valve lets me blow the oil out of the heater core during oil changes. At the moment I'm using the oil valve in the accessory case instead of the vernatherm to divert oil to the coolers.
The next step I`m considering is to install the vernatherm and feed the heater core from the prop governor pad instead. This should let me eliminate the control valve to the rear cooler and several fittings.
During the original building I installed a 1" x 2" bid conduit down the right side of the cabin. This turned out to be a huge advantage during installation as it gave a clear route for the oil lines even after they were insulated.
I used the same Earl's Performance Products oil coolers #21608 both front and back. This one is about 7 x 4 ¾ x 2 inches thick and seems to be enough for an 0-320 if you feed it enough air. The Earl's guys make every conceivable size and shape of oil cooler with any combination of fittings for about a third of the aircraft rated ones. And they test them all to 300psi.
The fan is a 7" 12v biscuit fan wire tied onto the heater core. The heater core is hung from F22 and F28 with simple aluminum brackets. I got the fan from Newark Electronics for about $90. I recently saw this same fan from Mouser surplus electronics for about $30.
I used about 25 ft of –8 (1/2" ID) Aeroquip AQP hose and fittings from a local hotrod shop for all my plumbing and have had ZERO problems with it. The AQP hose ends are the friendliest fittings I've used so far, they all have an integral swivel feature and are (somewhat) re-usable.
The Earl's -8 fuel shut-off valve is a key piece. In one fitting it gets the oil line through the firewall, secures the hoses attached to it and mounts the valve. An Earl's pressure gage adaptor mounts the Schraeder valve and converts the valve back from NPT to –8 AN for the hose end.
The 1/8 NPT Schraeder valve came from WW Grainger. Get the Aeroquip and Earl's catalogs and then find a local performance auto parts shop in the yellow pages.
To save time I bought about twice as many fittings as I thought I needed and sent back the extras afterwards. The control levers are mounted on the same shaft as the speed brake lever and are very handy. I've put the lever for fuel shut-off furthest outboard and it does NOT get bumped accidentally.
The next two levers control the front and rear oil cooler shut-off valves. The whole system weighed in at about 10 lbs and slightly improved my nose light balance problem. The fan pulls about 2 amps.
The system is good for about a 60 F temperature rise in the cabin in spite of a lingering air leak around the GU canard elevator. The hottest core temp I've measured under the canard with the fan off is about 125 F.
Here's some useful links:
Ion's photo album with EZ tech pix:
An Earl's Performance Products dealer:
Good luck,
Ion