From: FLYCOZY@aol.com Date: Wed, 19 Jan 2000 15:12:31 EST Subject: COZY: Re; Heaters/oilcoolers/ducts Builders Dana Hill E-mailed me and asked me why I used the Honda CRX fan motor in the heat system in the Mark IV that I built. I thought other might be interested too. So here goes. On a cold wintery day in Iowa last January I was rooting throught the local auto junk yark like a junk yard dog. I was looking for a small blower fan to push air thought the oil cooler in the nose of the Mark IV. I was building. Well I was cold, my hands were cold, my nose was running and thoughts like "what are you doing " were running through my head??... Maybe I should mount this fan, which I hadn't found yet , " but was just an illusion in my mind", behind my head. with the hope it would comes loose and knocks some sence into it. Well I wasn't finding what I wanted so I asked the guy behind the desk if he had any ideas. His first question was, whats it going in? as I said , an airplane .he looked at me funny and said; well....Honda makes about the smallest, I think. he looked like he hadn't changed clothed since 1995 , but I took his word for it. Thats why I used a Honda CRX fan. there are probably lots of others that would work . I made a squirrel cage fan around it and mounted it ahead of the co-pilot feet area. The Mark IV I built has two oil coolers one to heat the cabin and one to cool the engine oil. First, The oil cooler for the engine is mounted on the engine mount on the pilot side of the firewall. If I was to do it again I would mount it on the co-pilot side same place verticle about the same height as the main spar. I used Adel clamps and stand off tubes to hard mount it to the engine mount. I then put on the lower cowling.Then I took some 3/8 PVC and make a duct the same area size as the 13 row oil cooler so that it would exit air out the lower cowling. It exits about 5 in. aft of the main spar cowling lip. I duct taped the cooler and the foam mold and glass with 3 ply bid and an extra 2 ply at the flandges. You need to make sure there is about a 1/2 flandge to bolt the duct to the cooler and to screw the other end to the cowling and making sure the top cowl won't hit it. I liked this installation because when you take the cowling off for the hundreth time the oil cooler stays in place. It doesn't hit you in the head and the duct act like a chimney and drafts. The oil temps have been between 170 and 198 degreees. I used countersunk stainless steel area washers and countersunk screws for the cowling oil cooler flandge and in fact the cowlings have the same fasteners all around. I used camlocks on my Cozy 3 place and I didn't like the way they let the cowling move and abrade over time. Although the camlocks are much faster to remove. I think you could go either way on the fasteners By having the oil cooler on the mount you don't have to be such an octopus to put the cowlings on either. Now back to the heater, The heater fan up front I run on high all the time. To adjust temp I cut the oil flow back by closing ball valve on the floor on the co pilots side. If I were doing it over again I would run 1/2 in. solid aluminum lines up front to the instrument panel. And use dash 8 hose fittings and hoses to the cooler, like I did to the oil cooler on the engine mount. What I have noticed is that it takes up to half an hour on a real cold day for the cold oil to purge out of the cabin oil cooler. It takes at least 15 min to get the oil temp up to 180 at full throttle. Then the vernatherm opens all the way and you'll start getting heat. Not before. Oil temp has to reach at least 180 degrees or you'll get no heat. I have been blocking off the exit duct with a piece of cardboard to block off the exit air. I figure If I loose the cardboard and goes throught the prop it won't hurt anything. Well thats how I did the heat system. I know somebody did something just about like it and published an article about it in Kitplanes. I wish I would have seen what that person did before I did mine although I'm happy with it. Hope this helps somebody. Its snowin in Iowa today!!!.. A really good day to go to the shop and build sometin'..... Have Fun; Dennis From: "Epplin John A" Subject: COZY: Cabin heat Date: Wed, 10 May 2000 10:47:49 -0500 I made a box on the aft side of the firewall to get the cabin heat through the firewall as well as provide a metal shut-off and the connection to the carb air heat. The biggest problem seemed to be operating the slide valve for the cabin heat control. Thought of and discarded a pull cable with a spring return to off. While I was looking for some simple way to do this, someone brought me the servo motor from a car climate control to try to repair. Lights came on! This is a very light weight mechanism that uses a small 12 volt motor to do the same thing we need to do in the Cozy. It has a potentiometer attached that can be connected in a simple bridge circuit to drive a small panel meter for valve position indication. A simple DPDT center off switch is all that is needed to drive it. I made a trip to the automotive junk yard, seems these are not normally removed from the wrecks. It took a few minutes to get across just what I wanted, finally they told me to go out in the yard and find what I wanted and they would remove it. Took a few looks but eventually found a perfect situation, everything had been removed to expose the system. The guy removed the complete climate control box, containing the vacuum solenoids as well as the electronics. I was afraid that this might cost more that I wanted to pay but when I brought in into the office the counter man looked at it, said he wanted at least his labor out of it, pay the girl at the door $5.00 plus tax. WOW! The servo has a rotating output with an arm about 1.5 in long that turns through about a 110 deg. arc. Just about perfect for my system. Also, you guys that are building in computers, you can add climate control with very little additional hardware. The total installed weight is very little if any more that using a push-pull cable even including the wiring which I used #22 for. John Epplin Mk4 #467 From: cdenk@ix.netcom.com Date: Wed, 10 May 2000 21:55:10 -0400 (EDT) Subject: Re: COZY: Cabin heat I am assuming the slide valve is to shut off the air passing through the firewall. The main, if not only reason to shut it is fire, or noxious fume from the engine compartment. It's possible that there would be an electrical failure at the same time. I would prefer a bowden cable operation for simplicity and safety. In 800 hours of flyong, I can't remember having a reason to close it. Adjust temperature, but always air coming in.