Heater improvements

[bagarre]

Ok, winter is upon us and I don't plan on flying with frozen toes.
But my heater seems to be less than stellar.

What are the recommended heater checks to make sure you're getting all the heat to the cabin as you can.
A friend of mine mentioned a double walled scat tubing (sceet???). What size should I order? Has anyone else done this?

I do have quite a few leaks in the cabin and can see daylight around the door jams.
Whats the right way to plug up leaks and seal door jams?

For the record, mine is a '52 170B.

Thanks!

[flyguy]

Someone way before I bought our (1952) '93D had put in the late model heater modification shown in the 170B IPC page 95 Figure 55. It is a lifesaver for cold weather flying. I imagine some of the sheet metal parts could be found in salvage yards. You may also find the replacement muffler there. The mod does require the later model right hand muffler and shroud with the 3" opening for the larger 3" scat to the later model air box on the firewall.
As far as I know it is the only resource that will give you effective cabin heat, for both front and back seat pax, from the engine. After market heaters like Jantrol have become almost out of favor and pretty rare.

Get some good wx stripping for the doors and windows. PM George Horn for the numbers. He has all the samples of the good stuff.

[Bruce Fenstermacher]

Ok, winter is upon us and I don't plan on flying with frozen toes.
But my heater seems to be less than stellar.

This is because the heats system IS less than stellar on the '52 and earlier models.

The best thing to do first besides being sure the system is hooked up correctly and open and free flowing, is to stop cold air from entering the cockpit. Door and window seals are notoriously leaky. A major air leak can usually be found at the area of the wing root and windshield. Sealing these openings helps.

Since the windshield moves in relation to the wing route it is difficult to sell this area but I remember George describing a way he seals his on the inside. It is here on the forum to be found. My first 170 had this area stuffed with what seemed like a fiberglass blanket. I wouldn't use fiberglass personally but you want something that won't obsorb water. I've seen these areas simply stuffed with rags.

Correct door and window seals as they came from Cessna aren't available and it's been reported that Cessna doesn't even know what they used. The seal was a very flat pliable seal that fits in the little space between the door edge and the fuselage. Many types of seals have been fit in there with various degree of success. George has recommended a certain style of seal available from Brown which people have had good success with. George also recommends a window seal. These seals or one like them are probably the ultimate way to go.

I've had mediocre success with the self stick foam available at local hardware stores. The problem is you really have to study the way the door is suppose to seal and this stuff doesn't really work all that well duplicating it. But depending on how your door fits, and they are all different believe me, you can have some success with various widths and thicknesses of the self stick foam variety. Most of the time you put this foam in thinking you'll have this leak sealed and one of two things happen. You can't shut the door or the door shuts and you still have a gap because the foam isn't big enough.

The windows are a little less fussy with the self stick foam. But you have to get the right thickness. I've actually taken some of the foam about 1/4" thick and tapered it to about 1/8" to use on the side of the windows because the top of the window is tighter than the bottom.

Applying the foam seal can really become an art form. I would suspect removing all the old seal and replacing with good quality stuff like George recommends while much harder and more expensive to do will ultimately be more satisfying.

I will attempt to find links to other threads talking about this subject of door and window seals.

We also have a thread on the scat routing which differs depending on the year and what mufflers you have. By '52 the airplanes all had the Hanlon Wilson mufflers which narrows that down in your case. If yours is a stock set up you should have a all 2" scat single wall. I can't say if double wall scat will help hold heat but I suppose it can't hurt. Anyway on the right hand side (passenger) the scat should come from the front baffle to the front muffler shroud inlet. From the rear shroud outlet to the carb heat box. On the left side the scat will come of the baffle to the muffler shroud then out the shroud outlet to the 2" valve on the firewall.

On the front baffles you may or may not have scoops for the left and right inlet. I've been making a study of what years had these but haven't come to any conclusion. Adding them may help air flow but we haven't proven the will. By '52 in the inside of the cabin on the head manifold itself Cessna seemed to cut down the outlet size and make it more directional when compared to the earlier models which just had what looks like a deflector plate. Can't say either one works better.

So in conclusion my opinion is we haven't figured out a magic way to get more heat out of the early systems and so most just try to keep the cold out and dress warm. This is probably why Cessna redesigned the system in '53 which is what Ol Gar is talking about. It would be a nice addition to early models but is not an easy mod. Besides collecting all the parts including very expensive and somewhat hard to find muffler baffles and a different right side muffler, you would also have to relocate the battery to the left side.

Here is a link to a discussion on the heat system on a '48 but it is applicable to the '52: http://www.cessna170.org/forums/viewtop ... ter#p60377

Here is a link to at least one thread on window seals: http://www.cessna170.org/forums/viewtop ... =door+seal

[bsdunek]

This is one solution: http://www.aircraftdoorseals.com/produc ... ucts_id=88

The 120-140 guys are having some made. You might get an order in. http://www.cessna120-140.org/forum/viewtopic.php?t=6268

There was a guy on the Cessna 120-140 forum that had a nice replacement seal. He seems to have dissapeared. I bought enough to do my doors, but haven't installed it yet. It's very similar to the original.

[GAHorn]

[..., you would also have to relocate the battery to the left side....l

It is not necessary to relocate the battery. Richard Pulley has modified his to the later system and posted pics here in the forums.

It is also not necessary to obtain the right muffler of the later airplanes. The later system can use the early right Hanlon-Wilson muffler, albeit with somewhat reduced efficiency than the full-blown heat of later systems.

[Bruce Fenstermacher]

It is not necessary to relocate the battery. Richard Pulley has modified his to the later system and posted pics here in the forums.

It is also not necessary to obtain the right muffler of the later airplanes. The later system can use the early right Hanlon-Wilson muffler, albeit with somewhat reduced efficiency than the full-blown heat of later systems.

Of course George is right I was thinking of a stock installation.

Here is a link to Richards pictures: http://www.cessna170.org/forums/viewtop ... ter#p51014

[Blue4]

Some of the folks around here (Fairbanks, AK) swear by the cowl flap addition / modification to help retain heat in the winter. I've only seen it on a few airplanes and have no idea whether or not they have any sort of approval. I haven't seen mention of it here on the 170 board, but I haven't done an exhaustive search, either. Next time I'm out looking I'll attempt to get some photos of the half-moon-under-the-cowl-lip design.
-Scott

[bagarre]

Hmm, OK.
So, the early 170's weren't known for keeping your toes warm in the winter time.
And it sounds like quite a bit of work to upgrade the toe toasters.
For this winter, I'm going to seal up as many leaks as I can find, install 2" sceet and make sure everything works as good as it can.

Maybe I'll look into the '53+ heater system next year but, I'm guessing I can go pretty far with an extra sweater and electric socks

Thanks to all!

[flyguy]

[..., you would also have to relocate the battery to the left side....l

It is not necessary to relocate the battery. Richard Pulley has modified his to the later system and posted pics here in the forums.

It is also not necessary to obtain the right muffler of the later airplanes. The later system can use the early right Hanlon-Wilson muffler, albeit with somewhat reduced efficiency than the full-blown heat of later systems.

My '52 mod has the later air distribution box in the same location the old round one was. It just required a longer 3" scat to reach that side when I went to the later model muffler. George is right that you don't "have" to change the muffler but if you are going for the most heat available you want the later muffler with the 3" outlet on the aft end. That air flow is probably double over the old style. And as you are providing heated air to the rear seat area too you need more air flow.

[Bruce Fenstermacher]

I concur with Gar it is probably an airflow issue. My left toes were usually pretty warm. Getting the warm air to the right toes and any where else is the issue.