'52 and prior heater

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

'52 and prior heater

Post by bagarre »

Well, I finally did it. sorta

Instead of going thru the pain of upgrading the entire heat system, I decided to make a late model style heat plenum to span across the firewall and keep the rest of the '52 system.

We removed the round diverter on the inside of the airplane and replaced it with a 6" tall by 1.5" deep by 35" long box that we made up. it mounted to the existing holes for the old diverter and the battery ground bolt on the other side and we put 6 1/2" holes on passenger and pilot sides. (No pics at the moment but will have them soon)

I flew home from Pittsburgh today with OAT at -5C. Normally, my toes would be frozen and the flight barely tolerable.
This time, I almost wanted to take off my jacket!

This was using the '52 stock exhaust, heat muff and firewall valve. NO modification to the existing heater parts less removing the round diverter and mounting the box in it's place.

I'm quite impressed.
User avatar
Bruce Fenstermacher
Posts: 10313
Joined: Tue Apr 23, 2002 11:24 am

Re: '52 and prior heater

Post by Bruce Fenstermacher »

Pictures, drawings and a short article suitable for printing would be most appropriate. :D
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
hilltop170
Posts: 3481
Joined: Sat May 06, 2006 6:05 pm

Re: '52 and prior heater

Post by hilltop170 »

David-
That is essentially what I had done, except with C-180 parts. The 2" heat duct off the Hanlin Wilson muffler provides plenty of heat and the 2" cool air duct off the top of the engine provides plenty of cool air to the cabin.

The guillotine valve was not installed for some reason when the rest of the C-180 heater parts were installed and I didn't catch it until too late. I just found the parts and will get them installed at the next annual as I feel being able to close the guillotine valve is critical in case of engine fire to keep smoke, heat, and flames out of the cabin.

The C-180 heat duct has a provision for defrost but we could find no way to make it work with the limited space behind the panel in the A model.
C-180 heater valve in 1951 C-170A
C-180 heater valve in 1951 C-170A
C-180 heater valve in 1951 C-170A
C-180 heater valve in 1951 C-170A
C-180 heater duct in 1951 C-170A
C-180 heater duct in 1951 C-170A
Last edited by hilltop170 on Fri Nov 08, 2013 12:20 am, edited 5 times in total.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: '52 and prior heater

Post by bagarre »

That was six holes each one half inch diameter.

I took a few photos during construction so a quick write up could be done.
bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: '52 and prior heater

Post by bagarre »

Getting back to this

No mods to the heat muff or valve required. Height is the same as the existing heat diffuser so you can use the existing top and bottom bolt holes to mount. Heat valve remains unchanged.
photo 1.JPG
Passenger side is held on with a bracket via the battery grounding bolt.
It's mounted in front of the firewall pad to avoid any chafe issues on the firewall. Box runs about 220 degrees in flight (same as old diffuser).

Made it in two pieces to slip behind the control column.
A one pice back plate with pilot side riveted on, passenger side removable.
photo 3.JPG
Flying @25 OAT leaves me toasty warm and wanting to unzip my jacket.
bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: '52 and prior heater

Post by bagarre »

A few other shots that might help visually explain things.

Here, the inside diffuser is removed but the heat valve is still in place.
I re-used the beauty ring on the carpet as well.
photo 5.JPG
Paint drying with passenger side removed. without being two pieces, you'll never get it behind the column.
photo 6.JPG
Over all shot of the box. I dont have any shots of the back side where it mates to the heat valve.
Since the valve is a butterfly, I simply punched two 2 1/2 instrument holes to match up with the valve openings.
We used rubber foam insulation around the heat valve to seal things up. The valve gets to about 250 degrees in flight and we tested the insulation to a lot more than that with a heat gun.
photo 4.JPG
User avatar
T. C. Downey
Posts: 548
Joined: Sat Jan 26, 2013 5:58 am

Re: '52 and prior heater

Post by T. C. Downey »

What paper do you have on that ?
User avatar
Bruce Fenstermacher
Posts: 10313
Joined: Tue Apr 23, 2002 11:24 am

Re: '52 and prior heater

Post by Bruce Fenstermacher »

Tom of many words.

What paper do you think one should have on a interior heater baffle? Besides of course obligatory log entry the work was performed.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
User avatar
Sk Frmr
Posts: 3
Joined: Thu Jan 19, 2017 1:35 pm

Re: '52 and prior heater

Post by Sk Frmr »

I know this is a very old post, but is there any way to get the pictures to show? Would be helpful as we are now into the winter season here in the great white north! I think this would be a great mod for my 170A.
User avatar
dstates
Posts: 472
Joined: Sun Jun 30, 2019 5:50 pm

Re: '52 and prior heater

Post by dstates »

I've read this thread before and am also interested in this type of change to my 170A cabin heat plenum. I found this article for an experimental cabin heat system (https://www.kitplanes.com/cabin-heat-plenum/) and thought that something like this would be easy to do, but I wouldn't use PVC. My thought is if you can make a 90 degree turn at the outlet on the firewall you could use SCATT or aluminum tube to make a simple manifold that goes across the firewall without having to find 182 parts like in the previous posts. I haven't discussed this with my A&P IA yet, but I don't see a reason why directing the heat would be worse than just letting it flood out at my left foot as long as there is clearance to all of the flight controls. It's on my to do list, just not very high compared to everything else.

Doug
N1235D - 1951 170A - SN: 20118
User avatar
Bruce Fenstermacher
Posts: 10313
Joined: Tue Apr 23, 2002 11:24 am

Re: '52 and prior heater

Post by Bruce Fenstermacher »

The photos posted by bagarre are unfortunately not recoverable.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
User avatar
Sk Frmr
Posts: 3
Joined: Thu Jan 19, 2017 1:35 pm

Re: '52 and prior heater

Post by Sk Frmr »

Something tells me I did see the photos at one time. At any rate bagarre did a very good job describing the modification so I think I will try to reproduce it. My mechanic is on board with me so I think it is worth a try. If it works out well I will post my results. Like dstates, there are many things on the priority list, we’ll see if this makes it to the top of the list!
User avatar
GAHorn
Posts: 20968
Joined: Fri Apr 12, 2002 8:45 pm

Re: '52 and prior heater

Post by GAHorn »

Richard Pulley (hilltop170) posted pics of his method. I’ll search for them.
(A certain Smrtazz pointed out the pics above to me but I’m not looking for those, instead for the sidewall/pax outlets.)

Here ya go: http://cessna170.org/forums/viewtopic.p ... lit=Heater
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
User avatar
dstates
Posts: 472
Joined: Sun Jun 30, 2019 5:50 pm

Re: '52 and prior heater

Post by dstates »

Thanks to Gene F. for saving a pdf of this thread in the past with the images from bagarre. He sent me the pdf so I'm re-posting the images here. They are not the original quality as they are taken from the pdf, but they are still helpful. You'll have to tie them back to the comments above.

photo 1.JPG
heater_1.jpg
photo 3.JPG
heater_2.jpg
photo 5.JPG
heater_3.jpg
photo 6.JPG
heater_4.jpg
photo 4.JPG
heater_5.jpg
N1235D - 1951 170A - SN: 20118
User avatar
Sk Frmr
Posts: 3
Joined: Thu Jan 19, 2017 1:35 pm

Re: '52 and prior heater

Post by Sk Frmr »

Thank you for those pictures! It has been a while since I last logged in and that’s why I only noticed this now. Very much appreciated!
Post Reply