DHC-2 exhaust & cabin heater

[DHC2_in_ak]

We are investigating updating the beaver cabin heat system. And one question we need a answer to is:
What are the perferated holes on the lower aft end of the tail pipe for? (We've come up with some possible answers):
1. To relieve the exhaust system of back pressure, do to it's length.
2. Create turbulance of the exhaust for sound deadening.
3. Create turbulance of the exhaust to get it away from the cabin area.

You guys have any thoughts on this?

[lost in the north]

why do this when it already been done...

[HS-748 2A]

The cabin heat selector flapper door is mounted at the end of the pipe. Maybe the holes help dissipate heat to keep it from concentrating at the door and the bowden cable. Too much heat there could sieze things up.

Interesting question though and I'm just not tossing this out there. No idea really.

Maybe they're just saving weight and adding third-dimension ridgidity?

[HS-748 2A]

Have you ever seen this mod, with the muff over the short stack?

I wonder how effective it is?

Looks like it probably saves some weight and the stack-extension keeps some of the shieght off the belly.

[lost in the north]

Hi
The contact for the new system is mcrae185@hotmail.com

[sarg]

Have you ever seen this mod, with the muff over the short stack?

I wonder how effective it is?

Looks like it probably saves some weight and the stack-extension keeps some of the shieght off the belly.

To the best of my memory it works as good, perhaps a little better than the convential system. The big advantage was the maintenance side the machine with the can system had less exhaust issues, requiring attention between inspections.

[HS-748 2A]

Maintenance wise, of course AD CF-90-03R2 would still apply but yes, I'm sure you're right about fewer problems and the actual inspection of the exhaust stack would be much easier than the 'intensifier-tube' system on the old one.

The long, dirty, sooty, black old tail pipe with that goofy funnel looks better, but that's just MHO. I'm a traditionalist.

'48

[DHC2_in_ak]

Yes we've seen the "new" system. And yes its only a tad better than the intensifier system.... We want to extrapalate on that system by putting a 17" wrapper style shroud on the original "long" tail pipe with heat transfer fins welded on the tail pipe. Remove the intensifier. Weight savings is probally a wash.
The problem with the intensifier is mostly no volume (flow) of air, not heat. So if we design a longer shroud to cover the tail pipe AND increase the heat shroud air intake. You should be able to rest your coffee on the heater duct to keep it hot.
But we would like to omit the perferated holes on the bottom of the tail pipe

[sarg]

Maintenance wise, of course AD CF-90-03R2 would still apply but yes, I'm sure you're right about fewer problems and the actual inspection of the exhaust stack would be much easier than the 'intensifier-tube' system on the old one.

The long, dirty, sooty, black old tail pipe with that goofy funnel looks better, but that's just MHO. I'm a traditionalist.

'48

I'm with you on the looks issue.

[bronson]

the other advantage to the short stack is you hear a change when you are getting close to the (glassy) water. Always hated losing that so I could have heat!

[HS-748 2A]

the other advantage to the short stack is you hear a change when you are getting close to the (glassy) water. Always hated losing that so I could have heat!

Actually, and I bet Beaver Bob could vouch for this, but I have found that there is a sound difference even with the long stack.

Just as the keels touch the water, it forms a 'box' with the belly and the reverberation changes.

I only ever flew one with the long stack, so I have no comparison though.

[Caracrane]

didn't read all the replys but is there anybody that tought about a
stc for a jenitrol installed kind of like in a BN-2 or it already exist cause otherwise I'll do it!

[Caracrane]

cause I know a Beaver with auto-pilot so why don't a Jenitrol

[lost in the north]

Yes there is a stc or lstc to install a gas heater in the tail of the beaver.

[Caracrane]

ah ah! So U re not so Lost!

[Rsichterman]

Would anyone have a part number and or contact info to order the heat shroud and flapper assy. for the short stack exhaust/ cabin heat.[/b]

[PilotDAR]

Contact Acorn Welding, they hold PDA09-13 for DHC-2 exhaust parts

[pilotidentity]

You should be able to rest your coffee on the heater duct to keep it hot.

DHC-2 on floats. It was cold, small lakes were starting to freeze. River was still open. The cable to the heater on the exhaust broke so we lock wired the door shut so we could get full heat. What could go wrong?

30 minutes after takeoff I looked down at my feet. They were covered in smoke. River was below but no where to land safely. Boulders and wood. Quickly investigated and found the blue plastic tarp that was covered in moose meat was smouldering. No way to turn the heat off. Tried to move the meat and tarp but it was too heavy. Had to live with it.