Firewall connection for Autolite heater

[Hoogah]

I have an Autolite heater that has never been connected (and there is no hole in the firewall . . . yet). I've got the valve with the swinging flap that mounts through the firewall and extends into the back of the heater unit.

When the heater is in position on the manifold, the back of the heater "tube" sits about 1/4" away from the firewall. The tube (attached to the valve) that passes through the firewall from the cabin will extend into the heater unit by about 1" and is a snug fit. All good, except that I'm wondering about engine vibration and noise being transferred to the cabin as this setup will effectively connect the engine to the firewall?

I did a search of previous threads on this issue and read one post that recommended the use of flexible tubing to connect the heater to the valve. That makes sense, but there is no room to do this.

Am I missing something? Anyone care to post a picture of your Autolite heater connections at the firewall, with some advice? Thanks.

[pat in Santa Cruz]

I've never seen one with a metal tube coming out of the manifold part. Usually I see rubber hose, or air filter stove flex tubing connecting the two parts. I would imagine a solid metal tube would transmit a lot of noise and vibration. As it is, even with a flex tube, you will hear more valve noise, but its not bad.

[James Rogers]

The heater cover should not be connected to the flap. The reason for this is, the engine has a certain amount of movement separate from the body and connecting them could cause damage to the firewall or heater.

[AL in NY]

I installed the Autolite heater and the original Autolite heater door. The door, like yours, was a snug fit into the back of the heater cover. This created waaaaay too much noise and vibration. What I did was machine a 3/16" larger diameter recess on the back of the heater cover so when they are installed, the extra clearance allows for engine movement without the two pieces touching and causing noise and vibration.

[CarlG]

The guys in our club use SCAT hose, available at aircraft supply houses or repair shops.

[ursus]

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It's too bad those heater holes in the firewall can't be traded to the guys without a hole. I have two in my firewall and wish I had none. I told the wife the second hole was for air conditioning but I don't think she believed me.

[Hoogah]

Originally Posted by 1930 coupe

Someone has added a tube to your cover, you need to pull it out.
Some of the original doors came with a flexible tube in them, most of these tubes are now missing, so people find some kind of tube to replace it.
The tube must be flexible or loose so it can move when the engine vibrates. The picture shows a door with a original flexible tube.

On closer inspection, I reckon you're right. The tube looks like it is perhaps a home-rigged job, judging by the uneven back edge (cut with a hacksaw?). I'll get it out and replace it with a length of flexible hose.

Thanks for your advice!

[walt jones]

Hoogah,
Cars with pristine fire walls, that is with no holes cut in them are getting harder to find. You might want to reconsider cutting a heater hole if your fire wall is in like new shape. Manifold heaters were an after market item and they dont really supply much heat.
All the best, Walt

[Hoogah]

The jury seems to be out on how effective manifold heaters are. I've read a range of opinions on this forum. I would consider options to "spoiling a virgin firewall". Has anyone run a hose from a manifold heater to a floor mounted inlet?
Hmm, I also still have the original floor boards so I'm going to have to spoil something if I connect this thing.

[Tom Wesenberg]

Originally Posted by Hoogah

The jury seems to be out on how effective manifold heaters are. I've read a range of opinions on this forum. I would consider options to "spoiling a virgin firewall". Has anyone run a hose from a manifold heater to a floor mounted inlet?
Hmm, I also still have the original floor boards so I'm going to have to spoil something if I connect this thing.

Save your original floorboards and make or buy replacement boards to cut the hole in.

I rode in the back seat of a 31 Town Sedan with a manifold heater, and I was very comfortable when the outside temp was 30*, but I agree that I'd never cut a hole in the firewall. I'm going to reweld the hole in my firewall and use a hot water heater and bring the heat through the floorboards.

[Ed Saniewski]

Here is a link to some other heaters. http://www.fordbarn.com/forum/showth...t=Ed+Saniewski .