Heat stove and heat riser question

[chewychevy67]

I've only had 67s recently so I know 67s had a heat riser by the exhaust manifold but 67 never had the heat stove on the manifold to the air cleaner. When they added the heat stove to most 69 models did they have both the heat stove and the heat riser going forward or was it 1 or the other each seperate?

[Stocker]

All I know is my '72 had a heat riser on the passenger side exhaust (removed many years ago) and the stove on the intake which operates the choke on the Quadrajet.

[71CHEVYSHORTBED402]

1971 402 at least had a stove and pipe. Expedites carb. air temperature, part of the cold start system. Some notes:

The thermostatically controlled air cleaner operations are found in the 1971 service manual page areas 6M-19. The thermal sensor and diaphragm motor work with the heat stove and pipe to control carburetor air temperature. The assembly is designed to maintain carburetor air temperature passed through the air cleaner’s snorkel @ 100F or more. The thermostatic air cleaner is tested with under-hood temperatures below 85F:

• With engine off -The snorkel’s damper door should be opened.
• With engine running, vacuum applied, and air temperature below 85F - The snorkel’s damper door should be closed.
• With engine on, vacuum applied, and air temperature above 85F - The snorkel’s damper door begins to open @ 85F.

[chewychevy67]

OK thanks. Just wasn't sure if both came together or separate.

[Wrenchbender Ret]

My 72 with 350 engine never had a heat riser valve. It has the heat stove to the air intake.

George

[71CHEVYSHORTBED402]

Originally Posted by Wrenchbender Ret

My 72 with 350 engine never had a heat riser valve. It has the heat stove to the air intake.

George

Cool, didn't know that. I updated my post to include 402, though seems some 350 had a stove and pipe.

[Stocker]

Ah shoot, I had brain fade, sorry guys. I saw "heat stove" and thought of the gizmo for the choke on the carb. Forgot all about the heat stove on the drivers side exhaust with a pipe to the air cleaner. My K20 had all that but I took it off many years ago. Still have all the pieces in storage, along with a lot of other original stuff.

[Getter-Done]

I remember a Black truck in a Time capsule thread.

I think (Pretty Sure) it was a 67?

It had a lot of pictures.

I have searched High and low and still have not found it.

Best I recall, It had under hood pictures.

[Stocker]

This one https://67-72chevytrucks.com/vboard/...d.php?t=665004 has an underhood pic on page 1 and another on page 6.

[Getter-Done]

Originally Posted by Stocker

This one https://67-72chevytrucks.com/vboard/...d.php?t=665004 has an underhood pic on page 1 and another on page 6.

That is the thread I was talking about.

Glad you found it.

[Bob B.]

That truck has the V-6 in it. No thermostatic air cleaner, V-6's usually had a heat riser valve on the right exhaust manifold. Mine fell off years ago about the same time I put dual exhaust on it.

[71CHEVYSHORTBED402]

Interesting thing I found about the thermostatic snorkel door diagram is I tested it with a vacuum gauge with negative results. I read someplace they don't work that way, and I was thinking, well, why not?

Well, they don't work that way and after all, there's no reason to test them with a gauge anyhow, they work or they don't. It works like it's supposed to. 53 years on that thing, though I capped it when I got it 1989, because the riser was gone.

[Rust_never_sleeps]

My 70 still has the stove(on the manifold), the riser and the "Thermostatically Controlled Air Cleaner"
This is the LS9 CA emissions version, so maybe the 49-state versions didn't have all that
Page 376 of the Service Manual has diagrams ICAC