Hello!

Where is this hose / bracket / pipe connected on the 350?

See image attached red marker

 

That is the hot air duct. It draws air that is warmed in a heat stove around the exhaust manifold to help atomize the fuel when the engine is cold. That actuator is a vacuum diaphragm that is controlled by a thermal sensor on the underside of the air cleaner.

 

Does this 350 have a year and model?

 

Thank you for the reply! It seems I am missing this part as somebody changed the original air cleaner to a chevrolet one.
Can I get this hot air duct as a reproduction part?

Found this https://www.thepartsplaceinc.com/pro...55-motor/34011
which mentions 400/455 MOTOR on the title, but not 350

Any differences with AC and non-AC?

 

Yes, sorry, image is from internet but my 350 is from 71 cutlass supreme convertible with AC

 

Let me know if this helps.


This is the temp sensor located inside the base of the air cleaner



Temp sensor, vacuum actuator in red. Vacuum hose routing in green.





Vacuum connection on intake manifold, rear of carburetor.

 

Thank you, very helpful! The air cleaner I bought off these forums has temp sensor + vacuum actuator + vacuum hoses, and now I know where to attach the vacuum hoses

So all I need is the hot air duct? Or do I manage without it

 

Without a pipe similar to the one you linked above (but for a 350 car.......which may be shorter.........not positive on that), you won't be drawing in heated air when the engine is cold like the factory intended. This won't keep the engine from running, but it will make cold / warm-up behavior slightly less friendly. You should see the shroud around the passenger side exhaust manifold where the bottom end of the pipe would connected (held by a single screw IIRC). Worst case if you can't find the solid pipe for your 350, you should be able find an aluminum flex hose that will do the job.

 

Ok so one more missing piece, there is no shroud, somebody has removed that
but now it all makes sense

good info: https://classicoldsmobile.com/forums...-setup-106399/

Then again, I am planning on using thornton exhaust manifolds, does the original shroud even fit those? I do not know =)

Edit:
Apparently not https://classicoldsmobile.com/forums...nifolds-34893/
"... i did call Thornton and they told me to use the stock heat shroud, i would have to grind off the ribs of there manifold on the passenger side."

 

Correct, going to anything other than a factory manifold makes the "stove" and "pipe" pretty much useless. You might be able to fabricate something that works on shorties, but this might take time and $$ to pull off while looking nice. Everyone that adds headers leaves off the pipe or changes to a different air cleaner that doesn't have a provision for a stove pipe and suffers the cold-warm-up consequences . I suppose if you get desperate for improved cold-warm-up behavior, you could try using one of those flexible aluminum hoses and poke it's opening down between the header tubes to get some warmer air. It will never be as effective as the factory type stove though. From the looks of that air cleaner, you have a 2bbl 350 and a small snorkel, which pretty much prevents any small improvement you might get from shorties under better intake-side conditions (open air cleaner / 4 bbl).

 

Thank you, I will try to figure something out, my engine is 4bbl 350 (the one I posted here is from internet, not mine)
My current air cleaner looks pretty much like this, and cold start is ok (apart from the excessive cranking time needed to get fuel from tank to the carb)
But I think this air cleaner setup is probably not related to the cranking time