Tube from exhaust manifold to intake horn

[Bryan98801]

'76 C10 with the 350

I've heard it called a heat riser or a preheater hose. But the tube from the heat shield on the right exhaust manifold to the bottom of the intake horn. What did you use for this? The one on the GM engine in my Jeep is stamped/crimped sheetmetal. What is the one for the 350? And where would I get something like it? I've checked all the parts places online and all they have are the generic dryer duct looking things.

I'm pretty sure this is the reason my truck is so cold blooded. (doesn't like to stay running at first startup) Any other ideas would be greatly appreciated.

[THE "10" SILVERADO]

Originally Posted by Bryan98801

'76 C10 with the 350

I've heard it called a heat riser or a preheater hose. But the tube from the heat shield on the right exhaust manifold to the bottom of the intake horn. What did you use for this? The one on the GM engine in my Jeep is stamped/crimped sheetmetal. What is the one for the 350? And where would I get something like it? I've checked all the parts places online and all they have are the generic dryer duct looking things.

I'm pretty sure this is the reason my truck is so cold blooded. (doesn't like to stay running at first startup) Any other ideas would be greatly appreciated.

My 77 had a metal one to. The mechanical heat riser part on the manifold was gone but the metal tube was still there.

[donut]

I've seen them hanging on a rack at most parts stores, usually they get thrown away pretty quick, so not much call for replacing them. If your truck is cold blooded, I'd look at your choke adjustment. Sub-zero temps and my old '73 didn't seem to miss it.

For it to work correctly, you do need vacuum hooked to your flapper in your air cleaner, and it also must function.

[motornut]

mine has neither,once the choke kicks in it will run
i cover my rad so it heats up quick....-30 windchill the other day
Holley Carb,Electric choke

[tucsonjwt]

One quick way to solve your cold idle problem is to install a manual choke.

[77 ChevySport]

Originally Posted by Bryan98801

'76 C10 with the 350

I've heard it called a heat riser or a preheater hose. But the tube from the heat shield on the right exhaust manifold to the bottom of the intake horn. What did you use for this? The one on the GM engine in my Jeep is stamped/crimped sheetmetal. What is the one for the 350? And where would I get something like it? I've checked all the parts places online and all they have are the generic dryer duct looking things.

I'm pretty sure this is the reason my truck is so cold blooded. (doesn't like to stay running at first startup) Any other ideas would be greatly appreciated.

Here is picture of one from a 1977 Shortbed. Larry

[terryj]

If it doesn't idle at startup the problem most likely is your choke, I think those years of truck only ran two types of chokes depending on the carb. There either electric or they use the intake manifold heat. But it does sound like a choke problem.

[77 ChevySport]

Originally Posted by terryj

If it doesn't idle at startup the problem most likely is your choke, I think those years of truck only ran two types of chokes depending on the carb. There either electric or they use the intake manifold heat. But it does sound like a choke problem.

FWIW:

My 77 LS9 used a "divorced choke". Coil is embedded in intake manifold
and heat from the manifold opens the built in choke in the carb. In this
case it is a 4 bbl Rochester Quadrajet. It works very well I might add. Larry

[terryj]

Originally Posted by 77 ChevySport

FWIW:

My 77 LS9 used a "divorced choke". Coil is embedded in intake manifold
and heat from the manifold opens the built in choke in the carb. In this
case it is a 4 bbl Rochester Quadrajet. It works very well I might add. Larry

Larry, mine also used the same type of choke, I replaced the Q-Jet with an Edelbrock 1406.

[cory d]

i just let my truck warm up a couple minutes. also when the idle mix screw screws are out of adjustment it can runnn like hell just off idle when its cold

[billybobjimmyjoejack]

There is a "heat riser" that is part of this system, it is located where the manifold and the exhaust pipe come together on the right side. It is about 1" thick and has a spring loaded weight on it. The valve in the heat riser will decay or corrode or just burn up over time. Replacing this if it is defective should help with solving your problem but you still need to find a preheat tube.

[Fred T]

Replace the tube with steel tubing. Parts stores sell it as brake line. For bending you can use a set of spring tubing benders.