Exhaust leak from "riser valve"

[Nel]

Hi, I'm not sure if this the right name but it look like I have a exhaust leak from the valve that redirect the heat on the right end manifold on my 1970 340. Is there a rebuild kit to fix it or something?

[Rich G.]

( Heat Riser ) They do make a repair kit but most people will just remove the flap and weld or plug the ends.

[jimynick]

( Heat Riser ) They do make a repair kit but most people will just remove the flap and weld or plug the ends.

That's no fun! Then you don't get the characteristic jingle that every 340 made from that heat riser. All depends on your thrust restoration-wise, doesn't it?

[Chryco Psycho]

It is for cold weather but most of these cars are never driven in serious cold anymore so why have it , I usually block the heat crossover port in the intake so the carb intake etc  is cooler

[Nel]

 :lookatthat:òOkay found a kit at roseville.  Just have to make a decision. I have heard about the heat crossover in the intake, but I don't have a clue where it is and how to block it. If I decide to fix the heat riser is it hard to do? I probably don't need it at all since no more choke with the Fitech

[jimynick]

You're right, you don't need it with EFI and it'll boil down to whether you want that sound or not. Having said that, you'll need a decent torch somewhere along  the line should you rebuild the heat riser. Something to factor into your decision, eh? 

[Chryco Psycho]

I would not repair it , obviously your car is not stock if you are running EFI
the crossover port is the center port in the intake , I have no clue what intake you have with the EFI tho , but you would have to tpull the intake & fill the crossover port , I usually just use a piece of the old intake gasket assuming it is steel lined & cut it to fit the hole in the new gasket , with EFI I would definately block the port tho 

[Nel]

Car is all stock except for the Fitech that we try to hide the best we could.  It's the OEM intake to

[Chryco Psycho]

I would definately block the intake port