I had a question for all guys, I getting a dual exhaust system on my 1965 Olds but I was told by the Throton Reproductions that you can only run duals on one side as the passenger side is to be capped off. My engine guy is trying to run both passenger and driver's side exhaust directly from the engine, is this posible?

 

Not only possible, it is how it was normally done from the '30s through the '70s.

Crossover (a separate system) pipe is removed, and its flange, on the existing exhaust (your right) side, is capped. The new exhaust is connected to the opposite (your left) crossover flange.

The "heat riser" valve should either be locked in its open position, or removed

Thornton Reproductions sells exhaust manifolds. Would you expect a "salesman" to tell you about an alternative to purchasing his product?

Norm

 

Thanks Man,

Jonathan

 

I have the dual setup that 88 Coupe refers to in his reply. Its in my 67 Delta 88 convert w/425ci. The dual is created by removing the crossover pipe, having a new pipe built from rt manifold, follow crossover pipe route and run aft alongside the Lt pipe. The crossover flange is plugged with a piece of pipe flange with the end capped and welded. The stock clamps and new gasket are used. The pipes 'split' in center of car, cherry bombs installed just before rear axle. Usual exit out rear (see pics).

Best solution would be to find a correct dual manifold setup. I know Lt side is available, Rt seems to be very rare (don't know why). If you run Rt side directly down and aft, you also need a shift rod that has a 'half-moon' relief for the pipe. There is a post somewhere here that had the info. Don't know if it was slavaged after the servers crashed.

Good luck.

 

What ever happened to good ol' flipping the manifolds upside down and running pipes out of the hood.

 

YEAH! You could run the exhaust out of the hood like the cars on Mad Max. That is AWSOME!

Actually, I know Oldsguy ended up putting true duals on his 69 Delta 88 that he had. We found a driver's side manifold from a Toronado and cut the rear dump off of it. Then we turned the dump around so the manifold dumped up instead of down and had it welded back together. Then we had the passenger side manifold welded up instead of putting a cap on it. MUCH BETTER and looks better too! Once the project was done an exhaust shop ran duas from each side of the engine all the way back. If you purchase a manifold from Thornton I believe they will allow you to run duals without doing any modifications. The manifolds are made to clear the steering gear box which sits farther back than in later cars.

 

Yeah, that old cast is weldable. It took me about a half hour to cut each one by hand with a hacksaw! Talk about getting tired...