Single to duel exhaust questions

[PGG]

My 72 has stock exhaust would changing it to a duel be much of a performance improvement either in power or fuel economy? It is really close to full stock would that be considered a sin to do to one like that? Was it an option or even a dealer added option back in 72?

Thanks PG

 

[Greg72]

My 72 has stock exhaust would changing it to a duel be much of a performance improvement either in power or fuel economy? It is really close to full stock would that be considered a sin to do to one like that? Was it an option or even a dealer added option back in 72?

Thanks PG

Personally, For a truck as nice and stock looking as yours I would leave the single exhaust alone..... Take the money you were going to spend on exhaust and a carb rebuild, and get into a nice EFI conversion like Atomic EFI.

The carb-replacement systems are pretty straightforward swaps, and they are getting cheaper all the time. For the money spent you will improve drivability and fuel mileage. And the truck will still look and sound stock.


-G

 

[bp71k5]

Nearly anything you do that increases power will decrease economy. There may be a few cases where it wouldn't but it's generally true. I doubt a dual exhaust would do anything unless the existing one is so restrictive that your motor can't breath well.

Like Greg mentions, switching to some kind of fuel injection would be money better spent. I'll never go back to a carb.

 

[ashman]

I'll never go back to a carb.

Same here.

Exhaust is something that is easy enough to change around that I can't imagine that it would affect the value up or down. That said, I also don't think you'll see any noticeable difference from it. The money is better spent elsewhere.

 

[Drewfrazier]

Coming into the thread a little late but I can’t resist. BP71k5 is correct that bringing more air into the engine brings more gas with it, reducing fuel economy. But making it breathe easier through reducing the back pressure with a dual exhaust makes the engine work less exhaling. Free power. And a tuned header captures the momentum of gases exiting the combustion chamber, for more power at less expense. Am I right boys?

 

[bp71k5]

Coming into the thread a little late but I can’t resist. BP71k5 is correct that bringing more air into the engine brings more gas with it, reducing fuel economy. But making it breathe easier through reducing the back pressure with a dual exhaust makes the engine work less exhaling. Free power. And a tuned header captures the momentum of gases exiting the combustion chamber, for more power at less expense. Am I right boys?

I’m not an expert by any means, but from all I’ve read... and in a perfect world, you’re right. The big question is “how much” does scavenging and reduced back pressure really help on a ~50 year old engine design. Probably not noticeable at all in this case. Not just a theoretical guess either, I switched to dual exhaust when I got mine and there was no difference I could tell except for the noise was louder.

 

[radzzz1972k5]

My 72 has stock exhaust would changing it to a duel be much of a performance improvement either in power or fuel economy? It is really close to full stock would that be considered a sin to do to one like that? Was it an option or even a dealer added option back in 72?

Thanks PG