Mopar Action On-line – Tech Questions
colton herzog, PA, 1973 dodge charger 318
I am wondering if you know any way to get a little morehorsepower out of a 318 without spending a lot of money. I don’t want toget into changing the crank or cam, or even boring it. So if there any thngsmall that I could do for horsepower, what could it be?
Colton, there’s no magic. But “bolt-ons”, as these “small things” aretypically referred to, DO work. What you’re trying to do is get more air inand out of the engine, so it can burn more fuel.
If you pin me down, I’d have to say the first two places to start would be:
> Add a nice free-flowing dual exhaust system. It can be made by a localshop. The pipes should be 2.25″ min.
> Swap the intake manifold to a dual plane one that will accept a 4-Bblcarburetor, and add the carb. If it’s square-bore (bolt holes form anapproximate square pattern and the 4 large holes are all about the samesize), keep the carb as small as you can find: 450 to 600 CFM. If themanifold is spread bore, virtually any stock Thermo-Quad carb would be fine.
These two additions should add 30-40 HP, plus, as a bonus, the exhaust modswill improve mileage, and the carb swap will have almost no effect on MPG -if you can keep your foot out of it!