What engine does a funny car use?

Answer 1

Funny cars run 500ci pushrod( OHV) V8 engines based on the Chrysler 426ci. Hemi.

However, the sport long ago reached such a high competitive level that no funny car can use an actual production engine block and have a hope of winning.

The version in funny cars use parts specifically designed to win - and survive the incredible stresses involved in this class of drag racing. The street version of the Hemi from the factory was rated at 425hp( actually produced around 450-470 Gross horsepower, 390hp net/todays rating) while funny car engines produce 7,000-8,000 horsepower running Nitromethane/alcohol fuel misture and <45psi of boost. The funny car engine only needs to last for one quarter-mile blast at a time, it's disassembled, inspect, and replace major parts after every run.

So the basic architecture such as the cylinder spacing, angle of the two banks of cylinders (the "V" in V-8), the two rows of rocker arms in each head, the single camshaft and pushrod actuation of the valves and hemispherical combusition chamber shape that gives the Hemi its name -- all are clearly recognizable as developed from the Chrysler 426 Hemi. On the other hand, there may not be a single part that is swappable with a street hemi. Many racing parts are modified/completely unsuited to street use. For example, engine block of a funny car may have no regular coolant passages. There is no radiator, starter, battery, no mufflers,Aluminum connecting rods... all of this is fine for a quarter mile at a time but obviously would not make for a practical street engine.

Top Fuel dragsters also use a very similar engine set up.

For more information check out NHRA.com, the home page for the National Hot Rod Association.