Derrik Holmes Asks... How Does a Mopar Big-Block 505 Stroker's Larger Size and Better TFS Heads Affect the RPM Range and Overall Behavior of a Cam Originally Designed for a Standard 440 with Iron Heads?

In Mopar world, 505ci big-block stroker engines are among the most popular builds today, with seemingly boundless mild to wild combos available. You can build a 505 Chrysler for not much more than a 440, so it’s almost a no-brainer. Our late sister mag Mopar Muscle’s “Project 505” made 683 hp back in 2009 on this fairly high-end build.

- Marlan Davis

Q: I’m planning a Mopar 440 to 500ci stroker build. One thing I have had trouble picking out is the camshaft. The engine will be going in my 1970 Challenger that I want to be streetable but with a healthy lope. I’m looking at a hydraulic roller so I can have the largest usable rpm range. How does the larger displacement affect the behavior of the cam? If the cam is listed to have an rpm range of 2,200 to 6,000 rpm for a 440, will that change for a stroker? Should I be shooting for more duration or lift to accommodate the extra displacement? When do you pick higher ratio rockers versus just getting a cam with more lift? For background, I plan to use Trick Flow heads and an Edelbrock Performer RPM intake manifold with a Holley Sniper EFI system. This will be my first engine build, and I will be buying the stroker short-block from an engine builder.

HOLMES’ 505CI CHRYSLER ADDITIONAL INFORMATION

Direct conversation with Mr. Holmes returned this additional information.

Short-Block

Muscle Motors Racing short-block

Displacement

505.3ci

Bore x Stroke

4.35” bore x 4.25” stroke

Connecting Rod

7.100” center-to-center

Rod/Stroke Ratio

1.67:1

Cylinder Heads

Trick Flow Specialties PowerPort 240

Combustion Chamber

78cc

Valve Sizes

2.190” intake/1.760” exhaust

Peak Flow @ 0.700 Lift

334 cfm intake/262 cfm exhaust

Compression Ratio