reaching 500 hp with a 468 BBC

grumpyvette · Aug 11, 2014

Beaumont 69 said:
Hi, i'm building a 468 big block for street use. I want to reach 500 hp with it and i don't know how to choose the Rpm range of the engine. I need help. Thanks

GRUMPYVETTE said:
you failed to mention the cars transmission,
(manual?, auto? what converter stall speed? for those readers who may no be familiar a Beaumont, is a canadian/chevelle/pontiac

rear gear, ratio. tire height and car weight, what cylinder heads you have, what compression ratio , what headers and exhaust size will be used, tire diam. etc.)
a good deal of your choice will be based on maintaining reasonable durability and the cars gearing, and compression ratio, and intended operational range.
you also failed to mention the BUDGET LIMITATIONS and YOUR mechanical skill level, which I,m thinking in at least going to limit some aspects of a total rebuild due to the nature of the question, and you failed to mention if you have a place to work on the car and if its needed for daily transportation?
(does it need to pass exhaust emission testing? is mileage a big concern?)
ok lets assume your building or have already purchased a semi stock bottom end 468,BBC with a 4" stroke.
lets keep both the piston speed and valve train components semi reasonable , and use as much of the stock parts as we can,and assume youll be using the car mostly on the street
a 4" stroke limited to a reasonable 4200fpm in piston speed means youll want to keep the rpms limited to about 6300rpm,if youll have a stock short block.
this is also is a reasonable limit for a hydraulic lifter valve train, PROVIDED THE CORRECT PARTS ARE SELECTED. now reaching or exceeding 500 FLYWHEEL HP with a 468 is not going to extremely hard but it sure helps to know what your working with?

IF I assume your building a car very similar to the 1969 chevelle the car weights run from about 3200 lbs- 3700lbs and theres several transmissions and rear gears offered
http://www.oldride.com/library/1969_chevrolet_chevelle.html

the formula for hp is torque x rpm /5252=hp
a 468 should if properly built produce at least 500-540 ft lbs , if you get that peak torque up near 5000-5300rpm youll reach or exceed 500 flywheel hp, higher torque lets you have more options and higher compression tends to help improve torque

reaching 500 hp with a 468 BBC

grumpyvette

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