Marina Blue

I was at the Atlantic City Corvette show on Sunday and saw a 1967, 435 hp, L71 big block on a stand. It had an information plaque that said the L71 horsepower was underrated by the factory for insurance purposes and that it actually developed somewhere close to 500 horsepower. Last December a member posted an official 1971 Chevrolet chart that rated their engine lineup in both gross and net horsepower. The 350 cu. in. (RPO LT1) was rated at 330 gross and 275 net horsepower which gives a conversion factor of .8333 (275/330). The 454 cu. in. (RPO LS6) was rated at 425 gross and 325 net horsepower which gives a conversion factor of .7647 (325/425). Using the more conservative factor of .8333 the LS2 calculates to 480 gross horsepower (400/.8333). Using the big block conversion factor of .7647 the LS2 calculates to 523 gross horsepower. I believe if the LS2 were to have a gross hp rating for comparison purposes its rating would be somewhere between 480 and 523. Going back to that information plaque I saw in Atlantic City, it seems that the LS2 has comparable power to the 1967 L71 engine. If my logic is wrong let me know. Getting back to the thread title, can torque be converted just like horsepower or is it a different animal? If the same conversion can be made then can I conclude that the LS2 has a torque rating somewhere between 480 and 523 ft. lbs. using the old gross method?

need-for-speed

You did it right according to my logic. I've always thought the difference was about 20% so your numbers sound right to me. The problem with the back calculating is apparent in the numbers you quote, i.e. they range from 17% to 24% so we don't know which factor to use. The problem with applying the same conversion to TQ is that since HP=TQ x RPM/5252 , HP can be made with reasonable TQ at a reasonable RPM (V8) or it can be made via whimpy TQ at stratospheric engine speeds (16 valve turbo charged 4 cylinder). If you are comparing to motors (net vs. gross HP) that achieve peak HP at the same RPM, then yes, you could apply the same (allusive) conversion factor to TQ.

LS WON

performance category except in style which is personal and depreciation as we know the old corvettes go up in value but aren't daily drivers like the new ones.