Real HP for an R2?

[Ron Dame]

Did Studebaker fudge horsepower numbers for insurance? What was the more likely groos or net for an R2?

[Gunslinger]

It wasn't until 1971 or 1972 that net horsepower ratings were mandated.  Prior to that it was gross ratings reported by automakers.  Even then, they were often underrated for insurance purposes...or the reported horsepower was advertised at a particular rpm to downplay a much higher rating at the rpm an engine actually made peak horsepower.

Chevrolet advertised the L88 engine as 430 hp when it was actually much higher...it was a racing engine and the desire was not to sell so many so it was downrated from the 435hp L71 engines to make them seem like the hot ticket.  The L88 was actually closer to 580 hp in top form.  There's also some outright advertising fraud...the Pontiac GTO first reviewed in car magazines was not a Trigger-Power 389 engine...it was a Trigger-Power 421 engine...no street GTO could touch the reported performance figures.

I'm not aware whether Studebaker fudged figures I don't know.  The R2 was rated at the then magic one horsepower per cubic inch.  The R3 was allegedly supposed to meet 335 hp minimum but the Granatelli's had said a properly set up R3 was closer to 400 hp.  

Essentially on an assembly line engine like an R1 or R2 you'll probably see variations between individual engines as far as how much power each puts out.  Manufacturing tolerances, carburetor settings, altitude, etc., all makes a difference.

Edited October 9, 2017 by Gunslinger

[PackardV8]

Wish that Stude horsepower numbers were greater than published, however, based upon the 1/4-mile MPH speeds from contemporary magazine road tests, the R2 289 hp rating was pretty accurate.

Ted Harbit's R2 in the Stewed Tomato benefits from his more than fifty years of building racing Studebakers.   Bottom line - it's possible to build a blueprinted Stude R2 V8 which will qualify for Factory Stock racing and which exceeds the factory rating, albiet at considerable expense.

FWIW, the R3 engine specifications called for the heads to be hand ported.  Several here can confirm most R3 heads were not ported to match the prints.  So yes, Paxton Products may have custom built a very few 400hp R3s, but most wouldn't top 335hp.

Another FWIW, the Paxton racing supercharger had no warranty.  It produced more boost but had too much spring pressure to survive street use.  The racing lifespan was measured in hours.

jack vines