This .90 or 1.00 cu. in bar stock motor was developed after thousand of hours of testing. The motor has features such as; a through hardened "I" beam steel roller rod; a through hardened steel front end with the crankshaft fastened to the inner races of both front bearings; bell valve induction; head bolts that pass through the lip of the liner; an automatic fuel metering carburetor; & a threaded steel exhaust header. Fuel used; 80% nitro; 12 to 14% ethylene oxide; 6 to 8 % oil. THIS ENGINE IS COMPLETLY RELIABLE, EVEN WHEN RUNNING FOR EXTENDED PERIODS OF TIME AT 32,000+ RPM & 7+ HP! TYPICAL DYNO TEST TIMES OF 2 TO 2.5 MIN AT WIDE OPEN THROTTLE DETERMINED THIS RELIABILITY!