Indian 750cc Race Engine Approved for AMA Twins Pro Flat Track Racing And so the Harley/Indian racing rivalry returns.
Indian has shown interest in flat track racing recently by partnering with Roland Sands Design to build custom Indian Scout Hooligan bikes (shown), and then singing on as title sponsor for the first-ever “RSD Super Hooligan” flat track race in Las Vegas. Now, with approval of a race-only 750 twin engine for AMA Pro Flat Track, Indian is looking like it’ll be taking its interests to the professional level.
In a development long anticipated by insiders, AMA Pro Racing has by its Pro Flat Track Competition Bulletin #2016-03 approved Indian’s race-only 750 twin engine for competition.
This is an all-new engine which we suspect was designed by Polaris’ Swissauto division (because of its large experience in racing), not a result of combining existing Indian Scout crankcases with added race-suitable components such as crankshaft, pistons, heads, etc. as provided under the new rules.
This is an exciting development because not since Honda’s RS750 of the early 1980s has an all-new, designed-for-racing engine been approved for US flat track competition.
Because both the 1133cc and 999cc versions of the Scout are liquid-cooled DOHC four-valve designs, it is very likely that the new race-only 750 will share these features. Liquid cooling allows safe use of modern torque-boosting high compression ratios. Use of DOHC and four smaller, lighter valves per cylinder also allows high valve lift with short-duration valve timing—a combination that widens engine torque range. Although these features are already in use in dirt trackers based on the Kawasaki Ninja 650 twin, that particular powerplant was not designed as a racing engine.
If we imagine an engine with a stroke long enough to provide an efficient, fast-burning combustion chamber, we might consider dimensions like 86 x 64.5mm (that’s 3 3/8 x 2 17/32 inches in carpenter’s measure), able to operate routinely at 10,000 rpm while making 110 hp.
What does that mean for flat-track fans? Well, if anything, that you should at least look forward to a renewal of the ages-old Harley/Indian racing rivalry.