Nerd’s Eye View: Inside Fredric Aasbo/Papadakis Racing’s Amazing V8 eating 2AR Toyota Engine


The crankshaft is a stock Toyota part from a 1AR.  The 1AR is the 2.7 liter engine found in the Sienna van.  The 1AR has a 105mm stroke vs the 2AR's 98mm stroke.  By using this crank you can get the big displacement of the 1AR.  This gear turns the balance shafts and must be removed.  Balance shafts spin at twice the crank speed and would not be happy at speeds approaching 17,000 rpm!  The 1AR crank has induction hardened journals which causes the discoloration you can see here. 
Castillos Crankshafts modifies the rod bearing journals with a radius filet so that  2″ in diameter and 0.950″ wide domestic application ACL bearings can be used.  This is much like the development of the NASCAR Chevy engines, where a smaller rod bearing was used as the engine developed.  The reduced diameter lowers bearing surface speed, reducing friction and shear of the oil wedge which helps at high RPM.  Since machining gets rid of the stock induction hardening, the crank is ion nitrided to get the journals hard again.
You can see the 1AR crank with the balance shaft teeth removed here.
The big 4 cylinder can vibrate violently and make the weirdest things fail.  Here the pilot bearing is welded in place to keep it from falling out.
To help damp big vibrations, the big heavy stock balancer is used.
 Super strong Carrillo rods are used.  The team has never suffered a rod failure to date.  The rod is a long Chevy small block part with a long 6.2″ center to center length to help manage piston speed in the super long stroke engine.  It also helps that this is a very common rod.

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