[Formulabruce]

Originally Posted by SD455DJ

The Bad News, RAIII in the Formula has a slight, but deep, audible knock, so we are thinking one of the rod bearings isn't too happy. It came on after the maiden cruise down to last years TA Nationals, though the oil pressure was good (20 psi at idle and 65-70 psi at any rpm over 2000) and the running temps at 185-190 degrees during the hot muggy 90+ weather during that time of year, we don't want to push it.

The Good News is we caught it before anything really bad happened and, well, I have to rebuild the original, never been apart, RAIII. We're going to pull the engine this fall and do the usual routine (in the same spirit as the XV 400 in the '70 Tempest) with new Icon custom forged pistons (.010" - .020" over hopefully) with a slight dish, Eagle H-beam rods, and new Ferrea 1-piece valves and new dual springs in the #12 heads. We'll cut the head surfaces just enough to ensure they are flat and true. The block will be decked the absolute minimum to ensure reasonable 'squareness' and keep the pistons in the hole about .005" and set the quench at .040" with the head gaskets to get the compression to 9.9 (it Whistled at a true 10.5 compression). If the original 068 cam and lifters still are good, they'll be reinstalled. If not, then a 2801 cam with the 1.50 rocker arms. It will be dyno'd to see how it compares to other RAIII 400's in the past. We'll keep you informed as to our progress, but that will be no sooner than October after the dust settles from the Pure Stock Drags.

Dennis

Looks like you'll be forced to run 93 octane fuel.. sound's great if that's your mission.
Really cant compare it to a 1970 RA III as todays racing fuel, and oil and bearing material are much improved. Curious to see the "old" rod bearings too.