OK- - - - -more progress- - - - -The modified 292 rods are finished- - - -bronze bushings in the top end, and the big ends are reconditioned for an exact fit for the bearings, with no distortion or damage from the welding procedure to install the spacers. BTW, since the guy with the TIG welding rig really knows his job, I was not able to measure anything other than routine "used rod" wear even before I reworked them.
Here's a few specifications, comparing 216 and 235 engine blocks. The main bearing diameters are the same on both engines, but the 216 thrust bearing (#3) is about 1/8" wider than the 235 for some reason. Widening the thrust flanges of a 235 crankshaft makes it a "drop-in" fit into a 216 block. Here's the main difference in the blocks. To compensate for the use of the same length connecting rods and pistons with the same compression height on both engines, something must be done to prevent the pistons from sticking out of the top of the block with the longer stroke of the 235. ( 3 15/16" instead of the 3 3/4" stroke of the 216)- - - -so Chevy made the 235 block 1/8" taller from the center of the main bearings to the top of the block. When a 292 connecting rod is used in a bored-out 216 with a 235 crankshaft, the shorter 292 rod almost compensates for the added stroke. The piston tops only poke out the top about .015"- - - - -it's easy to shave that much off the piston crown without weakening it, and the deck clearance goes to zero- - - - -the pistons end up level with the head gasket surface.
End result- - - -a "sleeper 235" in a 216 block- - - -and one that also runs a higher volume oil pump, replaceable rod bearings, a leakproof rear main bearing seal, and a camshaft just a little more radical than the Corvette/261 item. The lightweight aluminum pistons and much stronger rods with smaller-diameter bearings should allow the engine to run 4K+ RPM with no reliability concerns so you can outrun your Stovebolter friends with a "216" engine that looks bone-stock!
Jerry
