Anyone done this before?

4.8L crank stroke (3.268")
4.8L rod length (6.275")
6.0L block bore (4.000")

Yields approximately 327 cid with a HUGE rod/stroke ration of 6.275/3.267 = 1.92:1



If I use 6.0L pistons made for the stock 6.098" rod length and 3.622" crank stroke, but instead use the 4.8L rod length of 6.275" and 3.268" crank stroke, I believe the piston will end up at the same compression height at top dead center.

If I use 61cc chamber (5.3L) heads, and flat top pistons, I calculate I will end up with a compression ratio of about 12.2:1.

If instead of flat top pistons, I use something like Diamond Racing's domed 6.0L pistons with a 10cc dome, I believe the 61cc chamber heads effectively become 51cc heads, and I calculate I will end up with a compression ratio increases to about 14.5:1.

Would this be a good purpose built LS1, LSx, GEN III E85 motor? E85 is 105 octane alcohol. I believe alcohol likes a high compression ratio and a high rod/stroke ratio. This combination of parts looks to be able to produce both.

If I use stock GM rods and impose a piston speed limit of 3500 feet/minute like typical GM cast connecting rods, this becomes approximately a 6500 rpm red line motor.

If I locate some stronger after market rods and impose a piston speed limit of 4000 feet/minute like typical GM forged connecting rods, this becomes approximately a 7500 rpm red line motor.

Anyone know of a source for forged 4.8L (6.275") connecting rods?

Can anyone find any flaws in my thinking here?