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I made some positive progress regarding my intent to do this. Flatlander racing was a waste of time, an important point to make about the 60 deg crank is individual crank pins versus shared on the other engines which means more labor to resize the pins than what would be necessary for the V8 and 90 degree V6 motors. I was quoted over $600 from flatlander in a not so friendly tone. So I searched some more.
Mike at Valley Crankshaft.Inc does a lot of offset grinds and was very accomodating and gave me an estimate of about $350 for an offset grind. Up to .11" increase in stroke should be possible if the 2" big end bearing 5.7" rod is used. Combine that with the 3.6L or the correct compression height 305 pistons and that should provide a sizeable increase in displacement in a 3500 block.
My plan is for forged LS1 pistons and adapted forged 6" sbc rods in my extra 3900 for a forged build up with a .075" offset for the 2.1" big end rod to maintain strength above the earlier cast 2" pin crank. The 3.9 and LS1 share the same bore diameter making forged pistons available in sets of 8 at roughly half the price of a custom set of 6 and there are numerous LS1 pistons and rod combos that will go together to achieve this process.
For those interested in a naturally aspirated setup there are LS1 pistons available within .001" compression height of the stock 3900 pistons that will push your compression ratio high enough to build a ground pounder like Superdave's only better.
While looking over old pics I happened across the bottom end of my old 2000 3100 V6 and noticed that the oil pan rail of the block does not have the connecting rod relief notches present in the 3500 and up V6 motors. When I return home I intend to do a mock up to see just how much room is available for the increased stroke that GM indirectly stated there was room for, for future displacement increases.
Given the deck area increase of the VVT 3500 and 3900, it can easily be turned into a 4.3L, if they took the 2.8L all the way up to 3.5L in the same package, I see no reason for them not to do the same with an engine series not only APPARENTLY more efficient than the 3.8L & 4.3L, but smaller and packed with even more potential with the VVT option.
Gas prices are going to force them to do more with little to stay competitive.
Mike at Valley Crankshaft.Inc does a lot of offset grinds and was very accomodating and gave me an estimate of about $350 for an offset grind. Up to .11" increase in stroke should be possible if the 2" big end bearing 5.7" rod is used. Combine that with the 3.6L or the correct compression height 305 pistons and that should provide a sizeable increase in displacement in a 3500 block.
My plan is for forged LS1 pistons and adapted forged 6" sbc rods in my extra 3900 for a forged build up with a .075" offset for the 2.1" big end rod to maintain strength above the earlier cast 2" pin crank. The 3.9 and LS1 share the same bore diameter making forged pistons available in sets of 8 at roughly half the price of a custom set of 6 and there are numerous LS1 pistons and rod combos that will go together to achieve this process.
For those interested in a naturally aspirated setup there are LS1 pistons available within .001" compression height of the stock 3900 pistons that will push your compression ratio high enough to build a ground pounder like Superdave's only better.
While looking over old pics I happened across the bottom end of my old 2000 3100 V6 and noticed that the oil pan rail of the block does not have the connecting rod relief notches present in the 3500 and up V6 motors. When I return home I intend to do a mock up to see just how much room is available for the increased stroke that GM indirectly stated there was room for, for future displacement increases.
Given the deck area increase of the VVT 3500 and 3900, it can easily be turned into a 4.3L, if they took the 2.8L all the way up to 3.5L in the same package, I see no reason for them not to do the same with an engine series not only APPARENTLY more efficient than the 3.8L & 4.3L, but smaller and packed with even more potential with the VVT option.
Gas prices are going to force them to do more with little to stay competitive.
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