Saw this article and was interesting in knowing how this displacement was accomplished. Anyone ?

Also what are the safe limits to boring or stroking a 4.6 liter stock block - and would you in a application with supercharger & nitrous ?

 

I'm no expert, but there are stroker cranks available for the 4.6 shortblock, and I believe you can also bore the block a maximum of .020 over to achieve the extra cubic inches. Sean Hyland Motorsport and others sell the blocks and should have some info on their websites.

 

I'm no expert either, but I've heard that these motors can be prone to "piston slap" when stroked. In other words, the pistons and valves might actually hit one another due to the increased stroke.

 

That's pretty funny. The acticle says he installed "a sport camshaft". Maybe after the paint job he could only afford to replace one of them?

 

I'm no expert. "Piston slap" is actually a different situation where the space between the cylinder bore and the piston is too great. The piston will actually move sideways and slap the sides of the cylindor as it travels up and down. It is an engine defect. It causes increased oil consumption, a knocking noise, diminished engine life, and scuffing wearing of the cylinder walls and piston.

I think the pistions in our stock 4.6L engines will already hit the valves if our timing chain were to break. I'm not sure what that specific condition is called.

To accommodate the increased piston travel of the stroker crank, the kits have shortened pistons and longer rods. This will prevent the piston from extending beyond the top of the cylinder bore or below the bottom of the cylinder bore. It is possible to stroke the 281 to a 302. But I think adding a supercharger is the preferred way to go. A super charger will give you more power for your money, and your motor will probably last longer. Increased stroke means increased wear.

 

Ok, thanks for clearing that up. The bottom line is, though, that an SC is probably better bang for your buck.