This line of code makes it impossible for anther mod (create additions) to add a create compatible furnace that runs at anything other then the base speed.

That line like could be replaced by something like:

float modifier = 0;
if (state.getBlock() == Blocks.FURNACE || state.getBlock() == Blocks.SMOKER) {modifier = 1;}
if (state.getBlock() == Blocks.BLAST_FURNACE) {modifier = 2;}
if  (state has a getModifier() method){modifier = state.getModifier();}

Alternatively an interface.

I'm totally not saying this to get a cheaper blast furnace, I want to uuh uuum, ues the... Crude Burner, yes that one.

This issue has been marked as stale because it has been inactive for 3 weeks. It will be closed if it remains inactive for another 3 weeks.

0.4c

Just use an interface with the needed methods.

ICreateFurnaceBlock.java:

public interface ICreateFurnaceBlock {
  int getModifier();
}

FurnaceEngineTileEntity.java:

float modifier;
block furnaceBlock = state.getBlock();
if (furnaceBlock instanceof ICreateFurnaceBlock) {
  modifier = furnaceBlock.getModifier();
else if (furnaceBlock == Blocks.BLAST_FURNACE) {
  modifier = 2;
} else {
  modifier = 1;
}