Contour Enthusiasts Group Archives Forums Modifications Duratec Performance balancing, boring, headwork, etc.

Head work can account for quite a few HP when it's done right, problem is to get the heads off on this engine, you have to tear it down quite a bit. Once that far, it's only a handful of bolts ad the whole engine is out.

Can't bore the sleaves easily or they'll pop, destroying the block in the process. Best option is to get a 3 liter block if you want more cubes (see 3 liter forum).

Balance and blueprint won't do a whole lot on these engines as they are already held to quite tight tollerances from the factory. Money is better spent elsewhere.

If you want to stick to the 2.5, you can swap over the the larger intake valves from the 3 liter heads. You might also be able to use the old 2.5 intake valves as new exhaust valves, but this may not be able to be done, depending on the metalic composision of the intake valves vs. the exhaust valves. i.e., valve meltdown...

EDIT Oops, Rara beat me to it... Ya, what he said...