Re: Dead 4.0
Posted: March 8th, 2011, 7:50 am
Forget about using the original pistons. You'll be using a 14-year-old block so you'd be well advised to have the cylinders rebored so that they're round and true for a good ring seal. The 677CP pistons have a bigger dish than the stockers and will lower the CR (which is good).thraxer528 wrote:Thanks. I am picking it up tonight.
Are the 677CP pistons necessary to keep the combustion ratio in check or am I able to use the original 4.0 pistons?
Am I going to have to run a piggy back cpu? OR will I be able to make it work with all the stock electronics?
Sorry so many questions I just want to make sure I do it right.
Thanks
You'll almost certainly need a piggyback computer 'cause it's pretty unlikely that the stock '01 computer program will get the A/F ratio close to ideal at all rpm even if the injector size is correct. It's only a question of deciding which one, and how much you're willing to spend.