Major engine failure happens to the best of us-usually when we least expect it. Recently, as we began a technical feature on a supercharged '00 GT, the worst happened: major bottom-end failure in our stock 4.6 short-block. We could have called one of our friends, popped in a crate engine (or a replacement short-block), and been on our way. But instead, we decided to let our readers learn from our mistake. Knowing that many a supercharged stock modular Ford has tossed its cookies during big-boost applications, we started hunting for an affordable repair that would allow us to get back in the game as quickly as possible.
Luckily, Paul's Automotive Engineering (a frequent stop on our testing and evaluation circuit) has a complete in-house machine shop facility manned by Steve Barker, an accomplished engine builder. Paul's cranks out all sorts of hot Ford iron, in addition to repairing 4.6 modulars on a regular basis, so this was a routine engine project for them.
Evaluating the damage, we found terminal piston failure due to elevated combustion pressures and perhaps a slight over-rev on the owner's part. The old 5.0 engines could take much more than the modular engines, which are saddled with hypereutectic (or hyper-pathetic as they've become known) pistons and cracked-cap, powdered-metal rods. The new stuff can go at any time. In all, we lost two piston rings, with the ring lands getting shattered shortly after. Surprisingly, the car ran OK until we got aggressive with the throttle (and boost), then we knew something was wrong. So, at a minimum, we needed new pistons and stronger rods.
Enter Dale Metlika from ProPower and his many different modular-engine kits. He's seen dozens of engine failures just like ours, and his company has designed kits for all sorts of applications. If you want to build something that will take 1,000 hp, Dale has you covered. If, on the other hand, you want to simply get your modular Mustang back together with some stronger parts for the least amount of money, you're reading the right story.
With our parts in hand, our test car's owner began removing the engine. This is a labor-intensive task, but it can save a bunch of money. Drop off the engine at your chosen machine shop, then pick it up after the work has been done. If you feel adventurous, you can strip the accessories, cams, and heads from the engine. But, unless you know your way around a modular engine, we'd leave that to the experts like those at Paul's Automotive Engineering. This is an account of what it took to get this once-damaged short-block back up and running.