Budget Ford Mustang Build - Back-To-Basics Budget 5.0 Buildup Part 2 - Tech

At this point, you need to take the block to your local engine shop and have the cam bearings removed. The cost to remove and replace cam bearings after the final cleanup (including a set of low-cost bearings) is typically about $50. For a bare-metal cleanup, a really good job can be done for the price of a couple of cans of barbeque-grill cleaner and an electric drill and wire brush. After this preliminary heavy-duty cleaning, redo the job with a stiff brush, Gunk, and a high-pressure hose. The Gunk leaves a thin film on the block that stops it from rusting right away, giving you the time needed to wipe down and blow the block dry with compressed air.

You are now at the point where a glaze-buster hone can be used to lightly clean up the bores. Don't worry that you are doing this without the benefit of a deck plate. Ford does it all the time, and the bores you are redressing are probably out of round by a half-thousandth anyway.

Next on the agenda is to go through all the threaded holes in the block with an appropriate tap. The head-bolt threads are especially important to clean out as this will ensure all the parts are properly tightened when they are installed.

Now is the time to do the final cleaning. The Gunk and a hose are once again your allies. Once it is absolutely clean, dry the block and apply WD-40 to all the machined surfaces, bag it, and take it around to the machine shop that removed the cam bearings for new ones to be installed. When you get it back home, wipe down the surfaces to be painted with lacquer thinner, then prime and paint them.

Crank, Rods, And Pistons
About the time you take the block over to the engine shop to have the cam bearings knocked out, consider what might need to be done to the crank. At the least, it should have the journals polished if they are still perfectly round and to size. Most engine shops can check the size of the crank and polish it for as little as $20. Ours, as is so often the case, was still within manufacturer's original tolerance and exhibited no measurable wear.

Now we had to fix the rod and piston assemblies. With the old rings removed, we performed a good cleaning, using barbeque-grill cleaner for the first round. While the Ford forged pistons may not look the raciest, they are tough and wear-resistant. The chances of these being non-reusable are slim. Just be sure to check that the ring grooves are still clean and square as they tend to wear tapered as the miles mount up. Use a new ring and check the clearance with a set of feeler gauges. If the clearance shows parallel and is less than 0.003 inch, then they are good to go for another 100,000 miles.

All our rotating assembly parts checked out, as did the oil pump, so all that was needed to rebuild this otherwise-stock bottom end was a full engine gasket set, rings, and bearings. You can source these parts as a kit from Speed-O-Motive for $199, or from Summit Racing or Jegs for a few more bucks. With the rings gapped and bearing clearances checked with Plastigage, the bottom end of our motor went back together.

Of course, while things went well for us, it could be that your engine's block is not in good shape. If this is the case, you will either need a different block or have the necessary machine work done. We had just such a deal with one of our engines, so it became necessary to recondition the short-block to the fullest extent. This could not have happened at a better time editorially, as KB Performance Pistons had just come out with a line of forged street pistons designed to hold up against the rigors of racing as a weekend warrior. These pistons, said to be fine with up to 150 hp worth of nitrous, are intended to be no-frills, tough pieces. These pistons were shipped to Speed-O-Motive, where the boss, George Ullrich, built us a new short-block assembly. Because of shipping costs to and from North Carolina to Speed-O-Motive's shop in West Covina, California, it proved more convenient for us to get a complete short-block assembly sourced from Speed-O-Motive. If you live in the Los Angeles area, then you can save a few bucks by taking over your existing core to be reconditioned.

The block was equipped with new bolts and was line-honed, bored, decked, deck-plate- honed, and enameled. The pistons were equipped with Total Seal rings, rods were reconditioned and fitted with ARP bolts, the crank was ground, and the complete rotating assembly was balanced. This makes it about as race ready as you can get short of using an aftermarket forged crank and rods. Assembled ready to this spec, the total is $2,175, or you can assemble it yourself and save $425.