Live and learn. We've been saying that to ourselves a lot lately. It's essentially just a nice way of saying you've just screwed up, but don't plan on doing it again. Because we did a lot of livin' and learnin', Project Mudslinger was delayed so much that the car was completed about the same time the season came to a close.
Once the racing season closed, work on the car went from steady (if slow) to sporadic. We live in the southern reaches of North Carolina, where it never stays very cold for very long, so our preparations for winter were basically limited to putting the car up on jack stands and closing the garage door. Unfortunately, it wasn't enough. One afternoon, Scott Helms walked into the shop and immediately noticed a puddle of water underneath the car. It didn't take too long to discover the source: a big, horseshoe-shaped crack in the block. It was between the number two and three cylinders on the intake side, and looked as if a chunk of metal had been pushed straight out.
Here's what not paying attention...
Here's what not paying attention to details can do for you. We left the engine full of water and it froze during a cold snap last winter, cracking the block.
So, I did the only thing I knew how to do in this situation: I made a panicked call for help. I called our engine builder, Johnson's Machine Shop in Kinards, South Carolina, to see if the block could be repaired.
"Sorry," was owner Richard Johnson's reply. "You can weld it up, but in two races it will just be leaking again. The only good solution is to machine up a new block and move all of your pieces into it."
Johnson continues with what I hope is a comment meant to make me feel slightly less embarrassed about the problem: "If I had a nickel every time somebody called me with a cracked block, I'd be a rich man."
Not that that made me feel better, but it did make me realize that this is a far more common problem with racers of every stripe than I had at first thought. Johnson recommends draining the majority of the water from the cooling system--simply unhook the lower water hose on the radiator--and even add a little anti-freeze. One or the other should work, but taking both precautions is good insurance. If your car stays outside or in a trailer, it's also a good idea to pull your engine at the end of the race season and bring it inside your shop for the winter. Just remember to tape up the intake and exhaust ports in the head, and any other access points moisture may have to the interior of the engine.
Project Mudslinger's 2.3-based engine had not been raced--only taken out on shakedown runs on a 1/4-mile private drive once the car was nearing completion. There hadn't been major wear and tear on any of the components. Regardless, Johnson's wanted to check everything out before moving all of our internals over to a new block. There was a fair amount of carbon buildup, which signals that the carburetor was running too rich. We suspect it was from a burst power valve in the carburetor. We had already found and fixed it, but the engine likely hadn't been run enough afterward to burn the carbon out.
Overall, there was a lot more involved to the engine repair than simply pulling all the parts out of our busted block and bolting them up to a new one. Johnson's Machine was very careful to recheck and refit every piece to its specified tolerances. Machining up a new four-cylinder block isn't too expensive, but a careless mistake on reassembly could be. The moral of the story here is that a little precautionary effort in the fall can save you from a lot of heartache in the spring.