Fast Talk with Jeff Smith: Disasters That Befall Us All

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I’ve mentioned in an earlier column about my recent adventures with my buddy’s Late Model stock car turned road racer. Our first adventure was a lot of fun as my first time on the track with this car. We experienced a couple of small issues – losing a power steering belt and a leaking pinion seal.

The car’s owner, Tim Moore, quickly repaired the offending bits and we were back at Willow Springs for our second outing that was completely successful. I am not really all that fast in terms of lap times, but I am learning what the car can do. It has far greater capabilities than what I’ve managed to pull out of it, so we were anxious to return for more testing. After that second session, we discovered a rear main seal leak – two-piece rear main seal small-block Chevys are famous for this affliction.

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So we removed the 355ci small-block and Tim disassembled the engine and replaced the seal with a new Fel-Pro unit. By this time, we were getting good at installing the engine and it went pretty quickly. Emboldened with how well the engine was running, we trekked back out to Willow Springs on a warm Friday morning test day and soon had the car on the track.

I was feeling pretty confident after about 10 laps in the car in this session and was pushing a little harder. Willow Springs is a fast track with the back straight leading into a wide Turn 8. I entered Turn 8 on my next lap, lifted, turned into the corner and got back on the throttle I heard a loud bang, and the interior instantly filled with white smoke and the tail came around. This was probably at 80 or 90 miles an hour going backwards into the dirt.

Luckily for me and the car, there isn’t much to hit on the outside of Turn 8 so I pedaled the clutch, shifted into neutral, pulled the steering around to get properly oriented and coasted the rest of the way back to the pits. It seemed that the engine had broken but I had no idea how bad. I had a feeling we were leaking oil so I stayed well inside the racing line and slowly coasted back to the pits.

We pulled the hood off and it was obvious our day was done. There was oil leaking out of the pan from several tears near the oil pan rail and that slippery synthetic was all over the back of the car. We pulled the truck and trailer around, loaded it up, and towed home.

The next day was Saturday and we pulled the engine out once again and soon had the oil pan off to find the gravel pit remains of Number 2 piston along with large chunks of cylinder wall.

At first, this seemed odd. We had assembled the engine with a really nice set of JE Sportsman forged pistons and the engine had not be detonating or knocking. We started to pull the heads off, but the MSD distributor would not come out of the block. We eventually had to remove it with the intake manifold by prying up on the bottom of the intake. With the heads off, it was clear what had happened.

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We had forgotten to check piston-to-valve clearance with this new, flat-top piston combined with a valve lift of around 0.640-inch lift. Plus, we had added a set of 1.6:1 roller rockers and that perhaps tipped us over into a tight area. As I mentioned, driving the car at speed, I never heard anything that would indicate the engine was having trouble and it absolutely sang at 7,000 rpm.

A closer inspection revealed that all but one of the exhaust valves were hitting the pistons and that Number 2 must have been the one with the most interference as it snapped the valve head off and that’s what exploded the piston. The rod then banged around and hammered the cylinder wall.

This also jammed the cam in the block so hard that it sheared off all three cam retaining bolts, broke the gear and jammed the cam in the block so hard that it would not come out. So the list of undamaged parts is the shorter of the two so we managed to save the crankshaft, intake manifold, the dry sump oil pan(after repairs), valve covers, and the exterior accessory drive. The dry sump pump was damaged but Tim had it rebuilt.

We estimate this loss at somewhere around $5,000 but Tim is philosophical. A friend assumed we would immediately put the car up for sale, but it’s funny that neither of us even thought about selling. I have a temporary 406ci small-block that makes around 500 hp with a smaller mechanical roller cam that we’re currently configuring for the car. This required some minor mods to my engine, including drilling and tapping holes in the front of the block that should have been there but were not. They mounted the dry sump pump, so Tim drilled and tapped the holes and we managed to accomplish this without hitting the water jacket!

We’re already planning a new engine. We have a 4.125-inch Dart Sportsman iron block that we’ll combine with the rescued 3.50-inch stroke steel crank and together we have two of the main pieces needed to assemble a 374ci small-block that should be a little screamer. We don’t have heads yet although we have all kinds of ideas. Our limited budget will make that a conservative choice, but we plan to move onward. There’s a race at the end of the season we’re aiming for although all we really want to do is gain more experience.

All of this is a very common situation in racing. If nothing else, it offers a wide range of topics for discussion come bench racing time. I also now have a couple more additions to my broken parts Shelf of Shame collection.

About Jeff Smith

A clue into how long Jeff Smith has been writing technical automotive stories might be his following of second generation readers. Writing continuously for nearly 40 years, his focus with Xceleration covers all things technical. His collection of cars includes a bevy of Chevelles and El Caminos. When not writing about cars, he likes to spend time with his wife Valerye, children Amber and Graham, and granddaughter Celeste.