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During our summer visit to Charlotte, NC, we carved out a day to drive down to Spartanburg, SC and visit a few engine shops in that area. We took time to visit PAR Racing Engines and owner Scott Duggins, who is known for building quality race engines for a number of racing applications and classes, so we were excited to see inside the Spartanburg, SC-based engine shop, which Scott started back in 1990.
In the 30-plus years since Scott opened PAR, the shop has become one of the most successful and well-respected engine machine shops on the East coast, and the choice of top racers around the country from bracket racing to Pro Mod. PAR does in-house design on cylinder heads from 9 to 15-degree symmetrical on 4.840” and 5.000” bore spacing to 16 to 24-degree conventional for nitrous and NA applications. The shop is fully equipped with CNC capabilities to do machining processes in-house. Additionally, custom manifolds and nitrous systems for PAR cylinder heads are available.
We got the tour of the full shop, which left us thoroughly impressed, but we also got the run down on PAR’s popular 615 cubic inch big block Chevy engine combo. According to Scott, these 615s are a popular build for Top Sportsman, Top Dragster and fast bracket racing classes, and can be built up in a variety of ways depending on a customer’s needs and wants.
“We build these big block Chevys in a variety of ways from an iron block to an aluminum block,” Duggins told us. “We’ve got about seven or eight different ports that we do on the cylinder heads here in-house as well. Some of the options depend on if a customer wants nitrous or no nitrous. Regardless, we try to tailor to whatever the customers’ needs are. The 615 big block Chevy is very popular, and it’s something we’ve been working on for probably three and a half to four years now and we’ve got them running pretty good.”
In the shop during our visit was a pair of 615 big block Chevys – one with an iron block and blacked out accents and another with an aluminum block and carbon fiber accents. As far as the internals of the builds were concerned, Scott says he utilizes very similar components to ensure a durable, fast combo.
“The engine features a Callies crankshaft, Callies or Oliver rods, a Brodix block and cylinder heads, T&D or APD rockers, and PAC valve springs,” Duggins says. “We use a 55mm camshaft and .904 bushed lifters, which we get from BAM. You can upgrade to a .937 lifter or a belt drive or the aluminum block version. With the manifold and valve covers, we offer them blacked out or in a carbon look where we hydro dip all that stuff in carbon.
“We spec out these engines so we can get longevity out of them because we’re making upper 1,300 horsepower and these guys want to run these things 300-350 runs. These engines are either carbureted or fuel injected, depending on customer preference.”
On the oiling side, Scott says he does some dry sump setups, but the vast majority opt for a wet sump system.
“Our oiling setups are the wet sump stuff with a vacuum pump to where there’s very little benefit to this type of engine with a dry sump,” he says. “We use a lot of Mickey Williams oil pans and Melling or Moroso oil pumps. We have good luck with both of those.
“What enables us to do a lot of stuff here in-house is our machining capabilities. We can cut and move and machine things to tailor fit what combination we got going on. Another thing that helps us is we’ve got three guys who work here in the engine assembly area. We’ve got the 615, a 632 and a 648 combination, so we are constantly changing camshafts, valve jobs, all different head arrangements, ports, etc. That helps us because we’re in-house testing, not just dynoing. You can give a man a number, but the big number is what’s on that scoreboard after the end of the pass.”
At 1,300-plus horsepower, more often than not, these PAR-built 615 big block Chevys are helping racers find the winner’s circle.
Engine of the Week is sponsored by PennGrade1, Elring – Das Original and NPW Companies. If you have an engine you’d like to highlight in this series, please email Engine Builder Editor Greg Jones at [email protected].
