Super Comp Drag Racing - Page 2 of 2 - Engine Builder Magazine

Super Comp Drag Racing

“Many racers are now using some type of data acquisition system that records engine rpm, torque converter and driveshaft rpm to see if they are getting too much tire slippage,” says Kwasiborski. “This kind of information is necessary to help them dial in their cars so they will be more consistent.”

Kwasiborski says most of the dragsters in the Midwest Super Comp Series are in the 900 to 1,000 horsepower range, turning 7,500 rpm and running 160 to 180 mph with 4.10 gears. The engines are equipped with one of two kinds of throttle stops: under the carburetor or in-line. The throttle is usually CO2 operated, which controls how quickly the throttle comes on and off. “You don’t want all the power to hit the wheels all at once; otherwise you’ll lose traction,” Kwasiborski explains.

He says most of the engines are lasting up to three seasons, thanks to the fact that most of them are being cooled by radiators to keep the heat under control. “A lot of these engines have radical cams that require a lot of valve spring pressure and strong pushrods, so you have to keep an eye on the valve springs and the roller lifters,” Kwasiborski says. “But other than that, the engines hold up well.”

General Engine Building Tips

If you are building an engine for a customer who wants to race a Super Comp dragster, consistency and reliability are essential. You want a strong block (cast iron or aluminum), a strong crankshaft (forged 4340 steel), and rods (H-beam) and pistons (forged) that can take the punishment. The top compression rings should be steel or ductile iron with a moly facing to withstand the heat. The compression ratio will depend on the fuel, so if your customer wants to run alcohol or a high octane racing fuel you can run more compression.

A leaded racing fuel rated at 107 pump octane can typically handle compression ratios in the 12:1 range. Run the engine on 110 pump octane leaded racing fuel and the compression ratio can be bumped up to 13:1. Use 112 pump octane racing fuel and the engine can be built with up to a 15:1 compression ratio.

[inpost_gallery post_id=3448 group=”2″]

Oxygenated racing fuels can typically make up to 3 to 7% more power than leaded racing fuels. The higher the oxygen content of the fuel, the greater the potential power gains it can deliver. An oxygenated fuel such as E85 ethanol (85% ethanol and 15% gasoline) typically carries an octane rating of 110 (or 116 for some E90 blends). A compression ratio of 14.2:1 works well with E85.

The compression ratio will also depend on the size of the combustion chamber (small versus large) and valve overlap and timing. The higher the compression ratio, the greater the thermal efficiency of the engine and the more power it will produce.

Camshaft selection will depend on the heads and how much power you want to make. You’ll need a cam with a lot of lift and duration if you want to make 800 to 1,000 hp, but you don’t have to go crazy with lift, duration and valve spring pressure. A cam that delivers a flatter, broader torque curve will be easier to race and tune than a cam with a narrower and peakier torque curve.

A typical cam profile that is capable of producing up to 1,000 hp in a BB Chevy 565 engine would be 283/296 degrees duration at .050” lift, and .824?/.785? of lift with 1.7 ratio rocker arms.

The roller lifters and pushrods should be stout enough to handle the required valve spring pressure for up to two racing seasons. The cam drive system should also be strong and reliable, and allow easy cam timing adjustments.

Engine oiling is also critical, so you want an oil pump that will provide plenty of oil pressure and flow, and a baffled oil pan to prevent the oil from climbing up the back of the pan when the dragster is accelerating down the strip.

Since the engine is going to be turning a lot of rpms, a good balance job is critical for reliability.

Engine assembly, break in and tuning is like any other performance engine you might build. Make sure everything is thoroughly lubricated when it goes together, and that the oil system has been primed before the engine is fired up for the first time.


You May Also Like

LTR Engine Build

This Late Model Engines build is centered around Concept Performance’s new LTR block, which is the first aftermarket as-cast aluminum Gen V LT block. 

The Chevrolet LT engine family from General Motors is rooted in the early ‘70s, when the LT1 was featured in the Corvette and Camaro Z28. After a 20-year hiatus, GM reintroduced the platform in the early ‘90s. The “LT1 350” came out in 1991, and was distinct from the high-output Gen I LT1 of the 1970s. It displaced 5.7L (350 cu in), and was a two-valve per cylinder pushrod design. The LT1 used a reverse-flow cooling system, which cooled the cylinder heads first, maintaining lower combustion chamber temperatures and allowing the engine to run at a higher compression than its immediate predecessors.

A Look at Lead Times

Lead times are no longer months upon months as they were in the middle of 2020 and throughout 2021, but the situation is still of some concern, and it’s forced engine builders to get creative at times.

LS Intake Manifolds

LS swaps are popular for many reasons, but there are a lot of variations and details to sort through – more of them than you may expect – and many of them are associated with the intake manifold.

Choosing the Correct Block for Your LS Engine Build

Whether you’re scouring junkyards, ordering cores, investigating factory options, looking at aftermarket cast iron or aluminum blocks, or spending big bucks on billet LS blocks, you’ve probably noticed it’s been harder to find exactly what you want for the foundation of your LS build than it historically has.

Open Loop/Closed Loop and Learning

Closed-loop control can be programmed to either add or subtract up to a certain percentage of fuel in order for the engine to reach the target air/fuel ratio.

Other Posts

Supercharged 406 cid Small Block Chevy Engine

Owned by Scott Mueller since the 1980s, this 1934 Ford hot rod features a supercharged 406 cubic inch small block Chevy engine capable of 1,000 horsepower and low-8-second passes. Check it out!

Scott Mueller’s Supercharged 406 cid Small Block Chevy Engine

Scott Mueller is no drag-and-drive rookie. He’s been drag racing and daily driving his 1934 hot rod for a number of years. Helping him compete is a supercharged 406 cubic inch small block Chevy and we got the details during Sick Week 2023 at Gainesville Raceway. It’s our Engine of the Week. Related Articles –

Turbocharged and Nitrous-Boosted 429 cid LSX Engine

It’s tough to beat the lines and looks of a Chevy Nova. Jason Sack’s 1969 Nova is certainly up there in terms of coolest-looking, and it doesn’t hurt that it has 2,200+ horsepower under the hood courtesy of a turbocharged and nitrous-boosted 429 cid LSX engine! See for yourself!

Jason Sack’s Turbocharged 429 cid LSX Engine

Jason Sack had arguably one of the nicest Novas we saw during Sick Week 2023. The car’s beauty had some sort of gravitational pull as we walked passed it in the pits. Naturally, we gave in and stopped to have a chat with Jason Sack about his 1969 Nova and its turbocharged 429 cid LSX