Affordable Small Block Race Engine - Cheap Street Secrets

Builder Brian Thomson Reveals And Hides Power Secrets During Our Look Inside PRO "Claimer" Engine

Barry Kluczyk Jan 1, 2004 0 Comment(s)
Sucp_0401_09_z Affordable_small_block_race_engine Flat_top_pistons 1/22

Another stipulation of the rules is flat-top pistons. Combined with the limited number of legal cylinder heads, compression ratio of the class's engines typically falls in the 10:1 to 12:1 range. Thomson makes the most of the rules, however, by using lightweight Diamond aluminum pistons that have a friction-reducing Teflon coating on the sides. Combined with lightweight GRP rods Thomson keeps the weight of the reciprocating assembly as low as possible, which allows the engine to rev higher and faster.

As for horsepower, the engine makes 450 by about 5,400 rpm and holds between that mark and the 479 peak until 6,800 rpm. On the dyno the nitrous kicked in at about 5,200 rpm and simply added 120-150 horses throughout the rest of the rpm range.

Thomson is certainly happy with the engine's performance, but the rules of Cheap Street are things by which he's not used to being limited.

"For a combination with no real compression, I think it made really good power," he says. "We were limited by the rules, but we also used the letter of them to any advantage we could take."

There, of course, lies the unknown. Other builders undoubtedly have bent the rules without breaking them-it's the nature of racing. And until the engine's owner is able to get his car to the track, it'll be difficult to judge whether Thomson built a big enough stick for the fight.

"At the very least, our engine should be reliable and get through the season with minimal tear-downs," he says. "It should also be quite competitive. The power is good."

Like we said, Thomson wouldn't reveal every secret to his Cheap Street recipe-and if you think any of the other competitors built a durable, competitive nitrous motor for just $3,000, give us a call; we've got a rust-free Mopar we want to sell you.

Sucp_0401_11_z Affordable_small_block_race_engine Camshaft 2/22

Here's the camshaft. "It's a flat tappet cam," is all Brian Thomson will say about its specs. We do know that the iron GM Vortec heads used on the engine warn against using a cam with lift greater than .475-inch. Duration, centerline, and overlap are secrets Thomson won't reveal. "It's the key to the engine's power," he says.

Still, no matter how you look at it, 649 horses is darn good for a 355 with a used block and crank.

In other words, Cheap Street sounds a lot like Fun Street to us.

Off The Sidelines:
GM Performance Parts' Gary Penn dives into Cheap StreetTalk a few minutes with Gary Penn and you'll know right away he's a racing enthusiast.

In fact, if you've been to an IHRA race, PRO race or even a Super Chevy Show during the last few years, there's a good chance you have spoken with Penn. During race weekends, he's usually found under the yellow awning of the GM Performance Parts trailer, dispensing catalogs, stickers and wisdom from his almost "Rainman"-like knowledge of Chevy engines.

But after several years of watching the races, Penn has decided to get involved. He's built a Camaro to compete in the six-race PRO Cheap Street series.

Sucp_0401_12_z Affordable_small_block_race_engine Lifters 3/22

Complementing Thomson's mystery cam is a set of Comp Cams' Hi-Tech Lite flat-tappet lifters.

"I've been racing since I was 16," says the 41-year-old Penn. "It's in the blood."

Penn found a tired '86 Camaro and sent it to Tom Lukans, at TL Race Cars in Jonesville, South Carolina, where it is currently undergoing a transformation from street beater to track heater. Although the Cheap Street series advocates restraint through its $3,000 claimer engine clause, that hasn't stopped Penn and Lukans from building a professional car.

"It has an elaborate rollcage," says Penn. "Besides adding strength, it makes the chassis tunable."

TL Race Cars also fabricated a unique rear torque arm and lower control arms. Other go-fast parts include Eibach Drag Launch springs, Koni struts and shocks, four-wheel discs from Stainless, Weld Alumastar wheels and Mickey Thompson tires.

Per the rules, Penn will run a small-block conforming to a 385-cid maximum displacement and single stage of nitrous. It'll be backed by a Hughes Performance Turbo 350 with a full manual valve body and trans brake. The converter has a 5,000 stall speed, and the rearend is a Moser 12-bolt with a spool.

The combination should be good for 9.70-9.80 e.t.'s, according to Penn.

"I'm just looking to get back into racing and have some fun," he says. "There are only six Cheap Street races and prize money is negligible; I just want to stay in the game."

Whether he's in the staging lane or under the big yellow awning, Gary Penn isn't far from the action.

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