4.9" Billet Hemi 'Big Dawg' Engine - Engine Builder Magazine
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4.9″ Billet Hemi ‘Big Dawg’ Engine


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When we spoke with Darrell Makins, shop manager of Noonan Race Engineering in Spartanburg, SC, the shop had 60 billet blocks in queue for production. Noonan Race Engineering starts each build from an 815-pound raw chunk of aluminum. With 60 engines on deck, that makes for nearly 49,000 lbs. of raw aluminum. After getting machined, each block comes out weighing around 127 pounds., which makes for roughly 41,000 pounds of aluminum waste and 7,600 pounds of finished aluminum blocks.

One of those hunks of aluminum were turned into a 4.9 Billet Hemi Big Dawg engine and we have all the details of the build in this episode of Engine of the Week.


Noonan Race Engineering was founded by Jamie and Renee Noonan in 2006, and today, the once Australian shop is located in South Carolina. The shop specializes in manufacturing its own billet cylinder heads, billet manifolds, billet valve covers, and billet engine block designs for both supercharged and turbocharged Alcohol Hemi and LS engines for drag racing applications like Top Alcohol, Funny Car, Top Dragster, and Pro Mod.

The 4.9 Billet Hemi engine called the Big Dawg starts out as a rectangular forged block of 60-61 aluminum. After 46 hours of machining time, the block weighs around 125 lbs. complete. The block, heads, manifold and valve covers are all manufactured out of billet in-house.


Other internals for the Big Dawg engine include a billet crankshaft, CP pistons, billet connecting rods, Total Seal rings, Trend wristpins, Clevite coated bearings, and a custom Bullet camshaft. When it comes to the 4.9-inch Noonan cylinder heads, those are equipped with PSI springs, Jesel lifters, Manley valves and Reid or Manton rocker arms. Remaining components on the engine include an RCD Engineering mag drive and fuel pump, a Barnes oil pump, Dan Olson oil pan, and a Noonan front cover and gear drive assembly.

“The big difference between the Big Dawg and our standard 4.9˝ is the standard version has a deck height of 10.225˝ and our Big Dawg, which allows more stroke, has an 11˝ deck height. We also always sleeve these engines, for which we use Power Bore nodular iron sleeves.”


The 4.9 Hemi enables the bore diameter of the engine to increase to four six hundred versus four five hundred. That increased bore diameter allows for larger intake and exhaust valves and the valve angle to stand up an additional three degrees. This flattens the combustion chamber out and allows the port to be raised an inch on the intake and exhaust.
Another big change was the lifter spacing from 2 inches to 3.3 inches, which frees up a lot of intake port development opportunities.

According to Makins, the normal lead time on one of these engines, for a completely custom platform, is about six weeks.

“We have built one of these engines in as quick as two weeks,” he says. “The cost for a standard Roots motor that you’d find in an NHRA Pro Mod car would be around $74,000. That’s ready to put your supercharger and fuel system on and go. There are some extra things you can add. We do have a higher end oiling system company, Auto Verdi, out of Sweden. They have an upgrade to the oiling system and there are some upgrades you can make to the engine that could add anywhere from $4,000 to $5,000 to that price.”


For that amount of money, customers are expecting top-level performance, and Noonan Race Engineering delivers. These engines run somewhere between 12 and a half to 1 and 13 to 1 compression, and can be used with a Roots supercharger, a Screw supercharger, a centrifugal supercharger, or turbochargers. The Big Dawg engine is capable of quarter-mile passes in the 5-second range, but is also right at home in tractor pulling applications as well.

If you have an engine you’d like to see featured, please email our editor Greg Jones at [email protected] Thanks for watching!

Engine Builder Magazine