On the Dyno: Project Boring 4-Valve Hits The Rollers

On the Dyno: Project Boring 4-Valve Hits The Rollers

It’s always a little bittersweet when you come to the end of something, especially a project on the scale of our Project Boring 4-Valve. We have been through ups and downs, but in the end, we persevered and stuck with our plan to build a budget-friendly road racing and autocross cone-killer out of an old 4.6-liter WAP (Windsor Aluminum Plant) block mated to a Mustang Cobra chassis.

When our colleague Ivan Korda came across the 2001 Mustang Cobra with over 200,000 miles on the clock, it was a roller that included a 2004 Mach 1 WAP engine in pretty rough shape. The engine was not the original Cobra mill and was of unknown origin (as it was on a skid next to the chassis when purchased).

The engine installation was straightforward and simplified because we were using the same blocks that come with these vehicles. Whereas, if we went with a crate Coyote, it would require more work to make the swap.

The plan was to build a naturally aspirated 4.6-liter Mod Motor that produces around 400 horsepower at the wheels. We named it Project Boring because it was not extreme in any sense, but we wanted to show what could be done to make a solid naturally aspirated engine as good as any crate engine Coyote. Ivan Korda (the project’s owner), is delighted with the result.

Ivan’s 4.6-liter Modular engine fits nice and snug, with no issues during the installation. He’s almost ready to hit the track after some dyno pulls. For a streetable build like this, Ivan says it could be done for about $7,500.

The next big step is to get it on the dyno and then out on the track by the end of the month. “We have not had it on track yet, but we plan to run it for the first time on July 23rd. But so far on the street, it feels awesome, with tons of usable power and a really strong mid-range. It pulls awesome to 7,000 rpm.” 

A Quick 4-Valve Synopsis

Our project leader and engine guru, Todd Warren of Apocalypse Performance, echoed Korda’s assessment of the build. He added that the basic short-block could be used with stock heads, stock intake, and the more affordable 1-5/8-inch headers to make between 370 and 400 horsepower with similar cams. Or, he says, the cams could be swapped out for more peak output or low- and mid-range power applications.

Our 1-3/4-inch primary tube headers from ARH made a big difference in the mid-range power we wanted, but our engine builder says that for other applications, he would consider the more affordable 1-5/8-inch header.

One of the most significant upgrades to the short-block was the addition of custom MAHLE pistons with valve reliefs that Warren selected to go along with his cam setup. “We wanted 11:1 to maximize the power. Ivan was a little concerned about going any higher than that, considering he will run it on 93-octane pump gas. But, I was willing to go to 11.5:1.” 

Even with the MAHLE 11:1 custom pistons, we were still within budget because we used 4032 alloy instead of 2618.

Warren adds that you need valve reliefs on Modular engines to get the most power out of them. With the stock pistons, you have to retard the intake lobe center to prevent piston-to-valve interference, and that kills all the mid-range power. “You can significantly improve the powerband by moving the cam a little. A couple of degrees of retard will increase the power and extend the RPM range while a couple of degrees of advance will shift the powerband toward the low and midrange. With stock pistons, you are confined to less duration and lift.”

Warren says there is no reason to be scared of compression with a 4.6- or 5.4-liter Four-Valve. The Four-Valve Modular combustion chambers are very efficient and are not prone to detonation. They are not unlike those of the Coyotes, which now have 12:1 from the factory, with the addition of direct-injection.

We went with a 200-amp alternator from Powermaster with a 3.0-inch pulley, so we wouldn’t overdrive the alternator at higher RPM.

Getting Ready For The Rollers

For the final steps of the build, we documented the installation at Korda’s home shop. Korda also added a few accessories like a high-amperage alternator from Powermaster (P/N: 57781, stock plug configuration). The 200-amp unit produces 130 amps at idle and comes with a 3.0-inch underdrive pulley to maintain a proper alternator speed with a 7,500 rpm engine speed.

The Importance Of Good Data

When it comes to data, there is a saying: “garbage in, garbage out.” If you don’t have solid, reliable data to work from when tuning an engine combination, at best, you’re just chasing your tail. At worst, you can hurt the engine. So, like many of the components on this engine, we discarded all of the sensors that were included, and opted to replace everything with brand new NTK sensors (as you’ll see in the parts list below). Having 80 years of experience and an OEM-level of quality ensures that when we’re tuning the engine on the dyno, we have the most accurate, reliable data possible.

In stock form, the Mach 1 engine produced 320 horsepower at 6,000 rpm and 317 lb-ft at 4,750 rpm — at the crankshaft. So when our mild performance build showed 413 horsepower at 6,680 rpm and  365 lb-ft of torque at 5,600 rpm — at the rear wheels — we were pretty pleased. Besides the peak numbers, the curve has quite a bit in the mid-range to better navigate those road courses. 

On the dyno, our 4-Valve Cobra engine made better-than-expected power at 413 horsepower at 6,680 rpm and 365 lb-ft of torque at 5,600 rpm, at the wheels. The stock engine only produced 320 horsepower at 6,000 rpm and 317 lb-ft at 4,750 rpm at the crank.

Warren’s parting thoughts about the build are that the 4.6-liter short-block is a great starting point for any 93-octane, naturally aspirated build. “It’s suited for everything from a lightweight Mustang to a Marauder or even a truck. This build shows that higher than stock compression is not to be feared.”

“I am very pleased with the engine overall,” says Korda. “Our goal was 400 wheel-horsepower, and anything more is a bonus. This engine makes 413 horsepower and 365 lb-ft on a 100-plus degree summer day while on the dyno, and has excellent performance, especially for such a simple combo. It’ll be a pleasure to race this engine in a lightweight chassis like our Cobra.”


In the final phase of the Cobra 4-Valve build, we added an ATI damper to calm any harmonics in the mid-to-upper RPM range.

Korda notes that while it is a straightforward combo, the guys at Apocalypse Performance could easily replicate it for customers and make adjustments for most street cars. And the best part — it doesn’t break the bank. “Because we are road racing with this engine, we spent a little more on insurance parts to protect us from some potential failures on track. But if this was a street engine, it could be replicated for around $7,500. This includes all the machine work, assembly, parts, and custom intake manifold by Matt at NEP.” 

Korda couldn’t be happier. He is anxious to get the Mustang out on track. Project Boring had some exciting parts added to make it an above-average performer on a budget. When we asked Korda if he had any “cons” for this story, he said he couldn’t think of any. That says it all. Another side benefit that Korda mentions is its simplicity. “You don’t have to deal with some engine swap challenges because this engine was originally in these vehicles.”

We can’t wait to see how it performs on the track! Stay tuned.

Boring 4-Valve Parts List 


  • Pistons – MAHLE, custom with valve reliefs, 11.2:1 compression ratio
  • Rods – Gen-3 Coyote 
  • Crank – Cast 6-bolt (13 pounds lighter than forged)
  • Main bearings – Clevite MS2259HC
  • Rod bearings – Clevite CB1442HNC

Top-end/Cylinder heads 

  • Cams – Todd Warren spec’d COMP Cams
  • Valve springs – COMP Cams 26123-32
  • Retainers – COMP Cams 799-32
  • Valves – Ferrea,  F1450P intake, F1451P exhaust
  • Head bolts –MAHLE GS33269

Timing Components 


  • Oil pan gasket & windage tray – MAHLE OS32426
  • Intake & manifold – MAHLE MS19506
  • Timing cover  – MAHLE JV1164
  • Valve cover set – MAHLE VS50273
  • Oil filter housing  – MAHLE GS33987
  • Engine oil filter housing – MAHLE B31703
  • IAC gasket – MAHLE G31324
  • Oil filter – MAHLE OC 705
  • Fuel Filter – MAHLE KL 181

Engine Parts

  • Oil pump – 3V Melling 10341 
  • Lash Adjuster – 11-14 GT500) Melling JB-7500
  • Rockers – 11-14 GT500 Melling MR-944 

By swapping out all of the crusty original sensors with replacements from NTK, we ensured that we would have an OEM-level of reliability and signal accuracy. Good data makes for good tuning.



  • Manifold – OEM Cobra with NEP 10-inch runner modification
  • Intake tube – JLT
  • MAF sensor – 2003/’04 Cobra
  • Injectors – OEM Coyote
  • Throttle body – Accufab twin 60MM  


Additional Parts:

  • Oil pan – Moroso
  • Alternator – Powermaster 57781 
  • Starter – Powermaster 9132
  • Engine mount –  Steeda polyurethane
  • Tuning device SCT X4 
  • Battery Dyna Batt
  • Spark PlugsBrisk GR14YS/GR15YS
  • Oil Cooler – Road Race1


  • Oxygen Sensor – NTK 22060
  • Throttle Position – NTK TH0098 
  • Camshaft Position – NTK EC0117
  • Crankshaft Position – NTK EH0201
  • Fuel injector pressure – NTK FC0011
  • Air Charge Temp – NTK AJ0023
  • Coolant Temp – NTK EF0103

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About the author

Brendan Baker

Brendan Baker is an automotive writer who lives in Akron, Ohio with his wife and two dogs. He started racing and building cars at a young age, building his first "racecar" at age 12 (a quarter-midget), which he put on pole position in its first race.
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