Jim Smart
July 1, 2003
Photos By: Julio Mayen

Last month, we walked you through the creation and assembly of a high-end Eagle 331ci stroker small-block built for JME Enterprises' Project Elvira by John Da Luz of JMC Motorsports in San Diego. This month, we're going to put Elvira's 331 through its paces on Westech's dynamometer in Ontario, California. Our objective is to show you what works and what doesn't. What surprised us most about this series of dyno tests was that they contradicted a lot of theories out there about power and what it takes to get more.

When we took Elvira's 331 stroker to Westech, there were actually two trips, and two very long days of dyno testing. Our first trip to Westech on May 2, 2002, consisted of 17 dyno pulls in different induction configurations and tuning. There were also minute adjustments to the ignition timing. Not convinced we were as successful as we could have been, we went back to Westech more than a month later on June 19 for nine more pulls. We're eager for you to see the results. But remember, you have to go through hell to get to heaven. There was a lot of work ahead of us.

May 2, 2002
It was a warm day in Southern California. After a 150-mile drive from San Diego up California's I-15, Julio Mayen and John Da Luz were ready for coffee, an engine hoist, and a dyno cell. More than anything, these gentlemen were interested in results. It had been a long and difficult engine buildup, with all kinds of problems that kept them assembling and disassembling the short-block until they had it right. Arriving at Westech to find out what this engine was made of was both bitter and sweet. Julio and John both knew it could go either way.

When John Beachtel and Steve Bruel of Westech installed our 331 on the dyno, there was lots of apprehension. Our goal for this engine was 500 hp. Were we being realistic? And were our struggles during the buildup an omen for things to come? Turning the crank and lighting the mixture would be the only way to know. There is something religious about starting an engine for the first time. We had a brand new 5.0L Ford block from Summit Racing Equipment. Everything inside that block--pistons, rods, crankshaft, camshaft, and valvetrain--was all brand new. It would be this engine's first time hot and under the gun.

When Westech's Steve Bruel fired the engine, he ran it at a fast idle for good warm-up, then did some lightweight pulls from 3,740 to 3,920 to get the Castrol 5W-30 oil good and hot. Timing was located at 34 degrees BTDC. Race Demon carburetor jetting was out of the box. On Warm-Up Pull No. 3, Steve leaned on our 331 and took it to 5,200 rpm. It was at this moment one of the freeze plugs blew out of the block, forcing us to shut it down for a fast repair. Par for the course with some dyno pulls. Steve looked at our numbers and decided to swap up on jet size to 78.

June 19, 2002
Convinced they could make more power, Julio Mayen and John Da Luz hauled Elvira's 331ci stroker back to San Diego and went to work. These guys closely examined the engine's data as it sat on the Superflow dyno. Overall, the Edelbrock Performer RPM Air-Gap intake manifold made 8.9 lb-ft more torque and just 5.5 hp less than the Victor Jr.--pretty good for a dual-plane intake manifold. Not bad for most folks, but not for Julio and John. They were determined to blow the benchmark off the map. Here's what they did.

Air Flow Research (AFR) provided JME Enterprises with AFR 205 heads with larger 2.02-inch intake valves for better breathing, and springs designed to accommodate solid roller lifters. These castings and stopcocks would surely close the gap, being so close to 500 hp. But would they? For added insurance, John and Julio fitted Elvira's 331 with 1.7:1 Comp Cams roller rockers to compensate for valve lash and maximize valve lift. Because they didn't want valve float at 6,500 rpm, they opted for mechanical roller lifters, also courtesy of Comp Cams. These lifters would ensure valvetrain stability to 7,000 rpm. Also added to Elvira's 331 for Round Two is a Meziere 5.0 electric water pump. This pump will ensure a constant water flow and reduced parasitic horsepower loss since a belt will no longer be required to turn the pulley to pump water through the motor.

Although John and Julio were convinced they had taken the Edelbrock Performer RPM to its very limits with the cam and cylinder heads chosen during the May 2nd dyno experience, both the RPM and Victor Jr. would return for the next round of pulls. A Wilson 11/4-inch open-plenum spacer tops the Victor Jr.Castrol 5W-30 engine oil is an outstanding lubricant for high-performance engines. But Royal Purple synthetic 5W-30 is slipperier. With less friction throughout, we stand to use power where it counts--at the crankshaft.

The Long Road
As you can see, making horsepower and torque isn't as easy, or as simple, as many of us perceive. It takes a lot of mental and physical energy to make power. Mental energy is the creative side, where we determine what to do next. This takes a lot of thought and a vast knowledge of what happens inside an engine to make power. Physical energy is the effort involved--swapping components, making adjustments, and testing, testing, testing.

When you study the numbers above, it becomes clear you're only going to make just so much torque with a given amount of displacement. Despite every single change made to Elvira's 331ci small-block, torque never varied more than 13 lb-ft across 14 dyno pulls. Horsepower baselined at 480.5 and peaked at {{{505}}}.9. Our message here is simple. There is no such thing as bolt-on magic. To make 500 hp and 420 lb-ft or torque from 331 ci, Julio Mayen, John Da Luz, and Steve Bruel had to put every ounce of their wits into the end result. Two days' worth of dyno testing netted just 25 hp and a variation of 13 lb-ft of torque. Persistence and the willingness to try seemingly useless adjustments and changes can often make the most significant changes in power. In this case these gentlemen not only met their goal of making 500 hp from a naturally aspirated small-block 331, but the horsepower/cubic-inch ratio ended up being 1.53 hp per cubic inch. Any engine builder will agree that this is a very respectable accomplishment.

Rejetting the carburetor and regapping the spark plugs netted the greatest improvements in power. Yet a head swap did very little for power. What does this tell you about what you can do for your engine, without even having to order a set of heads? Be modest in your power expectations and work from there. Little by little, one step at a time, you will meet the goal. And remember something else. You must plan for power. It does not happen by accident.

No. 1
After three warm-up pulls, we're doing a 6,000-rpm pull to establish a baseline to work from. We're going to follow this pull with a series of pulls that involve a simple swap and finite tuning.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesNone
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,300426.60.44612.00
6,100480.50.51310.77

No. 2
With four pulls behind us, we have baseline numbers to work with. Our goal is 500 hp, with roughly 420 lb-ft of torque. To get there, we will have to make changes and adjustments. We decided to swap the Race Demon's air bleeds. Take a look at what happened with just a finite carburetor adjustment.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesChange carburetor air bleeds
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,300427.80.45911.63
6,300487.80.48111.60

No. 3
If you watch Elvira's 331 dyno session long enough, you'll see that change often comes from minute tuning adjustments. Look how much power we gained from removing the phenolic four-hole spacer and installing a Wilson Manifolds billet 11/2-inch tapered spacer. Timing and fuel mixture remain the same.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesWilson 11/2-inch tapered spacer
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,300431.00.49010.85
6,300491.00.46911.83

No. 4
Prior to the fourth pull, we realized we had maximized the potential of our 331 for horsepower with the Victor Jr. intake manifold. Although we fell 9 hp shy of our goal, our horsepower-to-cubic-inch ratio came in at a very respectable 1.48 hp per cubic inch. John and Steve applauded us on the performance of our 331 and stated that their Chevy 350 they have used as a benchmark for all small-block engines makes only 1.42 hp per cubic inch. With this in mind we felt much better and decided to find more power on another day. At this time we decided to do a comparison by using a more streetable intake manifold and installed an Edelbrock Performer RPM to run through the paces. We knew we would lose horsepower but the dual-plane should make up for it with torque.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Performer RPM Air-Gap
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesManifold swap to Edelbrock Performer RPM Air-Gap
and Wilson 1-inch carb spacer
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
4,700427.10.45311.26
6,100471.10.53410.30

No. 5
Before the first pull, we made a minor fuel system change. We replaced the Wilson 1-inch four-hole spacer with a 1 1/4-inch open spacer and made no other changes. We gained 10.1 lb-ft of torque and 6.4 hp.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Performer RPM Air-Gap
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesSwitched to Wilson 11/4-inch open carburetor spacer
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,000437.20.39513.09
6,100477.50.49711.05

No. 6
Before the sixth pull, we made a minor fuel/air adjustment and spun the crank again. This is what happened. We gained 8 hp and 0.7 lb-ft of torque.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Performer RPM Air-Gap
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesMinor carburetor adjustment
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,000437.90.47511.61
6,300485.50.47311.88

No. 7
When 36 degrees of total advance didn't do it for us, we retarded the ignition timing to 32 degrees BTDC. We gained 2 lb-ft of torque and virtually no increase in horsepower. When you look at brake-specific fuel consumption (BSFC), there's essentially no change with adjustments to ignition timing.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing32 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesRetard ignition timing to 32 degrees BTDC
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,300439.90.40412.74
6,100483.30.48411.50

No. 8
Another 150-mile journey to Ontario witnessed Elvira's 331 back on Westech's dyno, for another shot at fame, and 500/420. Here's what happened on the first pull of the day.

Cylinder HeadsAFR 205
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller using
mechanical roller lifters to prevent valve float
Rocker-Arm Ratio1.7:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesSwitch to AFR 205 heads, 1.7:1 rocker arms
for greater valve lift, mechanical roller lifters to prevent float. Back to Edelbrock Victor Jr.
Melling standardvolume oil pump. Meziere electric water pump.Royal Purple synthetic 5W-30 oil.
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,700433.20.47911.20
6,700505.90.46812.48

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No. 9
Having achieved the 500hp objective, with torque holding steady around 437 lb-ft, Julio and John decided to fine-tune Elvira's 331 for real-world performance, with components that would make Elvira less temperamental and downright wicked. Here's where they headed next.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesSwitch back to AFR 185 heads, 1.6:1 rocker arms
for reduced valve lift, and hydraulic roller lifters.
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,300432.30.46611.76
6,300488.60.46011.93

No. 10
What we learned with the 10th pull was the value of the AFR 185 cylinder head. It gets us within 17 hp of the AFR 205 head, equipped with larger ports and valves. So how do we close the gap without changing heads? How do we close the gap, working our way back to 500 hp and a significant improvement in torque? John Da Luz made minor adjustments to the Race Demon carburetor. Julio swapped the Wilson 11/4-inch open spacer for a Wilson 11/2-inch billet-aluminum spacer with four tapered ports. Timing was kept at 34 degrees BTDC. Here's what Elvira did.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/ spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesMinor carburetor tuning. Swap Wilson 11/4-inch spacer
to 11/2-inch spacer with tapered ports.
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,200432.80.45011.92
6,300496.50.47711.75

No. 11
Look, Ma, no hands! Steve Bruel elected to run the engine again after a brief cool down to see what the dyno would reveal. Without touching the engine, look what happened. A warm engine makes more power than a hot one, and this is a case in point.

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.61
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesNo changes, just a cool down.
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,200433.90.42212.08
6,300501.90.46811.82

No. 12
As you can see from Pull 13, stepping up to a 750-cfm Race Demon made virtually no difference in performance numbers. John Da Luz downsized the jets for an 84/90 combo. Spark-plug gaps were increased from .035 to .040 inch. Do you know what happened next?

Cylinder HeadsAFR 185
Compression Ratio10.0:1
Intake ManifoldEdelbrock Victor Jr.
Carburetor/Jetting/Adjustment650-cfm Race Demon w/spacer
Camshaft TypeComp Cams 282 Hydraulic Roller
Rocker-Arm Ratio1.6:1
Ignition Timing34 deg. BTDC (full advance)
Header Type & Size13/4-inch long-tube headers
ChangesDownsize the jetting. Enlarge spark-plug gaps.
RPMPeak HPPeak TorqueBSFCAir/Fuel Ratio
5,200433.60.40513.06
6,300504.80.44612.57