Elvira 331 Project Engine Dyno Test

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 Heads	AFR 185
Compression Ratio	10.0:1
Intake Manifold	Edelbrock Performer RPM Air-Gap
Carburetor/Jetting/Adjustment	650-cfm Race Demon w/spacer
Camshaft Type	Comp Cams 282 Hydraulic Roller
Rocker-Arm Ratio	1.6:1
Ignition Timing	34 deg. BTDC (full advance)
Header Type & Size	13/4-inch long-tube headers
Changes	Switched to Wilson 11/4-inch open carburetor spacer

RPM	Peak HP	Peak Torque	BSFC	Air/Fuel Ratio
5,000		437.2	0.395	13.09
6,100	477.5		0.497	11.05

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 Heads	AFR 185
Compression Ratio	10.0:1
Intake Manifold	Edelbrock Performer RPM Air-Gap
Carburetor/Jetting/Adjustment	650-cfm Race Demon w/spacer
Camshaft Type	Comp Cams 282 Hydraulic Roller
Rocker-Arm Ratio	1.6:1
Ignition Timing	34 deg. BTDC (full advance)
Header Type & Size	13/4-inch long-tube headers
Changes	Minor carburetor adjustment

RPM	Peak HP	Peak Torque	BSFC	Air/Fuel Ratio
5,000		437.9	0.475	11.61
6,300	485.5		0.473	11.88

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 Heads	AFR 185
Compression Ratio	10.0:1
Intake Manifold	Edelbrock Victor Jr.
Carburetor/Jetting/Adjustment	650-cfm Race Demon w/spacer
Camshaft Type	Comp Cams 282 Hydraulic Roller
Rocker-Arm Ratio	1.6:1
Ignition Timing	32 deg. BTDC (full advance)
Header Type & Size	13/4-inch long-tube headers
Changes	Retard ignition timing to 32 degrees BTDC

RPM	Peak HP	Peak Torque	BSFC	Air/Fuel Ratio
5,300		439.9	0.404	12.74
6,100	483.3		0.484	11.50

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 Heads	AFR 205
Compression Ratio	10.0:1
Intake Manifold	Edelbrock Victor Jr.
Carburetor/Jetting/Adjustment	650-cfm Race Demon w/spacer
Camshaft Type	Comp Cams 282 Hydraulic Roller using
	mechanical roller lifters to prevent valve float
Rocker-Arm Ratio	1.7:1
Ignition Timing	34 deg. BTDC (full advance)
Header Type & Size	13/4-inch long-tube headers
Changes	Switch 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.