|
 |
RPM Xtreme (Oval Port)
The RPM Xtreme for big-block Chevy is an all new design that is CNC ported where it counts to achieve
optimal air-flow for maximum horsepower and torque in high performance street and light duty racing
applications. The casting and port design are all new and engineered to be as close to perfect as possible.
To ensure consistency from port to port, the RPM Xtreme is treated to a fully CNC ported combustion
chamber, and then CNC ported in the bowl area (above the valve) for a smooth transition into the valve
seats. The intake runner entries and exhaust runner exits are partially CNC ported for improved air-flow.
RPM Xtreme big-block Chevy heads have a 24.5° x 4.4° intake valve angle, 15.5° x 4.2° exhaust valve
angle, stock exhaust port locations, and the spark plug angles have been modified to produce a smooth
flame front for increased fuel efficiency and maximum power. Two port designs are offered, a 300cc Oval
and 325cc Rectangle. Both options are equipped with high-quality valve springs for valve lifts of up to .700"
Cylinder Head Specifications |
| Combustion chamber volume |
112cc |
| Intake runner volume |
308cc (lh) / 325cc (rh) |
| Exhaust runner volume |
133cc |
| Intake valve diameter |
2.25" |
| Exhaust valve diameter |
1.88" |
| Valve stem diameter |
11/32" |
| Valve guides |
Manganese Bronze |
| Deck thickness |
9/16" |
| Valve spring diameter |
1.55" |
| Valve spring maximum lift |
.700" |
| Rocker stud |
7/16" |
| Guideplate |
3/8" |
| Pushrod diameter |
3/8" |
| Valve angle |
25° |
| Exhaust port location |
+.125" |
| Spark plug fitment |
14mm x 3/4 reach, gasket seat |
| Made In |
USA |
|
|
Technical Notes: Match with Edelbrock head gasket sets. |
| |
| Description |
Bare (single) |
Complete (single) |
| RPM Xtreme with Oval Port |
N-a |
51459* |
|
Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28" H2O (4.31" Bore)
| #51459 |
| Valve Lift |
.200" |
.300" |
.400" |
.500" |
.600" |
.700" |
.800" |
| Intake |
143.6 (RH)
143.3 (LH) |
221.5 (RH)
222.6 (LH) |
282.8 (RH)
276.3 (LH) |
314.8 (RH)
318.3 (LH) |
332.2 (RH)
335.1 (LH) |
337.2 (RH)
337.3 (LH) |
337.7 (RH)
344.0 (LH) |
| Exhaust |
125.1 |
171.8 |
198.8 |
216.6 |
231.9 |
243.1 |
252.5 |
|
Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28" H2O (4.6" Bore)
| #51459 |
| Valve Lift |
.200" |
.300" |
.400" |
.500" |
.600" |
.700" |
.800" |
| Intake |
149.0 (RH)
144.6 (LH) |
230.5 (RH)
228.9 (LH) |
299.2 (RH)
289.0 (LH) |
337.1 (RH)
330.8 (LH) |
358.0 (RH)
351.4 (LH) |
364.4 (RH)
356.2 (LH) |
360.7 (RH)
363.9 (LH) |
| Exhaust |
126.1 |
172.8 |
199.7 |
217.8 |
234.4 |
248.9 |
257.5 |
|
AMC
Small Block
