Chevrolet Small Block Cast Iron Exhaust Manifolds
“Log” and “Chevy II” Style Exhaust Manifolds and Pipe Kits
CAST IRON “LOG” EXHAUST MANIFOLDS
The “under the plug” design Log manifolds are available stock or modified. If your chassis or rules don’t allow the use of “Center-Dump” manifolds, Log manifolds are the way to go!
- Easier to install on a Camaro or Chevelle than the Center-Dump style manifolds.
- Modified Log manifolds produce an 11 horsepower gain at 5,500 rpm.
Modified Log manifolds have a 2 1/4″ outlet versus the 2” outlet on stock manifolds. Manifold has 2 3/4″ flange bolt pattern.
NOTE: Due to “under the plug” design, stock type motor mounts must be used. Also, some type of spark plug shields are a must when running angle plug heads.
CAST IRON “CHEVY II” EXHAUST MANIFOLDS
Modified “Chevy II” type exhaust manifolds. These “Mini Ram-Horn” manifolds go over-the-top like the Corvette manifolds but angle back at a 45 degree angle for more frame clearance.
Like the Log manifolds, these Chevy II manifolds have a 2″ outlet in stock from. The modified manifolds have a 2 1/4″ outlet.
This is the starting point for your exhaust system. A = Floating 1/4 inch Thick Flange
B = Metal Sealing Ring welded to Pipe Adapter
Stock & Modified Log Manifold Dyno Tests
with 2-into-1 Collector
Log type manifolds really like 2-into-1 Systems. With our 2-into-1 collector, you can add 25 hp and 31 ft/lbs of torque at 5000 rpm.
Below 6000 rpm is where the 2-into-1 systems really shine. The addition of a 2-into-1 Collector added 25 hp at 5000 rpm. Also, the modified Log manifolds showed a solid 6 to 11 hp gain over the stock manifolds.