What are the best flowing BBC heads?
What are the best flowing BBC heads?
The 385cc heads are AFR’s largest and best flowing BBC heads! They feature 100% CNC ported intake, exhaust & chambers, A356 aluminum castings, Titanium retainers, and high quality components throughout. These heads are best suited for large displacement (540+) high RPM Big Block Chevrolet racing engines.
What size heads for 454?
Performer RPM 454-R heads have rectangular 315/300-cc (long/short) intake ports and 118-cc open chambers. A revised spark plug location promotes better combustion, but they do not clear high-dome pistons based on the LS6 Chevy chamber.
Are 781 heads any good?
781 are good heads and with compression and porting can make well over 800HP. Now you need to see what the parts and machine work will cost you to get a set of heads prepped for the HP level you want.
Which is better open or closed chamber heads?
Open and closed chamber cylinder heads differ in combustion chamber capacity. Although open chamber cylinders offer easier flow, the closed chamber cylinder is better for performance. Compression ratios are also affected by the size of the chambers.
Are brodix heads any good?
Usually, big performance heads give up a little downstairs for midrange and top-end improvements, but in this case, Brodix proved superior at every lift point on both the intake and exhaust sides, from off the seat through 0.800-inch lift.
What is a 18 degree motor?
In 18 degree heads, the valves are right on the cylinder bore centerline. The valves are also relocated to position the intake valve closer to the bore center, and the exhaust valve closer to the cylinder wall. This unshrouds the intake valve at maximum lift and allows the use of bigger valves.
Are all big block Chevy heads the same?
All production big-block heads have similar characteristics, including 7/16-inch rocker studs (except Gen V and Gen VI) and the same seven-bolt valve cover pattern. Mark IV, Gen V and Gen VI heads all have the same head bolt pattern, but they are not interchangeable due to different water jacket cooling passages.
Are BBC heads interchangeable?
Original Mark IV blocks are widely sought after and it’s important to properly mate their characteristics with the performance goals of your particular build. Their coolant passages are not compatible with earlier Mark IV engine blocks and thus cylinder heads are not interchangeable.
Are 781 heads open or closed chamber?
The ‘781 is the best choice for a 396 because it has the smallest open combustion chamber to help with static compression. Depending upon the year of the block you will have small dome pistons to make 11 to 1 compression with a closed chamber.
What size valves are in 781 heads?
The 781 heads have 256/114 cc port size runners, with 118cc combustion chambers. The 049 heads have 255/119 cc port size runners, with 122cc combustion chambers. It’s really a toss up on which ones to use as the 049’s flow more but the 781’s will give a little more compression.
What are the best factory BBC oval port heads?
Click to expand… My 063s with 2.19/1.88 valves flowed 300 cfm @ .600 on the good ports and 290 cfm on the bad ports. They’ve been worked pretty good. Dr Js performance states they get 321 cfm @ .600 and 327 @ .700 out of them.
What kind of cylinder head does a BBC car use?
Edelbrock’s Big Victor Spread-Port 18° CNC cylinder head is intended for high output, large cubic inch BBC racing engines with 4.84? bore spacing, this new head is an improvement over existing 18° designs.
What do you need to know about RHS BBC heads?
The RHS BBC Pro Action and Pro Elite BBC heads utilize stock rocker arms, intake and exhaust manifolds. The only special requirement is 4 longer head bolts or studs on the exhaust side of the head to accommodate the raised exhaust port required to overcome the restriction inherit in the OE design.
What makes the Reher-Morrison RM-20 BBC cylinder head so special?
No other conventional head can out power the DRM-20°! With air-flow and air speed, light years ahead of any other heads in its class, the DRM-20 supplies power gains of 80 hp to 100+hp! The RM 20 components include: Flows more air per valve size than any other conventional cylinder head!