3 replies to this topic

[V-SLR5000-P]

Fitzsi, your stock crate motor is a reasonable basis for a mild supercharger application. You will be limited by stock heads and valve springs, cam and cast pistons. I would recommend the 144 low profile blower for ease of set up and excellent low down performance in comparison with the larger 471. The smaller blower will build boost faster and therefore make superior power/torque up to around 4000 rpm. In any event, l would not suggest that you spin a blown crate motor beyond 5000.
l would also suggest the following:
� Maximum boost 6-7lbs (you must have a boost gauge)
� Single 750 Holley set up with boost referenced power valves
� Dizzy modified for mechanical advance only (34 deg total advance is OK)
� Minimum 3/8 fuel line and high volume fuel pump
� Pressure diversion valve to vacuum modulator if running an auto
� Minimum 2.25 dual exhaust with free flowing mufflers
You could reasonably expect a 30% power increase just by adding the blowe

[V-SLR5000-P]

Both the B&M and Weiand mentioned are low profile rootes type blowers designed primarily for basically stock stock engines in street applications. Theses blowers come with low profile manifolds to fit under the bonnets of most cars and can also be identified by their serpentine drive belts. Low profile blowers are typically driven at twice engine speed to produce around 7lbs boost, whereas a 671 is rarely driven beyond 1:1 on a street small block. The small blowers are limited in their ability to produce boost as their higher rotor speed heats up the incoming air, at which point power quickly falls away and detonation may occur. The differences between the B&M and Weiand units themselves is in design detail, the concept is the same. The B&M has teflon tipped rotors and can run tighter rotor clearance without case damage and the belt tensioning systems are different, although both use a spring to preload the belt. The Weiand has a displacement of 177ci while the B&M has been available with displacements from 58 to 250ci for a wide range of engines. The only B&M blowers of interest to Holden V8 or Chevy small block owners would be 144, 162, 174 or 250ci.