Reply to "news fans with or without shroud"

One thing with big fans is, using stock Pantera wiring may limit your cooling. There's about 5 or 6 extra feet of extra wiring folded into the front wiring loom under tape and the more wire & connectors, the less electrons get to whatever device is connected. An odd characteristic of electric fans is, a drop of only 1.0 volt to a motor may reduce the fan speed by 25%, so that advertized 2500 cfm airflow becomes 1875 or even less. When I analyzed several fans for their airflow in our '72 Pantera, that's what I found. The simplest way to check this is with a mechanical tach on the electric motor shaft, or simply connect the fans directly to the battery with jumpers. If the fan speed or noise increases noticably with direct connections, further checking of your wiring will likely show less than an optimum 13.2vDC going to the fans thru the stock wiring.

When I started checking fans & motors in the '80s for our car in trying to sort out cooling problens, I borrowed a $500 portable anenometer from the heating/AC maintenence men at the company I worked for. 20 yrs later (2012) I bought a Chinese airflow meter off the Internet for $29. My mechanical tach is a Stewart-Warner unit meant for checking machine tool shaft speeds with no electric hookup needed.

I also found that s-blade fans move no extra air over identical straight-blade fans; mfgrs use s-shapes 'cause they're quieter. More blades at the same speed do move more air. I also found that with sucker fans, spacing the whole shroud an extra 2" away from the rad core increases airflow by 5% due to less turbulence inside the shroud. The simple shroud extension I made covers 100% of the rad core with no open areas. Spacing the fan motors such that fan blade tips are positioned out of their large holes by 1/4 the blade-tip width also gives more airflow.