Quote:
Originally Posted by 'ol Pinion head
Below is a good example of a cast impeller in a tall 11 bolt wp, a pump that will work great for what it was designed for, a short deck (reduced cooling capacity) 301 or 265. Open the pics & skim to the one with a view of the impeller.
https://www.ebay.com/itm/NOS-GM-4882...p2047675.l2557
This is the late style abbreviated impeller designed to create less drag & move less coolant. This type impeller works fine on a short deck block & works equally well on std deck height blocks that have been hardblocked to the bottom of the freeze plugs. Needless to say, the parts usage description in the eBay ad is far from correct.
On the previous 8 bolt design water pumps, the early ones used a lazy impeller which was designed to move a certain volume of coolant due to the cooling needs of a '64 or '65. Later 8 bolt wps received a much more aggressive design impeller which moved coolant through the system quicker & will move the coolant too quickly to transfer heat into the coolant in an early system. On several instances, have ran across owners of vehicles having cooling problems which had sourced the incorrect cast impeller pump. |
That pump works great on my 461 500 hp with a 3 core alum. radiator / non electric fan / 8 years now & in Pa. with hot summers idles in traffic & never goes above 200 / 180 in motion.