Join Date: Sep 2000
Location: Shrewsbury, MA, USA
In a TH350, the bottom line is the supply out of the trans to the radiator, top line is the return from the radiator to the trans. For best heat transfer you want the hot fluid going into the bottom of the radiator. This is where the coldest water in the radiator is so you will get maximum heat transfer. It also keeps the transmission side of the cooler full of fluid, since you are pumping it from the bottom up. If it flows from the top down the cooler doesn't stay full all the time since the fluid will flow to the bottom by gravity.
This configuration is especially important when you are using one of B&Ms plate coolers. You must always keep the cooler full of trans fluid, for the longest possible time for maximum heat transfer.
A TH350 will pump about 3 Qts of fluid at about 1500 RPM.
1969 Indy Pace Car
350/300HP RPO Z11