VORTEC coolant bypass

[chefk85]

Finishing up my L31 vortec swap. Trying to figure out how to route my heater lines and the bypass needed for the vortec heads.

This is the water pump I have https://www.summitracing.com/parts/g...make/chevrolet

This is the intake https://www.summitracing.com/parts/edl-7116

A little confused but heres the idea I had. Run a short line from passenger side pipe on water pump(I believe bypass line) to front of intake manifold under thermostat.

Run another line from drivers side pipe on water pump to heater core in(I believe its on the bottom of core?)

Run a third line from outlet on heater core back to intake manifold on top passenger side coolant port.

Should I instead plug that heater core return on intake and run it back to the radiator?

Am I right about the passenger side short water pump pipe being the bypass?

I'm having a hard time finding any info that doesn't contradict other info. Anyone done this before?

Thanks in advance
chefk85

[B. W.]

You can do it just like you said. You can run the heater hose return to the water pump (driver's side) or to the radiator (if you have the port on the rad)

If you run the heater hose to the radiator, remove the driver's side coolant pipe from the water pump, it's a press fit, twist it out using pipe wrench/pliers/vice. Tap the hole 3/8" NPT & install a pipe plug. The hole is slightly large for 3/8 so go shallow on the tap.

Kinda hard to see in the pic but there's a pipe plug in the water pump.

[chefk85]

Okay so it looks like bottom hose on heater core is the inlet and top outlet. From what I gather the passenger side pipe on WP is for the coolant bypass only and the drivers side is the heater return. The engine is in and everything is put on so id rather not have to tap anything at this point unless I have to. It would probably be easier for me to cap off the radiator port for the return line and just run it to the water pump return pipe(I also picked up the nifty hard tube from the junkyard that the factory uses to route the heater return to the pump). Ill run a hose from passenger intake before thermostat to inlet on heater core. Sound right? Sometimes I just need to be reaffirmed everything is correct haha.

I suppose also I could just cap the return pipe on the pump and not pull and tap and leave my return right where it is in the rad. See any issues with my logic here?

I also forgot to reply to you but thanks for the fan and clutch suggestions. I ordered the fan and made the stock L31 clutch I got from the junkyard work.

Thanks again BW,

chefk85