Heater bypass block
Thread Starter
Joined: Aug 2012
Posts: 1,539
Likes: 85
From: Mesa, Arizona
Heater bypass block Has anyone blocked off the heater outputs without having any issues? The reason I ask is that I normally use a LOJ bypass block so when the vintage air turns off the heater hose circulation the water can go into bypass and return to the motor. The current build is pretty tight on space and I'm not sure I have room for a bypass block anywhere.
I have two cars with Vintage Air and LS engines, and they both have well over 100k miles on the swaps and never had an issue with the VA heater valve shutting the water off completely. They are also usually driven mostly in the summer months too, so I would think I would have noticed a problem by now if one was going to happen.
Teching In
Joined: Aug 2018
Posts: 23
Likes: 1
So here is what I've figured out after doing a couple ls swaps and troubleshooting my current projects cooling system. The water pump with the larger opening and one piece thermostat/neck has a little gap on the back of the thermostat, probably doesn't care as much about the heater bypass. My older swap has this pump and the lines have been capped for years. The one with the two piece thermostat (what I have on my current project). The bypass valve already has spring pressure holding it closed when the thermostat is installed. I did not have a heater loop plumbed in and sometimes at idle the thermostat would close after then engine cools down from the fans and it would fail to get enough hot water from the block circulating on it to own it back up. Engine temps would climb and fans would turn back on but temps would keep climbing and I would have no circulation. At one point my radiator was down to 120f and my engine was 230f.
I've done a couple LS swaps with standard HCVs. No issues. I do recall that there's a 4 port bypass that's electronically operated from a Lincoln LS that bypasses and could replace the VA valve.
