Vortec Heads Bypass Hose

[OldChevy1954]

I know this has been discussed in the past.
I have a GM HT383 crate motor in my truck and I have read that these engines need a bypass hose from the pump to the manifold.
If I have my heater hoses hooked to the top plug on the water pump and the passenger side water inlet/outlet on the manifold the ... does this satisfy the need for a bypass setup?

Thanks.

[pjmoreland]

That should work fine as long as you don't have an A/C system with a heater core coolant flow shutoff valve installed in one of your heater hoses. The coolant needs to be free to flow all the time. I ran a set of Vortec heads that way previously, and I observed no temperature spikes during engine warm-up.

On a side note, I built a complete Vortec engine for my truck recently. I don't currently have A/C, but I'm planning on installing A/C eventually, so I drilled a bypass hole in the passenger side head like older SBC heads had. I didn't want to have to run an external bypass line from the water pump to the intake manifold purely for aesthetic reasons. Fortunately, my l31 block already had the bypass holes in it.

[FirstOwner69]

I'm running a Vortec 350 GM crate engine. I called a GM technical assistance number (think it was included with the engine) about something else. During that call they told me to be sure to run a hose between the intake and water pump if I had A/C.

Here's a pic of what I did.

[OldChevy1954]

Originally Posted by FirstOwner69

I'm running a Vortec 350 GM crate engine. I called a GM technical assistance number (think it was included with the engine) about something else. During that call they told me to be sure to run a hose between the intake and water pump if I had A/C.

Here's a pic of what I did.

FO69, I like what you did, but I do not have another outlet on my water pump as you do on the passenger side there.
Strangely my only water pump outlet on this factory HT383 is on top. I'm using the top pump outlet as the return from my heater box, and the feed to the heater comes from the intake manifold.
I am getting some spikes on my dash temp gauge. The temp sender is in the drivers side head. I'm thinking I'll move that to the manifold on top and see if the spiking changes.
Thanks for your input on this topic.