Water pump ports
Thread Starter
Racer
Joined: Sep 2008
Posts: 454
Likes: 7
From: SB County CA
Water pump ports
Just wanted a sanity check before I install the water pump. It is an Edelbrock reverse rotation long pump. The block is Dart SHP. I don't know what the extra port on the water pump is, but it is internally connected to the water pump to radiator suction port. There is no provision in the block for this extra port. This should work fine, and seal ok? Thanks.
http://i740.photobucket.com/albums/x...g?t=1262119614
http://i740.photobucket.com/albums/x...g?t=1262119647
http://i740.photobucket.com/albums/x...g?t=1262119614
http://i740.photobucket.com/albums/x...g?t=1262119647
Pro
Joined: Jun 2005
Posts: 581
Likes: 60
From: USA
that's the thermostat bypass port. on a standard SBC block, there's a corresponding hole in the block.
drill a couple of 1/8" holes in your thermostat so that when the engine's cold, some of the water can still flow before the thermostat opens up.
on my SBC's, I usually put a pipe plug in that water pump hole, and drill the t-stat. looks like Dart saved you the trouble.
drill a couple of 1/8" holes in your thermostat so that when the engine's cold, some of the water can still flow before the thermostat opens up.
on my SBC's, I usually put a pipe plug in that water pump hole, and drill the t-stat. looks like Dart saved you the trouble.
Thread Starter
Racer
Joined: Sep 2008
Posts: 454
Likes: 7
From: SB County CA
Thanks for the reply. I don't mind drilling the holes in the thermostat, but I'm a little puzzled as to why the Dart literature (specs and installation instructions) doesn't mention the difference. It's been a long time since I've messed with a Gen 1 SBC. Is this a common mod? What's the purpose?
Since the port was approx 3/8" I assume 3 x 1/8" holes is the trick?
Thanks again,
Rob
Since the port was approx 3/8" I assume 3 x 1/8" holes is the trick?
Thanks again,
Rob
Pro
Joined: Jun 2005
Posts: 581
Likes: 60
From: USA
3 holes is perfect.
the problem with the factory bypass hole is that after the motor is warmed up, there's no way to shut off the water flow through that 3/8" hole, so you have this constant short-circuit of hot engine water being sucked out of the water jacket via that 3/8" hole going right back into the suction side of the water pump, back into the motor without having made a cooling pass through the radiator.
in effect it decreases somewhat the amount of water being sucked into the water pump via the lower radiator hose.
on big blocks, the same bypass function is performed by that short hose that goes from the front of the intake manifold to the top of the water pump.
the problem with the factory bypass hole is that after the motor is warmed up, there's no way to shut off the water flow through that 3/8" hole, so you have this constant short-circuit of hot engine water being sucked out of the water jacket via that 3/8" hole going right back into the suction side of the water pump, back into the motor without having made a cooling pass through the radiator.
in effect it decreases somewhat the amount of water being sucked into the water pump via the lower radiator hose.
on big blocks, the same bypass function is performed by that short hose that goes from the front of the intake manifold to the top of the water pump.
