waterpump bypass

[michael sommers]

Could someone explain the reason a bypass hose
is connected from the waterpump top boss to the
intake manifold?
thanks

 

[BarryK]

on SB motors it was only put on the SHP motors such as the 350hp and 365hp motors.
base 250hp, and 300hp motors didn't have them
The by-pass hose is to eliminate water pump cavitation at high rpm. (SHP motors have higher redlines)
all SB engines already have a bypass circuit through the passenger side leg of the water pump anyway even if your car had a bypass and someone removed it.
I believe all BB cars had the bypass also regardless of which BB motor because the BB motor water pumps didn't have the bypass hole in the passenger side leg of the pump like the SB motor pumps did

 

[michael sommers]

Thanks for the info.
I'll have to research this more, I'll start
by looking up the word cavitation. Then think about why the
effort and parts would be put into the duplicating for this effect
if the SB pump already has a hole to compensate for this.

 

[Tom Bryant]

Cavitation is when air gets mixed in with the liquid. The volume of liquid being pumped is greatly reduced when it has a high amount of air bubbles mixed in. You would also see a reduction in pump output pressure if there was a guage installed to measure it.

 

[michael sommers]

Tom,
Thanks for the education.

 

[JohnZ]

Then think about why the
effort and parts would be put into the duplicating for this effect
if the SB pump already has a hole to compensate for this.

The standard bypass hole in the RH water pump leg is only about 3/8" diameter; the added bypass fittings and hose on the SHP engines has five times the flow capacity of the standard bypass.

 

[michael sommers]

thanks John
and regards