Third hole on Waterpump

dgoodhue

BuSTeD 4.3
My factory waterpump and block has a 2nd hole on the passenger side of the waterpump (toal of 3 passages). I went to install my factory water pump on my Vortec block but I have only has the center holes (one per side). I have a 2 hole water pump gasket, but it would go no where on the vortec block.

Could this cause a problem, do I need a different waterpump?

Here is a picture of my stock motor.

LB4.jpg
 

dgoodhue

BuSTeD 4.3
Re: Third hole on Waterpump

I don't believe the lower hole enters the water jacket. i.e nothing should come out. Here is a replacement pump for a 98: http://www2.partstrain.com/includes...R01CLkpQRw==&title=R01CIFdhdGVyIFB1bXA=&text=
Doesn't look like the flow holes are any different.

The 98 pump looks like 03 pump that came on the jnkyard motor. The hole on my original block, almost looks like its a dead end but I doubled checked it with compressed air and it definates goes into the water jacket.
 

TYHOGG

Active member
Re: Third hole on Waterpump

Not a bad idea. Is the hole small enough to tap and screw in a plug?
 

sytyguy

Moderated User
Re: Third hole on Waterpump

I meant the top hole on the water pump. Not the top hole on the block. The pump I listed will accommodate the block, but it has an extra hole on the top for a heater core feed. Since our intake has our heater core feed outlet, you can either block off this hole or block off the intake and use this hole.
 

dgoodhue

BuSTeD 4.3
Re: Third hole on Waterpump

I think I may have confuse you, here is a picture of my factory LB4 water pumps and the third hole on the passenger side.
 

Attachments

  • LB4 Waterpump.JPG
    LB4 Waterpump.JPG
    50.1 KB · Views: 0

dgoodhue

BuSTeD 4.3
Re: Third hole on Waterpump

Here is the Vortec Block I am trying to mount it to.
 

Attachments

  • Vortec WP Openings.JPG
    Vortec WP Openings.JPG
    71 KB · Views: 0

sytyguy

Moderated User
Re: Third hole on Waterpump

Did you get the fan clutch/pulley from the new engine?

if not, modifying your current pump might be more desirable as I've yet to find a pump with an omitted 3rd hole and our style pulley/clutch. I'll keep looking though.
 

dgoodhue

BuSTeD 4.3
Re: Third hole on Waterpump

Did you get the fan clutch/pulley from the new engine?

I do have the water pump & pulley (different nose) from the new motor. I have electric fans, so the clutch isn't need, but this motor didn't some with one anywyas. I was kind of hoping to just bolt mine on.
 

TYHOGG

Active member
Re: Third hole on Waterpump

Sorry had it backwards. If your doing the extra work why not upgrade to the edelbrock for the extra cooling?
 
Top