S4 water pump and housing on a 76 13b?
there was an extra stud added on the '86 and later blocks. u'll have to block that hole in the housing on the water side and tap the hole on the pump side for a bolt to fit for the alt bracket. i found out all about this the hard way, wanting to keep the alternating cast, aluminum, etc on my '74 engine.
Joined: Oct 2003
Posts: 3,438
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From: Outskirts of Road Atlanta
Ahh, but it can be done much easier, young Jedi.
Put a counterbore in the back side of the water pump under the stud hole that you don't want. You have to put a bolt though there one way or another. The water pump will seal to the block fine, but will leak between the pump and housing without that bolt. A M8 bolt has a 13mm diameter head, so sink a 13.5mm hole into the back side 8.5mm deep and drop a stainless socket-headed cap screw in there. From the front, it will look like any other stud with a nut and all you've done is drill a shallow hole.
Put a counterbore in the back side of the water pump under the stud hole that you don't want. You have to put a bolt though there one way or another. The water pump will seal to the block fine, but will leak between the pump and housing without that bolt. A M8 bolt has a 13mm diameter head, so sink a 13.5mm hole into the back side 8.5mm deep and drop a stainless socket-headed cap screw in there. From the front, it will look like any other stud with a nut and all you've done is drill a shallow hole.
Originally Posted by Crit
Ahh, but it can be done much easier, young Jedi.
Put a counterbore in the back side of the water pump under the stud hole that you don't want. You have to put a bolt though there one way or another. The water pump will seal to the block fine, but will leak between the pump and housing without that bolt. A M8 bolt has a 13mm diameter head, so sink a 13.5mm hole into the back side 8.5mm deep and drop a stainless socket-headed cap screw in there. From the front, it will look like any other stud with a nut and all you've done is drill a shallow hole.
Put a counterbore in the back side of the water pump under the stud hole that you don't want. You have to put a bolt though there one way or another. The water pump will seal to the block fine, but will leak between the pump and housing without that bolt. A M8 bolt has a 13mm diameter head, so sink a 13.5mm hole into the back side 8.5mm deep and drop a stainless socket-headed cap screw in there. From the front, it will look like any other stud with a nut and all you've done is drill a shallow hole.

matt
Thread Starter
Joined: Nov 2004
Posts: 5,962
Likes: 1
From: Cartersville, Ga
Originally Posted by Crit
Ahh, but it can be done much easier, young Jedi.
Put a counterbore in the back side of the water pump under the stud hole that you don't want. You have to put a bolt though there one way or another. The water pump will seal to the block fine, but will leak between the pump and housing without that bolt. A M8 bolt has a 13mm diameter head, so sink a 13.5mm hole into the back side 8.5mm deep and drop a stainless socket-headed cap screw in there. From the front, it will look like any other stud with a nut and all you've done is drill a shallow hole.
Put a counterbore in the back side of the water pump under the stud hole that you don't want. You have to put a bolt though there one way or another. The water pump will seal to the block fine, but will leak between the pump and housing without that bolt. A M8 bolt has a 13mm diameter head, so sink a 13.5mm hole into the back side 8.5mm deep and drop a stainless socket-headed cap screw in there. From the front, it will look like any other stud with a nut and all you've done is drill a shallow hole.
hahaha, man, that confuses the heck out of me. but ill reread it and not read it so quickly and im sure ill get it.
also, is it worth it to do this mod?
Joined: Oct 2003
Posts: 3,438
Likes: 6
From: Outskirts of Road Atlanta
The studs hold the waterpump together as well as holding it to the block. You don't have a stud to hold the waterpump together in that one spot. You can drill a hole in the back to sink the head of the screw into and pass the screw through to the front. Now you can bolt the waterpump back together, without any leaks from the waterpump and housing even though you lack a stud there.
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