Mounting a Water Pump

[Larry M.]

I'm planning to dry/test fit everything to ensure I'll have alignment but, when I'm ready for final, do you/should I use a sealant like Permatex #2 on the pump to block gaskets?

I read a post where Duke Williams and others suggested using teflon tape or dope on the bolts in case there is an opening to the block water jacket in the bottom of the bolt holes and I'll do that.

The pump I traded to Bill Mock may have had a dowel in the internal bypass but the new one does not, so I guess I'll have both the external bypass to the intake and an internal to the block. I believe I read a post by Joe Lucia saying that was a non issue. Have I got this right?

[John H.]

Re: Mounting a Water Pump

The pump I traded to Bill Mock may have had a dowel in the internal bypass but the new one does not, so I guess I'll have both the external bypass to the intake and an internal to the block. I believe I read a post by Joe Lucia saying that was a non issue. Have I got this right?

Larry -

Yup, it's a non-issue.

[Jack H.]

Re: Mounting a Water Pump

To your first question, I like Permatex Ultra-Copper, but sparingly. Color kinda blends too. For dark/black applications, I use Permatex Ultra-Black.

[Larry M.]

Re: Mounting a Water Pump

After trial mounting I find that the clearance between the pulley and the pump, two places, at the bypass boss and at the heater hose boss, I have over 3/32(drill bit will go) but less than 7/64(drill bit no go). This is a 3839175 pump on a 64 FI car with a double groove pulley. Is 3/32 enough?

[Joe L.]

Re: Mounting a Water Pump

After trial mounting I find that the clearance between the pulley and the pump, two places, at the bypass boss and at the heater hose boss, I have over 3/32(drill bit will go) but less than 7/64(drill bit no go). This is a 3839175 pump on a 64 FI car with a double groove pulley. Is 3/32 enough?

Larry------


I've seen a lot of pump castings with grooves in them at the very locations you mention. This is caused by contact of the pulley with the pump casting. The deep groove pulleys used on SHP small blocks are wider than the standard pulleys used on the vast majority of small blocks. Since the number of SHP small blocks was relatively small, I suppose GM never felt inclined to modify the castings for adequate clearance. If they did, they never got it right.