70 Water Pump Attachment

[Bill L.]

I would like to install the water pump before reinstalling the exhaust manifold and alternator. I mention the exhaust and alternator because the one bolt for the water pump also attaches the alternator adjustment bracket as well as the bracket that attaches to the exhaust manifold as well as the alternator for the lower support.

Other than the bolt that goes through and holds the alt. brackets do any of the other bolts have washers? They did not when I took it apart. However, the water pump was a replacement. I have the original #608 ready to go back on.

Lastly, can I go ahead and install the water pump and later on remove the bolt that is used for the alternator brackets and reinstall without causing any leaks?

I am still detailing things so the exhaust manifolds and brackets are not installed. Kind of a crazy question but I do want to start putting things back on as I get them detailed wherever possible.


Thanks!




Bill

[Terry M.]

Re: 70 Water Pump Attachment

The water pump was put on at the engine assembly plant as were the exhaust manifolds. They had no (well at least not many) issues with leaks, but they did specify torque values.

If you have a small block the alternator adjustment bracket goes to a stud, and the stud does not have to be removed to install the bracket.

See the AIM for washers and proper fastener torque and orientation.

[Joe L.]

Re: 70 Water Pump Attachment

I would like to install the water pump before reinstalling the exhaust manifold and alternator. I mention the exhaust and alternator because the one bolt for the water pump also attaches the alternator adjustment bracket as well as the bracket that attaches to the exhaust manifold as well as the alternator for the lower support.

Other than the bolt that goes through and holds the alt. brackets do any of the other bolts have washers? They did not when I took it apart. However, the water pump was a replacement. I have the original #608 ready to go back on.

Lastly, can I go ahead and install the water pump and later on remove the bolt that is used for the alternator brackets and reinstall without causing any leaks?

I am still detailing things so the exhaust manifolds and brackets are not installed. Kind of a crazy question but I do want to start putting things back on as I get them detailed wherever possible.


Thanks!




Bill

Bill-----


The lower waterpump attaching bolts have no washers. The upper driver side position uses a stud. The hex of the stud retains the alternator bracket and the alternator brace. A split lock washer is used between the hex and the alternator brace.

The passenger side upper bolt also retains the lower "leg" of the AIR pump bracket IF you have an LT-1. As I recall, there was no lockwasher between the bolt head and the bracket, but I'm not 100% sure. If you have a 300 hp or L-46, there was no AIR and the bolt definitely used no lockwasher.

[Bill L.]

Re: 70 Water Pump Attachment

It is an L46, 4 speed vert. without A/C.

Well I looked at my AIM again and now I see why I am confused. The page showing generator mount shows a bolts in the upper LH side through both alternator brackets and the water pump.

On the back of the same page the fan mounting detail shows a stud in the picture. Since the engine was delivered with the pump attached, my AIM does not show the detail or part numbers of the fasteners.

When I bought the vette it had headers. If it is a stud, which is was not when I disassembled, that would explain the one non original bolt. It also makes sense given the order of factory assembly.

What is the original stud? I checked a couple catalogs and one says it is different than original and does not need a lock washer.

Thanks for all your help!


Bill

[Joe L.]

Re: 70 Water Pump Attachment

It is an L46, 4 speed vert. without A/C.

Well I looked at my AIM again and now I see why I am confused. The page showing generator mount shows a bolts in the upper LH side through both alternator brackets and the water pump.

On the back of the same page the fan mounting detail shows a stud in the picture. Since the engine was delivered with the pump attached, my AIM does not show the detail or part numbers of the fasteners.

When I bought the vette it had headers. If it is a stud, which is was not when I disassembled, that would explain the one non original bolt. It also makes sense given the order of factory assembly.

What is the original stud? I checked a couple catalogs and one says it is different than original and does not need a lock washer.

Thanks for all your help!


Bill

Bill-----


I was more thinking along the lines of an LT-1 installation when I posted the previous information and I did not provide complete information for a non-LT-1 application like yours.

The stud for the upper driver side water pump retaining bolt position was primarily used for the purpose of the AIR pump brace lower mounting. Without a need for a mounting brace (as with 1970-71 base and L-46 applications), there would have been no need for a stud. So, as far as I can tell, a bolt was used in conjunction with a split lock washer. This bolt was installed at St. Louis and was unpainted. It was a 3/8-16 X 2" standard hex head bolt. I THINK it was phosphate-finished, but I haven't been able to confirm that.

Is it possible that a stud was installed in some cases? Yes, I'd say it's possible, but unlikely.

[Bill L.]

Re: 70 Water Pump Attachment

Interesting for sure. So now do I install the other three bolts and torque as specified or wait until I am ready to install the alternator?

I am concerned with leaks when I fill with coolant.

Obviously the factory seemed unconcerned but that was with freshly machined surfaces.

Thanks again!



Bill

[Joe L.]

Re: 70 Water Pump Attachment

Interesting for sure. So now do I install the other three bolts and torque as specified or wait until I am ready to install the alternator?

I am concerned with leaks when I fill with coolant.

Obviously the factory seemed unconcerned but that was with freshly machined surfaces.

Thanks again!



Bill

Bill-----


If it were me, I would install a bolt in the upper driver side position when I installed the water pump on the engine. I would then torque ALL FOUR of the waterpump bolts to specification, 30 lb/ft. Then, when I was ready to install the alternator bracket and brace, I would remove this bolt and install the slightly longer bolt. Removing and re-installing a bolt at 1 position like this should cause no problem with leakage.