Water Pump/New 5.5 Head

[jayvee34]

Just received the new Snyder 5.5 head. Engine is still in the car. Removed the old head, then the water pump. Installed the WP in the new head. Tighten the
WP nuts hand tight and spun the fan. Heard a slight scrapping. Tightened the
nuts, (top right 1st.,bottom left 2nd., top Left next then the bottom right).
The WP would not spin, really tight. I loosened the nuts some in the same
sequence and was able to turn it, but was tight. I removed the WP and noticed
the top left stud casting had a rub mark along with the WP impeller edge.
Either the impeller diameter is slightly to big or the stud casting is to thick.
Has anyone has or had a problem like this? I believe a slight filing of the stud
casting would allow the clearance for the impeller to turn without rubbing.
Does anyone have a suggestion other than this? I would be very thankful
to know if I am doing something wrong. "The WP worked great in the old stock
head". John
I doubled the gaskets but no help.

 

[40-A Twins]

I recently installed a new 5.5 head and had to machine about 1/8" off the end of the pump shaft and adjust the impeller position using the shop press.
The old head was worn deeply at the pad where the pump shaft contacts, and shaft length and impeller location had been positioned to align the fan pulley correctly.
Kevin

 

[jayvee34]

Thanks very much. I will check into that, I may have to do the same think.
John