57 Water Pump Outlet

[Wayne Preston]

Pertaining to my 1957 which has an EL block, is the nipple on the heater hose outlet from the water pump 5/8" or 3/4"? Is it curved or straight? Page 54 of the judging manual indicates that on the 1957 it is 3/4", yet my hoses (which I believe are correct) are 5/8". Any help or history on this would be appreciated.

[Joe L.]

Re: 57 Water Pump Outlet

Wayne-----

1955-sometime in 1958 waterpumps used a heater fitting which was 3/8" NPT and had a nipple for 5/8" heater hose. The nipple end was curved about 20-30 degrees.

[Robert Willis]

Re: 57 Water Pump Outlet

Having been around 1955 to 57 Passenger cars for a while I have allways found that the 55 and 56 265 have the smaller heater hose while in 57 the 283s have one large and one small hose. The 265s were 3/8s pipe thread while the 283 water pump was 1/2 inch pipe thread. Early 57 Vettes may have been ???????

http://members.kos.net/willisb/vette.html

[John H.]

Re: 57 Water Pump Outlet

I believe both heater hoses on 57's were 5/8" I.D. (mine were); the change to 3/4" I.D. for the core-to-water pump hose didn't occur until sometime in '58.