Water pump "exploded"!
Thread Starter
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
Water pump "exploded"!
Well, not exactly... But, without warning, apparently the bearing did explode, cuz not only did the underhood get washed with coolant, but the pully wabbles so badly that it shakes the whole car and I thought at first there must be a couple cylinders that weren't firing.
Anyway, does anyone know off hand if the water pump on a 69 L46 350 SBC is the small one or the long pump? (It looks like the small one to me.)
Thanks in advance!
P.
Anyway, does anyone know off hand if the water pump on a 69 L46 350 SBC is the small one or the long pump? (It looks like the small one to me.)
Thanks in advance!
P.
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
I believe it will be a short pump. Take your old one with you when you go shopping. The best one I could find locally and close to stock appearance for my '77 was a new pump from NAPA. The GM pump is a total pig. I did do some surface and interior grinding to smooth out the casting before painting. mike...
GM pump.
NAPA pump.
GM pump.
NAPA pump.
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
Small block C3 Corvettes all use the short water pump. But there are two short pumps, the change occurred sometime during the production run. Best bet is to take your old pump with you when you go shopping and compare so you get the correct one.
Or you could do a search here (good luck with that) and find threads that give the actual dimensions
Pete
Or you could do a search here (good luck with that) and find threads that give the actual dimensions
Pete
Melting Slicks
Joined: Oct 2001
Posts: 2,064
Likes: 1,382
From: Halifax, Nova Scotia, Canada
If your L46 was using the correct water pump, it will be a short pump with a 5/8" shaft, small bearing, small bolt pattern for pre 1971 pulley/fan.
This pump was used until the end of the 1970 production year.
In 1971 the pump was revised (still short) however with a larger shaft and larger bearing, and larger bolt pattern.
I assume the changes were made due to the bearing failures in the pre 1971 pumps.
I had several failures with the small bearing pump. I finally went with a Stewart pump. Large bearing, large shaft, small bolt pattern to fit 1970 and before fan/pulley.
No failures with the Stewart pump.
P.S. My original water pump bearing failed at 6,500 rpm. Twisted the shaft off and the fan destroyed the rad and shroud.
This pump was used until the end of the 1970 production year.
In 1971 the pump was revised (still short) however with a larger shaft and larger bearing, and larger bolt pattern.
I assume the changes were made due to the bearing failures in the pre 1971 pumps.
I had several failures with the small bearing pump. I finally went with a Stewart pump. Large bearing, large shaft, small bolt pattern to fit 1970 and before fan/pulley.
No failures with the Stewart pump.
P.S. My original water pump bearing failed at 6,500 rpm. Twisted the shaft off and the fan destroyed the rad and shroud.
Racer
Joined: Sep 2012
Posts: 366
Likes: 0
From: washington
I too had the same issue on my 69 SB
but at a much lower speed and not as catastrophic.
Now I'm running electric fan off late model ford 4.6.
Someone on the board had an excllent
write on it with wiring spec
but at a much lower speed and not as catastrophic.
Now I'm running electric fan off late model ford 4.6.
Someone on the board had an excllent
write on it with wiring spec
