The Stovebolt Site Forums The Shop Area Engine Shop '40 water pump adaptor fit issues...

Hi,

I'm finally getting around to fixing my over heating problem (1940 Chevy with mid 50's 235) and when I get the pump off I see that the adapter plate is not compatible. The pump has a round turbine that fits into a round hole in the engine block, the adapter plate has no such hole.

See photos here:
http://picasaweb.google.com/lh/photo/Dtw4hRIF29e8PvhfwRHang?feat=directlink

http://picasaweb.google.com/lh/photo/RaWyPuw5jYFkdW_Wt5Fgrw?feat=directlink

http://picasaweb.google.com/lh/photo/Cnu1HoHeMym8yp0Zh_bQXA?feat=directlink

The pump installation instructions say that I must use a '41-'52 Harmonic balancer and pump or a '53-'54. Can anyone tell me from these pictures what I do have? (must be a pre 41 or a post 54???)

What does a proper 41-54 water pump look like?

There was also mention of an adapter plate between the pump and the block, which I did not encounter....?

thanks for any assistance,

Doug

The adapter plate you're hearing about is used to relocate the pump higher on the block, and it covers the original hole in the 235 block. It allows the earlier style pump for the 216 and splasher 235 to be installed, which does not have the impeller that extends into the block. The early pump has a rear cover plate, and the impeller is fully contained by the pump housing. The harmonic balancer swap is required because the earlier pump uses a wider belt. It will also be necessary to swap to a wider generator pulley.
Jerry

A water pump from a 53-54/55.1 235 should have a 3/8" pulley. Parts Manual Link.

Doug's images show the late model block and water pump.

The adapters to use the earlier water pumps on the late model block are usually available on ebay from pre68dave, a good 'bolter.

Hoyt

I just recently installed pre68dave's adapter on the '55 235 I installed in my '50 3100. If you follow Dave's instructions, you will have no problem installing it with the correct early style pump. Using hand tools, it took me about an hour. Just pay attention when you are drilling the 2 additional mounting holes you need so as not to drill too deep.

Thanks Drew,

It's nice to hear that it worked out well. What were your overheating problems/symptoms before the plate? My truck overheats in about a mile or so of stop and go.

and, I'm still trying to determine my harmonic balancer pully situation - it is 6 3/4" x 5/8" O.D. but the belt is actually 1/2" wide. Did you use the '55 balancer and was it of similar dimensions?

thanks,

Doug