Waterpump question

[MBF]

Last week my pump started leaking so I ordered one from NAPA. I don't know what yr engine is in the '52, but it does have the cast thermostat housing with the bypass. When I got the new pump, there was only a single threaded hole where the bypass elbow bolted to the pump. I threaded my heater shutoff valve into pump, and temporarily blocked off the bypass neck on the thermostat housing while I looked for the other type. Today I removed one of the non bypass type housings from a parts truck, cleaned it up, and painted it. After reading some of the postings from last year on this subject I'm not sure if this is a good idea. Anyone been through this conversion, and did you have overheating issues? Mike

[Young Ed]

Mike napa sold you the wrong pump. They have both types. Have them look it up for something in the late 40s.

[grey beard]

Early engines - pre 52 - had the bypass located above the thermostat, out there where they were visible upon opening the hood. Later engines used an internal bypass that showed up as a small 1/4-inch lump on the front of the head, just behind the water pump - and is also visible by looking down at the head gasket area of the head at the front center head edge area.

Here's what you need to know. Either bypass system will work. You can put an external bypass type thermostat housing and pump on an engine with an internal bypass. Having said that, if you remove an external bypass from an earl engine with no internal bypass built in - you guessed it - you have NO bypass and the engine will not warm up in the correct fashion. Just beware that you have one or the other. Works better that way. JMHO:)

[MBF]

Thanks GB. I pulled the pump I installed last week and NAPA ordered the external bypass type for me. I also pulled the thermostat housing and found the 165 thermo was stuck open which was why she was running cool w/o blocking off the rad partially. I'll get a new thermo, and hopefully have it together Wed nite in time for a Friday cruise. With my homemade PCV system, and a working thermostate I hope to chase away the condensation problem. Mike

[Guest Ole_Rawge]

Ask NAPA about their part number 55-713. It is a NEW (not rebuilt) Airtex pump with a lifetime guarantee. I had read back then that these pumps also had a more modern impeller design and great water flow. They are an internal by-pass type but also have the top water outlet so you can still use the external by-pass elbow. I bought a couple a few years ago and they were only about $60. I heard then that it was a limited run of production, so they may no longer be available, but it is worth looking into.

Maybe someone else has used one of these or know more about it?

[Byronb3b]

On the p15 d24 site look under techcical tips, scroll to the bottom and there is a link for water pump by-pass information, there it's explained with pictures, better than I can, I think the pumps are really the same inside, just different back plates and different opening on the top for the heater hose/ by-pass fitting.

[MBF]

I'm going with the rebuilt ext bypass type, and the next time I need one, I have a good core that I'm going to send out to a known rebuilder. I'm also going with a 165 thermo(I have both the 165 and a 180) to see how it works with the PCV system. Mike

[Powerhouse]

my NAPA doesn't have 55-713 anymore...and the one they do have is $80.

[MBF]

After replacing the non bypass with the bypass type I did a post mortem. I believe that the rebuilt non bypass unit would have been ok as it had the same backing plate setup as the rebuilt bypass pump I got from NAPA. I probably could have made that a bypass using an elbow and short nipple, but the right one is on there now and I'll let the sleeping dog lie. Mike