Thermostat bypass

BigSky

 So I’ve been trying to find a suitable plug so that I can block off the thermostat housing and water pump bypass, but I can’t find anything. What have people used?

KustomKreeps

Are we talking permanent or a temp solution as you paint or something?
How large are the holes? threaded? Not having a Hudson engine im unsure as to what they look like.
pipe fittings store should have brass fittings that would do the job.
or if it is something large that is bolted on you can cut a plate. drill holes for the bolts then makeup a gasket and bolt it on. Block off plate done.

If it is something like what a hose would fit over and be clamped down you could just put the hose on and use a suitable bolt in the hose with a clamp to plug it up.

BigSky

It’s around 11/16” & Napa has freeze plugs.  My goal is to put one in the thermostat housing end & the water pump end.  I’ll drill an 1/8” hole to allow some water circulation before thermostat opens.  The way it is now, with a “Standard thermostat” vs Bypass thermostats, I’m told can lead to overheating because there’s always a certain amount never going through the radiator to cool but back into the block instead.  

I had to laugh because as I was searching for freeze plugs on line a few minutes ago, I saw people selling used ones for $5 or more, plus shipping of $5!  Used ones!!!   

Off again to get parts for the ‘37, and maybe a frosty at Wendy’s too...

Jon B

You didn't mention which engine this was for, but you mention a 1937 in your posting, so I'll assume that.

First: I'm not sure whether you've gotten good information or not. I have had a bypass type setup in my '37 Terraplane for years, and have had no overheating problems at all, with it.

Second: if you don't get the info you need on the plugs, be aware that models 70, 71, 73 (business coupe only) and 78 had non-bypass type systems. The thermostat housing and the pump did not have the extra outlet. So the non-bypass pumps and mating thermostat housings are indeed "out there". Often, Hudson vendors have these lying around used, so it might behoove you to contact some of them (just look through the classifieds in the WTN). Possibly a rebuilder will have some in stock. Then, you wouldn't have to look for the plugs because they won't be needed. I can recall seeing some rebuilt pumps for sale, with the outlets blocked off using a pipe plug; this must have been done by some rebuilders, so that the same pump could fit a bypass or (with the plug in place) non-bypass system. My guess is that they drilled and tapped the outlets for the plugs.

BigSky

I’m pretty confident in the information I have received on this topic.  Additionally, here is an old thread which sights the rationale for a plug in the bypass when running a standard (non bypass) thermostat.  If one is able to find the correct bypass thermostat then the bypass does not need to be blocked off. 

https://openforum.hetclub.org/discussion/45902/what-why-is-a-bypass-thermostat


In reference to which vehicles did not have the bypass, all information says it’s the Terraplane, Deluxe & Commercial.  The Hudson Six (series 73), which is the vehicle I have, could come with the bypass, which is how mine came equipped.  Below is a photo from an original Hudson Mechanical Procedure Manual as reference.   Hope this helps & not muddy the waters.

Jon B

I missed the fact that you're running a non-bypass thermostat. In that case, you certainly would have to do a work-around.

I use the standard bypass type thermostat in mine.

BigSky

That’s a pretty cool thermostat, I had never seen one before.  Thanks for sharing!