Thermostat housing from NAPA?

[50farmtruck]

I found this on NAPA's site today & wondering if it will work on our engines. Part # 440180. Only measurements are: Outlet I.D. : 1.23"

Outlet O.D. : 1.64". I'm in need of a new one & this looks interesting but expensive at $50+.

Bryan

Edited June 1, 2011 by 50farmtruck

[NiftyFifty]

not to hijack..but my 50 has that straight t-stat housing but it never had a thermostat....in a non pressure system like my 50 should I be running one anyway...or seeing as it never sees winter am I fine to run it wide open?

Sorry to hijack, but as for your question you need to find out what the bolt holes are centre to centre first, also the height...it might not be tall enough for your stock hose?

[50farmtruck]

Yeah, the bolt spacing is my big question. Problem is, I'm sure they'll have to order the thing just so I can compare. I'm running in to that a lot with this project. So far they've been pretty cool about it but I don't want to push my luck.

Bryan

[Dave72dt]

Yes, a thermostat is important. It's designed to bring the engine up to optimum temperature quickly and regulate coolant flow to maintain it at least that warm. It does not prevent the motor from getting hotter than it's setting.

[Reg Evans]

Bryan, Is yours an internal bypass or external bypass engine? I have one of each with your name on them.

Reg

[HanksB3B]

It's about the paint.

Hank

[Reg Evans]

On the housings or the hood ....

[NiftyFifty]

Yes, a thermostat is important. It's designed to bring the engine up to optimum temperature quickly and regulate coolant flow to maintain it at least that warm. It does not prevent the motor from getting hotter than it's setting.

But doesn't that create pressure in the system? My style of rad doesn't allow for pressure as there is no over flow tank, and also a cap that's not designed for pressure either....when I took the housing off my project truck there wasn't one, and when I switched rads and housings from my parts truck it didn't have a t-stat either....I know in a normal later vehicle it has to have the thermostat...but I have doubts this sytem needs them

[Dave72dt]

Internal engine pressure, not radiator pressure and it really shouldn't create much of that. The radiator cap regulates the radiator pressure and after the thermostat starts to open, system pressure. The space at the top of the radiator is your expansion area and why you never fill them to the brim. It'll just puke out the extra.

Modern cars and cooling systems have thermostats in them for the same reason the older ones did, to bring them quickly up to optimum operating temp. We have chokes, manual or automatic, newer cars have computers to change the fuel mix for cold or cool engines.

Water cooled engines without thermostats indicate insufficient cooling capacity which could be from a variety of reasons and should be repaired. JMO

Edited June 1, 2011 by Dave72dt

[TodFitch]

Internal engine pressure, not radiator pressure and it really shouldn't create much of that. The radiator cap regulates the radiator pressure and after the thermostat starts to open, system pressure. The space at the top of the radiator is your expansion area and why you never fill them to the brim. It'll just puke out the extra.

What he said.

But I'll add that your vehicle came from the factory with a thermostat so the engineers that designed your truck thought it was a good idea. Heck, even my 1933 with its "unpressurized" cooling system came from the factory with a thermostat.

[NiftyFifty]

What he said.

But I'll add that your vehicle came from the factory with a thermostat so the engineers that designed your truck thought it was a good idea. Heck, even my 1933 with its "unpressurized" cooling system came from the factory with a thermostat.

Funny both trucks would be without one, and I ran mine last summer without and it never seemed hot at all, even on some pretty hot days. Anyone have a part number for the corrct one without the external bypass? Something like a 140 deg?

Anyway...OP needs a external bypass I have one you could have for free..but you would have to pay shipping...which might be high from my neck of the woods...not to mention our postal service may be on strike soon...then I'm really gonna be PO'ed as I'm waiting for my rebuild parts from the States

[TodFitch]

...Anyone have a part number for the corrct one without the external bypass? Something like a 140 deg?...

The external by-pass stuff did not happen until after my car was built, so my car uses one that is probably what you are looking for. I happen to be running a 160F in mine, the parts I look for in the store are:

Stant 13476 Reverse poppet thermostat

Stant 29706 Economy model

Tru-Temp 651

NAPA THM 91

[YukonJack]

I found this on NAPA's site today & wondering if it will work on our engines. Part # 440180. Only measurements are: Outlet I.D. : 1.23"

Outlet O.D. : 1.64". I'm in need of a new one & this looks interesting but expensive at $50+.

Bryan

It was my understanding that the thermostat housing from a 70's-80's 318 was the same if you have internal by-pass. Should be a lot cheaper, but compare them first to be sure it will work.

[Dave72dt]

Thermostats do not make an engine run hot unless they stick closed. It's good that it never ran hot but it also may have never reached optimum operating temp. Optimim on these engines was generally in the 160 -180 degree range, quite a ways from the boiling point.

Newer engines are often found running in the 195 degree range, much closer to boiling. Another reason for the high pressure caps is it raises the effective boiling point of the coolant higher.

[TodFitch]

It was my understanding that the thermostat housing from a 70's-80's 318 was the same if you have internal by-pass. Should be a lot cheaper, but compare them first to be sure it will work.

I believe it. I vaguely recall that the thermostat gasket and thermostat for my 1963 D200 with a 318 was the same as for what I use in my 1933.

[50farmtruck]

Thanks Reg! Mine must have an internal bypass as it is just the simple spout. No extra ports. What is that all about anyway? I am totally unfamiliar with the bypass deal. Here's a picture of what I have. Took it to work & bead blasted it today. it's even worse than I thought. Looks to be a little taller than the one you've got Reg. It may work though. I'll send you a pm.

Thank you again!

Bryan

[Merle Coggins]

Look down behind the water pump and see if there's a bump on the front of the head. If it's there that confirms that you have an internal bypass head. Then you'd have to assume that the block and water pump have the matching ports to complete the bypass system.

Merle

[50farmtruck]

Yup, looks like I bumped my head. So what is the bypass for anyway? Is it a fail safe in case the pump goes bad while driving?

Bryan

[TodFitch]

Yup, looks like I bumped my head. So what is the bypass for anyway? Is it a fail safe in case the pump goes bad while driving?

Bryan

No, starting in 1934 and on the premium models thereafter for a dozen or so years, the bypass style thermostat was fitted. Basically coolant is always flowing past the thermostat which directs the coolant either back into the water pump if cool or into the radiator if hot. If working properly it ought to circulate water through the block better when the engine is cold.

I don't think the effect was significant or you'd see it on cars today.

The internal bypass system has a small passage from the block to the suction side of the water pump to get coolant to circulate before the thermostat opens. However you have flow through that even after the engine warms up which decreases the cooling capacity of the system a little. Probably not significant either.

So it was just another of Chrysler engineering's great but unnecessary ideas like left handed threads on the wheels on one side of the car.

[Don G 1947]

50farmtruck,

I may have what you are looking for (used of course). If you are still looking for one contact me at jackofalltrades101947@yahoo.com and I will look around for it.

Don

[Merle Coggins]

Tod is correct that it allows coolant to flow through the block before the thermostat opens. With the thermostat closed there is still a small amount of coolant that will circulate for a more even, and faster, temperature rise throughout the block. However, it isn't just a gimmick used by Chrysler engineers. Modern diesel engines still incorporate a bypass system in their thermostats. In fact, in some diesel engines if you remove the thermostat you allow the bypass circuit to be open all of the time and the engines can overheat because it's easier for the coolant to recirculate through the bypass circuit than to return back through the radiator.

The earlier Chrysler flatheads utilized an external bypass system. These are identified by the larger thermostat housing that has a small jumper hose connecting to the top of the water pump, hence "external bypass". Then, around 1950, they began to introduce an internal bypass system. These engines have a more modern looking thermostat and housing, like you have, and that little bump on the head. Under that bump is a port that matches up to another port in the block that redirects the coolant flow back into the water pump. Since it's all on the inside it's "internal bypass".

Merle

[ggdad1951]

Thanks Reg! Mine must have an internal bypass as it is just the simple spout. No extra ports. What is that all about anyway? I am totally unfamiliar with the bypass deal. Here's a picture of what I have. Took it to work & bead blasted it today. it's even worse than I thought. Looks to be a little taller than the one you've got Reg. It may work though. I'll send you a pm.

Thank you again!

Bryan

if no one has a good for you, I'm pretty sure VPW has them. Yours is just like mine, I got a 180° thermostat from NAPA and it works just fine.

[50farmtruck]

Thanks for all the information gentlemen. I love learning this stuff but it only strengthens my wife's argument that I'm obsessed. Hey, you can't know to much about your vehicle right?

Don, thank you for the offer & I'll let you know if I still need one. I really appreciate it.

Bryan

Edited June 3, 2011 by 50farmtruck

[NiftyFifty]

No, starting in 1934 and on the premium models thereafter for a dozen or so years, the bypass style thermostat was fitted. Basically coolant is always flowing past the thermostat which directs the coolant either back into the water pump if cool or into the radiator if hot. If working properly it ought to circulate water through the block better when the engine is cold.

I don't think the effect was significant or you'd see it on cars today.

The internal bypass system has a small passage from the block to the suction side of the water pump to get coolant to circulate before the thermostat opens. However you have flow through that even after the engine warms up which decreases the cooling capacity of the system a little. Probably not significant either.

So it was just another of Chrysler engineering's great but unnecessary ideas like left handed threads on the wheels on one side of the car.

Don't get me started on those L/H threads..OMG....I snapped 3 withthe breaker bar before I had a moment of clarity...thankfully I was tossing all that old stuff anyway

[John-T-53]

if no one has a good for you, I'm pretty sure VPW has them. Yours is just like mine, I got a 180° thermostat from NAPA and it works just fine.

Yes. I got a new (used) housing from VPW after about a year's search elsewhere. When in doubt, I always call them first and start from there. They're pretty helpful on the phone.