Well I just joined today and this is my first thread. Hope you all enjoy.

I would like to share some of the information I found out about Mopar thermostat housings and thermostats while checking fitment of a product I make. Some of this information is easy to find but some of it I really had to dig to find. To the best of my knowledge this information is correct and accurate. Please feel free to add to the information, clarify or correct any errors. Also if anyone has pictures that they would like to add that would help clarify any of the information please do so.

First I would like to point out that thermostats are sometimes referred to as a T-stats. Thermostat housings can also be called T-stat housings, water necks or water outlets. It helps to know this when doing searches on forums or at online auto parts stores.
Here are the basics. There are essentially two different water outlet bolt patterns used by all Mopar engines from 1924-2003 . One is the older large size with a center to center bolt pattern of 3.25 inches. This pattern was used on all v8 engines from 1951 to 1978 and all flathead 4, 6 & 8 inline engines back to 1924. The thermostat diameter is 2.49 inches for this size housing. The other water outlet bolt pattern is 2.875 inches. This pattern was used on all slant 6 engines and the newer small block engines made after 1978. The thermostat diameter is 2.125 inches for this size housing. All flathead 4, 6, 8 inline, Slant 6 and V8s made before 1979 use 3/8 inch bolts. V8 Small block engines 1979 and newer use 5/16 inch or metric size bolts.
Things get more complicated. Even though the 3.25 pattern is the same for all v8s from 1951-1978 many of the 1950s water outlets have bypasses built into the housing. This is also true of most of the flathead 6 & 8 inline engines. If you plan to change to a different water outlet on these engines it is important to know what the bypass did and is changing to a non bypass water outlet going to have an adverse effect. Bypasses are used on these engines mostly to keep from having hot spots in the cooling jacket as the engine comes up to temperature because the bypass recirculates the water in the engine. They are also used were the winter temperatures are very cold so the heater warms up faster. In addition some of the thermostats were constructed to work in conjunction with the water outlet’s bypass and use a different size Thermostat. Most of these thermostats are 2.55 inches. Some of the small block v8 aftermarket manifolds have both the 2.875 and the 3.25 bolt patterns which allow you to use either size water outlet. Also not all water outlets use the same size radiator hose.

Can you use Chevy water outlets on a Mopar? The 3.25 inch bolt pattern is also the same as the Chevy v8s and they can be made to work on a Mopar engine. However it should be noted that the recess for the thermostat on Mopar engines is in the water outlet and Chevys are in the intake manifold so using a Chevy water outlet on a Mopar is not a slam dunk. In addition the housing of the Chevy is about 1/4 inch smaller diameter so it doesn’t cover all of the mounting area and looks a little odd. The thermostat size used by Chevy is the same as used with the slant 6 and 1979 and newer small block v8s.

 

Come back and post some more. Your url link doesn't work.

 

Oh wait I think I fixed it.

http://www.coolviewthermostat.com/

 

You even have a video. Cool.

http://www.youtube.com/watch?v=CnVoV...layer_embedded

 

From what I found from 1958 to 1978 all the thermostat housings/waternecks were the larger style. That includes 273 cid all the way up to a 440. In 1979 they went to the smaller size thermostat housing/waterneck. And yes I call it a thermostat housing because it is recessed and that is where the thermostat resides. One easy and cheap way for you to check is to go to an autoparts store and order a waterneck for both sets of dates and compare them. I have big block and small block ones on my cars and even the smaller one on the 1981 Gran Fury.

 

I'm glad you found the video. The large size housing was the same 1978 back to 1924 all engines but the slant 6. My brother has a Cool-View on his 51 Ply flathead 6. I'll try to post a picture of it tomorrow.

 

The only problem I have with you stuff is that your asking us to put a Chevy thermostat on our Mopars. Get those thermostat housings from an auto parts store and redesign some that will use a Mopar stat and even I will buy one.

 

Where do I begin? First, I would not ask anyone to put anything on their car that they did not want to put on their car. Second, the thermostat that is in the Cool-View unit fits about 22 different car manufactures including Dodge. It is not a Chevy thermostat. Third, because the bolt pattern for chevy is the same as Mopar you can use either a Chevy or Mopar housing on top. They will both work. Mopar housings are a little bigger diameter is all. This just gives you more options.
Attached are a couple of pics of my brothers 51 ply flathead 6 with the Mopar unit and a Mopar thermostat housing on top.
Please let me know if you have any other concerns.

 

Then you should change your wording on your website. I still see Chevy Thermostat.

Mopar Cool-View

with 180° F thermostat



Part #: CV-0180-MO
Cool-View thermostat assembly for Mopar engines. Comes assembled with 180°F thermostat installed. Includes o-ring.
Assembly is 2 inches high. Designed to use a standard Chevy thermostat housing. Bolts and thermostat housing not included.
Fits non-bypass type SB & BB Mopar V8 engines, 1964-1975 318, 340, 383, 361, 440. May fit other engines with same thermostat housing bolt pattern.

 

CoolView made me a Mopar one. The thermostat will reside in the bottom like a regular Mopar housing. I will post pictures of it when it comes in and when I put it on my 440.

 

 

The Cool View vender popped up on this site and had Cheby written all over this product. I worked with him taking some measurements and such so he sent me a custom Mopar one. The bottom is milled to fit a Mopar thermostat. His other ones have the thermostat on the top. I got it last night and had a problem with the bolts going through. I have a Mancini pump housing and their billet water neck. The holes on the water neck were off by .050". Today I bought a small 6 buck rat tail file and oblonged the holes towards the outside. Worked like a charm. My new Milodon thermostat can be clearly seen. Now you can see if you have air pockets or possible blown head gasket or faulty thermostat. I will updated you on the progess.

 

very insightful, thanks!!

In search of

CHRYSLER FLATHEAD EIGHT THERMOSTAT HOUSING OUTLET - find lots for 6 cyc, none for 8 yet.

anyone?

 

I just use a thermostat that fails open, Fail Safe I think is a name but it’s been years since I’ve had to buy one.

 

I have a factory spec replacement thermostat, need the housing pls