CHRIS CRAFT COMMANDER FORUM ® .......A photo-intensive technical reference file and ongoing newsletter regarding the original fiberglass Chris-Craft Commander series. This is an independent not-for-profit and non-commercial web site, not affiliated with the Chris Craft Commander Club ~~ or ~~ Chris-Craft Corporation. Our mission here is to "have fun and share information" about the Commander series (and those associated fiberglass boats on the Chris-Craft family tree) for your individual personal use, and by doing so help promote the good name of Chris-Craft, and help preserve, restore, and appreciate Chris-Craft boats. The main reference feature is the ever expanding MASTER INDEX File which contains what we believe to be the world's largest collection of documentation photos and technical information on the Chris-Craft Commander line of boats, (like these original brochure scans, featuring the iconic first 38 Commander styled by Fred Hudson, and many of the great Dick Avery renditions that followed) , (a huge collection of Chris-Craft 427 tuning and specification information), and a few words about how to use the forum.

We extend to you a cordial "WELCOME ABOARD !" Come on in, make yourself at home, we are a friendly group of enthusiasts, and we also appreciate the classic Chris Craft Roamer, Corsair, and Lancer boats too , as they are all on the same family tree and share much in common ! Just start by posting a note introducing yourself to the group, that's all it takes here (we don't ask for or retain any personal information here, because our intention is to just "have fun and share information".

This forum is registered as


427 Thermostat ( Closed Cooling 163 - degrees )

November 25 2011 at 5:47 PM
Paul  (no login)

Response to 427 closed cooling system overheating issues ( remove that EGR system ? )

As noted eleswhere in this thread, the CC 427 operators manual indicates the desired temp range for the standard cooling (no antifreeze or heat exchangers) is 130 to 150 degrees, which is mighty cool by motor standards. This would seem too cool for proper combustion, etc., but the motor is set up to run that way and many have lasted 40+ years running like this. The compression, carb, plugs, etc., are all selected for good running and longevity under this condition, strange as it may seem.

The Closed Cooling System (with antifreeze and heat exchangers) is design to run from 163 to 180 degrees, which still is mighty cool by automotive standards, but the motor isn't in an auto!

I am converting from Closed to Standard cooling and I am looking at my circulation pump where the thermostat is housed. I pulled the thermostat and put it on a wire brush wheel to clean it up gently and it looks bran new. My 427 project is somewhat custom due to different components in the cooling system (different exhaust logs and risers) and I'm also going to be producing a little more heat than usual, so I'll be most likely experimenting with both thermostats looking for the best running temp. In order to assure the t-stat is working, I put it in a pan of hot water today and doublechecked everything with my trusty pyrometer.

The original thermostat is a very nicely done heavy brass unit that looks like it will last forever. The company is apparently no longer in business.

The notation on this CLOSED COOLING THERMOSTAT reads as follows:



(On the tip of the thermostat there are some other numbers)

163 A704

Here we go with the heat, we're at 153 and nothing is happening yet.
[linked image]

As the temp went up the thermostat started to open slowly, here it is nearly full open.
[linked image]

When it was clear the thermostat was fully open I pulled it out and dried it off to take
a look. Here it is, still quite hot.
[linked image]

I put it back in the water and watched it cool slowly as the water cooled down.
It is functioning perfectly.
[linked image]

I will start my water testing with this thermostat just because I have it and it will
serve as a baseline for all sorts of temperature readings on my custom application.
I am now hunting a standard cooling thermostat to keep on board in the event my water
testing shows the motor is running too hot.



 Respond to this message   

Contact the Chris Craft Commander Forum

©2005, ©2006, ©2007, ©2008, ©2009, ©2010, ©2010, ©2011, ©2012, ©2013, ©2014, ©2015, ©2016, ©2017, ©2018, Chris-Craft Commander Forum, Inc., ®, also known as and the Chris Craft Commander Forum, Inc.; Information and intellectual property on this not-for-profit non-commercial site may be copied for individual personal use, but any other reproduction or use requires written approval. Any entity who mines this site for names, material, or their other commercial/financial benefit in any way is subject to copyright and intellectual property law; the integrity of this site will be aggressively protected. The material here is for individual personal use and is not to be otherwise used or reproduced. Chris Craft is a registered trademark of Chris-Craft. Neither Chris-Craft nor any subsidiaries of Chris-Craft shall bear any responsibility for the content, comments, or advertising. Chris-Craft Commander Forum, Inc., is independent from Chris-Craft Corporation, and not affiliated with the Chris-Craft Commander Club in any way; it is an independent educational-based not-for-profit entity that is intended to share free information and have fun. Copyright/trademark/sales mark infringements are not intended, or implied.