no thermostat break in? - Pontiac GTO Forum
User Tag List

 
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 02-22-2018, 07:15 PM Thread Starter
 
Join Date: Jul 2017
Location: Winona, MN
Posts: 174
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
no thermostat break in?

Would it be fine to break a new motor and cam in on a test stand without the thermostat in place?
tjs72goat is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old 02-22-2018, 10:47 PM
 
PontiacJim's Avatar
 
Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Posts: 3,562
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 367 Post(s)
Garage
Good question. As long as you have a temp gauge hooked up on your test stand and can monitor the water temp so you can shut it down if it overheats, suppose it would be OK.

But for $5 bucks(?), why would you not install it and not have to worry - you are scarring me. Don't ask me if its OK to run the engine with extra oil in the pan and no oil filter 'cause then I will be scared.

So honestly, not sure. Might help to ensure no trapped air in the system or heads and create a hot spot.
PontiacJim is online now  
post #3 of 9 (permalink) Old 02-23-2018, 10:21 AM
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
The 'no trapped air' idea is a good one. I address that problem myself by drilling a very small hole (1/8" or less) in my thermostats to create a small "bypass" that lets air escape so I get the cooling system full even on a cold engine. The first startup happens with the radiator cap off so I can top things off when the pump starts to move coolant. Air can get trapped in the heater hose that connects to the head (or heads in my case - I connect coolant hoses to both heads and T them) if it's higher than the thermostat.

Bear

BearGFR
Springtown, TEXAS
BearGFR is offline  
 
post #4 of 9 (permalink) Old 02-23-2018, 11:57 AM
 
64GTOConvertible's Avatar
 
Join Date: Aug 2016
Location: NE PA
Posts: 193
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
OK, so a t-stat will prevent water from circulating until the engine warms up. What happens when you have no t-stat? 2 things.

1. The engine will not get up to operating temperature.

or

2. The engine will overheat as the water flows through the radiator too fast to allow cooling.

You won't know which will happen with a new engine. What I would recommend is take the guts out of an old t-stat if you want to run without. But I don't know why you would go through all this trouble. Put in a new t-stat.
64GTOConvertible is offline  
post #5 of 9 (permalink) Old 02-23-2018, 04:07 PM Thread Starter
 
Join Date: Jul 2017
Location: Winona, MN
Posts: 174
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
The guy I work with (engineer) who built the short block and heads, mentioned the no thermostat. I have been slowly finishing the rest of the bolt on components. He builds many engines and also drag races high end cars. I mentioned to him the thermostat and filling with water and air pockets. He said without the thermostat, the fill will allow the air pockets to come out and not be a problem. Once the cam is broke in on the stand, the thermostat will be installed and ready to put in car. I guess I never heard of running without a thermostat either, but I don't have much experience breaking in a new motor either.
tjs72goat is offline  
post #6 of 9 (permalink) Old 02-23-2018, 07:31 PM
 
PontiacJim's Avatar
 
Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Posts: 3,562
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 367 Post(s)
Garage
Quote:
Originally Posted by tjs72goat View Post
The guy I work with (engineer) who built the short block and heads, mentioned the no thermostat. I have been slowly finishing the rest of the bolt on components. He builds many engines and also drag races high end cars. I mentioned to him the thermostat and filling with water and air pockets. He said without the thermostat, the fill will allow the air pockets to come out and not be a problem. Once the cam is broke in on the stand, the thermostat will be installed and ready to put in car. I guess I never heard of running without a thermostat either, but I don't have much experience breaking in a new motor either.
Makes sense, but it seems each person has their own opinion on this even when checking other blogs. It was mentioned that without the t-stat that the temps may slowly climb up around 200 degrees - as your cooling system will only be as good as your radiator. A new engine will usually run on the hotter side because it is "tight." So it is recommended to keep a garden hose ready and watch the temp gauge and if it climbs a bit too high, then hose down the radiator to cool things down OR some use additional box fans in front of the radiator for extra air flow.

I drill 3 evenly spaced 1/8" holes in the outer rim of the t-stat which will also allow trapped air to escape. One blog mentioned he ran his engine at a slight tilt with the front upward slightly to aide in the trapped air to escape.

So I guess this one is your call. Maybe invite your engineer buddy over for some grilling and the first firing of your engine so he can be there to help. A good cook-out just can't be turned down.

Make sure your timing is correct. If it is retarded too much, temps will rise very quickly.
PontiacJim is online now  
post #7 of 9 (permalink) Old 02-25-2018, 07:14 PM Thread Starter
 
Join Date: Jul 2017
Location: Winona, MN
Posts: 174
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
I plan to run this at work on another co-workers test stand. So, the engineer who built the short block will be there to take the lead on the break in. He has way more experience on new engines than I do.
tjs72goat is offline  
post #8 of 9 (permalink) Old 02-25-2018, 07:35 PM
 
PontiacJim's Avatar
 
Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Posts: 3,562
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 367 Post(s)
Garage
Quote:
Originally Posted by tjs72goat View Post
I plan to run this at work on another co-workers test stand. So, the engineer who built the short block will be there to take the lead on the break in. He has way more experience on new engines than I do.
Perfect, then go for it and let us know how it turns out as I am curious myself.
PontiacJim is online now  
post #9 of 9 (permalink) Old 02-27-2018, 07:25 PM Thread Starter
 
Join Date: Jul 2017
Location: Winona, MN
Posts: 174
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
I asked his son who is also an engineer and just started working for us about six months ago. He said they run new engines without thermostats all the time on new break ins and they actually run cooler. That's why they do it.
tjs72goat is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, Lemans & GTO Complete Engine Compartment Discussion

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Thermostat Josh P Whitefish 1964-1974 Tempest, Lemans & GTO Complete Engine Compartment Discussion 1 12-26-2017 11:35 PM
thermostat Topkat 1964-1974 Tempest, Lemans & GTO General Discussion 8 02-12-2011 09:41 PM
thermostat help AlanSr Service, Maintenance and Technical Discussion 17 10-09-2009 07:07 AM
Thermostat The intimidator Engine Discussions 11 01-30-2009 05:19 PM
160 Thermostat cpowell Engine Discussions 17 07-10-2007 10:30 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome