Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Engineering/Technical
Engineering/Technical Ask technical questions about cars. Do you know how a car engine works?
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools Search this Thread
Old 08-04-2008, 10:59 AM   #1
fasthauler
AF Newbie
 
Join Date: May 2007
Location: Quartz Hill, California
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Drilling Hole In Thermostat

I read somewhere about drilling a small hole in the thermostat to help it bypass. I can't remember where I saw it. Does anybody have any information about such a procedure?
fasthauler is offline   Reply With Quote
Old 08-04-2008, 01:16 PM   #2
UncleBob
AF -Advisor
 
Join Date: Feb 2006
Location: Seattle, Washington
Posts: 1,482
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Drilling Hole In Thermostat

nothing too difficult, you drill a small hole in the plate that is the outer area of the valve

It is usually to help bleed the system when you don't have the right equipment to fill/bleed the system or it is used as a very poor bandaid when an engine is overheating for other reasons, such as a blown head gasket.

As a bandaid, it doesn't really "fix" anything
__________________
life begins at 10psi of boost

Three turbo'd motorcycles and counting.
UncleBob is offline   Reply With Quote
Old 08-04-2008, 02:20 PM   #3
shorod
SHO Off
 
shorod's Avatar
 
Join Date: Jun 2004
Location: Cedar Rapids, Iowa
Posts: 10,635
Thanks: 67
Thanked 280 Times in 274 Posts
Re: Drilling Hole In Thermostat

If the thermostat mounts in the block on its side, then place the thermostat with the hole (should you decide to drill one) up. That will help bleed the system of air.

-Rod
shorod is offline   Reply With Quote
Old 08-04-2008, 06:49 PM   #4
MagicRat
Nothing scares me anymore
 
MagicRat's Avatar
 
Join Date: Dec 2003
Location: City of Light
Posts: 10,700
Thanks: 12
Thanked 79 Times in 74 Posts
Re: Drilling Hole In Thermostat

Some thermostats actually are made with a tiny hole in place as specified by the manufacturer, for certain engines (I forget the model) which are prone to have air pockets when filling.
MagicRat is offline   Reply With Quote
Old 08-05-2008, 12:39 PM   #5
bobss396
AF Enthusiast
 
bobss396's Avatar
 
Join Date: Jul 2004
Location: long island, New York
Posts: 1,347
Thanks: 0
Thanked 0 Times in 0 Posts
Send a message via AIM to bobss396
Re: Drilling Hole In Thermostat

Here's a real old timer trick. The old Zerex antifreeze cans were metal and under the cap was this punch-out cap. If you carefully removed the cap, it would fit into any thermostat housing. We would drill holes in them and that regulated how hot or cool the car ran. We did it mainly on stock cars.

Bob
bobss396 is offline   Reply With Quote
Old 08-05-2008, 04:16 PM   #6
534BC
AF Enthusiast
 
Join Date: Jan 2006
Location: Babylon
Posts: 946
Thanks: 0
Thanked 1 Time in 1 Post
Re: Drilling Hole In Thermostat

Doesn't every thermostat have a tiny hole?
534BC is offline   Reply With Quote
Old 08-06-2008, 06:00 AM   #7
KiwiBacon
AF Enthusiast
 
Join Date: Jul 2006
Location: Otago
Posts: 849
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Drilling Hole In Thermostat

Quote:
Originally Posted by 534BC
Doesn't every thermostat have a tiny hole?
The ones in my vehicles all do. Must be some that don't though.
KiwiBacon is offline   Reply With Quote
Old 08-06-2008, 11:09 AM   #8
MagicRat
Nothing scares me anymore
 
MagicRat's Avatar
 
Join Date: Dec 2003
Location: City of Light
Posts: 10,700
Thanks: 12
Thanked 79 Times in 74 Posts
Re: Drilling Hole In Thermostat

Quote:
Originally Posted by KiwiBacon
The ones in my vehicles all do. Must be some that don't though.
All the new stats I have installed in my vehicles I have owned over the years (more than 20 cars and trucks) have not had this hole.

Mind you, this has been almost entirely older American cars. I have not changed a stat in a car newer than '91, so things may be different these days.
MagicRat is offline   Reply With Quote
Old 08-06-2008, 02:57 PM   #9
curtis73
Professional Ninja Killer
 
curtis73's Avatar
 
Join Date: Nov 2002
Location: Penn Hills, Pennsylvania
Posts: 3,561
Thanks: 0
Thanked 9 Times in 9 Posts
Re: Drilling Hole In Thermostat

Some stats have holes, others don't. The only time a hole helps bleed air is when you're filling the engine. All other times, the thermostat opens which lets air through.

Drilling a hole can affect how quickly the engine warms up, but if you block the bypass, no hole you can drill will be big enough to replace a bypass.

So, drilling a hole is mostly pointless. It won't prevent overheating, it doesn't improve flow, and other than when you're filling the engine from empty it has no real reason for being there.
__________________
Dragging people kicking and screaming into the enlightenment.
curtis73 is offline   Reply With Quote
Old 08-18-2008, 11:47 PM   #10
fasthauler
AF Newbie
Thread starter
 
Join Date: May 2007
Location: Quartz Hill, California
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Drilling Hole In Thermostat

The reason I asked the question was the fact that I put an Edelbrock high flow water pump in and they have a tendency to hold a regular thermostat closed due to this added water volume. You need to put a high flow thermostat in to help alleviate this problem. All of the high flow thermostats were 160 degrees and this keeps a 460 to cool for optimum performance, so I was trying to find a way to put a stock 190 thermostat in. I had read about drilling a hole in a stock thermostat to help it bypass so the added water volume would not hold it closed, but couldn't remember where I read it. Thanks for all of the responses.
__________________
Gary 1986 T-Bird 3.8L V6, 1977 F250 460 Hauler
fasthauler is offline   Reply With Quote
Old 08-31-2008, 12:04 AM   #11
partsmgn
AF Newbie
 
partsmgn's Avatar
 
Join Date: Apr 2008
Location: saskatoon
Posts: 74
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Drilling Hole In Thermostat

Why not try to use a fail-safe stat in it? These are designed to stay open and never stick shut. You can get them in any temperature and since you are afraid of the pressure keeping the stat shut try one of these fail-safe stats. They cost about 12 bucks or so.....
partsmgn is offline   Reply With Quote
Old 08-31-2008, 12:39 PM   #12
fasthauler
AF Newbie
Thread starter
 
Join Date: May 2007
Location: Quartz Hill, California
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Drilling Hole In Thermostat

I had never heard of the fail safe thermostat until you responded to this post. I googled it and came up with the MotoRad website. They have a video demo that you can download. I downloaded and watched it. It is a very interesting concept, but I believe that you would have the same problem with the high water volume holding it closed. It functions the same as a regular thermostat in that it opens against the direction of flow of the water and the pressure and volume from the water holds the darn thing shut. The high flow units have a v-notch that allows a small amount of coolant to flow even when cold and the spring is 50 percent stronger and allows for proper opening and closing of the thermostat even under high pressure and volume applications. You couldn't get a high flow over 160 degrees until recently and that was the problem. Now it seems like every body is making the in several temps, so the question is now mute. Thanks for the response, Gary
__________________
Gary 1986 T-Bird 3.8L V6, 1977 F250 460 Hauler
fasthauler is offline   Reply With Quote
Old 03-24-2011, 05:03 PM   #13
EdEveridge
AF Newbie
 
Join Date: Mar 2011
Location: Spring, Texas
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Drilling Hole In Thermostat

In my case, using a remote thermostat housing, There needs to be some leakage through the thermostat in order for the hot water to get there and caus the thermostat to open. Without a hole in the thermostat, no fluid flow so that the cold water near the thermostat does not circulate and stays cold. An alternative would be a bypass in the thermostat housing.
EdEveridge is offline   Reply With Quote
 
Reply

POST REPLY TO THIS THREAD


Bookmarks
Go Back   Automotive Forums .com Car Chat > Engineering/Technical

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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



All times are GMT -5. The time now is 07:35 AM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts