temp sending unit placement on 350 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 06-04-2011, 02:17 PM
Registered User
 
Last photo:
Join Date: Oct 2008
Location: louisiana
Posts: 145
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
temp sending unit placement on 350

hey guys, with all this heat were getting in Louisiana now it brings up some good questions about my 350's cooling system. which place is better to put the sending unit. the driver head, or the intake? will it run cooler with or without a thermostat? and which degree is better? if the sender is in the head does it actually read hotter than if it were in the intake? and how hot is too hot to run a 350?? the reason i ask is that my temp sender is in the head, and it runs a consistant no more, no less than about 220-230. it never shows signs of over heating or even really climbs at idle at red lights or traffic. iv head that a sending unit in a head can read up to 20 or so degrees hotter than if it were in the intake. if this is true then im running just about where i need to be.what brings up my other questions is if it really does run hotter than the intake then what is the right temp for a head?? you see all these head temp gauges that go up to 300 or so, so i believe its true, but whats a good temp to shoot for, or should i just move the sender??? thanks.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-04-2011, 03:37 PM
Member
 
Last wiki edit: Wiring diagram 1953 Chevrolet
Last journal entry: Spare Tire Dent Removal
Last photo:
Join Date: Aug 2003
Location: a little S/E of Nome
Posts: 789
Wiki Edits: 647

Thanks: 6
Thanked 4 Times in 4 Posts
What do YOU feel comfortable with?

If you engine isn't overheating and puking out coolant all over the ground, and its presently in the head. Why do you care where or why someone else's temperature is up at 300.

Temperature gauges are only relative, which means, they DON't work that good, and if they do, only in a narrow range. A mechanical temp guage is about 75 to 90% accurate at the best of times.

So, why sweat it! If its running cool enough for your use, leave it alone. If it isn't go to the bullet proof Wiki in Crankshaft Coalition and read that section over.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 06-04-2011, 08:16 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,654
Wiki Edits: 0

Thanks: 15
Thanked 58 Times in 55 Posts
Honestly it`s a decided preference on which place one puts it. Since it varies, I`ll say why I perfer them in the cylinder head. The head is where all the action is going on, it`s close to the combustion chamber and the valves, this is where all the action is so this is where the heat is.
My trucks sending unit is in the head, it runs no higher than 190 degrees, it`s got a 180 degree thermostat. And speaking of T-stats, one should ALWAYS be used. Why? When one is not in use then there may as well not be a radiator either, because it`s called a radiator so it can radiate heat away.
The engine is running, it gets hot, the thermostat opens, pushing the hot coolant into the radiator, the cooled coolant in the radiator rushes into the engine, cooling it back down, this cooled coolant reaches the thermostat and since it`s temp is below the thermostats opening point it closes. This stops coolant flow, now the hot coolant in the radiator is being cooled down by the oncoming air by the vehicle moving, or if it`s sitting then the fan is cooling it.
Now, remove the thermostat and refill the coolant system, now there`s nothing to stop the coolant flow, it`s on constant cycle, what happens is it can move the coolant so quickly, the radiator doesn`t have time to do it`s job which is to radiate the hot coolant of heat so in turn as you drive the temp gets hotter and hotter and hotter until it runs hot. In other words, the coolant, in terms of time, isn`t in the radiator long enough to cool.
If you running a small block and the cooling system is in good shape and your running around 230 somethings wrong as that is very close to the borderline of running hot. If my vehicle gets over 210 I get uncomfortable. Other things can cause them to run hot or hotter, vacuum leaks which create a lean fuel mixture. Carb set too lean, spark timing set too low and Vacuum advance not working or connected to the wrong vacuum port.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 06-04-2011, 09:50 PM
NEW INTERIORS's Avatar
Believe in yourself !!!!!!
 

Last journal entry: 41 WILLYS FRAME
Last photo:
Join Date: Jul 2007
Location: In My Shop..
Age: 49
Posts: 10,011
Wiki Edits: 0

Thanks: 1,153
Thanked 500 Times in 372 Posts
Did you check your timing ??? Make sure it is right, Also what kind of car you having this problem in? Do you have a fan shroud on it are not... This all makes a difference... The head usually show's hotter then the intake.. I run in the intake.. I don't like it around my headers.. That's me.But it can be ran either way... If your running to much timing it will run hotter. Tell us a little more what you have..

And you want to run the thermostat and the right mixture of coolant..


Where are you in Louisiana ???
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 06-05-2011, 05:01 AM
willowbilly3's Avatar
Member
 

Last journal entry: Body mods
Last photo:
Join Date: Jun 2004
Location: Black Hills, South Dakota
Age: 61
Posts: 1,208
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I never fuss over a cooling system that keeps the coolant inside the system.
I would say never leave out the thermostat, unless its fubar and you are trying to get home or something.
It's very typical for Chevy to run their engines at that temperature. I have been away from the technology for a while but they used to have one fan-stat that turned on the electric fan and it was 108C which equates to around 232F IIRC And they didn't make a cooler one.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 06-05-2011, 06:26 AM
GMCBEAST's Avatar
Registered User
 
Join Date: Apr 2011
Location: Kingsport, TN
Age: 33
Posts: 62
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I usually run a 180 stat and sending unit in the intake, like one said before, I also don't like them around the headers. I'm now in Georgia which is fairly hot, but this is the same setup I ran in S.Florida which is very similar to your climate.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 06-05-2011, 07:00 AM
Registered User
 
Join Date: Aug 2006
Location: Alexandria, VA
Posts: 1,747
Wiki Edits: 0

Thanks: 4
Thanked 64 Times in 62 Posts
I have tried installing the sensor for my mechanical gauge in my Edelbrock intake manifold, and in the passenger side head (driver's side has the sending unit for my electrical gauge). In my case I found there was almost no measurable difference in overall temperature (maybe 5 degrees at most) between the two locations. About the only difference is that in the intake its easier to see the change as the thermostat first opens, because the gauge sensor is right next to the thermostat.

Bruce
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 06-05-2011, 07:56 PM
Registered User
 
Last photo:
Join Date: Oct 2008
Location: louisiana
Posts: 145
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
thanks for all the replies guys. it all helps. my set up is a 350 very mild lunati voodoo cam edelbrock rpm intake, holley street avenger. the block is bored .060 over replacement pistons, fatory compression, running about 8-10 initial timing on an MSD dist. all cooled by an elec fan on an all aluminum radiator.... all this stuffed in a 84 jeep cj7. im currently not running a thermostat cause my old one was shot and this happened at midnight and the parts house was closed. it took me 2 years to rebuild this jeep so i was in a hurry to start it. i want to say it ran close to this temp 2 years ago too. but is a 160 or 180 better? i would say 180, this being the water has longer to cool in the radiator, and im a big believer of running my motors at the right temp. running to cold is just as bad as running too hot IMO. what do yall think?
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 06-05-2011, 08:57 PM
NEW INTERIORS's Avatar
Believe in yourself !!!!!!
 

Last journal entry: 41 WILLYS FRAME
Last photo:
Join Date: Jul 2007
Location: In My Shop..
Age: 49
Posts: 10,011
Wiki Edits: 0

Thanks: 1,153
Thanked 500 Times in 372 Posts
The water in the heads should get hotter faster then the intake..
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 06-06-2011, 06:16 PM
Registered User
 
Join Date: Aug 2006
Location: Alexandria, VA
Posts: 1,747
Wiki Edits: 0

Thanks: 4
Thanked 64 Times in 62 Posts
Use a high flow thermostat, like the RobertShaw.

You could run either a 180 or a 195, since it won't really make much difference on the max temp of the engine. The thermostat sets the minimum opening temp, but the max temp depends on the cooling system's ability to remove heat. You cannot fix an overheating problem by using a lower temp thermostat.

Bruce
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Temp sending unit busterwivell Hotrodding Basics 5 09-16-2008 07:26 PM
Temp sending unit Bart Engine 3 06-23-2008 01:28 PM
Temp sending unit Bart Engine 1 06-23-2008 12:51 PM
Temp Sending Unit? Seon Engine 2 06-23-2003 03:01 PM
Temp. sending unit dodge36 Electrical 10 01-14-2003 10:52 PM


All times are GMT -6. The time now is 10:22 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.