C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

70 Big Block, normal temp range?

Thread Tools
 
Search this Thread
 
Old Aug 5, 2010 | 09:43 PM
  #1  
BBCorv70's Avatar
BBCorv70
Thread Starter
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2007
Posts: 3,189
Likes: 111
From: Tolland CT
Default 70 Big Block, normal temp range?

My temperature gauge seems to level off around 210 degrees.
Is this normal running temperature?
How do I tell if the fan clutch is failing?
How stiff should it be once the engine is fully warmed?
I think the thermostat is 180, could be 190.
Reply
Old Aug 5, 2010 | 09:52 PM
  #2  
baxsom's Avatar
baxsom
Le Mans Master
15 Year Member
Liked
Loved
Top Answer: 1
 
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
Default

Originally Posted by BBCorv70
My temperature gauge seems to level off around 210 degrees.
Is this normal running temperature?
How do I tell if the fan clutch is failing?
How stiff should it be once the engine is fully warmed?
I think the thermostat is 180, could be 190.
my 72BB has a brand new engine, and oem radiator. When I had the crate motor installed last year I had the original radiator cleaned and then installed an electric fan. Make sure you have a correct reading temp sender. In the hot San Antonio summer mine would idle at 180-190 degrees. I at first used an autozone temp sender and it said 220. I read on here that parts house senders read incorrectly. I bought one from Lectric Unlimited and read their ohm vs temp reading. I verified with their chart that their sender read correctly and installed it. with a 180 degree thermostat the temp gauge never goes above 190.
Reply
Old Aug 5, 2010 | 10:01 PM
  #3  
BBCorv70's Avatar
BBCorv70
Thread Starter
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2007
Posts: 3,189
Likes: 111
From: Tolland CT
Default

Thanks

I'll check into the sender. I have access to a temperature gun which I just point and
pull a trigger, gives the surface temp of what I'm pointing at. Wonder is this may help me determine whether it's running hot?
Reply
Old Aug 5, 2010 | 11:43 PM
  #4  
thatcorvetteguy's Avatar
thatcorvetteguy
Burning Brakes
15 Year Member
Conversation Starter
All Eyes On Me
Photogenic
 
Joined: Jan 2010
Posts: 958
Likes: 88
From: Rexburg Idaho
Default

My 68 BB is .030 over and it runs about 190 with out side temp of 85 and a 180 T-stat.
Reply
Old Aug 6, 2010 | 11:55 AM
  #5  
Easy Mike's Avatar
Easy Mike
Team Owner
Supporting Lifetime
20 Year Member
 
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Default

210 is okay. A bad fan clutch will windmill after the car is at operating temperature and the engine is turned off.

Reply
Old Aug 6, 2010 | 06:16 PM
  #6  
BBCorv70's Avatar
BBCorv70
Thread Starter
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2007
Posts: 3,189
Likes: 111
From: Tolland CT
Default

My fan clutch never seems to really lock up. Even when the car is fully warmed up I can spin the fan without much resistance.

Should the clutch become stiff when the engine is heated up?
Reply
Old Aug 6, 2010 | 06:23 PM
  #7  
mar's Avatar
mar
Burning Brakes
 
Joined: Dec 2007
Posts: 889
Likes: 0
Default

I have an IR temp gun - where should it be pointed to get an accurate reading?
Reply
Old Aug 6, 2010 | 08:45 PM
  #8  
BBCorv70's Avatar
BBCorv70
Thread Starter
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2007
Posts: 3,189
Likes: 111
From: Tolland CT
Default

I assume the temperature sending unit. See if the IR gun reads the same?
Other thought was the expansion tank. Anybody have some other suggestions?
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-1

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-2

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-3

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-4

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-5

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-6

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-7

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-8

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-9

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
Old Aug 7, 2010 | 09:37 AM
  #9  
HamadUP's Avatar
HamadUP
Melting Slicks
Supporting Lifetime
20 Year Member
 
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
Default

Originally Posted by BBCorv70
My fan clutch never seems to really lock up. Even when the car is fully warmed up I can spin the fan without much resistance.

Should the clutch become stiff when the engine is heated up?
The general role is to watch the fan when you shut off the engine (when fully wamed up) if it turns more than 3 revs before it stops, then you have a bad clutch.
Reply
Old Aug 7, 2010 | 09:39 AM
  #10  
HamadUP's Avatar
HamadUP
Melting Slicks
Supporting Lifetime
20 Year Member
 
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
Default

Originally Posted by mar
I have an IR temp gun - where should it be pointed to get an accurate reading?
I point it to the thermostat housing, gives me a pretty accurate readings there, unless you have the chrome one, then your IR gun wont pick up the correct reading because it can't read the temps off a shiny, mirrored surfaces.
Reply
Old Aug 7, 2010 | 01:42 PM
  #11  
chevymans 77's Avatar
chevymans 77
Melting Slicks
Supporting Gold
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Default

Originally Posted by BBCorv70
My temperature gauge seems to level off around 210 degrees.
Is this normal running temperature?
How do I tell if the fan clutch is failing?
How stiff should it be once the engine is fully warmed?
I think the thermostat is 180, could be 190.
Normal temp would be the factory T-Stat setting for that year car

Fan clutch is as others have indicated, check during shutdown

There will be some drag present but you should still be able to spin it fairly easily

verify T-stat to determine temps

Neal
Reply
Old Aug 7, 2010 | 01:45 PM
  #12  
harrin's Avatar
harrin
Burning Brakes
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Nov 2005
Posts: 840
Likes: 19
From: Oshawa
Default

Originally Posted by BBCorv70
My temperature gauge seems to level off around 210 degrees.
Is this normal running temperature?
How do I tell if the fan clutch is failing?
How stiff should it be once the engine is fully warmed?
I think the thermostat is 180, could be 190.
Mine runs around the same temp as yours

Rick
Reply
Old Aug 7, 2010 | 08:26 PM
  #13  
Lemans Blue 69's Avatar
Lemans Blue 69
Racer
 
Joined: Jan 2010
Posts: 348
Likes: 2
From: Lowell MA
Default

For a 69 L46, 210 is the normal operating temp for emissions purposes. Have to assume your 70 is the same. Info came out of the owners manual. I do now run mine at 180.
Reply
Old Aug 7, 2010 | 09:44 PM
  #14  
UBETRUN's Avatar
UBETRUN
Pro
10 Year Member
 
Joined: Oct 2004
Posts: 573
Likes: 0
From: Stafford VA
Default

If these cars are running 190-210, what's the point of a 180 or 190 thermostat?
Reply
Old Aug 7, 2010 | 09:54 PM
  #15  
noonie's Avatar
noonie
Race Director
15 Year Member
 
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Default

Originally Posted by UBETRUN
If these cars are running 190-210, what's the point of a 180 or 190 thermostat?
That's for running in sub zero ambient temps
Reply
Old Aug 8, 2010 | 06:54 AM
  #16  
baxsom's Avatar
baxsom
Le Mans Master
15 Year Member
Liked
Loved
Top Answer: 1
 
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
Default

Originally Posted by UBETRUN
If these cars are running 190-210, what's the point of a 180 or 190 thermostat?
Thermostats do not determine how cold the engine runs, only at what temp does it allow water to circulate.
Reply
Old Aug 8, 2010 | 10:40 AM
  #17  
UBETRUN's Avatar
UBETRUN
Pro
10 Year Member
 
Joined: Oct 2004
Posts: 573
Likes: 0
From: Stafford VA
Default

Originally Posted by baxsom
Thermostats do not determine how cold the engine runs, only at what temp does it allow water to circulate.

I know how a thermostat works and if your car's "normal" operating temp is above the thermostat's opening temp, the thermostat is not doing anything in that application. Other than warming a cold motor up faster, the thermostat is wide open during normal operation.

This is a good thread, saved me from buying a thermostat for my new big block.
Reply

Get notified of new replies

To 70 Big Block, normal temp range?

Old Aug 8, 2010 | 11:30 AM
  #18  
HamadUP's Avatar
HamadUP
Melting Slicks
Supporting Lifetime
20 Year Member
 
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
Default

Originally Posted by UBETRUN
I know how a thermostat works and if your car's "normal" operating temp is above the thermostat's opening temp, the thermostat is not doing anything in that application. Other than warming a cold motor up faster, the thermostat is wide open during normal operation.

This is a good thread, saved me from buying a thermostat for my new big block.
You DO need a thermostat, I remember last winter I was driving on the highway with around 50* ambient temp and the engine temp was WAY too cold! .. I used a 160* thermostat and the engine temp was right at about 160-165*, so I imagine if it didnt have a thermostat it would drop to 150* or so which is just as harmfull to the engine as over-heating.
Reply
Old Aug 8, 2010 | 01:23 PM
  #19  
UBETRUN's Avatar
UBETRUN
Pro
10 Year Member
 
Joined: Oct 2004
Posts: 573
Likes: 0
From: Stafford VA
Default

Originally Posted by HamadUP
You DO need a thermostat
My car will not be driven in the winter.
Reply
Old Aug 8, 2010 | 02:06 PM
  #20  
HamadUP's Avatar
HamadUP
Melting Slicks
Supporting Lifetime
20 Year Member
 
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
Default

then thats another case, as my car is my daily driver all year around.
Reply




All times are GMT -4. The time now is 05:02 AM.

story-0
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-1
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-2
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-3
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-4
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-5
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-6
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-7
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-8
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-9
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE