ZZ502 Runs HOT!
Safety Car
Joined: Sep 2005
Posts: 4,226
Likes: 643
From: Orange County Ca
Check that your gauge is correct. A infrared temp tool on the stat housing may be a good check.
A lot of big blocks run hot in corvettes. Big engine, small space. Poor under hood air flow, etc.
Check that most outside air is going through the radiator. Install foam around the edges of the radiator.
Thermostat--check by boiling on your stove.
Timing.
Radiator.
Fan.
A lot of big blocks run hot in corvettes. Big engine, small space. Poor under hood air flow, etc.
Check that most outside air is going through the radiator. Install foam around the edges of the radiator.
Thermostat--check by boiling on your stove.
Timing.
Radiator.
Fan.
Last edited by Sayfoo; Nov 6, 2019 at 12:47 PM.
Melting Slicks
Joined: Feb 2003
Posts: 2,330
Likes: 6
From: Long Island NY
Check that your gauge is correct. A infrared temp tool on the stat housing may be a good check.
A lot of big blocks run hot in corvettes. Big engine, small space. Poor under hood air flow, etc.
Check that most outside air is going through the radiator. Install foam around the edges of the radiator.
Thermostat--check by boiling on your stove.
Timing.
Radiator.
Fan.
A lot of big blocks run hot in corvettes. Big engine, small space. Poor under hood air flow, etc.
Check that most outside air is going through the radiator. Install foam around the edges of the radiator.
Thermostat--check by boiling on your stove.
Timing.
Radiator.
Fan.
Race Director
Joined: Jan 2000
Posts: 13,017
Likes: 2,261
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
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2017 C2 of Year Finalist
Are you using serpentine system with the pump that came on it?
JIM
JIM
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Race Director
Joined: Jan 2000
Posts: 13,017
Likes: 2,261
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
That's some awful low timing. What does total look like? I routinely idle at 25-30+ at idle.
JIM
JIM
Tech Contributor
Joined: Jun 2004
Posts: 20,894
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Plug in that vacuum advance canister.
Race Director
Joined: Mar 2016
Posts: 14,395
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From: Napa Valley California
Check the lower radiator hose.
Make sure it has the spring installed and that the hose is not collapsing.
Burp the coolant system and make sure you get out all trapped air in the system.
Hook up the vacuum advance and set the timing.
Make sure it has the spring installed and that the hose is not collapsing.
Burp the coolant system and make sure you get out all trapped air in the system.
Hook up the vacuum advance and set the timing.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Retarded timing at idle will cause the combustion chamber temps to skyrocket. That is what the early '70s cars got for EPA requirements....timed/ported vacuum systems that had ZERO vacuum at idle were used to drive the vacuum advance can on the distributor. So....there was NO vacuum advance until the throttle was cracked open. At idle, the retarded timing caused the engine op temps to climb and that burned off any extra hydrocarbons from the spent fuel charge. But, those systems allowed the manifold vacuum to take over if the engine temps got too hot at idle.
If you are mostly using your car for street use, you NEED vacuum advance and it should be driven off of MANIFOLD vacuum. For most stock Chevy V8 engine, initial timing with advance can vacuum hose removed and blocked should be in the area of 12-15 degrees advanced range.
The only other possibilities for running hot at idle are bad/blocked thermostat, some other blockage in the water flow system (I have heard of a shop rag getting into a cooling system!!), or a malfunctioning water pump. Your engine is heating up so quickly, I suspect the bad/blocked thermostat (installed in proper direction?) or a non-functioning water pump.
If you are mostly using your car for street use, you NEED vacuum advance and it should be driven off of MANIFOLD vacuum. For most stock Chevy V8 engine, initial timing with advance can vacuum hose removed and blocked should be in the area of 12-15 degrees advanced range.
The only other possibilities for running hot at idle are bad/blocked thermostat, some other blockage in the water flow system (I have heard of a shop rag getting into a cooling system!!), or a malfunctioning water pump. Your engine is heating up so quickly, I suspect the bad/blocked thermostat (installed in proper direction?) or a non-functioning water pump.
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Just curiosity on my part, is the new pump high flow and do you have the bypass hose connected?
Oh and are the hoses to the heater core connected,
Do you know what the engine oil temps are when the coolant is at 230*?
Neal
Oh and are the hoses to the heater core connected,
Do you know what the engine oil temps are when the coolant is at 230*?
Neal
Last edited by chevymans 77; Nov 9, 2019 at 09:35 AM.
Thread Starter
Pro
Joined: Jun 2014
Posts: 705
Likes: 96
From: Ventura County CA
So far...Thermostat is 160Deg installed correctly, pump is correct reverse rotation for serpentine, bypass is connected, heater is connected, everything is new.
Leaning toward the timing solution.
Leaning toward the timing solution.