Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Nu-Relics Power Windows
American Auto Wire Hellwig Products IncPerformance Rod & Custom
Danchuk Catalog

Username Post: Engine Temperature        (Topic#365438)
"7th Year" Silver Supporting Member
Posts: 61
Reg: 06-29-11
06-05-21 05:07 PM - Post#2821186    

My 65 Bel Air has a 305 engine out of a 86 monte carlo. The engine temp is running at 185 on a hot day under 55 mph. When I speed up it will go to 195 deg. My rpm is around 2000 at 55 with the powerglide transmission. I let it idle and it went up to 210 deg. I put a large fan in front of the car and it stopped heating up but did not cool it down any. I have replaced the radiator core with a new 3 row core, replaced the thermostat and flushed the cooling system. I have replaced the temperature gauge from an electric to a tube type gauge. My sender in in the side of the left head not in the intake manifold. I do not have a shroud on the radiator. My fan is 15" has 6 blades and sits 1" from the radiator. I am thinking of replacing the water pump. I see they make a high flow pump. would it be advisable to install a high flow pump and a 160 deg thermostat? The only pictures of a car like mine with a small block engine with a shroud has a smaller spacer between the radiator and the core support. I have attached a couple of pictures of my car. Any advise would be greatly appreciated.

Attachment: 20210605_201954.jpg (4.12 MB) 2 View(s)

Attachment: 20210605_202004.jpg (3.91 MB) 2 View(s)

Edited by RATHD on 06-05-21 05:13 PM. Reason for edit: No reason given.


"6th Year" Silver Supporting Member
Posts: 619
Loc: Western NY
Reg: 06-15-02
06-05-21 09:32 PM - Post#2821195    
    In response to RATHD

Fine down the road and an issue at idle sounds like you could use a shroud. Air will always take the path of least resistance so if it's easier to recirculate the air you won't get the full effect of the fan pulling through the radiator. The 3 row is pretty deep so high air side pressure drop.


"7th Year" Silver Supporting Member
Posts: 1805
Loc: No. Virginia
Reg: 01-18-13
06-06-21 04:30 AM - Post#2821200    
    In response to RATHD

The cooling system should basically maintain the coolant temp at the thermostat setting (180F, for example) at forward speed (25 mph, or so). At idle/traffic; add about 10%. But the system should return to 'normal' when forward speed is resumed. Temps look mostly normal under the conditions.

A 50/50 coolant mix at 15 psi does not boil until about 265F.

The GM 'idiot' lights did not start to 'illuminate' until around 235F.

A 180F thermostat is recommended for cast iron cylinder heads; 190F for aluminum.

Ignition timing impacts temps. You may 'cool' a little by checking.

Here's a little reading that may be helpful:


Site Ambassador
Posts: 15404

Loc: Baltimore, MD
Reg: 11-27-04
06-06-21 06:34 AM - Post#2821206    
    In response to japete92

Putting a lower temp thermostat will not make the car run cooler. Your cooling system is capable of running a certain temperature for the way it is set up. A lower temp thermostat will only get the coolant flowing sooner. If your system is only capable of cooling the car to say 200 degrees, that is what it will run at.
Heating up while driving is not enough radiator, heating up while sitting still is not enough air flow over the radiator. As long as the components are good, radiator not clogged, water pump functioning properly, etc. A shroud will help pull more air through the radiator at idle. A high flow water pump may help, but I would do the shroud first. Your timing can affect temps as well as having a lean fuel mixture. If the temp tops out at 210, that is okay. You even have a fair amount to go before boil over. If it keeps climbing til boil over you need to do something about it.

Friends don’t let friends drive Fords.

1999 Silverado Z71 4X4 extra-cab short bed
1983 Malibu Fauxmad - tubbed
1978 El Camino Kustomized
1972 Monte Carlo
1957 210 handyman wagon
1957 Nomad sport wagon
1957 Cameo Carrier

Silver Supporting Member
Posts: 499
Loc: West Richland, WA
Reg: 02-05-17
06-06-21 07:19 AM - Post#2821208    
    In response to wagonman100

One other thing that can affect temps is running too lean. I learned that the hard way and burned some valves. It turned out the plug on the back of the carburetor that capped the port for the power brakes (my car didn't have power brakes) was cracked and caused a huge vacuum leak. The engine ran well, and the fuel economy was good (19mpg highway). I did notice that sometimes the high temp idiot light would come on. Anyway, after driving on a rebuilt engine that way for 2 years, it burned some valves. Only then did I look at the plugs and they were way too light.

Super Senior Member
Posts: 5903

Loc: paradise
Reg: 09-05-03
06-06-21 09:59 AM - Post#2821220    
    In response to RATHD

you could get a bigger fan. fan shroud is a must have.

70 L camino, grampa engine, g-force 5 spd, road rage suspension. Pray first before all else fails.

Very Senior Member
Posts: 4826

Reg: 12-29-02
06-07-21 09:00 AM - Post#2821279    
    In response to wagonman100

If that's a stock engine then it's not much engine to keep cool and there should be no temperature problems at highway speeds. I'd also recommend you look at the tuning. Is there a proper mechanical timing curve in it with manifold vacuum advance and is the air fuel ratio OK?

  • wagonman100 Said:
Putting a lower temp thermostat will not make the car run cooler.

It should though, especially while doing 50+ mph. Otherwise, there is something wrong with the ability of the cooling system. The other cause could be the engine or transmission pushing a lot of excess unnecessary heat into the cooling system.


06-11-21 09:04 PM - Post#2821505    
    In response to RATHD

I think the people mentioning timing could be right based on when you speed up the temp goes up. I would look at the timing. It could be that your timing is advancing too much, or not enough. A cooling system should run cool down the freeway and cool itself for the most part at speed, not heat up when going faster. Cooling systems for the most part are for lower speeds.


Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.176 seconds.   Total Queries: 17   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 09:50 AM