Rising temps

[69isfine 10]

I'm in break-in mode with a 69 block, heads, buddybar intake, Carter afb 4bbl. On drives around the city, I am seeing my engine temps creep up to an uncomfortable level. It has not been overly hot weather and I did not have temp issues on the old motor. Any thoughts on why this is happening?  Obvious move is to replace current 2 core with a new rad, but I'm tapped out after the rebuild. 

[barnett468 418]

what was the previous bore?

what is the current bore?

did you increase the compression?

did you set your timing curve to the optimum level?

did you change the exhaust?

did you change the cam?

what is your t stat rating?

what temp is it getting to?

does the temp drop quickly once you are moving around 30 mph or more?

is your rad plugged up?

[Brian Conway 264]

are you re-using the same temp sending unit ?

[69RavenConv 286]

Did you burp the cooling system? Air pockets around the temp sensor can cause it to read high.

[Ridge Runner 1,112]

I let my 351 run on the engine stand for 30 minutes ,temp stayed at 180 and it hit 90* here today  ,i have a 292 comp cam edlebrok heads ,bored 30 over ,11 to 1 compression and the radiator is a 2 row aluminum for a 66 mustang and a 5 blade flex fan ,thing will not over heat even holding 3 k rpms for a short time 

[rwcstang 201]

6 hours ago, 69isfine said:

I'm in break-in mode with a 69 block, heads, buddybar intake, Carter afb 4bbl. On drives around the city, I am seeing my engine temps creep up to an uncomfortable level. It has not been overly hot weather and I did not have temp issues on the old motor. Any thoughts on why this is happening?  Obvious move is to replace current 2 core with a new rad, but I'm tapped out after the rebuild. 

what's at an uncomfortable level? the needle hits the middle of (te|mp)

This link should help you trouble shoot. 

http://www.mustangandfords.com/g00/how-to/engine/mump-1109-how-to-troubleshoot-engine-overheating/?i10c.encReferrer=&i10c.ua=1&i10c.dv=14

[69isfine 10]

On 6/12/2018 at 3:14 PM, Brian Conway said:

are you re-using the same temp sending unit ?

 

On 6/12/2018 at 3:14 PM, Brian Conway said:

are you re-using the same temp sending unit ?

Yes, it's the same unit. Are you think it needs to be changed. 

[69isfine 10]

On 6/12/2018 at 5:07 PM, 69RavenConv said:

Did you burp the cooling system? Air pockets around the temp sensor can cause it to read high.

Yes, it was burped. 

[69isfine 10]

On 6/12/2018 at 1:39 PM, barnett468 said:

what was the previous bore?

what is the current bore? 

did you increase the compression?

did you set your timing curve to the optimum level?

did you change the exhaust?

did you change the cam?

what is your t stat rating?

what temp is it getting to?

does the temp drop quickly once you are moving around 30 mph or more?

is your rad plugged up?

It's a first bore on this block and it's at 30 over. Compression is now 9.5 to 1 with a combination of mild cam and flat top pistons. No change to header set up. I don't have an exact temp but it is uncomfortably close to high. Temp goes back to 60-75% of the gauge range when I get the car moving. How do I check the rad for restricted flow?

[69isfine 10]

On 6/12/2018 at 6:36 PM, rwcstang said:

what's at an uncomfortable level? the needle hits the middle of (te|mp)

This link should help you trouble shoot. 

http://www.mustangandfords.com/g00/how-to/engine/mump-1109-how-to-troubleshoot-engine-overheating/?i10c.encReferrer=&i10c.ua=1&i10c.dv=14

Thanks for the article. I'll check the ideas on my car. 

[barnett468 418]

you need an infra red gun or a numerical temp gauge.

you can remove the rad cap then lower the water level until you can see the tops of the tubes clearly then see if there is any rust in the tops of any of them.

incorrect ignition timing can cause higher than normal temps.

 

[Brian Conway 264]

10 hours ago, 69isfine said:

 

Yes, it's the same unit. Are you think it needs to be changed. 

I asked because the after market temp sending units have a reputation for inaccurate readings.  You state that the hottest your gauge reads is 75% of the dash gauge ?  That is acceptable and I would not be concerned.  When the radiator is spitting, you can smell rad. fluid and the car is stalling those are signs of problems.  A simple AC thermometer will tell you most of what you need to know.  Brian

[1969_Mach1 333]

I would try not to wait for the radiator cap to release fluid and the engine stalling to address a hot running engine issue.  At that point, the concern is engine damage might occur.  Not only head gasket issues, but more severely, there is the possibility of the piston rings collapsing.  Rarely happens, but things to be aware of.

If the temp gauge was 75% toward the hot position, I would definitely address it.  Make certain the gauge is correct, and if so, take some actions to bring the operating temps down.  The operating temps should be close to the temp of the thermostat.  Maybe 10-15 deg hotter than the thermostat at most.  As others have noted, there are many things that can cause a hot running engine.

[barnett468 418]

never, ever, ever, use the gauge as a guide as it does not tell you the exact temp, plus if the temp sender has been changed in the last 45 years, it most likely is reading inaccurately so it could red high or it could read low, but obviously in your case, it is reading higher than it previously was.

[69isfine 10]

I managed to shoot various locations on the engine with an infrared gun. Highest temp was 175. I'm going to install mechanical gauges to get a better reading. I'm told new engines will run hotter til they are worn in. 

The 75% reading seems to be the default when the engine warm and the car is moving. Yesterday, a line up at drivethrough knocked up the reading to just before the 1st line of the H. I think I'll park it and walk in next time. 

[MN69Grande 203]

1 hour ago, 69isfine said:

I managed to shoot various locations on the engine with an infrared gun. Highest temp was 175. I'm going to install mechanical gauges to get a better reading. I'm told new engines will run hotter til they are worn in. 

The 75% reading seems to be the default when the engine warm and the car is moving. Yesterday, a line up at drivethrough knocked up the reading to just before the 1st line of the H. I think I'll park it and walk in next time. 

These reading seem like what I used to get with my stock gauge.  My old engine ran pretty cool at around 165 when cruising in the Spring and was at the 1/2 way point on the gauge, I found 3/4 was about 180, and into the H section was 200.  But I hear people get readings all over the place.  I switch to a digital gauge so I know the exact number.  Put it in a knock off Shelby pod in the center console along with a digital Oil Pressure Gauge.

[barnett468 418]

175 is lukewarm.

 

 

[mwye0627 44]

17 hours ago, barnett468 said:

175 is lukewarm.

 

 

Please be a little more descriptive...

Lukewarm for an engine, or lukewarm to the human touch?

Most information I have found describes "Lukewarm" as being between 98°F and 105°F 

[Brian Conway 264]

The 69 Shop manual describes 175 degrees as ' LOW TEMPERATURE '  So tepid, warm and lukewarm are considered well within operating tolerances.   The ' HIGH TEMPERATURES ' are also within those same tolerances and are often describes as being beneficial.  Brian

[barnett468 418]

On ‎6‎/‎23‎/‎2018 at 11:25 AM, mwye0627 said:

Please be a little more descriptive...

Lukewarm for an engine, or lukewarm to the human touch?

Most information I have found describes "Lukewarm" as being between 98°F and 105°F 

your engine should be from around 180 to 190 at the engine side of the t stat housing. a 180 t stat and proper size cooling system will maintain this range.

an engine would not be considered to be running "hot" until around 210 degrees although this will temp still not typically damage it.