Topic: Overheat problem new motor

[S76GUY]

PW
Before you tear this thing down, do this.
I am about 95% sure you have an air pocket.
How did you service the radiator?
Just poring the coolant in?
If so you need to try this.
Get a hold of a coolant system flush tool.
Snap-on has one, but try the auto shop first. They are expensive.
It pulls all of the coolant out of the system with a vacuum.
It then allows the system to be serviced with that same vacuum.
It will pull the coolant back into the system.
That will ensure no air pockets.
If you like, send me a PM with you cell number and name.
I will tell you a few things to look for.
Don't jump the gun.
Tony T.

[Clint s]

It really could be an air pocket.  I had an old ford that would over heat,  got it to burp out running the truck up a hill at 45 degree incline and ran it with the cap off for a while..  I tried everything and that did it.  When filling an empty radiator you really should have the thing jacked up in the front to have the cap higher than the rest of the car.  Like above the tool would be the best, but I have had luck just parking it on and incline running it for a few minutes to burp it out.  Air pockets can be stubborn.   Did you check the top hose? If it is higher than the radiator cap you will overheat also. 

[Kevin]

Wait isn't it bad to leave the radiator cap off when it's running?

[pwrcat4000]

Anastasiofan92,
I think he meant temporally.
ClintS,  the cap is higher than the hose.  Talked with tony tonight, great guy, God is probably laughing because with his help I have a plan but if I don't get some shuteye it taint gonna happen.

[78ta]

 Did you check the top hose? If it is higher than the radiator cap you will overheat also.  

Wait. What? 

[S76GUY]

The tool gets used without the car running.
Then you put the cap on and your done.
Tony T.

[pwrcat4000]

the plan didn't work. Pulled the cooling  system down to 28 psi and it held. It hit 260 F on road test after refilling it.

[rkellerjr]

Is the gauge off or are you measuring with something else?  Is the coolant spewing out of the reservoir?  If no, then I'm skeptical that it is overheating.

[S76GUY]

Then you need to go in.

[Clint s]

  Did you check the top hose? If it is higher than the radiator cap you will overheat also. 

Wait. What? 

When any portion of the cooling system is above the level of the radiator/cap  any air in the system will almost always get trapped in that portion of the system,  it can be nearly impossible to get that air out with any consistency, as more air will just come along when the system expands & contracts and it cannot burp out into the overflow tank.
 In a cooling system air is only minimally compressible, after that it acts exactly the same as a solid obstruction does.  So any air in the upper radiator hose will act the same as an obstruction and obviously that will affect the coolant flow in said system...

Good luck finding the culprit, I am hoping it is not too serious.  Keep us posted.

[pwrcat4000]

Went to a old high school friend who is a mechanic and owns his on shop he loaned me the tool that Tony and I talked about used that then road tested took a while but hit 260+ F it was 106 today again so I was really dejected.
I went back to return the tool after updating everyone with the post.
He felt that this just had to be a gauging problem otherwise I would be boiling over at that temp and I was not.
I told him the whole story just as I have all of you and he stated that he just does not believe the temp again.
So of to the parts store where they now no me by name and what car I am there to see about bought a manual gauge and some adapters to make it fit in the block and Walla car is running at ~198 F according to the manual gauge

This was at idle for about 15- 20 min on a 100 + F day.
The t-stat is still out but it did not get any higher 199 adjusted some more timing back in to the motor.
Still at 195 199F.

So what the heck.. road test.

Used this set up

Nice huh!

Off I drove, drove around for a while 2 miles to get out of town to the highway stayed in the 200's F took it up on the highway and hit 229 F after some acceleration to 65 Mph or so. 
After 2-3 min at speed my cruise is not working now (added it to the list) setting just about 230 F.
I came off the highway and it bumped up to about 235 F at the stop sign so I could turn around sat there for a few minuets at idle to see if it would go higher it started going down 234 230.
Headed back to the shop at 65 -70 MPH started creeping up to 235 again.
Got in to the city and it started going down 229 pulled in to the shop shut off the car.

I never got over 239 F

About a min or 2 later after sitting it was at 250 F.
Started the car and let it idle for a few seconds.
Down to 220 shut it off.
I did some other stuff for about 30 min glued the seal back on my shaker painted some grill work car was reading 209 F.
Started it went down to 160 F in about a min then started going up again, so I shut it off.

Pulled the dash cluster in anticipation of replacing my H2O gauge and what do you know.
There was a jump wire on the temp gauge circuit. 
I then remembered doing this like in 1989 because the circuit plastic broke it was a piece of lamp cord, since the gauge works on resistance.
I suspect that this may be to blame since I am fairly sure the lamp cord has more resistance than the original circuit, but I don't really know.

SO..
Should I feel comfortable with those temps during break in oil additives and new internals ?

Do you all think that my assumption is right about the jump wire?

I am also told I am running "a little lean" in the carb and an going to have a pro redo it for me $100 and he will help me tune it.

I still plan to put in the 190 high flow t stat that tony suggested when I can get one in. I suspect that may help as rkellerjr explained.

I have put about 10 miles on the new motor now.

The car still has the gauge taped to the windshield so I will need to rout it through the firewall until I can figure out how to fix the in dash if you all think those temps are not dangerous.

[Clint s]

That is too hot, my car never runs more than 15 to 20 hotter than the t stat I use.  It runs 180 or less with a 160 stat.  I have had it out in 90 plus weather .  Anything over 210 is too hot IMHO

[S76GUY]

Bill
It sounds better.
But I agree those numbers are still to hot.
The temp rise after the car is shut off is normal.
The sender gets heat soaked from the exhaust.
It sounds like your fan is working.
But the radiator may not be giving you enough
cooling across it as I told you. Especially when your driving.
Test the gage with the resistors just like we talked about and get
that working right first.
Then do the temp gun across the radiator and check you temp drop.
You need at least 30 degree drop from the inlet to the out let return to the motor.
Get the 180 degree Hi flow stat I told you about and put that in.
Then get more temp readings.
Tony T.

[S76GUY]

Up date Bill?

[pwrcat4000]

Sorry I had to shorten my vacation.
Waiting on the t-stat to come in. I had to order it, a Mr. gasket hi performance.
I am planing on pulling the rad Saturday or Sunday and taking it to be cleaned (ultrasonic?) Monday. Same with the Carb. Even though the rad is fairly new It has had bars leak in it at one time, due to the diagnosis of the original smoking problem.
Long days at the old hospital 0500-2000 have prevented me from doing anything personal lately.  I will post Monday should be able to free up late next week take the remainder of my time off Thursday and Friday at least that is the plan.