quick overheat

Just throwing this out there, probably not going to be popular but I had a machine shop check out the first block I got and the cylinder walls were rusted and thin, if I had used that block, done the .30 over I would have had a real bad over heating problem.

Just saying are you sure your block doesn't have thin walls?

I am not sure but the machinist said everything looked good & it was a running motor when i bought it so i don't think it would have much of a chance to rust but maybe...

I did just run the car with the cap off... the level was down & when i started it the level came up & tried to overflow. I noticed small bubbles in the coolant. Thinking back i can't recall the cap ever having pressure against it when i've removed it. But I've never seen steam from the tail pipes or oil in the coolant. Could I have a head gasket that is leaking compression into the cooling system?

biginch=bigfun said:

I am not sure but the machinist said everything looked good & it was a running motor when i bought it so i don't think it would have much of a chance to rust but maybe...

I did just run the car with the cap off... the level was down & when i started it the level came up & tried to overflow. I noticed small bubbles in the coolant. Thinking back i can't recall the cap ever having pressure against it when i've removed it. But I've never seen steam from the tail pipes or oil in the coolant. Could I have a head gasket that is leaking compression into the cooling system?

Click to expand...

Do a quick compression test to be safe.

biginch=bigfun said:

OK, I need to update you & get your input!

I added a bottle of water wetter, changed the radiator cap. set my timing to 12 initial & 38 total. idle set at 900 rpm. I put on a seven blade factory clutch fan. The shroad i built has to be re vamped so i took it off. I have no hood on the car.
...

Click to expand...

Are you running a vacuum advance unit? If not, 12 at idle is your problem. It isn't enough. These things will easily swallow 50 degrees of total advance at idle and love it. Thats easily done with a vac advance. If you're not running one, lock out the distributor at about 34 degrees and get an ignition with a start retard.

Check to see if you have a water pump for racing, 440 source used to send them out without telling you and the fins were shaved down to redue flow at idle.
thant was my problem and solved with a new mopar performance pump.
Ralph

get yourself a coolant pressure tester. Pump about 15 pounds of pressure into the system and watch the gauge to see if it drops. Leave it on there for a good 4 or 5 minutes and see how far it drops. Crank up the engine with the system pressurized and see what happens.

Also, and I know this seems ridiculous but...is your thermostat installed the correct way? We had a customer come in the other day after he replaced his thermostat and his truck was overheating very quickly. I took his word for it and began checking all kinds of things...the last thing I did was pull off the water neck and sure enough the thermostat was upside down. Flipped it over and life was good after that

hendo0601,
right now i have a gutted thermostat/ restricter plate in...

I'm at a bit of a stand-still because i found some broken parts on the plastic body of my thermoquad. So i need to find another thermo or buy a new carb. Frankly, i'm sick of dumping money into the car right now. So i'm weighing my options. Maybe i'm ready to move on to modern mopar muscle?! But its difficult to let go of the car because i've had it since i left home in 1989.

thanks for the input!
have a good 4th of July all! America is the best place & now is the greatest time to be alive!

your prob. is your shroud get rid of the or better yet put it at front of the rad and reverse the POLARITY then get the proper shroud and fan and use the belt drive!!!overheating could also be motor is to tight at bearings or piston to cylinder wall??my car ov erheated when the bearings deteriorated???also after a overheat change oil,inspect oil for silvery deposites!!!also rerout the trans into a cooler??trans can get up to 250 degrees!! good luk

Lets step back one second everyone.

1. When in doubt do a coolant carbon Monoxide test. You can not hide from this test ever, chemicals mixed in a squeeze bottle turn color in the presence of Carbon monoxide gas. We can eliminate the issue of head gasket leak.
2. The radiator should never fill right to the top ever never. Coolant needs to expand.
3. Water pump impeller weld Impeller to shaft to make sure it does not slip.
4. Place a small amount of silly putty or dumb dumb inside the back of water pump housing and make sure their is no more than 60 thousands between the housing and impeller when you press impeller into housing with gasket installed.
5. Drill a 1/8 hole in the thermostat housing and install a verticle pet cock to bleed air.
6. Check the advance springs on distributor to make sure they are not weak or off the posts, this will cause immediate overheating.
7. Vacuum for distributor should be from Manifold vacuum and not ported vacuum above throttle plate. That is only for smog motors.
8. Mechanic timing should be 12 to 14 degrees at idle total 34. With vacuum advance it can be as much as 30 at idle. The vacuum module will take care of this.
9. Did you retighten the head ofter startup.
10. Shroud must cover entire radiator, and open hood will reduce cooling.
11. Thermo quad issues a very good carb. If it runs lean then you know it has to be richened.

3 pages of amazing reading here. The recipe that works for me is:

Copper 26" 4 row, factory clutch fan, 180 superstat, factory shroud, green coolant not filled above 2" below cap, no recovery tank, Mancini Billet thermostat housing.

a simple good way to handle it

Don't sell it. Just let it sit for a week or two and then come back at it with a clear head. The more I fight with my car and overcome the obsticles the more I love it.