Overheating Help BB guys~!

[mikewarme]

Ok here we go 69 3/4 ton factory 396

Has correct fan shroud
Has new radiator copper and brass 4 row
rebuilt engine with barley 1000 miles
Edelbrock performer manifold
Rebuilt quadrajet by holley
MSD electronic distributor
Has a New old stock Carter rebuilt water pump

Overheats mostly from hot weather and idiling like in a drive thru

1. The fan blade sits in the shroud. Should'nt it be 1/2 way in and 1/2 way out of shroud for maximum cooling?

2. I've tried running without a t-stat and now have a 180 just to try

3. How do I verify there is enough water flow. I can see it trickling thru the radiator slowly. And increases a little when i give it gas
3.5 Green antifreeze close to a 50/50 mix with distilled water
4. Should I do a compression test? I guess I will

5. Help!!

6. Could timing have a bearing?? I do have a torque type of cam. It's a mild one. What is your favorite way to time these motors.



Please ! =)

Mike

[67swb72klb]

how hot is it getting
check guage for proper reading
check timing also

[mikewarme]

Originally Posted by 67swb72klb

how hot is it getting
check guage for proper reading
check timing also

Havent put infared but gets so hot the cab heats up and the core hasnt even been hooked up yet! Oil pressure goes down a little as the oil thins more.

Timing with vacuum advance on is about 4degrees BTD. I have tried it in a few places all seems to overheat. Maybe she's running too lean?? Seems to run nice. I had a guy do a effiency tune for me. He leaned the metering rods and changed the springs and put the distributor on a degree machine.

[geezer#99]

Lean and retarded timing makes heat. Bump your timing up to 12-14 degrees.
How new is the quadrajet. Some can be easily richened with the apt.
Do you use a stock overflow tube on the rad with an open system or do you have a closed system.
When it overheats what does it do? Start puking on the ground!!
Do you have a coil in your bottom rad hose?
Your distributor was recurved. Got specs!
When it's idling can you feel air being drawn thru the rad? A piece of paper should be sucked to the fins at an idle.

[mikewarme]

Originally Posted by geezer#99

Lean and retarded timing makes heat. Bump your timing up to 12-14 degrees.
How new is the quadrajet. Some can be easily richened with the apt.
Do you use a stock overflow tube on the rad with an open system or do you have a closed system.
When it overheats what does it do? Start puking on the ground!!
Do you have a coil in your bottom rad hose?
Your distributor was recurved. Got specs!
When it's idling can you feel air being drawn thru the rad? A piece of paper should be sucked to the fins at an idle.

12-14 with vac advance connected?
Nothing is connected to the overflow tube. I haven't let it get hot enough to puke! Just at the first line on the right of the guage
No coil in the hose. The hoses get very ridgid when it's hot
Yes Air sucks thru, I tried that.
I still don't think there is much water moving.Im going to take upper hose off and see the volume that pumps through

Mike

[70monte]

What about your fan clutch? A working fan clutch is a must for proper cooling, especially at idle. I would put a new one on unless it already is new.

It could also be your timing. I had a similiar issue after the 396 in my 70 Monte Carlo was rebuilt. It turns out that the cam was installed 4 degrees advanced and was causing my overheating issues. Had the cam installed correctly and no more problems.

Wayne

[Dunenutt]

Fan clutch bad?

I had to install a severe duty clutch on my .060 350 to get it to cool down. A standard duty would not do it. The new clutch moves a ton of air at idle.

[geezer#99]

Yes 12-14 or even higher. Disconnect your vacuum to the distributor and plug it and set your timing. Then hook back up to the vacuum advance. Your idle speed will increase. Turn it back down.
How full are you filling the rad?
If it hasn't puked it isn't overheating.
No lower rad hose coil will let the hose collapse and the pump cavitates. No flow!
Be carefull pulling hose off. No flow till thermostat opens. Then lots of hot water. Not a recommended procedure.
Headers or stock exhaust manifolds?
If either are glowing red hot that tells you it's lean and retarded.

[406 Q-ship]

Do you have any idea what the actual temp is? What makes you think it is overheating? Timing should be at least 10° BTDC with a stock cam and 12 to 14° with a mild aftermarket cam, these are minimum numbers. If it is bowing water out of the radiator, check the radiator cap, it should hold 15 PSI at least.

[mikewarme]

Originally Posted by 406 Q-ship

Do you have any idea what the actual temp is? What makes you think it is overheating? Timing should be at least 10° BTDC with a stock cam and 12 to 14° with a mild aftermarket cam, these are minimum numbers. If it is bowing water out of the radiator, check the radiator cap, it should hold 15 PSI at least.

The temp when she showed cooking hot was : 195 at radiator. 216 on thermostat housing: 218 on water pump bypass hose and 275 at sender. Im using the sender location on the head which I believe is bad due to it being next to the exhaust! The manifolds are stock and they were 450 deg f. I will put a new sender on top of manifold. It never puked but i new it was hot cause it started pinging while needle was almost maxed out. So it must not be as bad as I'm thinking. I still think its not flowing as much as it should! I will check the fan clutch (It is new). OK NEXT! the timing tab says A and R. should it be on the R side for Before?? Seems to run worse. I set it too 12-14 on the A and it runs smooth but If I went to far I went out of travel to lower the idle. Pardon my ignorance on timing but everywhere I read on the net people suggest different. I trust the old timers HERE!

Thank you very much for helping me through this! By the way its almost 100 degrees outside

Mike

[geezer#99]

A is advanced which means btdc (before top dead centre). Think of advance this way. It's like shooting at a duck. You have to aim ahead of him to hit him when you shoot. That's called leading him or advanced. Your motor works the same way. You need to fire the spark before the piston gets to tdc. That's why it's called advanced or btdc.
On your timing tab advanced or btdc is to the left side of zero. Each line on the tab is 2 degrees.
Would you have a pic of your carb?

[Stocker]

Originally Posted by mikewarme

The fan blade sits in the shroud. Should'nt it be 1/2 way in and 1/2 way out of shroud for maximum cooling?

Yes, it should be 1/2 way in and 1/2 way out of the shroud. How far inside the shroud is your fan now? If it's too far inside, it can't pull maximum air through the radiator.

Keep a thermostat in place, at least a 180 or could go up to a 195.

I'd install an overflow tank and use a pressure cap for a closed system (15# IIRC). This lets you fill the radiator with coolant.