Projects Overheating problem 33 chevy

That video also measured them all at like 5-6 grand where a lot of people are not spinning a motor that high anyways.

 

The video also used a thermo-clutch fan with no heat in front of it, should have picked the centrifugal
clutch and had the flow gauge in front of all four of them. They could have done an air flow and hp test at the same time.
At the speeds and rpm I drive at, the 6 blade solid fan doesn't seem to hurt the power, I need to get it out on a fuel mileage drive to know for sure. I can sure tell it pulls more air just watching the temp gauge.

 

I have a update on my overheating problem. I really wanted to do one issue at a time but, that turned out to be a lot of work, so I did all of the great soluations that you all have suggested.
1) Added a lip to my existing fan shroud. (Tested the air flow with 3 x 3 plastic bag and it ****ed it to the grill real hard)
2) Positioned the fan to the somewhat correct distance in the fan shroud.
3) Moved my transmission cooler from the middle of the radiator to the bottom of the radiator, which is actually hanging in mid-air, not covering up any of the radiator.
4) I changed from a 16psi radiator cap to a 13psi cap.
5) Added a radiator overflow fluid can. (which doesn't do much for overheating)
6) Had to much ignition timing and got it set 10 deg. (It was15 deg. and hard to start.)
7) Fuel pressure set from 1.5psi to 7psi.

I then fired it up and put a 36" shop fan in front of the radiator for added air flow.
I left the radiator cap off so I could see when the thermostat opened up, then top off with anti-frezze.
Put the 13psi radiator cap on and waited for it to fully warm up, then shut her down when it got p***ed 200 deg.

So now I'm thinking these issues aren't why the engine is overheating. This is a fresh rebuild, only 2 miles on the engine. I let it cool down to 150deg. Removed the radiator cap to check coolant level and it was just below the fill opening.
I fired it back up to see if the coolant did any movement while it was heating back up.

What I noticed was a steady quarter size air bubbles coming up thru the filler neck. At first I though it might be removing air trapped in the coolant system, but they never stopped.

Now I thinking:
1) Blown head gasket. (Should I re-torque the heads to see if that helps)
2) Cracked head (I did inspect for cracks, and could have missed one)
3) Cracked block (And also looked it over)

I didn't see any steam coming out the exhaust.
The oil doesn't look like it has coolant in it.

What does the group think I might have missed?

The overflow can


This is what my filler neck looks like.


The coolant level was a little higher when the bubbles were coming out.

 

If water isn't in the oil then look for it in the exhaust, is the level going down ?

 

I would run it a while and see if the bubbles go away. Maybe do a compression test, for the blown head gasket theory.

 

I haven't run it long enough to tell if level drops, it gets up to 200deg pretty quick. I'll see if I can smell any anti-freeze coming out the exhaust.

 

I have the tester out and will be doing that tomorrow. What I'm surprised about is the engine runs good no misses and real stong va***n. Compression number will eliminate head gasket...maybe

 

200 degrees isn’t hot

 

Jack up the front and let it run, maybe there's an air pocket

 

I guess I'm not used to a sbc running that hot

 

Hot is boiling over.
I ran mine 210-215 all day long. Would bump up a bit to 218-220 on hot days in traffic
Never boiled over. It’s got over 30k miles on it doing that. Only issue was an occasional vapor lock.

 

What thermostat are you using?
Is the vacuum advance hooked up to manifold vacuum?


Is the rod ready to drive?
If so, I'd take it for a ride, while keeping an eye on the temp gauge.

Idling is the hardest time to keep it cool.

 

Thermostat = 160deg
Vacuum hooked to the 0 vac at idle carb side
Road ready...yes...wating on licence plates to come in.

 

10.5-1 compression 311” GMC, copper/br*** radiator in stock 1940 Chevrolet mount, 14” steel fixed pitch 4 blade fan, 180* thermostat. Doesn’t heat up; maybe 190 at a long line or traffic light.

 

You can get a test kit that checks for combustion gases in the coolant. You may also try an air lift to fill the coolant with. ****s all the air out and puts coolant in.

 

Check your spark plugs for fouling from water. Would be a gray color built up. At this stage of the game. I wouldn't sweat 200 degrees.

 

Have you checked the temp gauge for being accurate?

 

Yes, I removed the temp gauge out of the engine and put it in a pot of boling water and the gauge read 212 deg. on the dot. I did that because my lazor temp gauge would only read 195 deg. Now I'm ***uming the lazor gauge is not all that accurate.

 

The reason I suggested manifold vacuum, rather than the ported vacuum?
The two are identical at every throttle position and engine load EXCEPT at idle.
Manifold vacuum operates at idle and will add additional ignition timing after startup which will allow for a leaner idle mixture and cooler idle temperature.

 

A new engine will always run hot till the cylinders get broke in, you haven't run it enough yet. Go for drive around the block or at least up and down the street a few time. If it's still bubbling and hot after a 50 miles, then start looking for a problem.
Where is the temp sensor mounted?

 

Temp sensor is mounted in the front of the intake.


I finished the compression test.

1) 136 psi 2) 136 psi
3) 139 psi 4) 134 psi
5) 136 psi 6) 144 psi
7) 136 psi 8) 140 psi

 

What's that T in the pcv line hooked to on the other side ?

 

It's hooked to another pcv valve in the p***enger side vale cover.

 

That’s not how the system should work. You need air flow thru the engine to extract oil vapor from inside the engine.
Not saying you can’t do what’s installed, it’s not how it usually done….we can’t see the left side rear of the rocker cover so there may be a breather there but the PCV system normally needs crossflow thru the engine.

 

One pcv valve is correct. The other valve cover should have a fresh air breather or a hose to underside of air cleaner to draw filtered fresh air.
This provides fresh air in on one side and pvc on the other side ventilating to combustion in the base of the carburetor.
See diagram linked below.
https://www.streetrod101.com/uploads/8/9/3/3/8933135/1326301990.jpg

 

Thanks, Jimmy and Phill

I try everyday to learn something new, I have a breather/filter that will replace the one pcv on the p***enger side.

Thanks, again

 

Compression looks good.

See post #49 above regarding vacuum advance.

 

I'll switch it and see what happens, that ported and non-ported has been a hot topic on which is best.

 

I was hoping it wasn't, like was said air in on one side and ****ed out through pcv on the other. It has nothing to do with the overheating issue but something that caught my eye.

 

Looking again, the water pump looks very similar to some of the reverse rotation ones I've seen. Might check that.
Good luck!