Technical New SBC 350. Also new geyser. Getting hot while trying to break in

Alright guys need some help

have a T bucket. Pulled a really tired 283 and put in a new 350 block. Edelbrock 2101 intake. 1406 carb. Same radiator. Same water pump from 283. First time doing something like this.

today was first start. Fired right up. Timed it 10 degree advanced. Making 34 at 3000. Oil pressure 50ish. So far so good. Running it at 2000 rpm per break in.

the thing heats up quick gauge reading 240. Blows coolant out the overflow. Ok maybe air? Both hoses lower/upper seemed to warm up.

Pulled the thermostat just in case, running wide open. Left the rad cap off. Seems like coolant pouring in from top hose so****ume pump is working. Same thing. Gets hot. Coolant shoots out in spectacular fashion before I can shut it down. Not trying to blow the motor before break in

don’t see coolant in dipstick. Don’t see oil in coolant though I haven’t drained either yet.

where to go next?

 

Air in system....??
Jack front end up higher than back. Fill radiator slowly?
Try disconnecting heater hoses while filling ?
Some are harder to burp than others......
6sally6

 

Maybe? That’s what i hoped leaving the cap off would solve before shooting 2 feet out and dumping about a gallon of coolant. I’ll try the raising. There is no heater. Just hose to the pump and hose back to radiator.

 

Plugged radiator.

 

Hmm. Seems like water is circulating (e.g top hose heats up. Can see coolant flowing in when cap is off). How would one diagnose if this is the issue?

 

Put more timing in it.
2000 rpm , no load will need a lot of vacuum advance, get the timing up around 45-50° Total @ 2000 rpm will help it run cooler.
Retarded from optimal timing at the rpm you're at will make a lot of heat
You can turn it back down after the break-in.

 

I’ve wondered, are you actually breaking it in not under a load or just kinda breaking it in.
We built a 350 and ran it in a stand for several hours. Put it in my bus and the headers glowed orange for several miles.
Nothing changed on the engine other than installing it and the engine being under a load.

just curious.

 

If yr TDC is correct , need more initial timing,
(15-18) idle ,
Air in system , try a 160 for now, fan in front of Rad,
Check for vac leaks , richen up mixtures ,
Disconnect vac Avance if you have (for now)

 

Run hand over the core (front side only per laywer) and feel for cold spots.

 

is that timing with vacuum hooked up or no? What I timed 10/34 was before adding vacuum advance. Just confirming so don’t screw if up. Thanks!

 

will do! Checked TDC with a position stop. Balancer mark was dead on between the two stops. Stabbed on compression stroke. Totally positive I got that right. Motor was running great at least

 

in the driveway parked. Just started it up. Running between 2000 - 2500 rpm as per instruction came with the block. Started spewing after a few minutes.

 

Do you know for a fact that it is over heating? What is the temperature when the radiator cap blows? I bought a car really cheap once because the guy said it would overheat all the time. Turned out it was not overheating, the radiator cap was bad and would not hold pressure, so it looked like it was overheating.

 

Temp gauge is reading 240+. Did not measure independently. Def steaming. Using coolant. Cap is old school ford cap with wings. No pressure relief. First point of failure is the overflow tank.

 

I'd give her the Old Hose Treatment. Run it thru break-in period with a garden hose cooling down the radiator. Don't drown yourself or your Hot Rod.

 

Q? is this a "pressurized" radiator?

 

Either way, just get the total @ your break in rpm up into the high 40's-low 50's.
Crank up the mechaical and leave the vacuum off, or leave the mechanical alone and use the vacuum advance, doesn't matter.

 

Did you reuse the original pulleys and belts with the original pump.


Phil

 

Did the car have a cooling problem before the engine change?, did you use a replacement short-block or a replacement long block?, if a short-block, what kind of heads were installed?, did you use the right head gaskets/intake manifold gaskets and did you install them properly?

 

Is the engine of reverse flow cooling system design and you are using a regular waterpump on it?

 

Vacuum leak?

 

intake gaskets reversed?

 

Seems like a coolant flow/blockage issue. Fit a clear plastic tube in the radiator hose so you can visually confirm water flow.
If it's not flowing, swap in any good radiator you have on hand with flex hoses to rule out your T radiator as being plugged (as Gimpy suggested). It's a T bucket, making a radiator swap quick and worth the effort before pulling the intake, heads.

 

The others pretty well covered most of the normal car overheats and pukes water all over the place issues,
Air lock in engine or cooling system. Unless you added or changed something beside the engine it's self that most likely isn't the issue.
Blockage = lower hose kinked or ??
Wrong head gaskets ?
Air flow? Have you set up a fan in front of the radiator to blow air at the radiator?
That fan that kept up with cooling the worn out 283 may not be pulling enough air at low speed to keep the temperature under control with the fresh engine.
According to this it won't be a "reverse flow" engine as those are a ton different than regular small blocks. That should stop that BS GM LT1 Engine and Reverse-Flow Technology (brakeandfrontend.com)+

 

Thermostat in backwards? I would look for a cold spot in the radiator as suggested, if you do, drop the hoses and look for a plug or rag left in something... oops...

 

Alright so plan of action, thanks for all the advice.

drop the hoses and drain system. Check status of coolant.

drain oil. Check status of oil. Just making sure there was no contamination either way through gaskets. If oil/coolant both clean good go to next step. If no stop and open the intake.

Run hose through radiator and watch drain to see if there is blockage.

Change water pump. Make sure all tubing is a straight shot. Raise front of car. Fill block first. Than radiator. Let air out for a few days. Open whatever plugs as I fill to make sure coolant fills and and air is out.

Add timing. Richen idle mixture. Spray the radiator with hose. Get a big fan. Try again.

Anything to add?

 

Pops suggested the same thing. Thermostat was good, but removed it anyway and tried without it. No change.

 

was a long. Heads installed. No cooling issues with radiator/pump that were reused. Intake gaskets came with the kit. Felpro non gasket sealant type. Aligned well and tourqued to spec.

 

Did you install the intake manifold gaskets with the large coolant holes to the front of the engine or towards the back?, if you put them on backwards the engine will overheat.