'63 Super Seven Cooling

[TEM]

My swirl pot bolts directly to the head where the thermostat would normally be.  This is also where the temp probe is (in the head).  I have had this open many times.  It's wide open in this area.  I can not see any restrictions.  Because the home made swirl pot bolts directly to the head is why I don't think I can get a thermostat in there, the tube ID looks too small to go over a thermostat.

 

Water flow freely from the swirl pot out of the pump inlet so I don't think there is much restriction in the block.

 

I'm without a phone today otherwise I would shoot you guys some pictures. 

[SENC]

 

Unfortunately I fouled up the first video, from dead cold.  At cold, water level in the swirl pot is about 1/2" above the bottom.  Just jiggling with then engine at idle.  When rpms hit 1500-2000 rpms, water begins to gush in from the upper, inlet pipe.  This video shows the pot fairly full, but you can see the same effect.

 

[MV8]

There are two different metal pump impeller designs. One is cast iron and closed toward the block, the other is stamped steel with a semi-open face. Both have straight blades. I think the stamped version has more volume (cast iron version must be thicker) but the open face between blades reduces the efficiency. Most likely the most efficient would be stamped with a welded plate to close the openings between the blades on the block side. A slightly smaller pump pulley would work too.

[jbcollier]

Fill an electric kettle and bring it to boil.  Drop in your sensor bulb.  What does it read?

[joe7]

Had the same problem with my 7. It seemed to have an air lock. I figured that out by measuring the amount of coolant I poured in which was way short of what should be. Try opening the drain cock on the side of the block to let some air out. Another basic technique is to squeeze the upper hose to "push" the coolant through to check the system is full.

[TEM]

Thanks SENC for the video.  Mine appears to be about the same.  I don't see "flow" until about 2500rpm and then it gushes when I lift off the throttle.  Even with keeping the rpm's up between 2000 and 3000, temperature still rises pretty fast when standing still, nose cone on and fan running.  I'm trying to tune the carbs but the coolant temp keeps shutting me down.

 

My pump has the cast impeller.  I'll try the air bleed stop cock and see if that helps.

[SENC]

Timing, if wrong, can also be a big contributor to overheating - worth a double-check of that, too.

[TEM]

Timing has been triple checked sine I was having trouble getting first fire.  But worth a check.

[jbcollier]

With no rad in place, the engine will from hot to too hot in a blink of the eye as there is no cool coolant in reserve.

[TEM]

The radiator was removed for cleaning.  The bypass hose was temporary for engine flushing.  I expected the temperature to rise in that scenario.  What I did not expect was high water temperature and cool hose.  Block was very hot where the probe is but the swirl pot water was lukewarm.

 

The last test was done with the radiator back on, nose cone in place, and fan running.  Still can't keep the temperature from running away.  Bliping the throttle I could see flow in the swirl pot but also seemed to make the temperature rise faster. 

 

Once it cools, I'll try taking it out for a drive to see if normal driving can keep the temp under control.

[MV8]

What are the diameters of the crank and water pump pulleys?

I've seen bits of rubber clog the small holes around a single cylinder that caused an overheat, but that was a totally different engine (455cid Olds).

Edited May 31 by MV8

[SENC]

Sharing a couple notes from an old Autopress manual for the Anglia, Corsair and Cortina... could the water pump have been rebuilt without the slinger or with the impeller too big a clearance?  Trying to think of why else it may be working inefficiently or even direction water towards the pot rather than through the engine.

 

[jbcollier]

Hot block, no restriction, and cool hose means low/no flow.  Obviously the water pump is not performing at low rpm.  The video posted by someone else shows the same issue.  I would suspect too much impeller clearance.

 

First question: what direction were the impeller blades installed?  Do the fins/blades point towards the pump body, or to the block?

Edited May 31 by jbcollier

[jbcollier]

The "slinger" goes between the water pump bearings and the seal.  If the seal leaks, the slinger helps direct the coolant out the drain hole and away from the bearings.  This is so the bearings will last a little longer and give you time to notice and change the pump before it catastrophically fails.  The slinger performs no other function and can be left out.  Some pumps don't even have one.

[TEM]

A bunch of update:

 

For the previous test above I filled the coolant system from the swirl pot.  Test results were as previously mentioned.  When I opened the drain at the bottom of the radiator very little water came out.  When the engine was run the water level stayed at the top of the swirl pot indicating a full system.  I couple understand a little air but the radiator was nearly empty.

 

Temperature probe test:  I pulled the probe an placed it in a cup or boiling water along with a digital thermometer.  I took data every 10 deg. while the water cooled.  The end result is;

178deg on the digital thermometer = 178 on the dash gauge

90 deg on the thermometer = 105 on the gauge

 

Next I filled the system from the top hose of the radiator.  Took a lot more water this time.  Filled until I saw water coming out the thermostat opening.  Placed the swirl pot back on along with the top hose of the radiator and completed the fill from the swirl pot.  So I know the system is now full of water.

 

Started the engine and took it for a short drive <1mile at 25 to 30mph, nose cone on, fan running.  The temp gauge continuously raised until I shut off the engine at 210deg.  The faster I went, the faster the temp raised.  The top hose is cold, the bottom hose is warm and both the top and bottom of the radiator are cold.  There is no water flowing through the radiator!

 

Could this just be a thermostat issue?  Do I need the thermostat to shut off the re-circulation flow internal to the pump and force the flow through the radiator?  If so, what part number is the correct thermostat?

[TEM]

Crank pulley is about 4" and the water pump pulley is about 4.25"

[SENC]

No.  I don't have a thermostat in mine, nor are the swirl pots designed for them.  The only use for the thermostat is to allow the engine to warm more rapidly by limiting flow through the radiator until it is warm enough to circulate.

 

From all you've described and tested, it seems most likely you're just not getting sufficient circulation through the engine - whether due to restrictions or even blockages or due to an inefficient pump.

 

Have you flushed the engine?  Hose to the pump inlet and open the drain on the lower right side of the engine?  Good flow?  Clear or lots of crap?

 

I replaced my pump when I rebuilt my engine.  I'm 95% sure I saved the original - if you can't put your hands on one I'd be happy to send it to you to test if it makes any difference.  I didn't replace it due to known issues, but just part of my rebuild.

[TEM]

The impeller blades are cast and are open towards the pump.

[TEM]

I have done about a dozen flushes now.  Water flows freely out all of the ports including the drain stop cock.  The water has a redish tint but you can still see through it.  No crap, sludge, or bits or rust coming out.  It just doesn't seem to be pushing any water through the radiator.

 

I just pulled the swirl pot again.  The water in the swirl pot isn't even bath water temperature but the water in the head is smoking hot!

[TEM]

I just checked the thermostat opening again and a Thermostat won't help.  There's nothing for the secondary valve to seal against so the thermostat would just open the passage to the swirl pot which is what I already have.  It's starting to look like a bad pump.