Water pump impeller cut down

Don

Don

Well-known member
Has any one cut the impeller down to improve cooling on there model As. Had a overheating problem Sunday on a 100 mile trip ,checked everything and flow thru radiator.2 gallon in and 4 seconds to empty,same with engine.rechecked timing,seemed ok .opened gas valve some to help cooling,motor meter blew up so don't know what temp was to hot I know.Stopped ever 15 miles and put in water.radiator is 3 row flat type rows.and clean..Haven't had any problems in past trips but there were a lot of hill Sunday and running about 45-50 Tks. this is a 29 rd pickup..
 
Yes, I always ground the tips of the impeller down . The model A water pump pumps more than the radiator can handle . This was a problem since day one with the model A . Ford changed the early impeller from five blade to three blade in their first attempt to solve the problem . the problem was solved in 1932 when the water pump and impeller was redesigned . Snyders recommended cutting the tips as far back as the 70s . Some of the vendors now sort of blame it on the new repro radiators . If its the radiator , I say whos got a new old stock radiator . If any still exist they would be few and far between . If the pump is pumping the water out the overflow pipe , I can't see what cutting down the impeller tips can hurt . Some install thermostats to curb the flow . Thermostats can stick closed , I don't use them .
 
If you have a Snyder's new catalog. go to page 136 at the bottom of the page left corner you will see both original and cut down. The picture will show the difference, you can tell how much to cut down. If you don't have there catalog go on line you can pull it up. Any Snyder's catalog will show them.
 
I have seen the nail post but don't know what it means,but can guess,,, put a nail in the overflow to keep water in the radiator?????? I have an extension ( small piece of hose) to the upper opening of radiator ,think it helps some?
 
Don said:
Has any one cut the impeller down to improve cooling on there model As. Had a overheating problem Sunday on a 100 mile trip ,checked everything and flow thru radiator.2 gallon in and 4 seconds to empty,same with engine.rechecked timing,seemed ok .opened gas valve some to help cooling,motor meter blew up so don't know what temp was to hot I know.Stopped ever 15 miles and put in water.radiator is 3 row flat type rows.and clean..Haven't had any problems in past trips but there were a lot of hill Sunday and running about 45-50 Tks. this is a 29 rd pickup..
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Reads like something changed. Look for what changed.. you will likely have your answer. Determine if you are loosing coolant then it overheats, or is it overheating to a boil and loosing coolant that way. Check radiator flow top to bottom, place roofing nail in overflow tube as a test to loosing coolant. Check that head gasket is not letting coolant to the cylinder and out the exhaust. Do a pressure test for head gasket failure or possible cracked block at a water jacket. That is a start. Something changed if it did not overheat prior.
 
I use a 2.5 lb radiator cap on the overflow hose and haven't lost water, nor overheated on some very hot trips. (Dallas from Danville in 2008) Denny Specker in South Jordan Utah sold me this setup, and it also made the Dallas trip possible for a fellow from So. Cal, who had determined to go home because of the loss of water. We cut a piece of rubber (Bottle Opening Cheater.) to make a gasket for my moto meter, which still works.
 
I agree with 1930 Coupe in #7. Radiators can cause overheating if the tubes get a thin coat of grease or scale, which blocks heat transfer, or the tubes can be blocked enough to cause the coolant to fill the top tank and go out the overflow. I used Cascade for 3 days, then flushed it out and used pure white vinegar for 30 days, and was able to save my original 1928 radiator.

I do think the original impeller pumps more than it needs to, but a good original radiator should handle it. I do use a thermostat for quicker warm ups, but it does help slow the flow a little bit also. Last Saturday I drove 70 miles without the thermostat, and the radiator never lost a drop. I filled it to about 1/2" above the baffle plate, and that's just where it was when I checked it 70 miles later.
 
Some Model A drivers have found that their Water Pump shaft's impeller is too efficient and pushes the water faster than can be digested by the radiator. Some solutions have been to drill holes in the impeller; shave a bit off the impeller.

I (and a number of others) have chose to do what some race car drivers have done - install a 'coolant recovery system'. Mine consisted of a narrow 1 gallon container,(shape of an anti-freeze jug) laid in the cradle of the driver's side engine pan, opening toward the radiator, and running a clear flexible hose from the radiator's over-flow tube down to and inserted into the 1 gallon container. Every 100 hundred or so miles, I would stop and pour the jug's contents back into the radiator.

Under normal circumstances and local (i.e. under 45 mph) I never had a problem. But when cruising the highways at 55 - 65 mph, for sustained lengths and distances (5 hours - 250 miles) I did have to deal with the 'over flow' problem. My 'Coolant Recovery System', while primitive, worked beautifully for my entire trip to Alaska and back, and for years afterward.

I was running a 'C' engine (from my '34 Ford Sedan) with a 'B' water pump. The 'B' and 'C' water pumps have a much bigger impeller than does an 'A', so the reasons that may have caused my overflow, may not be the same reasons that causes your overflow from a stock 'A' engine.

- Doug Vieyra, Eureka, Calif
 
I can't find it on search, but I once tiped an account of a truck mechanic that invented the coolant recovery system. It keeps the radiator & the rest of the system TOTALLY full & eliminates AIR BUBBLES, which transfer heat POORLY.
If you splice a piece of clear tubing into your upper hose, the problem will be apparent!
Just think, on a cold startup with JUST enough water to cover the tubes, the WHOLE upper tank is FULL of AIR, just waiting to be whipped into BUBBLES!!!!
Bill W.
 
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When rebuilding my water pumps over the last 40 years I have always drilled a 3/16" hole in each impeller to slow down the water being pumped into the radiator.

My uncle, in 1928, purchased a new AA Stake Bed in Stockton, CA. He said when working the truck in the field it would heat up and run out the overflow if he idled it to long. He said after experimenting different ways found the pump put water into the radiator faster than it would syphon thru the radiator; that is how he arrived with the 3/16" hole in each impeller.

Ron
 
Well I repaired the motor- meter ( new theromerter from old meter ) installed a china temperature gauge,put a nail in the over flow tube,checked water level,went thru the timing procedure as per a video on u-tube ( Ted I think was his name,good info )went
for a drive on US 60 ,a few hill and good speed,about a 10 mile run,motor- meter would rise to btw of hole and temp gauge ran about 170 going up hills pushing it pretty hard then drop back down on the level ..checked water level and splash pan for water ,looked like about it had spit out about 1/2 cup ,water level was about same,, still might cut the pump down sometime..
 
I bit the bullet so to speak several years ago and installed a new core in the radiator after suffering from constant boiling. At one stage whilst sitting on the side of the road, waiting for the engine to cool down, a passer by stopped and said, "In my day, we drilled holes in the impellor, to slow the flow". I have not done that, but I did install a thermostat and have had no issue since then, I do also suggest the stocking over the inlet into the top of the radiator, to catch any bits and pieces and this hopefully will stop any blockages.
 
After replacing the china temp gauge with another china temp gauge,setting in the garage idleing with 3 different means of reading temp,it got to about 185 deg and pretty much stayed there with the 3 indicators within a couple deg. Of each other.Is this normal temp setting there ,.I have a 4 blade fan ideling about 800 rpm.Still trying to decide weather to remove pump and cut down impeller,im using a 50/50 mix
 
Sounds good. Took the second china temp gauge back also,got money back,tried several other places.everything china or India ' just made a thermocouple and using my Fluke tied to dash,very accurate.
 
The original "A" water pump made a flow rate of 38 gallons per minute. With a new style core radiator it works just fine. My "A" has no overheat issues even cruising in 95 degree weather up long grades.

An old airplane trick is to turn up the carb mixture knob (richer) when climbing, as the extra fuel does help cool the cylinders.
 
More fuel does not cool the engine. What you are doing is altering the fuel/air ratio so the engine is less efficient. Power is heat. Less power, less heat.
 
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