Mike V. Florida
Well-known member
A high compression head gives more power less heat.
Water pump impeller cut down
- Thread starter Don
- Start date
A high compression head gives more power less heat.
Jacksonlll
Well-known member
Don, this video should explain the system.
https://www.youtube.com/watch?v=Ug01EW7UZGM
It is impossible for the water pump to pump more than the rad can handle. It gets all of it's water from the radiator. Unless you are manufacturing water somewhere in the engine, the rad can handle the amount that comes out of it.
What the cut-down impeller does is make the pump smaller so that it does not draw as much low pressure in the engine which causes steam to flash, create a large bubble in the water jacket, and then the pump pumps the water out ahead of the steam bubble quickly and makes it look like it is pumping too much water. This is all caused by a plugged core. The stat, the smaller pump and the nail are all band aids that work in the right direction, but is not the answer. Get a good flowing rad and your problems will go away. jack
https://www.youtube.com/watch?v=Ug01EW7UZGM
It is impossible for the water pump to pump more than the rad can handle. It gets all of it's water from the radiator. Unless you are manufacturing water somewhere in the engine, the rad can handle the amount that comes out of it.
What the cut-down impeller does is make the pump smaller so that it does not draw as much low pressure in the engine which causes steam to flash, create a large bubble in the water jacket, and then the pump pumps the water out ahead of the steam bubble quickly and makes it look like it is pumping too much water. This is all caused by a plugged core. The stat, the smaller pump and the nail are all band aids that work in the right direction, but is not the answer. Get a good flowing rad and your problems will go away. jack
john in illinois
Well-known member
I have a James Rupert leakless pump that I have run for years.
When I bought it I asked about cutting down the impeller and he said he did not recommend it. Sio I did not grind it down. Works perfect.
I agree with Jackson,cooling problems on a Model A are usually the radiator.
On Flathead v8 s we are always trying to get more efficient water pump impellers. They cool better.
John
When I bought it I asked about cutting down the impeller and he said he did not recommend it. Sio I did not grind it down. Works perfect.
I agree with Jackson,cooling problems on a Model A are usually the radiator.
On Flathead v8 s we are always trying to get more efficient water pump impellers. They cool better.
John
silversink
Senior Member
nailed mine and it cost me 600.00-----don't do it---put a piece of hose to raise the level of the drain tube instead.
Joe K
Well-known member
One of the period "repop" water pumps addressed this problem by incorporating a V8 impeller (and seal system) into a near copy of the Model A water pump casting.
You no doubt have seen these pumps. Similar to the Model A but minus a gland nut - the shaft simply pokes out of the rear wall of the casting.
The weak point of these pumps is the front bearing which was a sleeve type bearing with a grease zerk centered on the top.
But you look at the impeller and realize it MUST be flow challenged by its very configuration compared to an OEM impeller.
Joe K
You no doubt have seen these pumps. Similar to the Model A but minus a gland nut - the shaft simply pokes out of the rear wall of the casting.
The weak point of these pumps is the front bearing which was a sleeve type bearing with a grease zerk centered on the top.
But you look at the impeller and realize it MUST be flow challenged by its very configuration compared to an OEM impeller.
Joe K
eagle
Well-known member
I see this subject come up every summer. I wish people would watch this video! It explains the situation very well. NO water pump can pump more water OUT of it than it can take IN.
Tom Wesenberg
Well-known member
That's what I used to think also, until it happened to me several times before I cleaned out my radiator. The Model A cooling system can pump the coolant from the block and lower radiator tank into the top tank faster than a clocked radiator can replenish the lower tank. My car worked fine is I never drove faster than 45, but so many like to drive 50 to 55 and that's when my top tank filled and went out the overflow until the coolant got low and the engine overheated.
A thermostat will help slow the flow and let many cars get by without cleaning all the radiator tubes. Cutting the impellor blades also helps to slow the flow.
A thermostat will help slow the flow and let many cars get by without cleaning all the radiator tubes. Cutting the impellor blades also helps to slow the flow.