Water pump impeller to head clearance

D

DavesAuto

Junior Member
I have my head off the 28 , I took the upper coolant neck off, I noticed there is about 1/4 inch of gap or more between the (new Macs)water pump impeller and the inner impeller surface in the head, should this not be closer ? It does run hot but there are lots of other reasons for that , there is lots of "mud" in the rad/head/block, timing is out , motor is wore out etc. Also my fan belt (new from Macs) fits the crank groove good , the generator pulley is worn, but the water pump groove is really wide, are there shims in there I can take out to close the pulley a bit ? its a tin pulley not cast, has a 4 blade fan.
 
I think that at this point in time the water pump is the least of your worries.
The Model A water pump has a habit of trying to move more coolant than necessary any way. As is evidenced by Ford changing the original 5 blade impeller to 3 blades early in production and an eventual redesign in 1932.
A look at a known good water pump should give you the information you are looking for.
Remember, the Model A cooling system is a heat siphon system with a "pump" to aid in coolant circulation. A step up from the Model T albeit I think a small step.
 
This is the sign of a worn impeller stop in the head. Years of running with nil to none lubrication have worn the center portion of the bridge and now allow excessive forward-back movement of the impeller shaft.

Solutions include buying the "long" shaft (they come in two overall lengths) and pressing the impeller on doing a sort of "trial fit" with component parts of the pump as guide (pin the impeller when you find your spot)

OR building up the end of the impeller shaft with weld and grinding flat.

OR similarly tapping the end of the shaft and screwing in a brass bolt - and then grinding down similarly.

OR drilling & tapping the head bridge to install a brass hex bolt to act as "seat" - some machining of either the bolt or the pump shaft may be required to get the proper lateral shaft motion.

Your target is 0.005 to 0.010 free motion, this being thought optimal by those who do this for either a lip seal (LIFETIME sealed pump) or the original packing seal.

Generally, pulleys as found are fine with "B" section belts. Some metric belts are now being sold by the vendors which are at best "variable" in how they meet the pulley grooves.

A Gates B43 belt may be the best. I had some problems with this but Joe at Tam's Auto Parts had some suggestions when I told him my model year, pulleys, how much free play I was seeing. I'm running a Tam belt of unknown source marked "42-6324" currently.

Good luck. It sounds like you're bringing this one back?

Joe K
 
Buy a leekless water pump, a new aluminum 2-blade fan and a new belt. I buy those items from brattons or Snyders. Throw out the 4- blade. The leekless pumps come with a collar instead of riding against the head. Much better design than Ford's. Take your radiator off and back flush it with air/water. Use short air bursts!. I use Lye for about 20 min first. That's what the radiator shops used to use to boil out radiators. Wear skin and eye protection.
 
Joe K said:
This is the sign of a worn impeller stop in the head. Years of running with nil to none lubrication have worn the center portion of the bridge and now allow excessive forward-back movement of the impeller shaft.

Solutions include buying the "long" shaft (they come in two overall lengths) and pressing the impeller on doing a sort of "trial fit" with component parts of the pump as guide (pin the impeller when you find your spot)

OR building up the end of the impeller shaft with weld and grinding flat.

OR similarly tapping the end of the shaft and screwing in a brass bolt - and then grinding down similarly.

OR drilling & tapping the head bridge to install a brass hex bolt to act as "seat" - some machining of either the bolt or the pump shaft may be required to get the proper lateral shaft motion.

Your target is 0.005 to 0.010 free motion, this being thought optimal by those who do this for either a lip seal (LIFETIME sealed pump) or the original packing seal.

Generally, pulleys as found are fine with "B" section belts. Some metric belts are now being sold by the vendors which are at best "variable" in how they meet the pulley grooves.

A Gates B43 belt may be the best. I had some problems with this but Joe at Tam's Auto Parts had some suggestions when I told him my model year, pulleys, how much free play I was seeing. I'm running a Tam belt of unknown source marked "42-6324" currently.

Good luck. It sounds like you're bringing this one back?

Joe K
Click to expand...

Or simply buy a thrust collar for ~$3.50... :rolleyes::rolleyes:

http://www.snydersantiqueauto.com/thrust-collar-washer
 
You can get a 2-piece shaft collar from the local hardware that can be installed on the shaft near the front bearing. You won't have to take anything apart, just put in the collar and give it a little clearance.
 

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Cool Hand Lurker said:
You can get a 2-piece shaft collar from the local hardware that can be installed on the shaft near the front bearing. You won't have to take anything apart, just put in the collar and give it a little clearance.
Click to expand...

Good luck finding in my local hardware stores! On inline at McMaster-Carr !
Order in the morning, have it next day!
 
Big hammer said:
Good luck finding in my local hardware stores! On inline at McMaster-Carr !
Order in the morning, have it next day!
Click to expand...

I agree,

Don't use force, just get a bigger hammer. That is so true. Many people however don't understand the proper use of hammers and get into trouble.
 
Joe K said:
This is the sign of a worn impeller stop in the head. Years of running with nil to none lubrication have worn the center portion of the bridge and now allow excessive forward-back movement of the impeller shaft.

Solutions include buying the "long" shaft (they come in two overall lengths) and pressing the impeller on doing a sort of "trial fit" with component parts of the pump as guide (pin the impeller when you find your spot)

OR building up the end of the impeller shaft with weld and grinding flat.

OR similarly tapping the end of the shaft and screwing in a brass bolt - and then grinding down similarly.

OR drilling & tapping the head bridge to install a brass hex bolt to act as "seat" - some machining of either the bolt or the pump shaft may be required to get the proper lateral shaft motion.

Your target is 0.005 to 0.010 free motion, this being thought optimal by those who do this for either a lip seal (LIFETIME sealed pump) or the original packing seal.

Generally, pulleys as found are fine with "B" section belts. Some metric belts are now being sold by the vendors which are at best "variable" in how they meet the pulley grooves.

A Gates B43 belt may be the best. I had some problems with this but Joe at Tam's Auto Parts had some suggestions when I told him my model year, pulleys, how much free play I was seeing. I'm running a Tam belt of unknown source marked "42-6324" currently.

Good luck. It sounds like you're bringing this one back?

Joe K
Click to expand...

Be sure to use a left hand threaded brass screw and a left hand tap (reverse thread).
 
I got two of the 2-piece collars at a local fleet-farm store by the name of Runnings but there are others too. Look in the nuts & bolts section in the blue drawers.

But if your own drawers are blue... you should be "running" to your doctor real quick! :)
 
Growley bear said:
I think that at this point in time the water pump is the least of your worries.
The Model A water pump has a habit of trying to move more coolant than necessary any way. As is evidenced by Ford changing the original 5 blade impeller to 3 blades early in production and an eventual redesign in 1932.
A look at a known good water pump should give you the information you are looking for.
Remember, the Model A cooling system is a heat siphon system with a "pump" to aid in coolant circulation. A step up from the Model T albeit I think a small step.
Click to expand...

I will be cleaning it all up real good and research plus modify things. Timing and overhaul should help alot
 
Joe K said:
This is the sign of a worn impeller stop in the head. Years of running with nil to none lubrication have worn the center portion of the bridge and now allow excessive forward-back movement of the impeller shaft.

Solutions include buying the "long" shaft (they come in two overall lengths) and pressing the impeller on doing a sort of "trial fit" with component parts of the pump as guide (pin the impeller when you find your spot)

OR building up the end of the impeller shaft with weld and grinding flat.

OR similarly tapping the end of the shaft and screwing in a brass bolt - and then grinding down similarly.

OR drilling & tapping the head bridge to install a brass hex bolt to act as "seat" - some machining of either the bolt or the pump shaft may be required to get the proper lateral shaft motion.

Your target is 0.005 to 0.010 free motion, this being thought optimal by those who do this for either a lip seal (LIFETIME sealed pump) or the original packing seal.

Generally, pulleys as found are fine with "B" section belts. Some metric belts are now being sold by the vendors which are at best "variable" in how they meet the pulley grooves.

A Gates B43 belt may be the best. I had some problems with this but Joe at Tam's Auto Parts had some suggestions when I told him my model year, pulleys, how much free play I was seeing. I'm running a Tam belt of unknown source marked "42-6324" currently.

Good luck. It sounds like you're bringing this one back?

Joe K
Click to expand...
Yes I see now the bridge is wore out as well as the surface closest to the impeller, those are good suggestions thanks, it is a NEW lifetime pump with sealed bearing, I ordered a B44 but will get a B43 , I might try a cast iron pump pulley which I have. I have cast rods that pour on nice , I can build things up or I have some used heads I will check out. Thanks again
 
RonC said:
Buy a leekless water pump, a new aluminum 2-blade fan and a new belt. I buy those items from brattons or Snyders. Throw out the 4- blade. The leekless pumps come with a collar instead of riding against the head. Much better design than Ford's. Take your radiator off and back flush it with air/water. Use short air bursts!. I use Lye for about 20 min first. That's what the radiator shops used to use to boil out radiators. Wear skin and eye protection.
Click to expand...

Its aready a leakless pump so all good there, my old pump is what caused damage to the head. I have some Lye on hand here , yes I will be cleaning it all nice. Is a two blade more efficient ? I have a good one here and I like the old look of it anyway. Thanks
 
Cool Hand Lurker said:
You can get a 2-piece shaft collar from the local hardware that can be installed on the shaft near the front bearing. You won't have to take anything apart, just put in the collar and give it a little clearance.
Click to expand...

I like this idea , my new leakless pump has no movement . It appears the modified sealed bearing in there prevents it from going in and out . Thanks
 
DavesAuto said:
Is a two blade more efficient ? I have a good one here and I like the old look of it anyway. Thanks
Click to expand...

Beware if it is a stock steel two bladed fan. They have been known to fling a blade, usually into the radiator or underside of the hood. Check closely for cracks. :p:p

Better to buy a new aluminum two bladed fan.
 
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