Best water pump for a B block in the desert?

[Gerald Morris]

Greetings Moparians!

I'm confronting again the issue of pulling and replacing the water pump housing on Mathilda before the worst of the summer heat comes on, and figure if I should upgrade the pump itself, THIS is THE time for it. I've been reading and have found that the aluminum housing I bought last spring might be sub-optimally configured on the lower ports feeding the block. Overheating issue resolved....interesting read !

While last summer seemed alright, this spring I'm getting lots of the symptoms described in this thread. since I have access to an inexpensive iron housing now of the sort for older configurations, I figure I can eliminate the possibility my aluminum housing is causing this creep up to 210 F one way or the other. If the iron housing solves the problem, I can relax awhile before getting a new radiator.

Anyway, I see much talk of the Milodon pumps being particularly well thought of. Is this merited, or should I stick with the Gates I got from Rock last spring? Experienced advice welcome.

Semper Mopar

 

[CBODY67]

Here's what I went through with my '77 Camaro and "creepin' heat".

Once, the water pump went south one weekend night, so I ended up at a chain auto supply store I bought stuff from for a reman pump. I'd been hearing about the "better flow" pumps being better, so we looked through the inventory for a pump that was not OEM casting. Found one. It looked great, smooth internal castings that were larger than the OEM castings. Great, I thought. Put it on and it work, got me home and farther. But I noticed that the temp needle was one needle-width higher than what it had been with the "poorer" factory casting. It was fine as it was, but to further prove the point, when that pump started leaking, I got an OEM casting reman pump and the temp gauge went back to where it used to be. So much for the "more flow" theory!

I suspect you'll really end up knocking out the core plugs and doing that messy full water jacket flush. All of the "stuff" in the cooling system settles out in the rear of the coolant jackets in the block. Until you get that cleaned out, chemical cleaners won't fully do that, you'll have some sort of elevated operating temperature, regardless of how "cool" the thermostat might be. That has also been the experience of other vintage vehicle owners in another forum I'm in.

Of course, doing a radiator cleanout might be needed, too. Plus ensuring the fan clutch and shroud are in good condition, along with the hood-to-radiator support "flap" on the bottom side of the hood.

There's a thread of putting a GenIII Hemi into a '68 Fury. The radiator used was a Charger SRT radiator, with it's radiator mount, attached to the back of the Fury's core support. Pretty slick and inexpensive when compared to a custom-built radiator. Neither one would look "stock", but the GenIII stuff would be less expensive and probably cool better, being high-efficiency and all.

Just some thoughts,
CBODY67

 

[Gerald Morris]

THANK you for your thoughtful reply.

Worry about knocking out expansion plugs or even punching coolant past the head gaskets into the crankcase has kept me from embracing one of these high flow pumps thus far. I'm VERY aware of the accumulation of detritus in the lower back of the water jacket, having replaced several expansion plugs closer to the front and dug out bits of magnetite particles et al as far as my fingers and tools could reach. When I need to replace the back plugs, I can then address flushing, digging and air blasting out the pile of oceanic gunk back by cylinders #7 & 8.

I got the old radiator as clean as I could for now with a vinegar flush followed by putting the garden hose onto the tee in my heater hose and blowing out the old liquid until I could taste nothing but garden hose water. Still no joy for the heat creep.

I use Stant's "Superstat" 180F thermostat, after testing it in a pan of hot water. It opened perfectly and I can always tell when it opens when driving. Mathilda runs at 190F at that point, according to the cheap old mechanical temperature gauge.

I believe I've been successfully warned OFF using any "high flow" pump after reading your comments. I'll replace the aluminum housing w an iron one, see if that brings the desired result, and replace my radiator hopefully within a month. I've been saving the back expansion plug job for a starter upgrade. That way, I can accomplish the most with the effort of removing the starter (driver side) and pulling the exhaust loose on the passenger side to replace the other expansion plug. I hope by that point, after having dug out MOST of the trash in the water jacket, that Mathilda will purr along at a nice 185-195 for the summer.

My first summer with Tilly, 2 yrs ago, she did pretty well w the heat, but I wanted a bit better. Looks like I need to step back one step and proceed forward with due caution.

Will keep folks posted as I complete these major steps. The aluminum pump housing matter is of particular concern now.

Here's what I went through with my '77 Camaro and "creepin' heat".

But I noticed that the temp needle was one needle-width higher than what it had been with the "poorer" factory casting. It was fine as it was, but to further prove the point, when that pump started leaking, I got an OEM casting reman pump and the temp gauge went back to where it used to be. So much for the "more flow" theory!

I suspect you'll really end up knocking out the core plugs and doing that messy full water jacket flush. All of the "stuff" in the cooling system settles out in the rear of the coolant jackets in the block. Until you get that cleaned out, chemical cleaners won't fully do that, you'll have some sort of elevated operating temperature, regardless of how "cool" the thermostat might be. That has also been the experience of other vintage vehicle owners in another forum I'm in.

Of course, doing a radiator cleanout might be needed, too. Plus ensuring the fan clutch and shroud are in good condition, along with the hood-to-radiator support "flap" on the bottom side of the hood.

There's a thread of putting a GenIII Hemi into a '68 Fury. The radiator used was a Charger SRT radiator, with it's radiator mount, attached to the back of the Fury's core support. Pretty slick and inexpensive when compared to a custom-built radiator. Neither one would look "stock", but the GenIII stuff would be less expensive and probably cool better, being high-efficiency and all.

Just some thoughts,
CBODY67

 

[bulldogchesty]

Try Evaporusts thermocool.THERMOCURE™ - Cooling System Flush - Evapo-Rust

 

[FURYGT]

I don't know if your car is an a/c car or not but one trick on non a/c cars is to use the water pump for an a/c car.

 

[Davea Lux]

I don't know if your car is an a/c car or not but one trick on non a/c cars is to use the water pump for an a/c car.

Going to a high fin count A/C radiator core would also help. Use the cast iron A/C pump as well as noted above.

Dave

 

[CBODY67]

Thanks for your reply. I suspected you'd already looked at some of the things I mentioned.

I think the aluminum water pump housing was more for weight decrease than for better cooling performance. The drive pulley ratio is different from a/c to non-a/c engines. This probably means the 6-vane a/c water pump runs faster than the non-a/c pump to move the same amount of coolant.

One thing about head gaskets is that the holes in the metal (non-stainless steel) flow restrictors can increase in size with age and poor coolant service intervals. Therefore, too much flow to be as effective as a heat-remover as the coolant could be. Not sure how much the incremental size increase might affect total flow, though. Slowing the flow can decrease turbulence and hot spots of the water jacket surfaces, very possibly.

When I can find them, I like to use the Robert Shaw-style of thermostat, but the normal styles work well too. 180 degrees, of course. Never could tell a big lot of difference on the gauge, but knowing it was "better" helped a little.

Thanks,
CBODY67

 

[Gerald Morris]

Going to a high fin count A/C radiator core would also help. Use the cast iron A/C pump as well as noted above.

Dave

Got the cast iron pump and housing off 69 commando 383 this afternoon. My current radiator is a 2524984 sort, which was rated for AC, auto trans and hi altitude. I'm looking at an aluminum radiator w 1 " tubes to replace it, though I WILL keep the old one. Those are highly rated radiators. Have a steel fan shroud for a 22" radiator from a 65 Imperial which I can put on when all else is done too. Just a question now of time to change stuff out, and money for the new radiator. I like the pump I picked up today! Original w the 8 blade impeller, matching serial numbers and pentastar logo. THESE can be rebuilt!

 

[Gerald Morris]

Here is the lovely pump I scored today. The fellow who sold it is quite a gentleman too. He scoured this thing clean w hydrochloric acid to give it the nice clean iron look you can see in the pics I cribbed from his Craig's list ad. Note how there is no breakable flange for the thermostat housing on this particular model. That was what motivated my original search for the aluminum housing I wound up purchasing cheap on eBay and trying. My old housing had cracked at the thermostat flange due to the former owner over tightening the bolts due to his negligence in removing the gasket! I got this beauty for less than I gave for the sino-rubbish I've used the past year. Mind you, at FIRST, and for last summer, it SEEMED OK, w Tilly only running about 5 degrees warmer. I dismissed that as statistical noise then, but with this early spring and her already running up to 210 occasionally, I got alarmed. I'll install the housing and keep the Gates pump I got last year unless I see something grossly amiss with it, then get the new radiator. If that doesn't cool Tilly down I'll have to dig into the block itself. Compression was between 125-160 psi on her cylinders last Fall, so I'm not apt to believe that the head gaskets have any leaks, yet..... Of course, the bell curve shape of the compression readings with the front and back ones low and the middle cylinders high indicates there has indeed been a good bit of wear and aging. I reckon I should just rob a bank or something maybe.....

 

[Gerald Morris]

Try Evaporusts thermocool.THERMOCURE™ - Cooling System Flush - Evapo-Rust

Worth a 2nd look. Thx

 

[66Newyorker]

www.dodgecharger.com/forum/index.php?topic=60599.175

Here is good reading about the output of 9 or 10 different water pumps.

 

[Gerald Morris]

www.dodgecharger.com/forum/index.php?topic=60599.175

Here is good reading about the output of 9 or 10 different water pumps.

Muchos gracias! I was LOOKING for that one! Will bookmark it this time.

 

[66Newyorker]

 

[fury fan]

What did that hydrochloric acid do to the seals on that pump? There's a spring and a carbon seal in there, I believe, and maybe also a standard lip-seal to seal it externally?

 

[Davea Lux]

What did that hydrochloric acid do to the seals on that pump? There's a spring and a carbon seal in there, I believe, and maybe also a standard lip-seal to seal it externally?

Toss the pump. Acid will have intruded into the bearings thru the seals and the bearing will fail in short order. Never use acid of any type on any Mopar cooling system! The housing is probably ok. Coolant going acidic is why things rust up and fail to begin with, more of the same is not going to help as acid will continue to degrade the iron and bearings long after it has been drained out.

Dave

 

[Gerald Morris]

Toss the pump. Acid will have intruded into the bearings thru the seals and the bearing will fail in short order. Never use acid of any type on any Mopar cooling system! The housing is probably ok. Coolant going acidic is why things rust up and fail to begin with, more of the same is not going to help as acid will continue to degrade the iron and bearings long after it has been drained out.

Dave

Good advice. I DIDN'T plan to use the pump. Just the housing. My Gates pump is doing very nicely w the new radiator. These Gates look pretty close to the heavy duty w-AC Mopar pumps of yesteryear. Thanx all the same Dave. My next cooling project will be to make a good custom shroud. Summit Racing sells a kit that looks MOST promising. It occurred to me putting a pusher electric fan in front of the radiator might alleviate heat in stalled traffic too, but its NOT an efficient solution, while directing airflow properly is!

 

[Davea Lux]

Good advice. I DIDN'T plan to use the pump. Just the housing. My Gates pump is doing very nicely w the new radiator. These Gates look pretty close to the heavy duty w-AC Mopar pumps of yesteryear. Thanx all the same Dave. My next cooling project will be to make a good custom shroud. Summit Racing sells a kit that looks MOST promising. It occurred to me putting a pusher electric fan in front of the radiator might alleviate heat in stalled traffic too, but its NOT an efficient solution, while directing airflow properly is!

Summit also sells a repop 26" shroud that works well. It won't have factory stock numbers on it but will function and look as the factory unit did.

Dave

 

[fury fan]

Keep in mind that different shroud shapes (flat plate vs contoured) will affect its performance. Those features are low in % improvement, though - merely having a shroud is the big jump.

The 'proper' immersion of the fan in the shroud is next biggest gain, and this varies with each fan/shroud combo. At least it's easy to experiment with shims on the fan. Quantifying the results will be difficult.

The biggest improvement gains to a shroud are to tighten the tip clearance to teh fan as much as possible. but with the fan and shroud mounted independently of each other (due to motor mounts and other bushings) the risk of contact limits how close you can get. Some diesel engine setups have a shroud-ring rigidly attached to the engine, with a flexible rubber thing to connect to the shroud on the radiator. Those can be pretty efficient shrouds.

A shrouded electric fan on the rear side of the radiator, without an engine-mtd fan, probably offers the best chance of high efficiency. Shroud should be contoured, though, to be a funnel and not a simple flat plate that restricts airflow. A fan array of smaller-dia fans will actually give the largest area coverage of the radiator core, and could run fans individually based on cooling needs. But even 4 fans would be a little silly for a streetcar? On top of that, 1/2 the fans need to be opposite rotation to reduce stress and noise where the bladetips pass each other, or need to have a divider-fence between them.

(sorry, former fan application engineer...)

 

[FURYGT]

Got the cast iron pump and housing off 69 commando 383 this afternoon. My current radiator is a 2524984 sort, which was rated for AC, auto trans and hi altitude. I'm looking at an aluminum radiator w 1 " tubes to replace it, though I WILL keep the old one. Those are highly rated radiators. Have a steel fan shroud for a 22" radiator from a 65 Imperial which I can put on when all else is done too. Just a question now of time to change stuff out, and money for the new radiator. I like the pump I picked up today! Original w the 8 blade impeller, matching serial numbers and pentastar logo. THESE can be rebuilt!

Your first step after swapping housings in my opinion is to get a shroud. If that does not work I agree with getting a new radiator core - a 3 row, narrow fin high capacity core.

 

[Gerald Morris]

Keep in mind that different shroud shapes (flat plate vs contoured) will affect its performance. Those features are low in % improvement, though - merely having a shroud is the big jump.

The 'proper' immersion of the fan in the shroud is next biggest gain, and this varies with each fan/shroud combo. At least it's easy to experiment with shims on the fan. Quantifying the results will be difficult.

The biggest improvement gains to a shroud are to tighten the tip clearance to teh fan as much as possible. but with the fan and shroud mounted independently of each other (due to motor mounts and other bushings) the risk of contact limits how close you can get. Some diesel engine setups have a shroud-ring rigidly attached to the engine, with a flexible rubber thing to connect to the shroud on the radiator. Those can be pretty efficient shrouds.

A shrouded electric fan on the rear side of the radiator, without an engine-mtd fan, probably offers the best chance of high efficiency. Shroud should be contoured, though, to be a funnel and not a simple flat plate that restricts airflow. A fan array of smaller-dia fans will actually give the largest area coverage of the radiator core, and could run fans individually based on cooling needs. But even 4 fans would be a little silly for a streetcar? On top of that, 1/2 the fans need to be opposite rotation to reduce stress and noise where the bladetips pass each other, or need to have a divider-fence between them.

(sorry, former fan application engineer...)

NO need to apologize! I DIG engineering level detail, being a EE myself. I can see how the old Mopar metal shroud I have funneled air to the fan. Having a 22" radiator makes things interesting. Mind you, its only when I have to eat other drivers exhaust heat in stalled traffic now that I still see temperature go over 210 F, but I DON'T want this, ever, if possible.

The flat cake pan kit shrouds from Summit look weak, but it might be the only viable option. I like some of the deep funnel shrouds I see, but am not impressed with their dimensions.

If worst comes to worst, I suppose going to an electric fan, bigger alternator and such and ditching the belt driven fan will be the thing to do. I know an old C body, (and B & A body) Mopar guru here who prefers this approach.