BBC Water pump and thermostat question

[AJs72K5]

Pulling the engine out for yet another cam swap (that's another post). While it's out, I'm going to change out the water pump....I've been running a Weiand that was on the engine when I bought the Blazer.

For those not in the know, it's a healthy 496 set up for a long, mechanical water pump....and I live in South Texas. Is the Edelbrock BBC water pump worth the extra expense?

I've also been running a 192* thermostat....should I change for any reason?

 

[nvrenuf]

I wouldn't mess with it unless you were having problems.

 

[bp71k5]

You’re running a serp setup right? Make sure you get the counterclockwise vs clockwise pumps correct. I’ve been happy with my stewart aluminum pump. I just wanted aluminum reverse rotation so I wouldn’t have to paint it. Seems to cool fine on crazy hot days, but it’s not quite as hot as Texas.

 

[AJs72K5]

You’re running a serp setup right? Make sure you get the counterclockwise vs clockwise pumps correct. I’ve been happy with my stewart aluminum pump. I just wanted aluminum reverse rotation so I wouldn’t have to paint it. Seems to cool fine on crazy hot days, but it’s not quite as hot as Texas.

No, not full serpentine. I'm running March brackets with two 6-rib belts... still standard rotation.

 

[dyeager535]

No, not full serpentine. I'm running March brackets with two 6-rib belts... still standard rotation.

I second not changing a thing if you weren't having problems. Quality of replacement parts is spotty at best, almost across the board anymore, regardless of whose name is on it. Always better IMO to change one thing at a time anyways, because if there IS a problem, you know it can only be what you monkeyed with.

 

[6872xtc]

While I agree that if you have no problem with the current pump, I will say that the Edelbrock pump on my '70 works well.
It's only a 462 with a small roller cam, but I do have A/C and an aluminum radiator.
I bought the Edelbrock due to how they present the design and testing done to the product.

 

[dyeager535]

While I agree that if you have no problem with the current pump, I will say that the Edelbrock pump on my '70 works well.

I'm assuming the Weiand pump is probably a "better than stock" replacement. Could be wrong, just part of my thought process.

 

[6872xtc]

I'm assuming the Weiand pump is probably a "better than stock" replacement. Could be wrong, just part of my thought process.

I agree with you there , for sure.

 

[AJs72K5]

While I agree that if you have no problem with the current pump, I will say that the Edelbrock pump on my '70 works well.
It's only a 462 with a small roller cam, but I do have A/C and an aluminum radiator.
I bought the Edelbrock due to how they present the design and testing done to the product.

It runs on the hot side. 205* at cruise. I've seen it go above 210* at a stop light during the summer. That said, I don't doubt the self learning tune with the current cam plays a part in that.

 

[nvrenuf]

Well, if it's getting a little warm then I can see moving to a 185° thermostat.

My old 454 had a 185° thermostat and ran right at 195° no matter what I did (street or bogging), this was with a belt driven fan & severe duty clutch. My current 454 has a 195° thermostat and wanted to run like yours around 200°-205°, I've had to shut it off and let it cool down once because it was slowly climbing. I've now changed to 185° thermostat but have yet to run it hard with it.

 

[6872xtc]

205* during normal driving is close to normal with that thermostat temp, isn't it? I found lots of vehicles run just under 210* with a 195 stat.

 

[nvrenuf]

Most "modern" engines are designed to run around 210°, I guess it just depends on how well the cooling system can maintain that.

 

[bp71k5]

Yea, thermostat just sets the minimum operating temperature, not the maximum. Max temp is dependent on engine load, radiator, water pump, and cooling fans.

 

[6872xtc]

Most "modern" engines are designed to run around 210°, I guess it just depends on how well the cooling system can maintain that.

True, but I don't really believe that an '87, (first TBI) is modern.
But I believe that you were involved in a discussion along these lines sometime ago. I believe that the last line in your statement surmised it.

 

[dyeager535]

What's the radiator like?

I went through this with mine, temps gradually got to the point where they would climb under long, heavy load on the freeway. Fan worked overtime to keep temps from getting out of control, but it was working harder than it should have, and over time I watched it get steadily, slowly worsen. Putting a new engine in it made a significant difference in how hot it ran too, even though I changed nothing on the cooling side. Same waterpump, same radiator, same hoses, same coolant even.

New radiator, temp is rock solid. POS plastic/AL to boot.

 

[AJs72K5]

It's an Entropy two row aluminum radiator with two 12" Spal puller fans,

 

[diesel4me]

The '80 El-Camino I had with a 267 V8 and 2:56 gears,TH350,used to run at 220 degrees on the dash gauge all the time--didn't think it was accurate until I added an aftermarket water temp mechanical gauge,and it read the same temperature..

The thing never boiled over once,even on the hottest days of the year,and the radiator was in nice condition,no leaks,new 195 thermostat,good water pump,etc..since it never "pinged" or acted like it was overheating,or peuked any coolant out-- I learned to ignore the gauge and decided it was "normal" for a small engine with tall gears to run hot..never gave me any trouble the 4 years I had it ..had great heat in the winter too!..

 

[dyeager535]

It's an Entropy two row aluminum radiator with two 12" Spal puller fans,

And its in good/great shape internally? Not sure how it happened, but I've seen folks have a radiator stop working efficiently in two years. Did everything short of replace the engine (to include head gaskets) because they "knew* the radiator had to be good!

 

[AJs72K5]

Positive the radiator is good inside and out

 

[dyeager535]

I'd say run it. I've got a "high flow" AL pump that I think is GMB to throw in the truck, but it's obvious that the radiator is doing it's job and the stock replacement pump is up to the task as well. When I can get around to testing the smaller radiator, I am thinking the better pump may be needed to help.

If the cooling system can't maintain thermostat temperature (whatever you run, but really no need to run anything other than ~195*), then you need to think about addressing that. But doesn't sound like you ever noticed an issue.

Only options to potentially combat overtaxed cooling system, is to increase coolant capacity, move fluid faster (physics is the rule on that one, not anecdotes), increase surface area of the radiator, or increase airflow. Hell, what I could access on the heads I put on the last engine, I took out as much excess material in the cooling ports as I could. Some are worse than others, but I figured any little bit would help.

I also think it would be interesting to plumb in a "reservoir" that increases fluid capacity, because that seems to be much of what GM did when they used the huge radiators in these trucks (The opening in the core support to allow air to enter is fixed, and much smaller than the radiators). But finding something low-cost enough to test this, that is easily plumbed in, has been impossible so far.