[Old Goat 67]

Kevin,
Agreed, your impellor is not tapared as much as mine was. If it works, good....
What I am saying is that if the impellor and the chamber are a good match, there has to be efficiency there.
Perhaps we could get a professional reply from Malky on this?
Charles

[getmygoat]

To answer a few questions.... My radiator cap is a reproduction of the original A/C cap from Ames, seems to work fine.. Ames has good stuff usually.

George, my radiator appears stock in most ways, the radiator shroud fits normally, the radiator is definitely higher than the thermostat, etc. so I don't think the latest theory holds, but it was a good try!

I'll try running full coolant, but the sucker will probably just spit it back out again.

BTW, here's some pictures of the latest adventure:

[getmygoat]

Here's the custom water pump.. Its a NAPA 55-975 impeller on a '69 short case. Built by sandiegowaterpumps.com... You're looking at $115 worth of water pump.... Wow......

[getmygoat]

Assuming the impeller above looks good, here's the part you need....

[getmygoat]

And this water pump bravely gave its life so that my short neck pump could go on to cool another Pontiac.... (It must be getting late).

[getmygoat]

and here's a blurry shot of my clearance.. it doesn't get any closer than this boys....

[grandville455]

You know its funny when i did my cam swap 2 weeks ago i had a bad bearing in my pump so i changed it and guess what it had the pump with the stamped impeller never ran hot once and it had like 1/4 clearance!Figure that one out....So i put in one with the cast big impeller still runs the same..So it may not always be linked to the pump and that plate..JMO

[george kujanski]

GMG: actually, the stamped impeller you have looks good; tall, long vanes, I would think it would perform well, much better than the the stamped impeller on the 11 bolt pumps we have seen.
Gville: obviously it's not always about the impeller and plate. As jafuzz1 and GetMyGoat have seen, they have all the good pieces, but still have problems. One has to go back to the basics and eliminate the suspects one by one. There HAS to be a reason for the heating. Reading their posts baffles me also, but in the engineering biz I've learned that there is an explanation for everything; you have to be a detective to find it sometimes.

To reiterate the basics: You must have good coolant flow thru the engine and to the radiator. Maximizing the pump assy and removing restrictions are necessary. Pump speed. Look into the rad to make sure you have the flow. Minimize the waste heat generation from the engine: mixture, timing, vac advance. Maximize heat transfer from the hot radiator to the air; fan size, clutch, shroud. Have the proper amount of coolant, eliminate air pockets in the engine.

What about auto trans cars? Could there be a problem where too much heat is transferred into the radiator from the tranny coolant lines?

There HAS to be a reason for the problem. Don't get discouraged.

Deep thoughts......

George

[Rugratman]

O.K. I have a new question, With a new cast impeller, with the plate on, stick your finger in to the hole.
How far in before you touch the vanes on the impellor?
Is there a standard distance?
Should you be able to see the starting tip of the vanes through the hole? Mine seem to be farther in from the shaft.

[jafuzz1]

George, that is a good question about trans coolers...and last summer, I installed the radiator from my Lemans (manual trans) and installed an external cooler. Looked terrible, but it did seem to run just slightly cooler...like 5 degrees. My trans is also rebuilt-original to the car, and seems to work good. Running 3:36 gears. What about hot tanking the block? Can that do anything to the metal that may create some cooling issues? What really blows my mind about this whole thing is, that my car came from SoCal and spent it's whole life there, and ended up in Pheonix when I bought it. The car was complete, and had never been disasembled. Still had original belts and hoses. The only thing missing was the fan and clutch, and the radiator. Why did this car run down there with no apparent problems.

[george kujanski]

jafuzz1: What's the history of your car?
You've stated it spent it's life in SoCal, bought it in Phoenix. Any work done to it? You mention hot tanking.

One idea: in those areas, there is probably not much concern to run anti-freeze with it's corrosion inhibitors. If true, maybe there is a lot of rust and scale in the cooling jacket, impeding heat transfer to the coolant.


Another item that we tend to forget: reporting the temps, how do we know that the temp gauge readings are accurate? OEM gauges are not, as far as absolute values, but certainly show trends. If aftermarket, are the sensors attached to a proper location?

How about the sleeves that connect the divider plate to the block on each bank for a 11 bolt? Everyone have those in place with good rubber seals? If not, there goes the coolant flow.

George

[jafuzz1]

Yea, in '96 I bought the car in it's original state...however, had not been run in at least 15 years. Not sure of any history. There was no antifreez in the system because rad was missing. I rebuilt absolutely everything on this car from the ground up...no stone left unturned. In one of my previous posts, I mentioned the engine rebuild and components. The machine shop did all the milling, and I assembled. The block was tanked and cleaned...and came out looking great. Waterjackets looked very clean. I think it was '97 or '98 'till I fired it up for the first time while it was sitting in the rolling frame. It's had antifreez in it ever since, except last summer when I was trouble shooting, I used purified water. I even took the brand new radiator to the shop to take apart to see if the tubes were plugged with solder. The brand of rad is Dessert Cooler. Maybe this is a problem, but the rad shop said it should cool great. The gauges are AutoMeter Phantom...brand new, and check to be accurate with my inferred (I don't know the spelling) thermal gun. It has the original distributer, and the AFB. It seems to run great. I don't know what to think. I do know, this is the first time since the resto, that I'm excited to drive it on hot days, just have to shut it off when I get to my destination. And hope I don't get stopped in too much traffic. As a side note, even on the days when the gauge was nearly pegged, it cranked and started perfect...no heat soak problem.

[bills72sj]

I was directed to this thread by the 69GP72 group on Yahoo. My 72 455 SJ was running 220 in 85 degree heat on the open highway on a 2 hour trip. After reading the posts I decided to tear into my water pump to see what I could see. I found out I have the good tall, long cast impeller vanes but it had just under 1/4" gap between it and the plate. Using a piece of mushroomed flat stock and a hammer, I tapped the entire 6" perimeter of the plate to lower the entire ring down to the impeller. Hint: Put the water pump in a metal coffee can half full of bolts to hold the pump if you do not have a vise. Avoid letting the pump shaft take any impacts. Anyway I worked it all the way down until it just barely scraped. Adding the gasket provides the clearance needed to not rub but gives me the tightest reasonable clearance. I strongly suspect this will solve the problem.

As an aside, I solved a few other issues while I was in there. A broken bolt screwed into the block, leaking front crankshaft seal, a timing chain with LOTS of play, a water leak between the block and the timing chain cover, the bottom rubber insulators missing from the radiator shroud, cracks in the shroud, and the lower 4" of the radiator cooling fins totally clogged with dirt and oil. I also found out I have a 3 row radiator when I should have a 4 row radiator based on a GP with a 455 and A/C.

Thanks to all for the information and explanations which provided the motivation.

Bill N.
72 SJ 455 (Grand Prix that is)

[mc67gtoconv]

This is my first time posting,I have been reading this thread and thought I would try the divider plate clearance mod.I have a 67 GTO and I had a flowcooler pump which was not keeping my car cool.So I went to Napa and got the 58-299 8 bolt pump with high vanes. I am in the testing phase now.
I was running a little hot even with the flowcooler 220-230.I want to get down in the 190-200 range.I will report my results soon.This is a fanstastic forum.

[george kujanski]

Welcome, elk, almost in my neighborhood, I see. Looking forward to your results.

How about bills72sj? any news?

George

[mc67gtoconv]

Well I drove it to work yesterday and she was running about 200-210 and more stable,not as much fluctuation. But when I would get stuck at a light for a few minutes she would start to rise getting up to about 215-220 then cooling back down to 200-210 when I got moving again. A definate improvement!
This is with a rebuilt numbers matching 400 with a ram air 3 cam and 9.5 to 1 compression timing advanced to maybe 12 to 14 degrees (I don't have an advance style timing light) and she is running on the rich side to help with cooling,a 160 degree high flow Robertshaw,a HD 6 blade clutch fan.The radiator needs to be sealed to the shroud,but I have tried many different things to get her to run cooler.

[mc67gtoconv]

Oh ya, it has a harrison replacement type 4 core radiator with good flow,and I have a trans cooler(a large one)which is mounted below the the U support so it does not block any air flow thru the radiator,the car is a non A/C car.
The engine was rebuilt .030 over the first rebuild and about 4 years ago I had the engine rebuilt .040 over.
My next step will be to seal the radiator to the shroud with pipe insulation.

[JSchmitz]

Well, I'm going to add some info that hasn't been covered yet. I hope. I'm running a Flow-Cooler aluminum pump, Griffin 1-1/4" tube 26"x19" radiator, brand new 7 blade Hayden heavy duty clutch fan, no shroud (yet), with a 180 deg. stat with 3 holes drilled in it (like the one Stewart sells). So, that's my basic cooling system. Also, I have an 18# cap and a recovery system. I feel a recovery system is very important. It allows you to utilize much more of your radiator. As opposed to a "puke" system. The aluminum pump impeller is similar to the Carter pump. Except it has a sheet metal cup welded to it. So, the gap issue shouldn't be as important. I don't know what the gap is between the "cup" and the divider plate. There is a potential for the fluid to recirculate outside the cup. I will check it and post the findings. The info I hope to post is, the difference between the aluminum pump and a "good" factory style one. I went to six different parts stores looking for a good one. Five had a stamped steel impeller. One had a smaller than desired cast iron impeller. So, I will keep searching until I find a good one. I will post pictures and performance changes. I will say that at this time my system works pretty good. I drove the GTO looking for pumps. It was about 80 deg. outside. The car ran between 175 and 190 almost the whole time (while cruising side roads at about 45mph). Until I got stuck in about a half hour of stop and go traffic. It slowly crept up to 210. It immediately cooled down to 185 once I got moving. So, I think a shroud may be a big improvement. I'm fabricating one. I will be thrilled if the new pump makes a difference. I will post the results later.

[JSchmitz]

I also want to mention, I have always ran used clutch fans in the past. I've also ran a plastic flex fan, and a Black Magic 2800 CFM electric. I finally broke down and bought a new Hayden clutch. It made a big difference. Second only to the aluminum radiator. Clutch fans are the way to go.

[mc67gtoconv]

Even after sealing the shroud to the rad,I did not see that much of a difference in the temp especially when stuck at stop lights.It did help some,good for maybe 5-10 more degrees on average but it is still only in the 60-70 degree range outside.
I would like to know if anyone has had a significant temp drop with an aluminum radiator when all else has failed.
I have a severe duty Hayden clutch that is working good.
I am waiting on a rodney,hopefully in combination with the divider plate mod and other efforts of mine I will be able to drive without constantly watching that temp gauge.
It really takes all the fun out of cruising around.