Who is using a Max Performance Cold Case radiator AND their dual 12" electric fans shroud?

[biomedtechguy]

This involves "our" (my wife's) 1965 Pontiac 421 Tripower in our 65 GTO.
We have made a lot of changes, but I'll focus on what matters.
Vintage Air AC system, CVF Wraptor serpentine belt and accessories system, and a model specific Cold Case radiator and dual electric fan and shroud assembly they recommended that fits..well exactly like it's made for the radiator and car, very nicely.
Their radiators are the "advanced design" large tube type, 2x 1" tubes and 2 row in the case of the one we have.
The Wraptor changes all of the pulleys and accessories down to the timing chain cover, as that is the "back" of the water pump. The Wraptor water pump has the best impeller vanes (cast, not stamped) and is aluminum for heat dissipation, and has a higher volume than the factory pump.
Here's the impeller:

Here comes the "Pontiac wierdness"...
There's a divider plate that is installed in the timing chain cover, and then the water pump gets installed over that plate to the timing chain cover.
Here's what that looks like, notice the dome shape and hole in the middle:

sorry for the small pic.
Anyway that dome shape and hole edge has to be spaced away from the impeller vanes as tightly as 1/10th of an inch, or the pump doesn't work efficiently and overheating is a common problem with Pontiac engines. Since I didn't do the work I can only go by what the installer tells me. He says the gap is less than 1/8th" but more than 1/16th". I'm going to have him bring a piece of test equipment by to test the pressure of the cooling system. The idea is if the water pump assembly isn't working properly because of too great a gap, and it's cavitating or the gap is too big, pressure will DROP as RPMs RISE.
He wants to remove the 2x 12" fans and shroud assembly and try the mechanical fan. I'm ok with that, but I believe the gap is too big between the plate and impeller.

Anyone have any comments on first hand experience using the Cold Case dual electric fans setup?

 

[Ccas]

I understand most of what you have posted. That divider plate is for the OEM water pump. You'd have to confirm that the aftermarket pump is still suppose to utilize that OEM plate. I believe it should.
Anyway, the issue seems to revolve around the divider plate. So what is the purpose of removing the shroud and fan kit? I don't see the correlation.

The Pontiac community has a very similar forum community as the 'For B-body Only' community here. It's managed by our Parent company Max Performance Inc. I would highly suggest you post this same question there for some good advice.

http://forums.maxperformanceinc.com/forums/

 

[biomedtechguy]

I understand most of what you have posted. That divider plate is for the OEM water pump. You'd have to confirm that the aftermarket pump is still suppose to utilize that OEM plate. I believe it should.
Anyway, the issue seems to revolve around the divider plate. So what is the purpose of removing the shroud and fan kit? I don't see the correlation.

The Pontiac community has a very similar forum community as the 'For B-body Only' community here. It's managed by our Parent company Max Performance Inc. I would highly suggest you post this same question there for some good advice.

http://forums.maxperformanceinc.com/forums/

Thanks, I've already got a couple of threads and/or posts going over there. Great forum too.
Have you or your coworkers experienced situations where a Cold Case radiator with your fans and shroud assembly had overheating issues that were then resolved by switching the mechanical factory FAN back in, with the Cold Case radiator remaining in place?
The reason for removing the Cold Case Max Performance fans and shroud assembly is to determine if that assembly is the problem. That's what the installer wants to do, and a couple of respectable people with experience have suggested it.
I don't believe that is the problem, I think it's the gap between the water pump impeller vanes and the divider plate is too big. Checking the fans vs the gap is much faster and easier.
I haven't decided yet. Part of me wants to just dive in and "prove I'm right" and go after the gap adjustment, but the other voice tells me that is the most difficult area to reach, and I'd feel stupid if just swapping the fans to my mechanical solved the problem.

 

[Ccas]

Have you or your coworkers experienced situations where a Cold Case radiator with your fans and shroud assembly had overheating issues that were then resolved by switching the mechanical factory FAN back in, with the Cold Case radiator remaining in place?.

There's been a very few isolated situations where a car gets hot at higher speeds where our shroud traps some air from fully passing. This is very rare for a dual fan kit. The other reason might be because the fans are not properly installed and don't have the proper amps to pull enough air.

There's minor plus's and minus's but If both systems are installed properly, they yield very comparable results.

I think you are much more on the right track with making sure that divider and water pump is functioning properly. Cavitation problems will not be solved by any fan system and conversely, if the cooling system is functioning properly, our radiator is big enough to not require any shrouds at all. The Shrouds give you that extra 10 degrees. A shroud isn't going to solve other problems. Hope this helps.

 

[biomedtechguy]

The other reason might be because the fans are not properly installed and don't have the proper amps to pull enough air.

The best information I can provide regarding that concern is that each fan has its own relay and independent power circuit. I would think that arrangement would be the most conducive to provide the necessary power to the fans. The alternator is a 140 amp, so it's larger than stock by about 50 amps.
The installer did express a concern directed at the fans themselves in that they "only" draw a little less than 7 amps each of current, but again I have been "defending" not only the quality and performance of the fans, but the radiator as well.
One point I will make is when I asked why Max Performance/Cold Case used 2x 12" fans rather than a larger single higher CFM fan, the reply I got was misleading.
The way I took it was that 2x 12" 1,400 CFM fans provide more flow than a single larger fan. That may make some people think that the CFM of the 2 fans is additive, in other words 2x 1,400 = 2,800 CFM, when in fact it is still only 1,400 CFM, over the area of the 2 fans.
I AGREE WITH YOU, and I think that laborious task of having to remove everything to tighten up the internal gap between the water pump impeller vanes and the divider plate is going to solve the problem that that gap being left too large has caused, but I'm trying to explore the feasibility of other suggested solutions.
Thanks

 

[Ccas]

Sounds like it is setup correctly. You answered all the buzzwords. The only concern I have is the 7 amps. Our tests showed that the 12" fans peak at more like 17+ amps. So if they are only drawing 7 amps, they may be defective or something else preventing them from getting the full amps.

We do in fact promote 2800 cfm for the 2 12" fans. I suppose there is some cfm loss because the 2 fans could be sharing some of the pulled air? However, we maintain that the 2 1400 cfm fans will slightly outpull our single 16". Just as a side note, when we tested 2 10" fans on radiators where 2 12's won't fit, we got dismal results. In the range of 800 cfm each. So that's why we don't market any fans less than 12".

I'm certainly no thermo expert, but in real world testing, I'm sure there is some amount of air flow that you could pull through a 'defective' motor that would make it run at a reasonable temperature. I'm just saying that I don't think there is a practical air flow solution if what's behind that timing cover is not set up right.

It would be very revealing if you can get that car rolling at about 35-40 mph where some real air flow was passing through. I'd love to hear what happens to the temps because if they come down, then you can concentrate on air flow. If they go up, you are pretty much guaranteed that you have to deal with the water pump area or some other motor related issue.

 

[biomedtechguy]

The only concern I have is the 7 amps. Our tests showed that the 12" fans peak at more like 17+ amps. So if they are only drawing 7 amps, they may be defective or something else preventing them from getting the full amps.

All of this stuff was installed by someone, and he is the one who commented on the low amp draw, in a manner intended to impune the quality of the fans. I was not privy to the testing methodology, so while I am handy with a digital multimeter, I don't know what the testing parameters are.
So...how would I test the amp draw on the fans? Insert the multimeter in series with one leg of the power wire to the fan, right?

It would be very revealing if you can get that car rolling at about 35-40 mph where some real air flow was passing through. I'd love to hear what happens to the temps because if they come down, then you can concentrate on air flow. If they go up, you are pretty much guaranteed that you have to deal with the water pump area or some other motor related issue.

Well that's the thing!! On the way home from picking it up, we were doing 55 mph on the interstate. On my test drive, I was doing between 40 and 50 mph.
Those are the conditions where the temps rise. Once back home and stationary, both fans running, 900 RPM idle, the temperature drops quickly and steadily, appx -2° every 20-30 seconds!
HOWEVER
Raising the idle speed to 1,600 RPMs, the temperature immediately begins to climb, and THAT makes me think the water flow is the culprit.