[Old Goat 67]

Would love to have seen a side shot of the impeller, but it looks like it has some curve to the vanes.

Let's talk about water flow and air flow for a minute. If you have the cap off the radiator, engine warmed up and rev the engine, do you get an aggressive movement of water past the neck? Relative I know, but when I did that on mine with a cooking thermometer in the neck, it jumped up & out of the cap opening.

How about some shots of your fan and shroud? To tell us how the fan fits in depth and circumference of opening to shroud.

How about rubber baffles in front of radiator? Are there seals to the bumper and surrounding the radiator at the core support?

[67Twistytee]

The fan is the stock 19.5" seven blade for a/c cars. Is mounted 2/3 in the shroud and 1/3 out. Not much space between it and the shroud circumference and It seems to be pulling air through well. Unfortunately the shroud was cracked through at the top and deflected into the fan last night. I lost a 4 inch chunk of plastic. I got a new one today and will mount it after I redo the pump. I'll post a photo tonight.

I would say I have steady flow across the top of the rad but not aggressive. Certainly would not make a thermometer jump. I may have cooked the t-stat when it overheated so will replace that again too. I'm guessing it's still a pump flow issue and hoping the new divider plate helps reduce the clearance. It seems flatter and less convex than the original plate so maybe that will help.

I have the original lower seals for the a/c radiator that I plan to remount. I think you responded to a question when I posted photos. Not sure about rubber baffles in front of the radiator. Will have to check tonight and report back.

[67Twistytee]

Attached is a side shot of the impeller on the Napa pump;
a shot of the corroded divider plate;
a shot of the clearance with original housing & divider as on the Napa pump when it overheated;
and a shot of the new housing and divider after adjusting the clearance.

Hoping the tighter clearance does the trick this time. Also drilling a hole in the thermostat for air bleed.

[67Twistytee]

Two photos of the fan depth in the shroud and the damage from where it cracked and then deflected into the blades. I purchased a replacement shroud to replace the damaged one.

Charles, I checked and I don't have the A/C side seals as shown on 6A-11 & 6A-12 of the service manual. I do have the lower seal and retainer assemblies which I plan to re-install. The top rubber seal is there but has a bit of a gap between the radiator and bumper. Is there an after-market source for the side seals? Any chance you have a photo from your car you can post?

I appreciate all the help and advice from those who've responded. Hopefully the third time is the charm.

Andy

[Old Goat 67]

Andy,

The pump looks like it should be good. The Fan looks like it is in the proper position.

Here is a clearer photo of the arrangement behind the bumper and a shot of the right side of the replacements I made for mine. I did not buy the kit of pre-cut pieces, rather just went down to my local Rubber House and procured a length of 1/8" masticated rubber to make new pieces using the old ones as a pattern.

The side ones on the radiator are not shown here but they are just pieces doubled in the sides and secured to the core support. I could find you a better picture I think.

The top one is shown in the third picture.

I've never really run mine without those baffles, I think you may be on the right track with the fact that you state that it gets hot at speed.

Charles

[67Twistytee]

Thanks Charles.

I don't have the original side seals to use as a template, but ginning up something like you did looks like a good option. Not sure if there is a local building supply around here to source the rubber but I'll look around.

My car didn't come with the metal finger guard originally, just the fan shroud. I'm sure the crack originally developed from leaning over the front and putting pressure on the plastic. I may install a guard just to prevent a repeat of yesterday.

[67Twistytee]

By the way, very clean engine bay - impressive

[Old Goat 67]

Andy,
I'll look tomorrow and see if I still have the old pieces I can get measurements from.

Mine is an AC car also and didn't have the finger guard either, added for same reason. Couldn't get people to stop trying to lean on it.

Charles

[67Twistytee]

I found them Charles so I have all the baffles. The rubber on the lower ones is dry rotted so I'll replace and remount those. I also found the lower mounting bolts still screwed into the frame and useable. I plan to refill the system tonight and do another test run for temps. Hoping these changes solve my cooling issues.

[Old Goat 67]

Andy,

Try searching for a rubber supply house locally. If you need, I can procure a piece in Baton Rouge and ship it to you. Masticated rubber is what they call it. Impregnated with fiber for strength.

Charles

[GT182]

Andy, I've seen Charles' GTO and what he did is even better than the original seals. Looks like a heavy duty tunnel ram for the radiator. LOL

[67Twistytee]

It looks great from what I can see of it in the photos Gary.

I found a rubber supply house out by the airport but didn't have a chance to call yet on the masticated sheets for the baffles. I need to replace one of the fender splash guards too. I was able to use most of the original material on mine except for the vertical uprights on the bumper mounts. As a short term solution I used some rubber mud flap material from Wally World and cut to fit the original patterns. I had all the hardware still so they mounted up without too much effort. They haven't been on the car since it was stored in the late 70's. Mini miracle that the baffles and hardware stayed intact with the car all these years.

I decided to wait and fill the radiator in the morning. Hoping for a steady and cool first run with the new divider plate, fan shroud, and baffles in place. Is there a way to test the fan clutch? It was replaced in 2001 and I assume it's still working. No wobbles.

[Old Goat 67]

Originally Posted by GT182

Andy, I've seen Charles' GTO

Seen it and driven it, I might add. Seems I remember him saying something about the temp gauge needle being painted on at 180°, it really does function correctly all the way across the scale.

[67Twistytee]

Well I had partial success. No leaks and good aggressive flow of coolant through radiator once the t stat opened. It stayed pegged at 180 while under idle in the garage. After 10 mins of driving it got up to 195 at street speeds (30 - 40 mph). When at a light or behind traffic it climbed again and ranged between 200 - 210. Couldn't tell if it would keep rising and I didn't want to risk another overheat situation so I took it back home.

So:

180 Stant superstat (verified working on stove and also with temp gun on car) drilled for air vent;
Napa rebuilt pump, cast impeller, new divider plate and housing clearanced per heating & cooling thread;
Good flow of coolant through radiator;
16 psi radiator cap;
Original 19.5" fan with replacement thermal clutch (2001) - not sure how to identify manufacturer but it appears to be working;
Replaced fan shroud and ensured proper clearance to fan blades;
Clean a/c condenser and original Harrison radiator (recored in 2001);
All factory a/c air seals now in place around radiator

I plan to work on the timing this afternoon and update this thread.

[GT182]

I don't know if I'd run a 16# cap Andy. I've been running a 13# with no problems. But then again my 3 row radiator was recored and is now the same a 4 row.... extra tubes and fins. I can run at 180 all day but at a long traffic light the temp will go to 190/195. As soon as I get rolling again it drops back to 180. Also check to see if the vacuum advance on the distributor is working. That will affect your timing. If you blow or suck on the hose and get air... time to get a new one.

Charles, I didn't want to scare anyone that I'd driven yours. Besides if you recall, I almost wet myself. LOL

[Old Goat 67]

Andy,
I have a couple of thoughts here.

Seems to be you either have an air flow problem at speed or timing problem. Wondering if you have a fan clutch problem or maybe bad vacuum advance canister?

GT182 had the later problem which we proved by sucking on the hose and holding the end closed with the tongue. His vacuum advance was totally not working, easy to see with the distributor cap off.

Has the fan clutch been changed yet? I replaced my original unit with a Hayden from O'Riellys. $50.00

http://www.oreillyauto.com/site/c/de...3389&ppt=C0331

[67Twistytee]

I checked the vacuum advance per Gary's tip below and didn't get any air so I think it's ok. I do agree that it must be timing or maybe the clutch. The clutch was replaced about 6k miles ago when the car came out of storage in 2001 ( I can't tell looking at it who the manufacturer was). Maybe I should change it again? Would running manifold vacuum rather than ported help the advance? It's currently running of the driver's side nipple on the carb which I believe is the only ported source on this Qjet.

[Greg Reid]

My question would be why is it suddenly running hot with nothing changed but the water pump?

[67Twistytee]

Not sure why. It was running warm pre pump swap (210 - 220) but never overheated and the light never came on. I added a mechanical gauge and started with the pump first suspecting a stamped impeller, which is was. I've then been going down the rabbit hole of all the possible contributors.

I just checked my dwell angle which was off. It's now set at 32. Initial timing is set at 6. I had to jump on a call so haven't been able to check advanced and total timing yet. I did discover a small vacuum leak that could be affecting my advance. The T intersect where it joins the vacuum hoses that pass through the firewall to the dash controls was coming loose. The vacuum hoses to the dash controls are still original and becoming hardened making it difficult to get a good seal. The advance ties in at this T intersect.

Btw- I'm still running the original 400, standard bore with a 068 cam. I haven't changed the pistons yet to lower the compression. It's in my longer term plans.

[Old Goat 67]

Originally Posted by 67Twistytee

I checked the vacuum advance per Gary's tip below and didn't get any air so I think it's ok. I do agree that it must be timing or maybe the clutch. The clutch was replaced about 6k miles ago when the car came out of storage in 2001 ( I can't tell looking at it who the manufacturer was). Maybe I should change it again? Would running manifold vacuum rather than ported help the advance? It's currently running of the driver's side nipple on the carb which I believe is the only ported source on this Qjet.

This car was designed for full manifold vacuum. Run the vacuum line to the manifold, not the vacuum going inside the firewall. I have always run mine that way.

I would change it to full vacuum with 10° advance on timing. Timing set with vacuum advance on dist disconnected and engine side plugged.