[67_400]

Forgot to post my update, seems like a combination of things were making my car run hot, this WP plate being way out of spec and even rotted out

And once I ditched all my MSD sh!t / slapped on a HEI / found my correct Poncho dist hold down and gave her like 12* initial and ~40 total, not only has the car never ran better but it stays at 180* HELL YEAH

[Junkyard Dog]

No heating problems, but when I stripped down my engine, I discovered that my water pump had the stamped impeller, so I will replace it.

[R68GTO]

I know I'm a glutton for punishment but after finally getting my 400 runing cool last summer (11-bolt) water pump, I decided to put a correct 8-bolt on it this winter. I purchased a correct pump (rebuit from autozone), cast impellar and also the stainless divider plates. Today I went to check the impellar clearance and it is over 1/8". The 8-bolt plates dont have as pronounced of a "crown" to tap down as the 11-bolt. I think I could tap the opening down closer but as I get toward the outer dia. of the impellar I'm afraid that there will still be a large clearance. It looks to me like the impellar is pressed on the shaft too far? The shaft is sticking out about 1/16? Has anyone tried to pull the impellar out? If so, how did you do it? Any other suggestions?

[Old Goat 67]

R68GTO,
I know I've moved them before, but I think it was just pushing it on farther.
Is there anything you can use on the impeller to pull with? If not, can you put a bit of pressure below the impeller, and tap the shaft easy to get it to come out farther?
Can you make us a picture to look at with you?
Maybe have them order another pump that doesn't have the impeller pushed on as far?
Charles

[R68GTO]

Thanks for the quick reply!

[Old Goat 67]

R68GTO,

Check my plate clearance on Page 1, Post 16.
I'm not sure you need to fool with that, what ya think?

Charles

[R68GTO]

Yours looks quite a bit closer than mine. Based on some of the other posts the .12" clearance I have is too much.

[merlemac]

I just had my water pump die on my 70' Bonneville and decide to follow the suggestions on this post. After checking local auto stores, I finally found a water pump with a cast impeller from Carquest. The first one off the shelf was a stamped version and didn't match the picture on their screen but they checked their inventory and found two pumps with cast impellers. I had about an 1/8 clearance from the plate to the impeller out of the box and worked it down to about 1/16". Put it back together and did a maiden voyage. Everything looks good (no leaks) and the car seems a lot cooler. Thanks for the great advice.

[STVSHOBRD]

Hello, My car is a 67 bird w/326. My old water pump started leaking so it's time for a new one. My old pump looks to be the good one. It has a 4 3/4 dia. cast impeller with 3/4" tall fins(6). After reading 50 pages it seems like finding a replacement should be fun.

Somebody in an earlier post asked this question and I believe nobody answered. My divider plates are the two piece type and the internal housing has a dovetail shape cutout at the bottom. The plates have some corrosion so I thought about replacing them with the stainless version. These do not have this cutout, nor does the pontiac service manual show this. Does it matter?

The clearance between the impeller on mine looks to be about .130, but the plates don't fit the timing cover very well. There is a dimple in the internal housing on the top just to the left of 12:00. It looks to be a stop so the housing can't go too far in, but if you push it in so it hits the stop your impeller clearance would at least double. Do you modify this so it doesn't move around so much?

Thanks for the info
Great thread
Steve

[Slick]

Great thread, the best I've seen (well maybe that girl of the day....).

I needed to read the whole thing first to be sure what I had to say wasn't already covered.

This thread has provided fabulous information on getting rid of heat and a little information about tuning to minimize heat production. There still seems to be an area not touched on and I wonder if many of the owners are aware of the specifications involved in their rebuilds?

It was always drilled in to me to avoid/ignore those old TRW piston/wall clearance suggestions of 0.002"-0.0004" or so (I don't remember the exact number). I was always told to run the pistons loose or the engine would heat up. I always fought with machinists who were Chevy guys who balked at setting 0.006"-0.008" depending on application. I usually had to sign a waiver saying I took responsibility if a skirt failed or some such. None ever has, thus far. Many times, when I came across a Pontiac that ran hot, or didn't seem to run "better than it should, for what it is", it seemed to have such machining performed (if the owner knew).

Another source of mystery heat in rebuilt engines is tight cam bearings. Frequently in 70's blocks I'd find that after having cam bearings replaced, the cam couldn't be turned in the block by hand (no valve train in of course). "Machinists" always seemed to want to grind away some cam bearing material with a knife. I sought out a shop that could cut the bearing saddles first, then the bearings crush just fine and the cam rotates with just a few inch-pounds of torque.

I wonder if either of these two (and maybe other) machining issues could be contributing to excess heat production by the typical rebuilt Pontiac engine?

Stuart

[dean7276]

My 78 T/A 400 ran at 200 around town/220 highway. I did the backing plate mod and sealed the shroud to the rad she now runs at 160 around town 180 highway.
I'd like to thank the guys who started this thread. I still cannot believe the difference in temps.Thank you,thank you,thank you!

[george kujanski]

It's good to hear owners are running cooler but I'm not getting any richer.

yep, it seems that over the years, the proper clearancing and pulley size information has been lost. Little known facts such as A/C cars having higher pump pulley ratios and improper pump setup have caused inadequate cooling performance on surviving Pontiacs where back in the day, cooling did not seem to be an issue. Compound that with scale and crud built up in the water jackets and we end up with the current situation.

Once known tho, we can deal with it.

George

[lester]

well i think i got other problems. i did all that to the pump. first off it a rebuilt 9to1 400 , new aluminum 3 row rad, 180 t-stat, two 12" fans, clutch fan. 16 advance on timing. rodchester carb. and running 220+
.030

[East]

I have read through this thread and wanted to wait until I tried two more adjustments before I posted the information but I'll just add the information after I complete them.

I bought a Rodney Red radiator for my 1969 Firebird about a month ago and installed it in place of the Griffin 6-567AE-BAX Camaro 67-69, TL BR, 1.25" w/transcooler radiator. The Griffin was purchased 0n 05/07/02 and had started leaking coolant around the end of 2008. I noticed that the outlet of the radiator that connects to the timing cover was eaten away quite a bit, as was the driver side of the water cross-over on the intake manifold.

I drained all of the old coolant and forced compressed air into the block after flushing with water. I followed the recommendations of Jerry Wirth and filled up with distilled water and fresh antifreeze. I bought eight 1/4 inch rubber packings for a faucet from the hardware store and dipped the new bolts with tool dip to insulate the radiator from shock and as an electrical ground. I am still a little confused about letting the radiator be a path for current. I was told to place a ground wire from the radiator to the body or engine. I thought that if the radiator was insulated from being grounded, the current would find another path. I am usually wrong but would appreciate the confirmation with this.

I drove the car back and forth to work for a week and noticed that the average temperature was 198 degrees. In the mornings when it was below 90 degrees outside, the temperature was 180 while the car was in motion. At the light, the temperature would climb to 190. In the evenings driving home (5PM), the outside temperature would be above 105 and the car was parked out in the sun all day, the water temperature would top 205 degrees at the light and drop to 189 driving at 45 mph between lights.

The next weekend was the water pump plate modification and water tube replacement. You can read about that debacle in the 69 GTO Water Pipes post. The water pump had the cast impeller and I modified the plate to very close clearances. I replaced the tubes with replacements from GM and drove the car for a week with the previous results of 190 degrees at 45 mph and 201 when at the stoplights.

I modified the top radiator hose and no changes.

I want to reinstall the Griffin and drive it for a week while the weather is still around 105 - 110 degrees. I have not used Water Wetter. The fan shroud mounted on the Griffin also positioned the fan between 1/3 to 1/2 inside of the shroud and screwed to the first bolt hole on the top. With the Rodney Red, the shroud fits flush to the radiator on the second hole (engine side).

The reason I want to try the Griffin is because it ran below 180 degrees at speed, and stayed below 190 even with the leak. That was also before I modified the water pump plate.

I figured that the Rodney Red's 1.00 inch tubes would be comparable to the Griffin's 1.25 inch tubes because it had several more rows of tubes from top to bottom. I will post the results of the swap in the coming week.

[Old Goat 67]

What you are dealing with is this I believe.

http://en.wikipedia.org/wiki/Galvanic_corrosion

[vidguy]

Just an update. I have followed this thread for years it seems.
I am putting my motor together and was getting the water pump plate clearance set. I did this previously on the motor that was in this car and this is the same newish water pump that I'm going to reuse on the new motor, but im using a new plate. I did the clearancing before using a hammer. I was starting to do it and was wishing for a more consistant "tweak".

So I put the plate between two blocks under my backyard press and used a large galvanized pipe nipple say a 3 inch diameter by 3 inches tall that just fit the round opening. I pressed it gently.. I ended up going back and forth to press it in and out but man did I get a super tight clearance that is real consistent.
Hope that helps someone.
BTW Thanks George (thread starter) I'll make a deposit in your Caribbean vacation fund!

[Nu2pontiac]

I'll be pulling my pump this weekend on my 65 Cat as my temps range from 190 to 225 with boiling gas in my center carb (after car runs for about 40 minutes it will not go below 200). Temp creeps up at lights and creeps down when moving. Has stalled out more than once when coasting down hills to a stop although I can keep it running by putting it in neutral and giving it some gas. Considering blocking off exhaust crossover on manifold (already installed a 1/4 wooden spacer between carb & intake to help with boiling problem). Back to the pump, what are the ranges of the height of the cast impeller vane heights on the 8 bolt water pumps? I saw some mention of it in the 50 pages but can't remember where.
Thanks! Rick

[george kujanski]

In the first few pages, Old Goat 67 shows two versions of the impeller vanes.....his original replacement pump had almost .5" of clearance whereas his new replacement pump had very little clearance and the vane height looked larger.

As far as the ranges of vane height, I don't recall if a list was developed in that thread.

George

[Old Goat 67]

Will be glad to help if needed.

Charles

[Nu2pontiac]

Looks like I get the honor of being the 1000th post. Way to go George!

Charles on Post 15 you wrote: "Tried the fit before bending the divider plate, and was surprised to see that the Cardone pump had vanes that were 3/16 " taller than the old one." Do you happen to remember what the total height of your pump vanes were on the Cardone pump? Thanks. Rick