[69-er]

Originally Posted by STVSHOBRD

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

I noticed too how the housing and divider plates don't fit very well at all on the 8 bolt pumps. The hole in the housing that transitons to the hole in the timing cover doesn't line up very well either. They can move around a bit.

I wonder if using a few spots of epoxy to hold them in place to prevent them from moving while the is installed might be an idea. I even wondered if an attempt at closing the gaps betwwen the edges of the plates and timing cover with a good sealer might help too.

[69-er]

Originally Posted by Slick

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 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

I had the exact same problem after installing new cam bearings and cam in my 68 400. It would alternately turn ok a few degrees and then tighten up considerably. The machine also suggested scraping the cam bearings. Using a magic marker, I coated the bearings to see where the interference was. But after several trys, it wasn't helping and the bearings wear looking like hell. I couldn'e see how this hand-"machining" was worth a darn!

So, I chucked the cam up to a lathe and discovered the cam was bent about .006"! The bearing clearance is only .002", so it was obvious that the cam was gonna wear the hell out of the bearings when the engine was started.

They got me a new cam and bearings and everything turns smoothly now.

[69-er]

Originally Posted by 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!

What thermostat are you using? I have noticed quite a few posts that after everything is cooling OK, they are commenting on how the temps vary at idle, town and highway cruising.

It seems to me that, theoreticaly, a cooling sytem will cool an engine down to a certain point at a given ambient temperature and load. If the t-stat is set above this point, it should always be able to cool the engine at the t-stat's setting. That allows the t-stat to control the temp, not the engine's cooling system maximum ability.

Does that make sense?

[69-er]

Originally Posted by PMDRACER

The impeller is pressed onto the shaft with a tapered fit, like a ball joint in a spindle. Unless you created some sort of sleeve or other retention device, you will not be able to move the impeller towards the plate.

I didn't find that to be the case in my situation. Both pump's impeller shafts were straight, not tapered.

Larry

[aronhk_md]

Nothing personal here about the discussion. Nobody ever accused me of being nice, and I'm not always. I dont have time for the pump quiz tonight, but for those interested pump/flow dynamic info is all over the net and you can find graphics showing where hi and low pressure is on a pump. Same info is out there on air and water based propellers.

Meantime, have fun everyone...summer is over and winter is a good time for wrenching.

[ronaldrust]

Hi George,

Have read most of the post about overheating. Have a question. Have a 67 gto so have a water pump with two divider plates. Have 1/4 inch gap at the tip of vanes and about 1/2 inch gap at the back ends of the vanes. When you say close the gap are you referring to the gat at the tip or the opening of the plate. Reducing the gap at the end of the vanes closes the distance between the two plates and has the chance of closing the opening for the water flow to the right side of the engine. Can you please clear this up for me.

Ron

[george kujanski]

Sorry for the late response...didn't notice your post till today....don't know why....

I suggest you check the pix in the first few pages of this thread...OldGoat_67 posted pix of his two water pumps; a replacement from several years ago with a large gap between the edges of the vanes, and a new replacement that has higher vanes and therefore closes the gap. It's this gap which should be minimum; too large a gap and water from the pressure side (towards the cylinder banks) will recirculate around the impeller disk to the large round inlet instead of the impeller pulling coolant from the radiator lower hose.

He was able to find what looks like the correct impeller for his application; the previous one was not.

If you can't find a pump with a similar impeller, the gap needs to be closed up, but as you say, the divider plate should be centered on the impeller height to divert the flow equally to the cylinder banks.

To close the gap, you can try pressing the impeller on the shaft to compensate, if the divider plate still ends up in the proper position, or adjust the internal housing to close the gap with the impeller you have to maintain the divider plate position.

I don't have an 8 bolt pump with the divider plate, but the pix from OldGoat67 tell the story pretty well.

George

[Old Goat 67]

If you stop and think about it, for maximum efficiency you need the impeller and divider plate to conform to each other as best as possible across the face of the impeller, otherwise you will have turbulence and therefore "cavitation" so to speak which will result in decreased performance of the pump. JMO.

Charles

[GT182]

I'm going to jump in and probably put my foot in my mouth as I've done before.

I've no idea who built the water pumps for GM in the 50s, 60s, and up to the end of the 81 model year; but I bet the gap between the divider plates was a closer tollerance than what we get today. And is one reason we didn't have the overheating problems like we're having now. Pumps we're buying today seem to just be 'slapped' toether with no thought put into the gap and how close the impeller needs to be to the divider plates. It's not always a question of do I need a new radiator or not, but a question on how careful the pump makers of today are on the quality of the pumps they're sending out. Do they even stop to think on how close the gap needs to be or not? And has anyone seen a new or rebuilt pump in these times that needs no tweeking of the divider plate?

These aren't Chevy water pumps that need no tweeking like our Pontiac pumps do today. They slap one on and have no problems or worries like we do.

BTW, I'd still like to find out why there is that keyway in the original divider plate for the 8 bolt pumps, and none in the new repos. It had to be there for a reason, and someone somewhere must know the answer.

[Old Goat 67]

Read page one Gary. The pump I found required NO tweaking of the plate.
Kinda like finding a needle in a hay stack.

Charles

[aronhk_md]

Gotta figure.....they push the impeller onto the shaft. Even if they don't have a clue what proper tolerance is they KNOW it has to go on at least SO far or it hits....so they are instructed to make sure its put on at least that far. Its no wonder that some are going to by accident be pushed on the perfect amount....lol

[GT182]

Originally Posted by Old Goat 67

Read page one Gary. The pump I found required NO tweaking of the plate.
Kinda like finding a needle in a hay stack.

Charles

Page one read... several times. And yes, I say your original divider palte withthe keyway. At least I 'believe' it's the original. Tho you have been know to, as they say, "pull my leg". LOL

True Charles, but let's say that's only one in a "million". Unless Cardone's pumps are all built to the same tolerances. And hopefully they are....

[67Dan]

I just had my water pump die and found out the idiot put a ½” spacer on the water pump which stressed the bearings and seals! Of course must have had alignment problems with probably wrong pulleys!

To the point, know Charles very well and about the 57 pages of the thread on water pumps and problems! Went out to find one like Charles’s which I promise you is a fluke! After bringing in 5 to 6 of Cordone’s which are very well built reman pumps, but wrong as far as the clearance of the blades to the plates. Also saw three other brands that ranged from a sorry stamped steel new pump to some garbage that looked like from India and have no idea the manufacturer!

Bottom line I called Cardone and talked to their tech guy, told him about the problem, sent pictures and talked to Charles and had him explain to Stanley with Cardone what the issue is! Stanley as of today got all the emails with pictures and will be talking to the engineer to see what they can do!

Charles and I have talked at some length and noticed that on each Cardone pump they are shaving the blades back on the impellor! If they wouldn’t shave the impeller it might be way better than with the 1/8 to ¼” gap between the plate and impeller!
At this point the ball is in Cardones hands and I pray they may make a custom one for me to test on my 67 GTO! We will see!

I am curious about what other people have done to rectify the problem! If you pushed the plate in, how did you do it? One catalog talks about the Stainless plates which I have, being modified to work! What did you do and how did you do it and was it successful?

Did anyone come up with another solution? I notice The Flow Cooler water pump with all kinds of amazing claims. Anyone try one? Results? Worth the money?

Dan Mascheck
Wharton, TX

[Old Goat 67]

Good news, I THINK.

Gary Carr (GT182) and I just got off the phone with Therese Lal at Cardone. She has listened to us for 32 minutes and has agreed to get the engineers to have a conference call with us and possibly have a "show and tell" session with Gary in the near future.
Time will tell, but I brought up the company values off of their website.
http://www.cardone.com/English/Club/...te/default.asp

She was very receptive I believe and seemed interested and willing to help.

Charles

[GT182]

Originally Posted by Old Goat 67

Good news, I THINK.

Yeah same here...

I'm going to try and get Chris from PY involved too.... a Team effort. Hopefully he'll be willing lend a hand too and be our backup.

[Old Goat 67]

Conference call scheduled by Therese with head of engineering department for next Wednesday at 1315 hrs.

We will report back when that's over.

Charles

[67Dan]

Originally Posted by Old Goat 67

Conference call scheduled by Therese with head of engineering department for next Wednesday at 1315 hrs.

We will report back when that's over.

Charles

Well all that seems nice, but I'm without a pump now! While I’m glad I got the ball rolling, it may be a year from now before they do something even as simple as it is! While you have been without your car for a year, I would have major withdrawal issues going more than a month!(GRIN)

Just got off the phone with Jonathan Amo with Gates. Nice guy! They make new pumps and I checked theirs and they have the same ¼” gap, but he is passing it upstairs, and he might be a source for bearings and seals for the two original pumps I ordered from Bob that will have to be repaired.
Here is Jonathon’s numbers and email address if interested.
Jonathan Amo
Application Research Engineer
Aftermarket Product Application
ASE Master Certified & L1

Gates Corporation
1551 Wewatta St
Denver, Co 80202
303-744-5605 -Direct Line
303-744-5069 - Fax
ja2010@gates.com

Now my immediate options are Flow Kool and there is one more I will call about to get some info on from Summit. After that I don’t have a clue unless someone on this board knows a miracle and I don’t want to slam my plates.

[67Dan]

Talked to Bob Divan the other day and found out he has some old original 1967 GTO pumps on hand! Of course they have to be rebuilt, and I have two coming to see if I can!
I asked for a picture of the fins and he just sent one!

Dan Mascheck
Wharton, TX

[GT182]

Originally Posted by 69-er

It just occured to me, why didn't the designers of this pump incorporate the necessary divider and housing into one assembly? The clearances would then be easily verifiable during manufacture.

69-er, this has been my thoughts all along. If Edelbrock can do it I'd think the rest could too. When I get to talk to Cardone or see them, that's what I want to suggest to them. Then they can say.....

"We believe the quality of our products and services is the most important issue to our customers; therefore quality is the foundation of our corporate culture.

We will produce products and services that meet customer requirements every time on time.

We will continually improve products and processes as the path to excellence."

[Old Goat 67]

Well guys and gals,

Just proved one thing to myself today. It's VERY easy to pull the impellor off of a water pump! Ten minutes, 7/16" coarse tap and a puller.



Charles