[BVR421]

yes

[george kujanski]

Make sure that your measurement is done with the housing and the pump body in the final assembled position relative to each other. .2" is still a lot.

On a 11 bolt pump, for example, the plate-to-vane clearance can be as small as the gasket thickness for optimum performance, in fact that's how some members did theirs; adjusted the gap for contact without a gasket, then assembled with a gasket.

George

[mhgamber]

Pulled the pump off my 65 GTO, used a 5 lb sledge to pound plate into a hay bale to spread the blows out, got it to a .1 without gasket. Reinstalled and idle temp went from 210 down to 160, sat for 30 minutes rock solid, drove it it about 75-80 mph for 30 min and temp only reached 170 max while idling in a parking lot for 10 minutes. Drove home very happy! Great mod, thanks a lot George.
Mike

[P@blo]

A sledge hammer on the divider plate !! I used a little auto body hammer and just needed to lightly tap it evenly down but see where the bale of hay helped. The mod worked the same for me but I still owe George the two dollar fee and have decided I will put it into a high yield savings account so he can retire when he chooses.

[george kujanski]

2 bucks here...two bucks there.....soon we're talking real money..

mhgamber: do you know if yours was an original pump assy? I'd like to know for my database, i.e. if the clearance issues show up on remans and not on OEM.

p.s. you owe me two bucks...hey, maybe with spring and summer coming I can start charging three bucks....hmmmmmm

Glad it worked for you guys.

George

[jjscerbo]

George,

Throughout this forum and with all of the vendors, the general opinion is to use a four core or aluminum tube radiator for the 64-67 GTO's for overheating problems.

With what we all NOW know about the proper way to set up clearances for the water pump divider, Do you still feel the need for a larger radiator than the stock three core unit?

As someone that was a Pontiac dealership technician in the day, I do not recall a continual problem with overheating engines due to radiator size. Circulation problems yes. Largely due to excessive divider clearances as you have time and time again have posted about.

It bums me out since the stock three core radiator insulators are no longer available(AND I NEED SOME) because the assumption is that most convert to the four core or aluminum radiators.

What do you think?

Joe

[george kujanski]

I'm not an expert, but my feeling is that for a stock or near-stock engine setup the OEM sized radiators should do the job. GM tested them in all climatic conditions such as Arizona summers with the A/C on.

Now as one moves away from a stock configuration, i.e. one that creates more waste heat, a cooling system that can move the heat out to the air may be necessary.

Compound that with engine blocks with scale buildup inside, which reduces heat transfer in the block, A radiator that can further reduce the temp of coolant circulating back to the block from the radiator, may be the ticket.

George

[rdk]

sorry but apparently none of you know what you're talking about,I just returned my engine to the builder for a overheating problem, he said there is no difference between the cast and stamped impeller or the clearance of the divider plate, he also told me that its normal for combustion to travel up past the head bolts. p.s. it seems to me that all of the so called aftermarket and high performance waterpumps have cast impellers instead of stamped, so are they all wrong too -when I said you did'nt know what you were talking about i was being sarcastic- hope i did'nt pi** anyone off

[george kujanski]

Sarcastic remarks cost $5.00.

It's almost May...the start of the overheating season......

George

[jjscerbo]

I'll bet that your machinist does'nt believe in the Easter Bunny either..

Does he?

BTW..Is your machinists name Fulper???????

[LouisianaGuy]

Well I decided to chekc my pump to place clearance on my TA since I had cover off to weld in oil drain back holes, and what I found was not too bad.
With pump and plate still stuck together after I removed them from the engine I found a clearance of .118 which still seems BIG when looking at it, so think im going to massage it down to about half that.
Car idled fine but when running at 70-80 MPH for sustained periods it would get around 210.
I also have a cast iron impeller.
Mike

[LouisianaGuy]

Well tightned the clearances up to .060 with ou the gasket, so it should be around .065 with the gasket which I hope will help out with interstate crusing...will know in a few weeks :P

Mike

[Geoff]

An easy way I found to close up the impeller-to-plate clearance is to get another plate & cut out the impeller section. Then pop rivet/screw/weld this to the front of the plate you are going to use. Keeps the gap more uniform, rather than trying to do 'surgery' with a hammer.

[FantomPoncho]

Originally Posted by jjscerbo

I'll bet that your machinist does'nt believe in the Easter Bunny either..

Does he?

BTW..Is your machinists name Fulper???????

Yet another Fulper dig. Gotta love it!!!!!

[scatpac1]

hello fellows,im the proud owner of an overheating firechicken,anyway has new pump,dont know if its cast or stamped as i did not know about all this overheating madness at the time,new radiator,t-stat,etc... car is tuned timed and and evrything fits like socks on a rooster.now my story like many others the car could idle from sun to sun down at a steady 170/180.get on the highway over a period of 35 miles temp creeps up to 220,no a/c 70 mph 3000 rpm,now here is what i have noticed,i felt my lower radiator hose and it does not have an anti collapse spring in it,hmmmm,do you think that the water pump has enough suction at 3000 rpm to collapse it.i dont know but its worth a shot,all the parts that i swapped are autozone specials,i think ill upgrade a couple of them if the lower hose trick doesnt help,but i did go to oreillys and their gates hose does have a spring in it.ive also heard that the hoses they make today have the anti-collapse technology in them? anyway ill keep you guys posted.if not ill definitely do the divider plate trick.goerge i dont know you but thanks a bunch,need a routing number for the account in the caymans.haha

[a67goatnut]

I thought that I would try this fix on my '67. I bought a stainless divider plate set. When I removed the waterpump I found that it has a cast impeller. I measured the distance and it ranges from 0.145-0.210 between the "internal housing" and the impeller. The new stainless part ranges from 0.150-0.175. I will close the gap as suggested and give it a try.

Now for my question. If you look back at post #16 it shows the internal housing with a circular opening as well as an additional amount of material removed from the center. Kind of like an old "skeleton key" slot. The replacement part that I bought only has the circular opening in the center. Exactly like what is shown in post #17.

Can anyone tell me why these are different or how this might affect cooling?

Thanks,
Scott

[george kujanski]

I've wondered about that myself. Perhaps Malky may have an answer...he's the pump expert.

George

[a67goatnut]

Here is a picture showing the difference in divider plates that I was talking about. Why are they different? I sure wish that both of them were shaped the same. Nothing like throwing a new variable into the experiment.

I measured the distance incorrectly the first time. I measured from the outside of the diver plate to the impeller. The new stainless diverplate is .048so each of the dimensions that I wrote before are .048 less.

I spent time tonight working the divider plate closer to the impeller. This took more time and effort than I had expected but the new piece is stainless and considerably stronger. I should be able to install this tomorrow. I'm anxious to see how well it works.

With any luck, I'll be able to get out for a test drive tomorrow night! It sure has been nice around here lately!!

Scott

[67 goatman]

I'm a new member to this site, but a longtime sufferer to the '67 GTO overheating problems!! I've had mine for 7 years now and have seen it boil over more than I care to remember. I bought a new Cardone water pump and got it yesterday. It (and the one I replaced) has a cast impeller. My divider plate also had the notch on one side. My gap between the plate and the impeller on the old one was very big, almost enough to stick the tip of my little finger in the gap (~0.200"). I banged the new one to almost touch with no gasket and then installed the gasket. I couldn't finish last nite due to a stripped bolt but I'll get a new one today and see what happens. I live in Orlando, where its already in the low 90's and mine heats up in a hurry. I'm preparing to go on the Hot Rod Power Tour in about 3 weeks and I've got to get this overheating under control. I hope I'll be one of your success stories!! I may go get me a high flow thermostat as well just to try and cover all the bases. I have a 4 core radiator with a shroud, fan extension, and an electric fan...I'll keep my fingers crossed and let you know....thanx, 67 goatman

[Pontirag]

So If a person wished to purchase a new aftermarket heavy duty aluminium waterpump which one offers the largest DIA. impeller with the most blades and the tallest blades. After reading 41 pages over a 6.5 hour period of time I'm still unclear on this. With regards to the specific water pump issue what is the silver bullet for a 1970 and later V8.