[denden 68gto]

I have a 68 GTO with a rebuilt 400 pushing 380 horses somewhere in there.It has the comp extreme energy cam, trw forged pistons,stainless valves, runs and looks great.This was all done in 2000. Timing and carb. are where they should be.In 80 to 90 temps it would run around 190 on the road. In town for a cruise barely moving, it will climb to 210 and higher, never boiling over.When I put the water pump on, I didn't notice if it was cast.it was a new one from napa.Pulled the pump wednesday and it was a cast impeller unit.between the plate and vanes it Appears to be 3/16 without the gasket.My question is what are you putting between the vanes and the metal plate to get the distance desired.My feeler gauge does not measure up to .80 or.100.and do you bend just the inner edge of the metal plate or the full length of the vanes?

[Old Goat 67]

Denver,
If you were to bend only the center edge to get the reduced clearance, it would not be as efficient as if the impellor were to fit the plate all over the impellor vane outer surface of travel. It would help some, I’m sure, but in my mind the impellor would be less likely to cavitate anywhere in it’s chamber if it had a minimum area all over the impellor outer range to operate in. Why not try to get another pump to fit well as I did in the second picture I posted on page one. Go back and look at the pictures good, that’s why I tried to give a perspective inside the chamber with the photo’s. That is the biggest reason I purchased the Cardone pump. When I saw the difference in the size & shape of the two impellors, I knew right away this was the direction I wanted to go. It fit the plate much better and the tweaking I did was very minimal. Works so good, it’s scary! And “It Ain’t Rocket Science”.
Good luck, Let us know how you made out,
Charles

[6t7gto]

old goat,i have a cast finned water pump. did the tweaking. put in 160 degree stat. took it for a ride. put in meat thermometer and it shows 190 degrees. in 50 degree weather. only thing diff is i don't have the cast fins such as that cardone pump. think it would help to put the cardone in?
thanks,david
p.s. 67 gto 400

[6t7gto]

follow up... when i had the radiator out i back flushed it. lot of rusty crap, even though the antifreeze was pretty clean when i drained it. could be the radiator needs to be professionally cleaned?
david

[Old Goat 67]

David, do you have a stamped steel or a cast impellor? Refer back to the pics that “eric17621” posted on page 5. Also, how is your water flow going past the radiator cap hole when hot? After doing mine, it was enough flow so as to cause the water to come out of the radiator cap hole when I revved the engine a little. It would hit the thermometer I had standing up in there and try to jump out the top. Sure sounds like that radiator could use some cleaning though. Especially if it was coming out of there in pieces big enough to see and hold onto to. Looks like you have a 67 GTO , right?
Charles

[NOZZLENUT05]

Well, I checked mine today. It was WAYYY off. It was almost .250. So I got out the BFH and mashed it down. Amazing. I will post my results as soon as I get my radiator.... My dad kept asking me, why will it run hot? why is it so different now? My car never ran hot. "doesn't make sense to me" Now here I am mashing the divider plate....jeesh. You'd think that I woulda learned by now....

[rudytadow]

So, how do you make the suggested gaps when you seal the divider plates together? Can they be between the timing chain cover and water pump without being sealed together? Last fall, I flushed the motor, radiator,heater core (now toast - bypassed) and replaced all the hoses, t-stat,coolant and the water pump with what appeared to be a cast impeller, ran over 210 F. I'm getting it out of storage in two weeks and wonder what to do now.

[soupman]

I want to put a new waterpump on witht the cast impeller. I want to keep my original off the car. I cannot find one with a cast impeller. I've checked Autozone, Advanced auto, napa and no one has one with a cast impeller. Were do you find the later style pump? PMDracer, what one at Autozone did you get?

[Old Goat 67]

Rudy,
What do you mean about sealing the dividing plates together? What temp thermostat? First, what car are you working on? 67? Your profile does not state that information. The pictures I posted on page 1 were with both plates in place on the pump. Then you check the gap and adjust as needed. If gap is too much, I’d suggest a pump with a better impellor casting. That’s what I did.
Charles

[grandville455]

I have a 455 .040 over summit 2801 cam and i just put in a super 160 stat and it stays right there I believe its the original 11 bolt pump yet, but its making noise so i picked up a new one at champion auto stores here in town and it has the cast impeller i could take a pic if anyone would like...It cost me 20 bucks! I will be putting it in next month when i change cams

[Old Goat 67]

Soupman, try finding a parts store that can supply you with a Cardone pump such as in this link, and check it good before you walk out with it. Cardone is a remanufacturer. Bring a pic from here and your old pump and plate(s) to check while you are there.
Charles

[6t7gto]

got my pump coming from parts america, which is also advance auto parts.
they have to order it in. should be here saturday?
i talked to a local radiator shop tuesday. he has cooled down many gto's. told him of my concern of a blocked radiator. i asked if i could flush it with CLR. he said no problem, just bypass the heater core as any flush product can damage them.
ran the CLR thru the system last nite, took the thermostat out, so the flush would circulate immediately. ran the car at high idle for an hour and it never went over 170.
letting it sit overnite and i will drain and flush clear tonite.
will let you know what happens tonite.
after tweaking the water pump saturday,water didn't seem to flow that fast. but last nite with the flush in it and no thermostat, it's moving real good.
david

[PMDRACER]

Soupman -
My pump was from GMB.

[soupman]

The Cardone pump for a later style car is a stamped impeller. I'll try to find a GMB like PMDracer got.

[rudytadow]

Old Goat,
My car is a 65 LeMans with a 326.
I sealed the divider plates together because
that's what kept them together when I took them out. There was a sealer between them when I took the original water pump off. If there not sealed together and loose next to each other then how do you adjust the gap your talking about?
Rudy

[rudytadow]

Old Goat,
The thermostat is for 180. I got my replacement water pump from Auto Zone. The impellers sure looked and felt like the original. I understand I can get the original water pump rebuilt for $25.00 at a local parts shop. Do you think I should have that done and swap out when I pull the other off to seperate the divider plates and attempt this adjustment you mentioned if I can figure out how as you suggest?
Rudy

[rudytadow]

Old Goat,
I just looked at your pics. Now I'm only going from memory from last fall, but unless there is more than one divider plate, I must have sealed the internal house to the divider plate. If that's the case, I hope I can get her home 30 miles without an issue in two weeks. I also see what it was you were talking about regarding that adjustment. I'm an engineer but not a mechanic. Nothing like trial and error!

[Old Goat 67]

Rudy, the two plates in my 67 are just sitting in there next to each other. They are held in position by the timing chain cover housing and the pump. No sealer or anything else. Not that I didn't think about it, though. Rudy, if I still had my original pump, I would surely have done the rebuild thing. Just bearings and seals, why not?
Charles

[rudytadow]

Charles,
Thanks for your reply. How exactly did you close the gap around the opening? Would taking a 2x4,resting it above the hole and taping on it with a hammer do the trick without radically bending the metal? I would think the wood, being softer than metal, would be less damaging. Also, what exactly does the divider plate do? Is it possible not to put it back in or does it divert the flow of water entering into either the block or the pump itself? Your thoughts?
Rudy

[Old Goat 67]

Rudy, in the 67, the combination of the two plates is what channels the water through the pump into the two heads. Both parts are necessary, because the water enters through the large opening in the center and is channeled to the heads by the combination of both plates. Both must be in there for it to function correctly.
I had very little bending to do after getting the replacement pump. Maybe 1/16”. Tapped it with a ball peen hammer.
Charles