[grandville455]

here's the pic

[george kujanski]

Firechicken; can you post the diameters of the two cast impellers you have and the type of pump (11 bolt, etc.)

George

[george kujanski]

Denver: in the previous post you said the temp was at 210 and climbing cruising around town but did not boil over.

You also said the clearance with the Cardone pump is now .6".I hope you meant .060", and during idle it went to 195.

Does not seem logical at all for the situation to be worse; perhaps give it a longer test at idle to see if the temp stabilizes at a reasonable point.

I believe everyone here agrees that minimizing the clearance improves the pump; the results therefore should be either an improvement or no improvement at all, but not getting worse.

if, in fact your temps keep climbing, your system has other issues, but that's ok. You have to go thru each part of the system to insure it is doing it's job. At least you have the pump optimized, (hopefully, it's .060!)

George

[pont406]

I had a pump with the same shorter fin setup as pictured by Grandville455, when I bought it at the local Carquest years ago, they said it was for air conditioned cars,the larger fin are for non-air cars, if I remember right. I think I still have it up in my garage attic, I'm currently running a flowkooler pump on my 66 Lemans, I may have to pull it apart and check my clearances as well, as I've chased a "to hot at idle" problem for several years now. I made several recent improvements, but this may finally "fix it"

[kate`s67gto]

I just measured the center of a backing plate, from top to flat surface counter top. It is 13mm or 1/2 inch in height. I did this because we all know GM did not tweek backing plates. So if anyone has a original backing plate in good condition could you measure it for all to know. What we need here is the original specs.backing plate to impellor clearance.(cast impellor)

[grandville455]

So 406 your saying that my impeller thats 5/8's of inch tall is the small one...To me it looks like its pretty tall...we need someone else to measure there impellers height and diameter

[george kujanski]

Kate's67gto: your measurement: Just to clarify, is your measurement of a '67 style pump and housing such as shown by OLD67GTO's pics, or of the newer 11 bolt style pump and plate?

So you have the plate on a counter top, convex side up, and measured from the top of the plate to the coounter and measured 1/2"?

I'm getting confused about what I've been reading. To summarize: We've seen on the '67 style pump with internal housing (like on OLD67GTO's pix) that at least 2 different vane heights are available thru parts houses, obviously, if the lower vane height pump is used with a non-matching internal housing, too much clearance results and certain overheating.

On the later style 11 bolt pumps, there seem to be cast impellers of different diameters and vane height also. Grandville reports a 3&3/4" diameter and 5/8" vane height. If the variations do exist, there must have been different divider plate shapes to match the different vane heights.

If anyone out there has an exposed 11 bolt pump, can you report the diameter and vane height?

BTW, a larger diameter pump will move more coolant, perhaps those were used with A/C?

In any case, it seems when buying pumps, we cannot assume the parts houses are supplying the proper stuff, and even if the new matches the existing pump, make sure the new is the proper fit for the engine.

George

[grandville455]

Intersting...one thing i forgot was my didvider was lost so i got this one off of a 78 firebird with a 400...so maybe there the same as far as the 11 bolt pumps?

[george kujanski]

The plot thickens...even more.....

George

[denden 68gto]

Yes,the pump is .060 everything was put in new when the car was done.It has 5,000 miles on new engine,new 4 row radiator.The only thing I did not hook up is the heater.I blocked all four fittings with rubber caps.I run a 50/50 mix of water and antifreeze.

[6t7gto]

rudy, i drained as much antifreeze out as i could. with the thermostat closed it pulled a vacuum and didn't drain completely. when i disconnected the heater core more coolant came out. then i bypassed the heater core. took out the thermostat so the CLR would start flowing thru the system immediately. i poured a gallon of CLR into the radiator and topped off with water.approximately a 2:1 mix. CLR instructions say to use it with warm water.i filled with hot water from the tap and ran at high idle so the car would heat up faster and the water agitation was higher. i covered the front of the radiator with a fender cover to attain a higher temp faster.it got to about 170 and i removed the fender cover and it maintained that 170 temp for the hour i ran the car.
why one hour?
that's how long it took me to drink the three beers i had in the fridge.
i left the cap off during all this as i have the idiot lites and wanted to keep an eye on the temp. used my wifes meat thermomemter for this. she doesn't know it.
i drained it the next nite, as much as would come out. refilled with water and took it for a ride and it was at 160 when i got home.with no thermostat.i'll drain and refill a couple more times before i put the antifreeze back in. i noticed the water was foaming somewhat after the first drain of CLR, so i guess there is still traces of the CLR in there.
david

[soupman]

I went out and measured my original waterpump, 11 bolt type. The cast impeller is 4 1/4" in diameter and the height of the divider plate is exactly 1/2" from a flat surface. Hope this helps some.

[kate`s67gto]

George yes it is an 11 bolt water pump. I have a cardone water pump bought through Napa cast impeller. Yes convex side up and used a scale to measure the height. Sorry water pump is in car so can`t measure vane height or diameter. Took car out last night about 6:30 for a good run, when i came home got thermometer removed cap took temp, guage showed 160 thermometer read 150. So my guage is off by 10*. Temp was 50 at that time . I`m still going to wait till warmer temps before i get 180 stat. Scott

[george kujanski]

What I'm reading here is there are two cast impeller diameters in the 11 bolt water pump variety. Could it be that a 455 used a larger diameter than a 400/326 or something like that?

Not inly that, the stamped type seems to be inferior to everything else, but there are many around.

As we peel the onion, how many variations are we going to find? No wonder there are so many overheating complaints!

George

[grandville455]

George just called the part store where i got my pump its the same # for the 455 and 400....now what ,lol

[grandville455]

soupman did you measure just the vanes or the whole impeller?

[george kujanski]

Grandville: is that real or the parts houses just decided to make the part no.the same since they were "close"? I don't trust these guys anymore.....

George

[grandville455]

You know I am not sure but he said they were the same.....as for soupmans measurment if he just measured the diameter of the impeller vanes than its bigger but if he measured the impeller as a whole i bet there the same... I will check when i get home in a hr

[george kujanski]

Just don't stop at the Leine Lodge in Chippewa Falls on your way!

George

[grandville455]

No I won't ,lol thats on the other side of me i am by the north crossing........plus dont drink anymore I only get goofy on NA beer now lmao!