[jjscerbo]

Originally Posted by Old Goat 67

Couldn't tell much from that picture, but couldn't you tap the impeller down onto the shaft with a socket and small hammer to get a bit more clearance?
Charles

ABSOLUTELY NOT!!!!!!!!!! There are ceramic seals inside the pump that will be damaged and leak if you impact the shaft. If the impeller is correctly installed, it can not be driven on any more.

[techteacher5561]

I was't having much luck last night with resizing pictures for posting, as i was nodding off while typing I figured I should go to bed. Now after several cups o' joe heres the pics I tried to post last night.

Where the vanes are "unworn" there is about 1/32 clearance which works out to .03 clearance, good right????

However where it is "worn" it's probably closer to 2/32 or maybe 3/32 so thats either a .06 or .09. Still within "spec" for what is suggested on this thread.

Duhhhhhh, oh crap I just remembered this is checking clearance WITHOUT a gasket. maybe I need another cup o' joe.

OK is there a "normal" thickness on a waterpump gasket that I could add to my numbers to see what the clearance is?

[Old Goat 67]

ABSOLUTELY NOT!!!!!!!!!! There are ceramic seals inside the pump that will be damaged and leak if you impact the shaft. If the impeller is correctly installed, it can not be driven on any more.

NOT TRUE!!!!!!!! I've done it on mine without any damage, but you don't tap or press on the impeller without placing the opposite end of the shaft (where the fan hub is) on something solid. The replacement unit I got for mine was not pressed on far enough, necessitating getting it further down on the shaft for maximum efficiency. They press the impeller on the shaft in manufacture, how do you suppose they do that?

[Old Goat 67]

Teacher,
Seems like I see about 3 or 4 vanes that are worn, and the others not?
Could the impeller have been cast poorly when it was made?
Is it running true, or is the impeller wobbling as it rotates?

[techteacher5561]

worn quite "evenly".
Heres some pics of whgat they look like from the side profile.

I was wondering does everyone elses kind of taper as the vanes go from the center to the edge? mine do.

When I was taking these pics I experimented with the different plates, it almost appears as if this might have been installed on the engine at one time without the first plate being installed. the divider plate with the smaller hole fits directly on to the hub with the worn area in the vane lining up directly with the hole. Could it be it was put together improperly and made a hell of a racket once started. Torn back down, missing plate reinstalled and then vola' no more noise.

Oh yeah to answer your question - no does not appear to wobble.

[Old Goat 67]

Looks like it could have been just what defect my new pump (in the first page of this thread-post#16) came with. The rear of the impeller was about 1/4" away from the pump body. This would not allow for full efficiency of the pump. IE, water allowed to bypass the impeller. I therefore "pressed" it further onto the shaft, by using a socket and a few hammer taps, while the other end of the shaft was held firmly to an anvil, to get the impeller further down. A press would be better, if you have access to one.
Could that be what has caused this to wear the vanes on this pump? If so, I would recommend you get a new CAST impeller pump and do a proper installation to rid yourself of this problem.
Charles

PS Come on George, chime in here.

[techteacher5561]

After inspecting my waterpump vanes and divider plates I noticed what appeared to be evidence of fluid leaking from a hole on the lower portion of the shaft. Now I did have to add fluid to the radiator now and again over the summer. I never saw any on the ground under the car, and my puke tank isn't that good car came with an old soda bottle to catch the overflow. But I still had to add coolant or water every so often. Never alot, but maybe 10-12 ounces at a time.

Is this an indication that this pump needs to be replaced. By the way the clearances were good when I checked the divider plate and impellor.

[Old Goat 67]

Yes, that's a common indication of impending failure.
Charles

[techteacher5561]

oh boy,,, I was afraid someone was going to say that. Better to find it now I guess. Now to try to find a good cast iron impeller pump.

Howard

[Billy177]

I just installed a Mildon High volume pump last night. very pleased with it, aluminum housing and a cast impellar

summitt MIL-16281

[techteacher5561]

on line and found one of the cardone remans listed at Advance Auto Parts for 33.97. Pics show cast iron impellor.

Billy I checked the one you listed, it does not cross reference to my 350 engine, and pic showed a 11 bolt pump- mines a 8 bolt.

Not sure if it is the pics only, as they might not be correct. have to go there and see for sure.

thanks for the info always good to hear what others have used with successful results.

Howard

[surfnuke9]

Howard, I bought one of the cardone units from advanceautoparts last summer and it had the cast impeller.

[techteacher5561]

Surf, I started another thread that shows my "new" rebuilt waterpump, had several small cracks in the cast impellor. Reordered another, but Charles (Old goat67) had suggested alumn cast impellor is maybe not accepable. Out of curiosity,,, was yours a cast iron or cast alum impellor last year? Do you remember? Mine failed the magnet test this am.

Thanks alot!! Howard

[F ROCK]

thanks guys, this may help my monster hot starting problem.

[blown 68]

Originally Posted by Billy177

I just installed a Mildon High volume pump last night. very pleased with it, aluminum housing and a cast impellar

summitt MIL-16281

i have this one also, and like it. 6-71 blown 474, runs 180 all damn day,(that's where my fans are set to come on, will run cooler if i set them there....) block is hardblocked, heavy duty four core with factory tanks. the hottest it's gotten is 195, in 95 degree heat, highway speeds, 3000 rpm or so......

[1967Tempest]

Finally got mine running. Run the motor for about 45 minutes never got over 180. Not a radical 400 anyway. Havent driven it. Need to work on tranny before she moves on her own power. But I made sure that my water gauge was correct before I started the engine for the first time. I boiled some water and used 5, yes 5, different thermometers to make sure temp gauge was dead on. I was shocked to se at idle, temp never crept over 185 and when throttleing the engine temp came down IN A HURRY!!!!! Nice to see at least I have one problem fixed. Thanks for all of the help.
Dave

[BobDef1]

before i pull my pump off i emptied the radiator partially started the car up looked into the radiator and the coolant was shooting out of the radiator fins. is that an indication the water pump is working adequately or could my cooling problem still be from the pump?

[Old Goat 67]

Are you saying the water was flowing UP?
That's the wrong direction. Water should flow down.

[BobDef1]

i emptied the radiator and the water was flowing out of the top (exposed) fins from the drivers side out the passenger side

[sixtyeight]

I've been reading all of the posts and have the same problem with my 68 firebird. 406, 10.25-1 comp. summit 2802 cam Rodney Red rad and his electric fan and alum. shroud. AED 750 dp carb. tomahawk intake. My water pump is a high performance pump but has the stamped impeller. I did close up the gap between the backing plate, but maybe not enough. I will have to check it again to make sure.
My car does get hot, trying to get it smogged and it will heat up to 230-240, this is with a 160 t-stat and timing retarded to 12 deg btdc and vac. adv. disconnected. I have a 180 high flow t-stat in it now and reset the timing to 16 deg btdc and hooked up the vac adv to manifold vac. My total timing is at about 36 deg all in at 2500rpm I beleive. I was just at the shop where it is getting smogged and they said it looks like it will pass but had to stop because it was getting hot. He didn't say how hot though. So I'm not sure what difference the timing and carb adj. made on the temp. yet.
One thing I noticed on the fan shroud I got from RR was that their are slots cut into the back side of the shroud next to the fan hole. I don't know if this is causing a lack of flow being pulled through the radiator or not. I am going to cover the slots up so all air has to be sucked through the radiator and see if that will make a difference. Does anyone know of any reason you would want extra openings behind the shroud? Thanks for any input.