Water pump grenaded today--

[DFRESH]

I never realized that the front portion of the water pump where the fan/pulley bolts run through is just a press on piece---mine decided today it didn't want to be pressed on any longer---can't figure out how that could happen----is it possible to have to much weight over the front of the water pump (I.e. fan spacer, fan clutch, etc?). This pump appears to be stock, has GM stamped on it--is the one that came on the car when I purchased. Luckily I was close to home on a test drive---it took out the shroud, but it appears the radiator is still ok.

So, recommendations on water pumps would be appreciated--This car will see track days, auto X and lots of driving.

Doug

[eville]

I have a Stewart, they are good pumps.
I've also head good things about Edelbrock.

[ccracin]

X2 on the Stewart. Top notch stuff! They lived on my circle track cars forever. Never had a failure.

[Vegas69]

Already puked a victor jr. water pump on my ride. They didn't stand behind it due to time. Second seems fine.

[70rs]

I have used the Stewarts on several small blocks in 4X4 trucks. I beat them on a regular basis for a very long time and never had any troubles. One engine (383) was in three different trucks over 5 years. The pump never gave up. Wish I could say the same about the rest of the drivetrains:rofl:

[GregWeld]

Doug -- can't remember... you a bb or sbc?

If SBC - go to the CORVETTE pump it's a larger shaft diameter... more surface area to hold that fan...

I've had Stewart and Edelbrock pumps... had to return the last Edelbrock pump that came from Billet Specialties with my TruTrac... the core shift was so bad the O ring wouldn't seal...

[ccracin]

If SBC - go to the CORVETTE pump it's a larger shaft diameter... more surface area to hold that fan...


The stage 3 Stewart has a larger shaft and bearing. BBC and SBC. Go here:

http://www.stewartcomponents.net/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=ChevyS3

That car deserves the best!

[Fluid Power]

When you say test drive is it safe to say that the car has not been driven very far? If that is the case, I would check pulley alignment. If the belt is off center a little bit, it will but an amazing amount of stress on that bearing. It won't make a difference whose pump you use.

Darren

[DFRESH]

Doug -- can't remember... you a bb or sbc?

If SBC - go to the CORVETTE pump it's a larger shaft diameter... more surface area to hold that fan...

I've had Stewart and Edelbrock pumps... had to return the last Edelbrock pump that came from Billet Specialties with my TruTrac... the core shift was so bad the O ring wouldn't seal...

Greg, sbc gen 1 406. Shocking how bad production tollerances can be, especially on an Edelbrock product----it's got Vic's name on it.

[DFRESH]

When you say test drive is it safe to say that the car has not been driven very far? If that is the case, I would check pulley alignment. If the belt is off center a little bit, it will but an amazing amount of stress on that bearing. It won't make a difference whose pump you use.

Darren

Darren, that makes sense---if my belt alignment is off, it is putting forward stress on the water pump pulley---is this a common thing if belts are out of alignment? I've heard of shafts breaking, i've just never seen the actual pulley mount come un-pressed from the pump itself. I've had the car close to two years---thanks for the tip.

Doug

[DFRESH]

The stage 3 Stewart has a larger shaft and bearing. BBC and SBC. Go here:

http://www.stewartcomponents.net/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=ChevyS3

That car deserves the best!


Thanks for the link Chad--very cool of you to provide. I will contact them tomorrow.

Doug

[GregWeld]

Doug --

The STEWART pumps have a set screw to add some additional security to the fan hub... and their hubs are billet (on the stage 3 stuff) instead of a machined casting. Either way - I'd make sure you have the big shaft version (3/4" vs 5/8")... or you might get the big shaft again! LOL

You can check your pulley alignment using a straight edge against the pulleys.

Oh... you have that SMALL small block.. :>) -- Actually - I'm thinking of de-stroking mine when I rebuild it. Those little bitty pistons (in mine) just aren't good for a high milage motor.. :willy:

[GregWeld]

Found this on the Stewart website... Very interesting.



When using a mechanical fan, a properly designed shroud must be used. Most mechanical fans are not designed for high RPM use: they can have serious vibrations problems, due to air turbulence, when run over 6,500 RPM. This is a turbulence problem, not a balance problem, and will destroy the water pump and components in front of it. The large fans preferred by dirt oval track racers can consume up to 18 horsepower at 6,500 RPM. Do NOT run a mechanical fan that is any larger than required for the application.

Flex fans are a poor design for performance applications. They move less air at higher RPM, and only consume a fraction less power than standard fixed pitch fans.

Clutch-style fans are inconsistent and we do not recommend their use for any application, if possible.

[Flash68]

Sorry to hear Doug... hey it could have been worse and at least you were close to home.

[Fluid Power]

Yep,pulley alignment is critical, ask me how I know. The first go around on the Camaro I swapped the six for a junk yard 350. I went thru 2 napa water pumps, pulling the entire pressed in piece thru the front both times. The NAPA dude was super cool and returned them. When I went back in for the replacement after the second one failed he pulled me to the side and told me to check the pulley alignment. I fixed the alignment and the pump lasted about 8 years until the entire motor was jerked and the new and improved car was built.

Darren

[DFRESH]

Found this on the Stewart website... Very interesting.



When using a mechanical fan, a properly designed shroud must be used. Most mechanical fans are not designed for high RPM use: they can have serious vibrations problems, due to air turbulence, when run over 6,500 RPM. This is a turbulence problem, not a balance problem, and will destroy the water pump and components in front of it. The large fans preferred by dirt oval track racers can consume up to 18 horsepower at 6,500 RPM. Do NOT run a mechanical fan that is any larger than required for the application.

Flex fans are a poor design for performance applications. They move less air at higher RPM, and only consume a fraction less power than standard fixed pitch fans.

Clutch-style fans are inconsistent and we do not recommend their use for any application, if possible.

Great stuff there Greg. I will ditch the clutch fan---I am literally just buying time until the other motor goes into the car. It's then that I will clean up the engine compartment to my liking and get rid of many things--that should happen in this coming year---I say "should"---depends on what else comes flying off the car before then. Thanks again man.

Doug

[DFRESH]

Yep,pulley alignment is critical, ask me how I know. The first go around on the Camaro I swapped the six for a junk yard 350. I went thru 2 napa water pumps, pulling the entire pressed in piece thru the front both times. The NAPA dude was super cool and returned them. When I went back in for the replacement after the second one failed he pulled me to the side and told me to check the pulley alignment. I fixed the alignment and the pump lasted about 8 years until the entire motor was jerked and the new and improved car was built.

Darren


Ok Darren, I am on it and will check it----I am suspicious of the A/C belt being the culprit---

Doug

[DFRESH]

Sorry to hear Doug... hey it could have been worse and at least you were close to home.

yeah, in my bare feet, no phone and kids at house----there goes that "Parent of the Year" award I was looking to get.

Doug

[Flash68]

yeah, in my bare feet, no phone and kids at house----there goes that "Parent of the Year" award I was looking to get.

Doug

Driving with no shoes! I like it! :lol:

[projectile]

Doug- I had the same problem a few years back. My problem started when I installed a "Heavy duty/towing" fan clutch. It took too long to disengage and would overspeed the fan. The fan vibration would rock the flange back and forth until it moved on the shaft. Luckily the belt was thrown before the fan fell off the pump shaft. I went back to the standard clutch instead of the heavy duty one and it solved my problem. I thought heavy duty meant that it could withstand more rpms. It is really designed to just move more air. May not solve your problem, but thought I would share...

[DFRESH]

Doug- I had the same problem a few years back. My problem started when I installed a "Heavy duty/towing" fan clutch. It took too long to disengage and would overspeed the fan. The fan vibration would rock the flange back and forth until it moved on the shaft. Luckily the belt was thrown before the fan fell off the pump shaft. I went back to the standard clutch instead of the heavy duty one and it solved my problem. I thought heavy duty meant that it could withstand more rpms. It is really designed to just move more air. May not solve your problem, but thought I would share...


Cool--thanks Ray--that is also good info----great car by the way--cool color

Doug