ConeKLR

1996 Corvette LT4 electric water pump questions:

My current OEM water pump is leaking from the bearing/seal. Can i still install electric pump and have no leaking. Will the bearing/seal cap that comes with the pump plug the bearing/seal completely even though it is leaking from that area? Have any experience with that?

I tried calling them directly but the tech is out to lunch right now.

99svrcpe

Hey Steve,
It should seal. I cracked the cast pump housing when I pressed the bearing out on mine, my neighbor is a machinist and he made me a plug out of aluminum an TIG welded it.

Nathan Plemons

The pump won't leak, but you might have issues with an oil leak. If the oil pump drive shaft isn't supported on both ends it will wobble which will eventually wear out the seal and leak, but it might not happen immediately.

TONYDEE64

Honestly I would not go with a Mezierre or any other electric pump. I too spoke with Jay from Mezierre many times regarding a pump for my motor (532 BBC)... and he was dead wrong about what I needed or how the cooling system worked as a whole.. I bought both the 33gpm and the 55 gpm units because my motor is large Jay said I needed the bigger pump. $700 later a guy here in Indy helped by telling me that you DO need to run a thermostat (Jay said not to) because the electric pumps push water through the system WAY too fast and in effect the radiator does not hold the water long enough to cool it... Just a warning.. I'd stay away from an electronic pump.. what a nighmare... I ended up going back to the 33gmp pump with some restrictors and some other tricks... we'll see how it does this summer....

Nathan Plemons

The coolant flow speeds is a misunderstood concept.

Think about it, if a molecule of coolant moves through the radiator faster it must also move through the engine faster. So although the molecule might not have as much time in the radiator to give off heat, that same molecule is not in the engine as long ot absorb heat.

If your car overheats or otherwise doesn't work there are plenty of other issues at play. Obviously you have a very nonstandard setup. For a stock or even modified LT1 / LT4 the electric water pump is a very reliable and proven solution.

cprgmr

If you buy the Mez, it'll come with a freeze plug which can be pushed into the hole where the water pump drive shaft enters the pump (in the rear). You'll reuse the inspection cover gasket when you mount the Mez on the housing.

When I had the freeze plug installed, they also used a sealant around it so it wouldn't leak no matter what.

You'll also need to plug the water pump driveshaft hole in the engine front cover. I had my local machine shop press fit a plug and then I filled the remaining void left over in the rear with JB Weld for a complete seal.

Corvette Kid

There are many here, including myself, running the HD Meziere w/ no issues. Mine's been installed for 10,000 miles now. And yes, you should ALWAYS run a thermostat in ANY street car and most race cars unless you know what you're doing. And if you do go this route, spring for a new cover O ring when installing the pump. Under $5 even at full retail GM dealer prices.

99svrcpe

I've had mine installed now for about six months with no issues. My engine stays cosistantly at around 185* even in traffic, before it would typically run above 230*, however I installed it when I did my rebuild which included removal of the drive gear, 160* stat and PCM reprogram.

93 ragtop

One other thing to consider with the electric pump is the relay. I use the fan relay kit from ecklers that is designed to upgrade the fan relays on the the older vettes 84-87 i believe, to the 88 and up style. The kit is about $16.00 and includes the factory wiring connector and relay. The nice thing about it is you can mount it next to the other 2 fan relays already on the shroud and it dosnt looked rigged.
I have others say a fan relay is not heavy enough but I disagree. The generic relays may not be, but a direct replacement fan relay is rated higher then the pump requires. Heck check the fuse protecting the fan motors and I believe it was a 40 amp fuse.
By the way, when spring gets here, why dont you come down to the manassas drag strip for a test and tune. Rarely is there any other corvettes there other then mine. It starts march 13th.

Strick

I, too, have the Mez HD pump and it does a great job. I like the ability to run the pump with the engine off for a nice cool down after a hot run. Check out the C4 tech tips under Meziere pump install.

https://www.corvetteforum.com/techti...=231&TopicID=2

ConeKLR

Good info.
BTW - your engine build came out really nice.

ConeKLR

Not really sure what you mean. Oil pump drive shaft comes off the oil pump which sits in the oil pan. I know the Water pump shaft goes into the front timing cover and gets turned by the gear on the cam shaft.That hole will also need to be plugged up when switching to Meziere water pump. But I'm not sure how what you describe above relates to using the electric pump?
Can you expand on this?
I'm a little slow you know.....

ConeKLR

Good info here. I'll keep this in mind when and if I speak to Meziere.
I know from experience that most engines require a thermostat or at minimum use a flow restricting plate in place of the thermostat. Your monster is a whole different type of animal compared to my stock LT4. Sorry to hear it did not go well at first. Can't blame ya for not wanting to run an electric in the future if you had problems with setup. The setup for the LT1 or 4 seems really simple and problem free. Yes, the pump can go but I would rather deal with changing out the electric again than having to deal with the OEM pump. The second AC Delco pump only lasted from 70,000 to 110,000. I'm installing a new opticrap so I want to minimize antifreeze leaking on the new one even though it is possible with an electric if it was not seal correctly.

ConeKLR

Yeah, that's my thinking also. I would like to have a faster cool down after stomping on it during autocross, track and drag race events. I know SonnyinVA (402 LT4 pushing around 500HP) also runs the HD mez. He runs at V.I.R. road course and has had no overheating issues.

TONYDEE64

Can you really cool the motor down though if the thermostat is shut? I guess you could cool the motor doen "until" it shuts.. or drill a couple of small holes in it..

Strick

I have a 180 stat installed and with the engine off and the coolant pump on with the fans manually turned on I can get the temp down below 160 in just a few minutes. Besides, anything below 180 is really not necessary.

Nathan Plemons

Typo, should have said water pump drive shaft.

99svrcpe

Thanks..I have about 1500 miles on it now and it seems to run stronger evertime I drive it.

ConeKLR

Thanks for the info on the fan relay. I did see a relay kit on Ebay that also may work. I started scanning thru the catalogs Summitt, Jegs for relays but I may use your setup. I know about ODS, I have been autocrossing there for years with the Northern Virginia Corvette Club. We also started using the drag strip but mostly for autocrossing. My LT4 is really not setup for 1/8 mile. The party is over before it even begins. It is ideal thought for testing launching technique or testing a setup change. MIR is always packed especially on Friday nights. The best drag strip events are joint track days with the Mustang club going to Mason Dixin, you get as many runs as you would like. I also enjoy going to NJ Corvette Challenge series. It's worth the trip. I'm hoping to have my car in back in the proper condition for racing this summer. Let's see how it goes this year.

ConeKLR

What have you guys done for the pump shaft hole on the timing cover?
Like to hear about a couple of solutions.