My opti died in some very heavy rain a month ago. The MSD one will be here in a few days. Thought I'd replace the water pump as its of unknown age, ive had the car for 5 years. I looked in the forums and saw no refrence to one pump being superior to another. I(m not interested in going electric.
Any of you have an opinion on this or are they pretty much the same?

 

With the LTx engines you only have 2 choices in mechanical water pumps, OEM and rebuilt OEM. I would spend the extra money and get a new OEM pump. Summit Racing sells them for ~$185.

 

With waterpumps I've always had bad luck with rebuilts!

 

Personally, you might want to reconsider an upgrade to electric. Many reasons why to do it.

 

thanks for the posts. I known the electric will free up about 5hp. I was under the impression they were best for raceing. From what I can recall reading along the way is that they arent as reliable as a mechanical. Comments?

 

I've always used rebuilt water pumps on all of my vehicles and have never had a problem with them. The only exception is one particular time when it was covered under warrenty. I got a new one then.

If you're looking to stay mostly stock and aren't racing, what are you fixing with an electric pump? We're talking what... 2% HP increase here? Don't do it just for that!

 

Here's something to think about. If the stock water pump fails, it will be over time. If an electric water pump fails, it is immediate and the car will overheat within a matter of minutes. Ask me how I know.

Having said all that. My car isn't driven that often, and I'm still running an electric water pump for the improved performance.



-Mike

 

I put an aftermarket WP on mine 2.5 years ago. There were new replacements available at the time from all the usual brands.

A quick check at partsamerica shows they currently carry three aftermarket WP for my car.

 

Pretty much the same.

 

Who makes the aftermarket water pumps, or are they just rebuilt OEM's?

 

It seems to me that using an electic water pump would just cause the alternator to absorb the power that used to go into the mechanical water pump in order to make the electrical power to run the electic pump.

I would imagine that your actaully loosing power with the electric pump over the mechanical pump since you have to convert mechanical power to electrical power then back to mechanical power and that's not anywhere near as effiecient as just driving the mechanical pump directly.

Scott

 

Why go with an electric coolant pump? Let me list some of the bennies:

1. It does away with one possible source of an oil leak, gear driven seal on timing cover.

2. OEM water pumps start to leak out the weep hole which is right above your opti. This is the first signs of a failing pump. Electric upgrades don't leak.

3. If your electric pump does fail, it only takes about 30 minutes to replace.

4. How long does an electric pump last, Meziere says about 2500 hours. Do the math, that's a long time. Longer than any OEM pump.

5. At idle in the summer with the A/C running, your electric pump is moving much more coolant than your OEM, it's constant.

6. When you change your coolant in our LT1s, there is always the problem of "burping" the system to get the air out. With an electric pump, you just turn the key on with the radiator cap off and the coolant is flowing allowing the air to escape and making filling easier.

7. Let's say you ran your Vette pretty hard on a hot day. When you shutdown the engine is hot and the whole compartment gets hot. If you have a few minutes, you can shut the engine off and turn the key back on and the coolant is flowing allowing a cool down. If you wire your fans to come on manually, you can also cool it down even faster.

8. There is a reluctancy to give up a manually driven accessory in place of an electrical upgrade. Hey, GM changed the fans to electric and they work just fine.

9. I haven't talked about racing yet, so I'll start now. I autocross and in the summer things can get pretty hot. The engine cool down option is quite nice. Yes, you do gain a few ponies over the less efficient manual pump. Yes, the work required to move the coolant is about the same, but the electric route is more efficient which frees up the few ponies.

10. Removing the OEM style pump also allows you the option of upgrading your timing chain as there is more room once the gear driven assembly is removed.

11. You can wire up a system check that will alert you to the pump failing. I watch my gauges so this isn't a priority for me.

12. Mine has been in for a little over 4 years now or 15k. No problems so far.

Check out my article in the Tech Tips about installing a Meziere coolant pump.

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

I know, it's too long.

 

I've never used any OEM water pumps, always a remanufactured one from NAPPA or other parts stores, but I'm one of the fortunate ones I guess, cause I've always had good luck with rebuilts, starters, alternator, etc.

 

I was referring to new aftermarket pumps. Just do a search at your favorite online retailer.

 

Yes and no. At idle the stock waterpump is probably going to give you more power, but as the rpm's increase the stock waterpump becomes more and more ineffecient. The Elec waterpump stays turning at its one speed all the time, so as the rpm's increase, your drag created by the need to turn the alternator stays the same. There was a one time dyno posts of before and after an elec waterpump install.

With an electric water pump and dewitts radiator and 160 degree t-stat, my car stays at 175 degrees all the time.

 

I change mine in the last six months, got it from "thepartslady" on eBay. OEM and new. Got a new one because I didn't want to go in there again, soon.

 

Napa's premium water pump for my 90 vette was only 59 bucks...I bought it a couple days ago. Mechanical kind. Seems like that's a good route to go. It has a warranty.

 

Whats your take on a Meziere pump for a car that does a few (or more) lapping days a year. I guess I've been given the impression that this is more of a drag racer mod, than for a road racer? How do they perform with sustained high rpms???

 

LT1
http://www.ws6.com/mod-14.htm

On an LS1
http://www.ls1howto.com/howto/fbody/...pics/_dyno.jpg

http://www.gmhightechperformance.com.../photo_33.html

There were some others. Still looking.

 

I'm pretty sure they would be good for a road racer. You'd always have your waterpump, and thus your entire cooling system running at its maxium, so your car would run cooler, and cool faster. The heavy duty Meziere waterpump moves 50GPM.

Does anyone know much does a stock waterpump moves?

Running a elec waterpump might put you in a different class though. It would give you more RWHP.