POLOVETTE 94

Is it worth going to the electric water pump on the LT1? Has anyone shown any real gains on the dyno? I heard 10-20 hp at around 6000 rpm. What about longevity? Maybe I'm one of the lucky ones, but my car just hit 70,000 miles, and I must say that my water pump is yet to spring a leak. Please share any experiences.

dizwiz24

Although the high RPM HP gain seems tempting, I have been straying away from one for reliability reasons.

This is a case of if it 'aint broke dont fix it'. Id stay with your stock pump. I reused my stock pump after an opti replacement at 33,000 miles. I have 41,000 on the car and the water pump still seems to be doing fine.

I read a recent post about someones electric pump stopping and they overheated.

Another post about 2 years ago, someones electric pump went out overheating so bad they thought they warped the cylinder head.

Some people have their pumps wired so that if it stops working it will sound some kind of alarm.

But, if you are in the middle of nowhere with your car....what good is the alarm going to do you if something internal in the pump has failed?

Maybe someone who actually has an electric water pump for a few thousand miles will chime in with how reliable they feel it is. Good luck in your decision!

black bart

If you intend to drag race your car you can gain performace with electric pump by removing alternator and run on the battery. You will need to recharge the battery after each run. A electric pump on a street car will gain you nothing. The engine don't have to turn the water pump but it has to make the current to run the electic pump.You are looking for perpetual motion no such thing. Their will be friction to the electric pump friction in the alternator it takes power to make all that energy to run the electric pump so the only way to gain power is to get the energy from another source. That would be the energy stored in the battery then at the end of the run replace the energy in the battery. For a street driven car installing one is an exercise in futility. If you don't believe me get out your physics book. Just because you see something on a race car don't mean it will work on a dailey driver.

Brand-X

I went with the electric water pump so I could run a true double roller timing chain set--I run a big, small base circle cam to 6800 rpm.

black bart

I run a small base circle custom grind roller cam with a Cloyes true double roller timing chain with a cast aluminum timing cover instead of the thin stock cover and I use a Stock water pump just made a new back plate for it from a piece of scrap plate that I had laying around cost nothing other than 30 minutes of my time to build it. Much cheaper and more reliable than going with a electric pump. The stock water pump will not work do to the bulge on the plate on the back of the pump install a flat plate it will fit and you just made a high flow pump out of it for Zero $$$$$$

lcvette

I have to disagree, I run electric waterpumps on all my vettes, only way to go in my eyes. the amperage draw on the Meziere is not enough to even come close to matching parasitic loss the gear driven waterpump creates especially at 5k + RPM. i have almost 17,000 miles on the first one i installed, and it runs flawlessly. i had two stock WP's go out on me and if you think when they go out your in much better shape if your in the middle of nowwhere, think again, the first one destroyed the bushing and hot coolant drowned the opti in about 10 minutes, car went dead on sight.
second pump went started leaking at about 69k miles and killed the opti on the 95 vette, both cases were a complete pain in the butt. the meziere is a closed setup which plugs the housing completely in the rear. if you are anything like me i check my guages about every 5 minutes or so while i check my speed. the analog guage reads temps in the head, when a pump fails, this is the guage that begins to rise rapidly. i noticed this the first time i wired a pump and forgot to connect the groud lead from the relay. other then that, if your wiring is routed correctly and crimped correctly the expectancy of the pump is on average longer then the gear driven pumps last. on a dyno my 95 LT1 saw an increase of about 11 RWHP across the board and 14 RWTQ. the pump impeller design is also far superior then the stock stamped steel pump wheel, the billet machined impeller is more efficient and the cars all run right at the thermostat opening temp with the car in motion and stay right the same in traffic with the fans programmed to come one for the 160 stat. i plan on replacing the pumps at about 50k miles for general maintanance and with the wiring harness i forsee about a 20 minute job of it! two thumbs up in my book!

Chris

Brand-X

Black Bart,
Nice water pump mod!
CT

black bart

ICVETTE glad you are happy with it. :thumbs:

That is one mod that I will never do. Also won't have to worry about a bad connection causing my pump to fail. As far as leaking on the Opti-Crap I wouldn't have to worry about that because if I had one of those I would replace it with something that was reliable. I'm still using the pump that GM put on in 89 83K and counting.


[Modified by black bart, 4:52 AM 8/31/2003]

lcvette

Bart,

We have an 85 L98 also, the waterpump designs between the two motors, LT1 and L98 are completely different. the shaft seal in the back of the waterpump on the LT1 is a weak point prone to failure. on the belt driven L98 waterpumps, there is a proven design, the stock WP on the 85 is still going strong with 160k miles. if i saw an LT1 with that many miles on the original pump i would be affraid to travel further then the nearest gas station for a pack of gum. not comparing apples to apples basically is what it boils down too. i think one of the main reasons for failure is the sloppy design of the drive shaft for the waterpump, couple that with high frequency vibrations coming of the camsprocket created by the engine and the seal at the back of the pump and impeller bushing get a hell of a workout. once it starts to get beyond its tolerable runout, the coolant is no longer contained in the pump housing, guess what sits directly underneath it..... lol the heartbeat of the ignition system...Optispark. anyone who's washed a motor before and gotten moisture under a standard distributor cap knows that starting the engine is at best futile. fortunately you can pop the cap and dry it out on the old style blocks, not the case for the opti on LT1's. at any rate, i agree if there is no concern such as in your case, leave well enough alone, but for the LT's i think its a great update. as far as wiring, there are tons of wires that can keep that car from running, if you take care to do the job correctly you should be just fine. keep them tires rolling!

Chris

tjwong

I know a lot of people using the electric water pumps on their LT1/4s. However I have often wondered what their performance was like at freeway speeds and such. At higher RPMS, does the electric pumps provide adequate flow. Even though in 6th @75 MPH a LT1 is humming along at maybe 2000 RPM. As we all know either a belt or gear driven pump increases in speed with the engine while an electric pump is steady state all the time.

And for reliability views even if the belt of gear driven developes a small leak often enough if there is adequate coolant in the system you can often get home. Whereas if the electric pump motor stopped or shorted out you are stuck. Granted if the gear pump didn't puke all over the Opti and didn' leave you stranded as well then for the most part one could get home even if one had to refill the system.

Both designs have their ups and downs. The old L98 style pump is about refined as it's ever going to get. I have one still going strong in my rusty 77 K5 Blazer with nearly 200k on the pump. My LT4 pump was just replaced when I did the cam job a couple months ago. It was in perfect condition with no signs of any leaks. But I had it apart so replacing it was just a matter of choice while it was apart. Anyone want a slightly used LT4 pump?

I guess it is nice to be able to use a standard Cloyes double roller timing set vs say a LT4 Extreme set which is a substantial cost over the double roller. I have found that the LT4 chain set up is adequate for most any cam that would be streetable and that includes most solid rollers. My friends stock eliminator class car runs some very big (255+) duration numbers while at the same time having to stick with OEM lift numbers. They run some very high spring rates but use the same LT4 setup without any reliabililty issues.

For me even if I wanted to install an electric pump, I can't. If I did I would never be able to get at the tensioner to remove the blower belt in order to remove the blower. Right now my arm has to slid into that area to get at the tensioner So I wouldnt be able to get at it without doing an R&R on the electic pump. It would just be rubbing more salt into the wound of having to R&R the blower.




[Modified by tjwong, 12:03 PM 8/31/2003]