markinkc69z

Your question is exactly why I bother to contribute on this board. Its good to ask why something does, or does not work like you think it should. So don't feel bad for questioning.

The electric pump is fixed in its volume, whatever that is. When the speed an load increases on the engine the flow of the pump is still fixed. More heat is being put into the system (water), but the in and out doesn't change so the overall temperature must go up. This is why you see a power increase as the pump isn't ramping up to demand as the stock pump does.

When a conventional system gets hotter as speed increases its usually due to a lack of airflow or cooling capacity, such as having a 2 or 3 row radiator and needing a 4 row.

The mechanical pump on an LT1 is driven off the cam. There are seals that contribute to drag, but it is mostly attributed to the drag of the impeller moving the water against pressure.

I know of no flow tests on a stock LT1 pump, but there might be one out there. One way to do it would be to run an engine on a dyno with a large resevoir of water to feed the pump under standard operating pressure and restrict the outlet to duplicate the water pressure in the engine as installed in the car and measure the volume discharged. This would be a rather elaborate setup and something not likely to be done just because.

Now one of the board members could do a free flow test for us by turning on their electric pump and measuring and timing the volume of coolant coming out of the system into a bucket. This would drain their system and be a pian in the *** but maybe somebody would be game.

A/G

What do you have as a source for this info?

According to Meziere, their HD pump flows ~55 gpm in the LTx engine. This is more than their pump for the std. SBC is rated at or flows due to the (apparently) less restriction (better efficiency) of the LTx reverse flow system.

According to Yunick in S-A Design book 'power secrets' originally published in 1983, "I have never tested any stock Chev water pump that can push more that 68 gpm through the stock (traditional SBC) block and heads. The biggest problem is air cavitation." This problem was due to the stock coolant flow system. "... when the shaft speed exceeds the point where a stock type pump puts about 68 gpm through the system, the pump starts pushing air into the engine along with the coolant...." This tells me the stock pump could pump MORE with a more efficient system. The OEM LTx cooling system being more efficient, would lend credibility to the Stewart claim that puts the LTx system/pump at a higher figure. The stock (OEM) LTx pump may put out 25 gpm, but not at anything close to 6000 RPM.

CALL911

Also keep in mind here my intent behind posting this thread. It is more to find out between the stock WP and the Electric ones, which will hold up the longest, and still keep my engine cool for worst case scenario driving (i.e. wide open throttle for 5 miles on a hot highway, or back to back runs at the strip, including the fact that the car will be regularly driven on the street as well). I am not concerned at all with the power gains it will give me. I will have more than enough power as it is.

97WS6Pilot

It was in one of the hot rod magazines where they did an actual test with actual flow rates. This was way back when I first bought my car in 97. I can't find a reference now.

Basically the stock pump flowed around 35gpm at 3500 rpm but began to cavitate at higher rpm. Whereas the Meziere flowed just enough where it would not cavitate.

Summit and meziere #'s are not flowed with the pumps on the car at full pressure at full rpm. The stock pump works best as it was designed between 2000-3500 rpm.

Kevin Blown 95 TA

My experience has been that the stock pump let the engine get a lot hotter around town and stop-n-go traffic, but they are both pretty cool on the interstate with the CSI being maybe slightly hotter than the OEM mechanical. The CSI makes me nervous, cause I have had multiple instances of not having it on when it needed to be on (mostly from turning it off to program the PCM) and I def need to foolproof it by hooking the WP relay to the FP relay and rigging an early warning system.

CALL911

So in simple form, has anyone had any issues running the stock WP with their SC? It sounds like (with a few arguments aside) the stock waterpump is the safer bet between the two for the use with a Supercharger.

streetbad

I used to have to hand push my car in heavy traffic to keep from melting it.

CALL911

WOW, this thread is just slightly old...

Kevin Blown 95 TA

Yeah it is OTH my same pump is still in there kickin. I did wire the WP relay to the fuel pump relay, but never foolproofed it with an alarm system. 8 years later, not sorry I went electric.

mzgp5x

I run a Mezz 55gpm pump.
Yes... 97 383 w/ F1A application.
Also...
BeCool rad, Rad supports moved forward, AfterMkt fans, relays for full fan function, No thermostat (did my own bypass), and... Evans NPG.
Also, modified the cylinder head bypass circuit flow.
I have found that with the polyGlycol, and, increased flow, much better cooling and heat removal is possible.
Ray Bohacz (sp?) has also documented this in his cooling book. A good read.

Runs very cool in 90*F summer w/ high humid weather with the blower run @ high rpm.
Many say I go over the top. Maybe, but, what else am I going to wrench on. My rolling experiment. Always modding in the winter.

From my experience, the stock T_Stat can be a problem with poor seal of the pump internal bypass.
Hope this helps. B.