[95wagon]

The coupler IMHO gives enough " flex " if kept lubed and the alignment dowels are in place.
I have seen water pumps where people have broken the dowel hole out and off brand pumps that did not fit properly resulting in side forces.
Neither the pump , front cover , gear likes that much.

I too tried the gutted nipple and drewl plugged it. Made hole slightly bigger and put a pressed in tube.
It was clear when I went to the electric in search of ET.

My personal experience with electric pump and temps.
Cooler in stop and go traffic
Hotter running down the highway .

 

[storm9c1]

My issue is that damn inline restrictor to the heater core. I don't think anyone makes one that doesn't start leaking.

I'd like to make one out of metal with the same internal parts as the plastic version. I have some ideas that don't require a machine shop. But may take me a while to build it.

I've had too many plastic ones fail suddenly over the years. The plastic is junk. It just gets brittle with age.

Using an EWP, I question whether the restrictor is needed. I believe the restrictor is there to allow full flow at idle and to snap partially shut (restrict some) at higher or full throttle. I believe this is to protect the heater core. But I also believe it slows down flow through the heater core to allow more efficient heat transfer (warmer heat to the cabin) and limit cavitation in the core itself.

That said, maybe you don't even need the restrictor with an EWP? Since you have a fixed flow rate, I'd be tempted to build a metal (static) one that just necks it down to about the size of the hole in the plastic restrictor when it snaps shut. This may be super easy with a male and female hose barb and a washer inside. Or a piece of steel rod as thick as the hose, with a barb machined into it, and a hole drilled in it. Easy work for a lathe.

 

[95wagon]

Yes believe cavitation - erosion was the big thing.
The hole size required to protect at high speed would hinder low speed heat.

Agree, fixed diam orifice for electric pump would be good .
Edit: if needed at all
Never got to it but also a vacuum or electric valve connected the AC max setting to shut off water completely when you wanted MAX cool with no regulation or when on vent .

 

[Marky Dissod]

... I know some people really like EWPs. I haven't graduated from that class yet, mainly because 20+ years ago, when I was racing, I noted several LT1 cars at the track would overheat with EWPs and the guys hated them. They seemed to do well at idle but couldn't keep up under stress. I knew a guy who tried 3 different brands. Two caused overheating at the track, one worked better but had poor heater performance in the winter (maybe because it was circulating too fast?). Guess they've gotten better since then???

Do all of the people here that run EWPs have any heater problems in the winter?

Whereas OE mech H2Opumps are variable flow

Electrical vs Mechanical Water Pumps

Before the GDL'09, someone on this forum was trying to correct misinformation regarding electrical vs mechanical water pumps. I forget who, but he mentioned things like: 1) Stock mechanical water pump flow was measured while attached to the LT1 cooling system, whereas electric water pumps are...

www.impalassforum.com

Electric H2Opumps spin at a fixed speed regardless of engine RpM.

The question that the linked thread above never answered (nor a bunch of other threads linked to that thread), was
At what engine RpM does the OE mech H2Opump exceed the Meziere WP118HD's performance?

Some people with electric H2Opumps have good heat, some don't.

IFF you've a160°F Thermostat for the winter … do...

IFF you have a 160°F thermostat for the winter … 1. Do you have 'good' heat in the winter? (If ANY of your passengers are cold, the answer is NO.) 2. Does your cooling system still have that variable restrictor to protect the heatercore? 3. Is your waterpump mechanical, or electrical...

www.impalassforum.com

That did not get definitively answered either.

 

[1slow96]

Not only do EWP spin at a fixed rate ,they spin at an optimum rate for transferring heat into coolant from engine. Also for coolant to shed it's heat in radiator. I've never come close to overheating coolant regardless how many laps on road couses. Something else gets way hotter first. Brakes/trans usually ,but P/S fluid is a close contender. If one dislikes EWP for whatever "reason" ,don't use them. Broad generalizations that those of us who've run EWP for decades know to be total B/S doesn't help anyone. Same can be said for the "gossip" surrounding 160 degree stats.

 

[Marky Dissod]

Not only do EWP spin at a fixed rate, they spin at an optimum rate for transferring heat into coolant from engine.

I've no way of proving or disproving this statement, but I still have a very strong suspicion that the different electric H2Opumps for LT1s
Meziere WP118 vs WP118HD
CSR had two different pumps
think there was another maker?
have different power consumption and flow ratings.
At best, only one of them spins at the optimum rate.
Things may have changed since that thread I linked, but I bet it's still the WP118HD.

According to the graph in
this post
the OE mech H2Opump peaks @ 66Gallons per Min at 6,000 PUMP RpM.
6,000 pump RpM ≈ 4725 engine RpM.

WP118HD rated @ ≈ 50GpM. Note that this was never measured through an LT1.
All the other electric H2Opumps were rated to flow less than the WP118HD.

 

[95wagon]

I would argue the " optimum " speed for a pump is due to impeller design and housing.

The too fast to pick up heat in the block and too fast to have time to release heat in the rad story is ,,,,,,, well,,,,,,,,,

The car over heats with no thermostat because the water moves too fast = sasquatchs and unicorns.
More to due with no restriction = less pressure = more localized boiling

Stewart Components are not idiot's

Home - Stewart Components

www.stewartcomponents.com

 

[1slow96]

I suspect that higher horsepower motors (450+hp) require higher rates of circulation within the motor.
Compared to motors making 300-400hp. Mechanical pumps can only flow water to the point where impeller begins to spin thru coolant (cavitation) which mechanical pump proponants never mention ,nor their relatively poor rates of flow when stuck in city traffic.

 

[95wagon]

Mechanical pumps can only flow water to the point where impeller begins to spin thru coolant (cavitation) which mechanical pump proponants never mention ,nor their relatively poor rates of flow when stuck in city traffic.

I will go along with that.
To put a sharper point on it a pump impeller ( electric) could be very optimized if it only turns one speed.

Yes agree with cavitation , pumping a bunch of air around badly doesn't cool very well.
The Chev powered race cars I take care of I get away with running at less than 1/2 crank speed.

 

[Marky Dissod]

... the "optimum" speed for a pump is due to impeller design and housing.

Unless GM has a different part number for the '96 LT4 'vette H2Opump - and yet another part number for the '97 LT4 Camaro SS / Pontiac FireHawk LT4 H2Opump - I think it's safe to assume that the LT1 H2Opump was rated to handle 350 peak horses.

... too fast to pick up heat in the block and too fast to have time to release heat in the rad story is ...

long story, too short: backpressure, anyone?

Here's a thought: with a 180 degree F tstat, and coolant moving @ 66 gallons per minute through the system, with both radiator fans blowing, the radiator would still be coldest, the heads would still be hottest, and the average temp of the coolant would approach 195 degrees F ... right?

Does LIQUID coolant ever flow through the steam pipe behind the heads - or just steam?

... Mechanical pumps can only flow water to the point where impeller begins to spin thru coolant (cavitation) which mechanical pump proponents never mention ...

For whatever it's worth ...

To put a sharper point on it a pump impeller ( electric) could be very optimized if it only turns one speed.

Now we need a pic of a mech H2Opump impeller and an electric H2Opump impeller ...

 

[95wagon]

The only time there is steam or air coming out of that tube is when it is generated or trapped.
Pretty much straight coolant coming out in normal conditions.

 

[storm9c1]

Now we need a pic of a mech H2Opump impeller and an electric H2Opump impeller ...

Maybe this will help?

Maybe glean the impellers from those? I don't have an opinion yet about all of the various claims for and against electric or mechanical water pumps. In fact I only go off what I've been told by other electric pump users 20+ years ago. That's why I asked if others noted issues (either overheating or heater performance). Real facts cannot be determined without engine dyno comparison, testing WPs at specific RPMs and checking engine temps and coolant flows. It's been touched already on but there is a lot of factors involved, cavitation, heat transfer of materials, fluid heat absorption, nucleation sites, etc, and how water flow speed and pressure affects all of those factors.

 

[95wagon]

I had to look up nucleation

 

[95wagon]

The lt1 vs L98 pump comparison , to me , is a little misleading.
The open vs closed difference is due to bypass design .
The L98 had only that small bypass port from the pass head to the water pump inlet.
They barely moved any water with the stat closed.
The LT1 has the giant bypass and dual acting thermostat and moves water big time thermostat closed.

I remember a respected member here years ago arguing that a old style thermostat worked fine in the LT1. Yeah maybe 1/4 mile at a time !!

 

[BALLSS]

I know some people really like EWPs. I haven't graduated from that class yet, mainly because 20+ years ago, when I was racing, I noted several LT1 cars at the track would overheat with EWPs and the guys hated them. They seemed to do well at idle but couldn't keep up under stress. I knew a guy who tried 3 different brands. Two caused overheating at the track, one worked better but had poor heater performance in the winter (maybe because it was circulating too fast?). Guess they've gotten better since then???

Do all of the people here that run EWPs have any heater problems in the winter?

IDK about EWP getting "better since then"...My Meziere 118HD is over 22 years old now with close to 100k mi on it. Driving and tracking the car for years (Pomona, Famoso, Firebird, The Strip, Carlsbad) in heat sometimes over 100 degrees at midnight (The Strip) and never a overheat issue. Never AutoX other than heavy hard driving through canyons here in SoCal and no issue

IMHO the issues I ever saw with people running EWP's is crap electrical to them. You need a solid relay/fuse/power source...fortunately Gary makes a nice set up but long after I installed mine using a Painless Wiring relay/fuse.

As far as heater in winter, not much of an issue here in SoCal, but my heater works OK. Granted not as hot as stock as I run a 160 stat with fan on temps lowered so the car runs just over the 1st hash mark on stock gauge (185 on scan tool)

I will state I was VERY skeptical of using a EWP on a streetcar as they were always on 1/4 mi cars but given the chronic mechanical WP fails, thus Opti deaths, I switched at 37k mi when my car went out of warranty and have never looked back. I even bought a spare about 15 years ago because I assumed EWP would not live over constant use....for me the spare has remained in the trunk. At some point my spare ill be needed, 10 min swap, and I will send my Meziere in for their $100 rebuild and let it live in the trunk

 

[storm9c1]

Thanks for the details. Based on this, I think the heater issue might be a legit concern in northern states. On really cold days, like 0 degrees F or lower, even with the mechanical pump and fully warmed-up engine struggles to get me heat. And that's on a well-maintained car. If the EWP is 15% colder heat, that will really make a difference down that low of temps. But there's nothing stopping me/anyone from using one on a "summer" only car.

Some folks like reusing the AIR pump circuit for the EWP. But yeah if it were me, I'd be running a dedicated circuit with 10 gauge wiring through a relay and fuse.

 

[1slow96]

I'd prefer a circuit breaker to a fuse ,but that's just me...

 

[storm9c1]

I'd prefer a circuit breaker to a fuse ,but that's just me...

Sure, that's fine too. I used the term "fuse" loosely there. Because if I hadn't mentioned a fuse, someone like you would probably come in and correct me.

 

[BALLSS]

Thanks for the details. Based on this, I think the heater issue might be a legit concern in northern states. On really cold days, like 0 degrees F or lower, even with the mechanical pump and fully warmed-up engine struggles to get me heat. And that's on a well-maintained car. If the EWP is 15% colder heat, that will really make a difference down that low of temps.

If you are referring to my comments....a EWP has zero effect on heater output. My comments were referring to a 160 stat and fan temps programmed to come on lower thus a much lower "operating" temp relative to cooling system. It is that lower operating temp that mute's heater output compared to a stock system, EWP or Mechanical WP as stock programming and a 185 stat the motor "normal" is running 200 degrees ish and heater is warmer output due to higher coolant temps in cooling system

The lower operating temp due to programming are designed to allow for more timing and fueling for performance purposes

The heater "restrictor" is because a mechanical WP output/flow increases with RPM so there is a restrictor inline to protect the smaller cooling core of a heater core from rupturing when motor sees high consistent RPM use

Given an EWP has constant flow regardless of RPM I would think the restrictor could be abandoned but see no hindrance that it remains

 

[95wagon]

Water pump drive and coupler

The dimensions of the drive at the spline

Are identical to the pump splines

As seen together

Coupler spline depth , o ring area , the same.
Where it differs is the grooved end the splines have a " lead in " taper.

Pump end

Grooved engine end

Assembled , I see ZERO functional operating difference.

What I do see is on assembly a person with pump coupler on the pump reversed could conceivably hit the blunt ends of the male -female splines, crank the pump on, f#$% stuff up.
Assembled with coupler on pump , groove towards the engine as per factory, the mating of the coupler to the drive as you push the pump on would have much less chance of going wrong.
So, thats what I am going with ,,,,,,