They look different, but as far as I know they are interchangeable.

 

i wonder if the LS2 water pump has more flow since the radiator veins are 1 1/2 inches?

might be good for us old ls6's ?????????

 

I've got an LS2 water pump. It's going on my LS2 block, but it is interchangeable. The main difference is the pulley is smaller in depth, not diameter, and lighter, and the whole pump weighs 3.5lbs. less. Also the impeller is different and the rear cover is pressed in instead of screwed on. I got an LS2 water pump kit from SDPC. It came with pump, thermostat housing, and thermostat. Also the stock LS2 thermostat is set at 86C or 187F.

 

many people use the Evans water pump..
Its manufactured for high volume & high velocity..

1000% better....

http://www.evanscooling.com/main13.htm

 

They are interchangeable--most parts houses sell only the LS2 pump for all applications anyway--BUT I believe that the older LS1 pumps use a thermostat that is replaced with the entire housing assembly-and the newer LS2 pumps use a thermostat that is like more like the conventional "thermostat only" type---

 

Yes they are interchangeable but the t-stat is different

 

Directly interchangeable physically with the thermostat being the primary difference.

 

so I can use the same stock belt if I move from an LS1 to an LS2 water pump?

 

Yes, you can keep the same belt size when you switch to the LS2 water pump.

 

Thanks, Jason!

 

 

The LS1 - LS6 style pump is far better than the LS2 pump. Bigger shaft, better seal and larger bearings than those on the LS2.

The Evans pump is superior to the factory pump. I had Caldwell Development do some testing a couple of years ago. The stock factory pump gives uneven bank to bank flow distribution above 5,000 rpm. The Evans give much more even flow bank to bank above that speed.

Stock LS1 pump and stat flows 55 gallons per minute. Evans pump and stat flows 85 gallons a minute. Evans pump with their external stat housing flows 110 gallons per minute.

Evans now has various pulley diameters for over and under drive. For most street applications you want to drive the pump roughly 10% faster than crank speed. The standard Evans pump is set up that way. You need their belt to go with this setup or you can get the stock GM diameter pulley to use the stock belt.

www.evanscooling.com

 

I'm using my LS1 water pump on my LS2. I'm 99% sure that I'm re-using my Hypertech 160 degree thermostat from my LS1, also.

 

I see the Evans pump also available with ceramic coating to prevent corrosion, is it made of aluminum? Also I do not see higher flow version with external thermostat listed??

EVANS COOLING SYSTEMS, INC. continues to expand their product line with the release of a high flow coolant pump and pulley combination for the hot-running GM LS1/LS6 engines. The new LS1 Coolant pump and pulley combination, part number EP3913, is designed to fill the current void in the LS1 Aftermarket. Flowing over 20 percent more than the OEM style replacement pumps, the EP3913 maintains equal flow to both cylinder banks at any engine RPM. OEM style pumps do not.

Evans has improved the design of the OEM casting to include a Billet pulley hub, heavy-duty 3/4” roller bearing, and ceramic shaft seal. The EP3913 also includes the Evans 3.8” OD 8 vane scrolled impeller to reduce parasitic horsepower loss at high RPM. A new shorter serpentine belt must be purchased separately for the specific application. Belts are available through Evans Cooling Systems for $49.95 each. (Please specify Corvette - EB3913-C or Camaro / Firebird—EB3913-CF.)

The EP3913 is available for $469.95. Corrosion free ceramic-coated housing is available to finish the look of the pump in a show car. Ceramic coating is done on both the inside and outside of the housing. Ceramic-coated pump is available for $594.95. Evans can also build a pump from your existing LS1/LS6 housing for $399.

To take full advantage of the increased flow capability of the EP3913, Evans has developed modified 160° (E3022) and 180° (E3023) thermostats specifically for use with the EP391 3. The modified Evans thermostats flow up to 55 percent more coolant than other aftermarket thermostats. Both the 160° (E3022) and 180° (E3023) thermostats are available for $49.95 each.

EP3913C ($594.95) Ceramic coated LS1/LS6 High Flow Coolant Pump with Pulley

EP3913 ($469.95) LS1/LS6 High Flow Coolant Pump with Pulley

E83913-C ($49.95) Corvette Serpentine Belt

E83913-CF ($49.95) Camaro / Firebird Serpentine Belt

E3022 ($49.95) 160° LS1 high flow thermostat.

E3023 ($49.95) 180° LS1 high flow thermostat.

 

hi steve - i bought an evans pump used and now i get high temps at idle (they come down very quickly when I rev to 1500 rpm). i think the pulley on it doesn't work well with my under driven crank pulley. what diameter should i use with an under driven crank pulley on an ls1? thanks.

 

There are various underdrive crank pulleys available. Most are 10% or 25% under. You must know what you have in order to get the correct Evans pump pulley.

The stock GM ratio is 1.285:1. - the pump turns 1.285 times per one crank revolution. This is a good drive ratio for street and high performance street use.

Measure your crank pulley diameter. Call Evans and speak to one of their techs. They will get you the correct pump pulley for your set up.

The external stat housing is still available as far as I know even though it is not listed in the catalog.

Steve

 

This is all great and timely information.

The 55 GPM mentioned above to the stock pump, was that at a specified RPM? Reason for asking is the Meziere is supposed to pump 55 GPM but some of the road course guys have run into problems with heat above 4,500 RPM and the thought was the stock pump put out more flow than 55 GPM aboce this RPM.

 

The Meziere pump flows 23 gallons per minute at any engine rpm.

A good rule of thumb is one gallon per minute per ten horsepower.

Check out the attached chart.

 

Were these independent tests? Meziere advertises 55 GPM and 35 GPM for their "race pump". Not sure which is included in the plot above.

The 1 GPM/10 HP that you state in your post, is that a rule of thumb to use the curves? Also, is the flywheel or rear wheel hp (since most posts on here usually refer to dyno numbers).

I have also corresponded with Evans on their thermostats and got some interesting information (I also asked about their ceramic coating):


"The stock t-stat from GM will work on our pump. But our t-stat works better as it opens much farther then stock.The stock t-stat, as does ours, allows for coolant flow, but they also have a foot connected to them that when the t-stat opens, this foot blocks off the bypass. Ours does a better job of closing off the bypass and does not allow coolant into the bypass circuit. The stock one does not have that strong of a spring to close off the bypass. As far as the ceramic look goes, I will say that for a part to look like polished aluminum ,it must be totally smoothed out. Our ceramic coated pumps are not smoothed out, just coated, so you have the ease of cleaning it and it is shiny but not a "polished look" shiny. The pump is also coated inside and out before assembly. That gives it protection and better flow capabilities inside as well. I don't have any pics of it online but if you ever seen something that is Jet-Hot coated, that's what the ceramic coating looks like. We also can powder coat any pump to match a specific color too. The difference is only the outside is powder coated, but you have many more colors to choose from....hope this helps...........Tom"