vettef6

Does anyone know of a company selling HD LTx water pumps?? Don't know if there really is a HD pump on the market.

Thanks

96capricemgr

iTrader: (1)

Stock is far and away the highest flow pump available. Moves 66gmp as installed on the engine. The electrics have varying FREEFLOW ratings up to 55gpm but based on guys seeing RAISED coolant temps at cruise with electric pumps the stocker outflows all of the electrics by 2500 engine rpms.

The electrics do flow more at idle..........................when the engine is making no heat to speak of.

Tony Shepherd

iTrader: (4)

This is the heavy duty pump that I have been running for many years. Flows more than you will need.

http://www.meziere.com/ps-813-781-wp118hd.aspx

96capricemgr

iTrader: (1)

As said those with street cars find raised coolant temps at cruise with the electric pumps. Not overheating but higher than with the mechanical.

I am not saying electrics are without purpose or bad, just urging some vague understanding which is usually quite unwelcome.

The 66gpm figure I spoke of is from an SAE document on the LT1 cooling system, again the electrics are all freeflow rated.

For a drag car the ability to cool down between passes certainly makes an electric worthwhile, for a roadrace car they are often found insufficient and for a street/strip car well you have to decide if the .1 is worth the greater possibility of sudden complete coolant flow stoppage be it from the pump motor dying or an electrical fault. The mechanical will usually weep and let you know well in advance so you can change it before it really fails.

I eventually put an electric on my car for the .1 at the track, but even in 40degree weather the car runs warmer on the highway than in town, even with cool 70mph airflow the electrics are just starting to lose control. I can cruise for a 2.5hour drive home and it wont overheat or anything but the temp will come down once I get near home and speed drops to 35mph.

vettef6

Tony, that's the pump I've been using for many years. I have the Meziere HD pump which is supposed to flow 55gpm but it's just not good enough as it seems. I've been having trouble ever since I swapped to a EWP.

I have a LT1 Corvette, and I agree with 96capricemgr. I want to switch back to a stock pump. It's exactly as he says, temp at idle is great but past 2500 rpm the temp will go up to the hatch marks and when I step on the pedal the needle goes beyond and the water boils in the surge tank.

96capricemgr

iTrader: (1)

It is just simple physics the electric pumps take a lot less power to operate because they do a lot less work. People like to argue that but they probably couldn't pass a third grade science test.

I wont claim the stock pump is perfect the road racers do find it to cavitate at high rpm. Stewart's pump(real racing pump) teased us with the idea of an improved LT1 pump for awhile but as with so many other LT1 R&D ideas it never flew.

Part of me wonders about modifying a nicer EWP impeller for use on the stock pump. The stock impeller certainly leaves some room for improvement, what I don't really know though is how fast the electrics spin and if the impeller would work decently over the mechanical pump's rpm range.

I haven't seen anything about anyone really playing with the guts of the stock pump to try and improve it. I know one guy who welded the impellers on because he would twist them off but it is a 1500hp car, the rate of acceleration(Pump has to accelerate the water within the system) there is beyond what the rest of us will see.

Tony Shepherd

iTrader: (4)

Sounds like to me there may be other issues with your cooling system. Have you had your radiator checked out? It could be the culprit. I have been there.


A stock one will work fine for you as stated. Some have to go to an electric for other reasons such as using double roller timing chains which can't drive the stock water pump shafts.

vettef6

The radiator is ok. I'm using a HD radiator and measured the outgoing temp to the water pump. It was 140°--155° measured with a infrared gun.

96capricemgr

iTrader: (1)

I forgot about the timing chain excuse. Hell you will find more engines ruined by an electric waterpump or wiring failing than the LT1 timing chain failing.

Fastbird93

iTrader: (10)

This really has me chewing on moving back to a stock water pump. My front mount turbo setup is having a hard time staying cool at speed with the Meziere I've got.

vettef6

I'm definitely going back to a stock pump. I'll also have to switch back to a single roller chain, and I'm considering buying the Cloyes 9-3651X3 set up. http://www.summitracing.com/parts/CLO-9-3651X3/
My springs are pretty stiff with 560 lbs. Hope I wont get any problems going back to a single roller.

pancho toco loco

iTrader: (8)

Like said before you may have a underlining problem. For somebody wanting every last tenth it makes sense but gotta understand the trade off.. Also lots of ppl forget the operating temps from the factory. Everyone has a 160 stat and fans that come on at 180 range. So when driving w/ the electic pump and temps are in 210-220 range ppl freak. Even with my stock pump and a hot day ( 160 stat fan on 187 off 180 something like that) my temps get around 200-205 if Im driving 70-80. The 4.10's dont help that cause.

97Z28SS

iTrader: (5)

Here's a thought would something like the fuelpump voltblaster work with an ewp to speed it up for short periods of time by giving it more voltage?

lt1slowz28

not really something you want to over volt... a fuelpump dying without warning just makes the car shut off... a water pump going out can trash an entire motor.

BIGCAT7274

are you sure it good?
assuming its a 180* incoming temp. a drop across the core that big is a flow problem. first thing i would do is check voltage drop to the pump. then get a set of moroso water restrictors. put the smallest one in and check your temps incoming and out going. then move to the next size up. and keep going though them one by one. we look for a optimal 10* to 15* differential from inlet to outlet. if there is no or minimal change from the smallest to the largest restrictor. you need to pull the radiator and have it flow checked.

vettef6

A couple of weeks ago when the engine was idling I had an incoming temp of about 180° and 150° going out. Does this mean the coolant flow is too slow going thru the radiator?? It could also be that the water pump isn't capable of pulling the coolant faster thru the radiator.

BIGCAT7274

Yes its a flow problem. You just need to determined if its the radiator,water pump or some other restriction.

Blk98Vert

iTrader: (2)

Can't say I ever had a problem with my CSR pump on the street

vettef6

Yes, that's the problem!! Checking the radiator is probably the easiest, but how can I check the EWP or if there are any restriction (head gasket bores)????

BIGCAT7274

like i said above. try the water restrictors and see if there is change and check the voltage drop to the pump. low voltage will cause the pump to not move enough water.