I will have the 800hp Griffin radiator, stock fans, and currently have an Meizere electric water pump. I think most of you guys would agree for HPDE and even Autox the EWP has to go. So if I go back to my stock water pump, will the upgraded radiator be enough to ensure adequate cooling? Is their a nicer pump that I should look into (something cost effective)?

Yep, I would try it with the stock radiator, pump and a coolant additive.

I ran the electric water pump in my LS1 that had about 380rwhp without a single problem. When I changed to a 480rwhp LS3 I used an Edelbrock water pump which failed during an 8 hour race and replaced it with a parts store water pump that also failed during a race weekend. Both times I had to replace the water pump at the track. I'd try the electric pump and see what happens.

You've already got the electric pump. Might as well try it. Amount of flow isn't always the biggest thing. Having the right amount of heat exchange is. Those pumps flow what... 55 gpm? And they flow it all the time. It just may be enough.

I use an HD Meziere electric unit on my 440 RWHP LT1 with no complaints. It does get a little warm sometimes with a lot of WOT stuff, but manageable. And that is on a stock radiator with stock fans. I would give the electric a try, and have a backup stock pump on standby.

Isn't the right amount of heat exchange the most possible? I've never understood the physics behind the "don't flow too much or it won't cool." Yes, more flow means it spends less time in the radiator, but it also means it spends less time getting hot in the engine.

I haven't seen a flow chart for the electric water pump compared to stock, but if the engine is putting more power to the wheels with an electric pump, to me that means less energy is used to pump water. I would assume that the pumps are fairly close in efficiency, so at high engine RPM's the stocker is flowing more water than the EWP.

Since you have it already on the car, I am curious how it will work out. But, I think for sustained high RPM use, I think the stocker is a better choice (or another mechanically driven pump). For drag racing or auto-x, the short runs with the ability to run the pump with the engine off might make the electric a better choice.

A belt driven water pump also helps to pressurize the water jacket. That raises the boiling point in the engine block. If there's no thermostat, the radiator becomes the restriction that it pressurizes against. That's one of the advantages to a real water pump. The electric pumps just don't have the power to pressurize the block. If it cools the car, that's all you need. But there's more to it than just flow rate.

I would think the water temperature would be a much greater determinant of pressure than the flow rate of the water pump.

When I had my 412 Ls2 I had the Mezier electric pump and it was great for the street and kept the car cool in traffic. If I recall it spins at the equivalent of 4500 rpm all the time, but when I was at 7000rpm I would over heat real fast. I would pass 220 in under 3 minute. The rad was a Be Cool. It worked fine for autocross. That motor made 519rwhp.

I now have a Ron Davis Rad, with a Ron Davis Water too oil cooler. The pump is an Evans. Not sure if they even make them anymore, but it seemed to work pretty well with the new larger 455 LS7. I also use Evans coolant at 3psi.

I like the mechanical pumps better even if it costs you a few hp.

The Evans pumps are an 'upgrade' as far as belt-driven, OEM style pumps go, but they are co$tly (but still ~ half the price of an LS1 Meziere).
There is no requirement to use their coolant/fluid with their pumps, as some out there (mostly those who dis the company) think.

They DO warranty though (I beleive even if it is known their pump was used for racing purposes).

The Meziere was cheaper at the time. Only $550 or so. The Evans with ceramic coating was in the $750 range. I wanted no cooling issues this time around, and even with the rad and this pump had crazy oil temps. 320! The oil cooler should help as well as sealing top rings.

I use the Evans coolant due to the fact I have wet sleeves and it was recommend buy the block mfg.

Just as a general statement, cooling the oil has a huge effect on keeping everything in the motor cool... So if the OP doesn't have an oil cooler, it should be thought about.

Also ducting into the radiator without any gaps is a huge step. I half assed this step before my first event this season and paid for it. 250* water temps in 2 laps. Added an oil cooler and ducting and now rarely see over 200* water and 240* oil.

So make sure everything else is up to snuff before you discredit the electric water pump about being able to do the job.

They are up to what, ~$800.00 list now (maybe more!)??!

I only paid ~$375.00 or so for my Evans, but that was almost 7 years ago, and it was not ceramic coated.

BTW; what exactly do they ceramic coat, is it the internal passageways/impeller/etc., or just the outside to make it pretty??

http://www.nastyperformance.com/shop/evans...low-water-pump/

Base unit is $389 + Ceramic $130 + Small anodized pulley $129, + Evans 180 Tstat $46 + their belt $49 = $743 before shipping and taxes. Mine is about 4 years old. I knew I paid upwards of that. The Candian dollar was getting closer to par then too.

I got all the coatings and their Tstat.

The $800.00 statement was in regards to the current Meziere price.

What does Evans claim the ceramic coating does; hold in the heat like long tube coatings, help coolant flow through the pump, longevity of impeller/housing due to corrosion/pitting resistance????

BTW; Evans upgraded my old, uncoated, spun alloy pulley for the newer anodized one FOR FREE (I just had to send back my old one after exchanging it)!

I do not recall the benefits of the coating. I think it smoothed things a little to improve the flow a little bit. I did it more for looks. Same on the hard anodizing.

Mezieres must have went up a fair bit. I do not recall mine being anywhere near that much and the Canuck dollar sucked back then. I guess I sold it too cheap.

Nice!

Got any pointers on how to make sure the radiator is perfectly sealed? I will be getting an oil cooler over the winter, and this event coming up is just autox, so I think I can get by for now. I know sealing it is important, but I might need a little advice on physically how to get it done.

Thanks!

The hard anodizing on the pulley actually DOES help stop the belt from wearing a deep groove in the alloy pulley.

I know this as fact, since the original silver, non-anodized pulley had a DEEP groove worn into it (without even having that much tension on it-I have a Katech solid tensioner), and the anodized one they exchanged for me has NO groove whatsoever after ~3 years on the car.

So just run the engine oil through the trans cooler in the rad? or through an external small cooler as well?