Gen 2 Water Pump Flow rate

[ACR_VP]

I know this is a stretch, but does anyone know what the flow rate is of the stock Gen 2 water pump? Having a custom radiator made and they obviously need that info.

[dave6666]

As someone that has worked in engineering in the chemical industry for decades I certainly understand that info request from the shop, but as someone that has also dealt with custom radiator fabrication before I've never heard that question asked while discussing car radiators.

Any chance they would tell you what their concern is? Pressure drop? Residence time? If you are simply having a new core made with an additional row like many do with the stock radiator, can they not just copy the tube sheet layout and tube dimensions that are already established?

[ACR_VP]

Hell if I know... My dad is with a manufacturer that specializes in radiators and every other type of heat exchanger out there. They are making a significantly upgraded replacement from scratch, may even make a triple row. They have my stock rad, and fan w' shroud (a '99) and are looking to establish an accurate baseline on their bench. I'd go the other route, but this way is free for me, and given that they do high end specialized custom heat exchangers all the time, seemed like the obvious choice. I wasn't questioning their request for info haha.

[dave6666]

Ok then lol, I might accuse them of overthinking it. Which anyone in engineering would do.

Coming from my experience with Gen 2 radiators of which I have tested all of these in the 110+* TX summer heat:

* Stock 2-row
* Modified stock 3-row
* Ron Davis
* Roe 3-pass
* Howe 3-pass

And... that all of them cooled adequately. The limiting factor in Gen 2 cooling is therefore in my opinion only related to the radiator if there are other contributing factors such as radiator fouling, both internal and external.

There are many, many other modifications to do to a Gen 2 to enhance cooling. Fixing a fouled, or possibly failed, radiator, is just one of them.




Sooooooooooooooo, back to your dilemma, rain on their parade and tell them to just copy the current core design. You won't be able to tell the difference with a new, clean, standard core, versus anything enhanced that they can dream up.

[ACR_VP]

Sooooooooooooooo, back to your dilemma, rain on their parade and tell them to just copy the current core design. You won't be able to tell the difference with a new, clean, standard core, versus anything enhanced that they can dream up.

Thanks for the input. This is for a fully built NA engine, which will be putting out over 750hp, and see lots and lots of track days lol. I'm not worried about around town driving, and all other aero mods for cooling have been done.... To add to this, I had been able to run on the stock rad for about 15 minutes on the track with about 620hp in 85 degrees ambient until the temp started to climb, with the added power, obviously an upgrade is warranted.

[dave6666]

obviously an upgrade is warranted.

No disagreement. And to clarify my previous statement, yes, I would certainly add a 3rd row when modifying your radiator. But regarding the core design, was were my comment about leaving well enough alone was for; using the factory core structure specs will work just fine. IMO.

I'm assuming since you say you've done "all other aero mods for cooling" that you have the Roe duct? Good mod and will help with airflow over the radiator starting at speeds in excess of 30 mph. Other good mods are the center hood vent and/or vented cowl.

Triple fans will also help a lot at lower speeds. Testing in my car showed that above 70 mph the coolant temp equilibrates with the fans never cycling any more. So if you are on a low speed track your cooling demand may needs the fans periodically, and the triple fans certainly help a lot.

Some other things that you may already have a handle on... A lower temp thermostat does not cool the car more. The only thing installing a lower temp stat will fix is if you're taking out a broken stat then you'll have a new one. If your stat works good and you run at 200 with a 195 stat, you'll run at 200 with a 180 too. Another thing I tested is water wetter. Made zero difference. Waste of money. Drained it after the test.

In conclusion, the single biggest item(s) I found to improve cooling were:

* Addressing heat exchanger fouling

* Improving heat exchanger surface area

* Improving air flow to the heat exchanger

Or in car talk terms, use the biggest damn radiator you can find, and fit as many fans to it as you can fit.

Good luck on your project. Keep us posted on what the scientists brew up for you. And sorry to go well past your original question. I have a tendency to rant on cooling threads.

[ACR_VP]

Thanks Dave. The only thing I didn't read out of your rant was messing with the water to coolant ratio :-) 60/40 to 70/30 vs. standard 50/50 stock is enough of a difference for the fans to cycle on/off in traffic on hot days vs constantly running. Just throwing that out there, it's a small difference but still a difference. Also I don't have the vented cowl, but on hot track days I've just taken it off (it's only 4 screws after all) and it does make a difference for sure.

[Boosted Motorsports]

I'm assuming since you say you've done "all other aero mods for cooling" that you have the Roe duct? Good mod and will help with airflow over the radiator starting at speeds in excess of 30 mph.

Interested in this does Roe still produce it or do you have any pictures? Checked Roe's site under cooling products but didn't see it.

[AZTVR]

Interested in this does Roe still produce it or do you have any pictures? Checked Roe's site under cooling products but didn't see it. It might be better to ask Roe Racing whether they still can supply it.
I do not see it on their website where they used to have it. Here is a snapshot of their site from 2013 where you can see the kit.
web.archive.org__roeracing.com__Front-Bumper-Fascia-Cooling-Duct-96-02-Dodge-Viper (https://web.archive.org/web/20140913050207/http://www.roeracing.com/productcart/pc/Front-Bumper-Fascia-Cooling-Duct-96-02-Dodge-Viper-157p228.htm)


22276

[dave6666]

Thanks Dave. The only thing I didn't read out of your rant was messing with the water to coolant ratio :-) 60/40 to 70/30 vs. standard 50/50 stock is enough of a difference for the fans to cycle on/off in traffic on hot days vs constantly running. Just throwing that out there, it's a small difference but still a difference. Also I don't have the vented cowl, but on hot track days I've just taken it off (it's only 4 screws after all) and it does make a difference for sure.

Never had to mess with the coolant. Short of trying w/w just because someone said it worked. I have always gotten adequate cooling system performance @ 50/50 mix.

[dave6666]

With no disrespect to Sean and his ingenuity and creativity on his "Roe duct," it's a very simple piece that could be easily fabricated yourself from an inexpensive piece of sheet aluminum. No advanced tools need at all.

By the time I got done with mine it looked like this. Far cry from the starting point.

http://i241.photobucket.com/albums/ff224/dave6666waybad/Roe%20Duct-Splitter%20Mount_zpsndg06jhj.jpg (http://s241.photobucket.com/user/dave6666waybad/media/Roe%20Duct-Splitter%20Mount_zpsndg06jhj.jpg.html)

[ViperTony]

Interested in this does Roe still produce it or do you have any pictures? Checked Roe's site under cooling products but didn't see it.

I have my front fascia off and will take pics of it installed for you. This is a commitment....once you cut out the opening under the fascia you are committed to it, no going back. :witless: But I've had this since 2008 and it works well. It helps especially on track days, highway driving, movement. Even on track days with my mods (GenII) I never saw temps rise above ~200. I don't recall the sequence of mods for cooling but I personally found the combination of a Vented Cowl + Lower Temp Thermostat + Reprogrammed Fan Turn On Temps + Front Fascia Duct = really good results. Interestingly enough, since I have my engine out for more mods I decided to get my stock radiator rodded. It was completely clogged @ 27K miles.

I've seen several members, including the Wizard himself, see meaningful improvements in coolant temps after they had radiators rodded and cleaned. I'd start there first.

Like Dave I use a 50/50 mix of coolant, no water wetter.

[dave6666]

This is a commitment....

Not a poser or garage queenie mod....


radiators rodded and cleaned. I'd start there first.

The OP is having a new core designed. Starting point should be super clean.

This was my OEM core after about the same miles.

http://i241.photobucket.com/albums/ff224/dave6666waybad/OldOECore.jpg (http://s241.photobucket.com/user/dave6666waybad/media/OldOECore.jpg.html)

[AZTVR]

I wonder how close to "like new" performance that rodding gets a clogged radiator to. I understand that it significantly restores the flow; but, how well does it remove that scale from the internal surfaces of the tubes to expose the metal again? Do the remaining deposits still significantly reduce heat transfer?

The reason that I wonder this is that I did not see the improvements that I had expected when I had my radiator rodded. The shop, which is a highly recommended one, said that it had been 50% down on flow rate.

[98RedGTS]

Good read here. On the subject of radiators. Anyone recommend a shop in central Texas to rebuild a stock radiator? I removed mine when it developed a small leak in it. Would love to have it restored and/or re-cored to a 3 core design. Then I could keep my X2 as a back-up.

[99RT10]

Good read here. On the subject of radiators. Anyone recommend a shop in central Texas to rebuild a stock radiator? I removed mine when it developed a small leak in it. Would love to have it restored and/or re-cored to a 3 core design. Then I could keep my X2 as a back-up.

Any competent radiator shop can re-core the radiator.

[dave6666]

I wonder how close to "like new" performance that rodding gets a clogged radiator to.

Good question. Regarding your experience at elevated hp levels and moderate results, versus others that have claimed superior results at lower hp levels, that film that likely remains could be a factor.

Did a quick look at thermal conductivities. Copper is 400 whereas calcium silicate is 0.05. Big difference.

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

[Lemay88]

While we are on the cooling performance subject...I have some questions.

What is the best mix for the Viper cooling system??....50/50, 60/40, water only??
How can I chack the mixture of my coolant??
Reason I'm asking, I had a hose change and coolant "refill" last spring. ( I know, should have done a complet coolant flush, but I didn't have any engine temperature problems, so keeped it like that)
Since the coolant was a little "light" in color, my mechanic said I should "concentrate" the mix a bit. So he added 100% coolant to the mix to top it off. Now, coolant is dark green but engine is running a little higher in temperature. Nothing in the danger zone but a bit higher.

Again, thanks a lot to the Viper clan for all the help you provide the noobs

Ben 1997, stock red (of course) R/T

[dave6666]

50/50 is based on average this, average that. Unique situations can warrant changing outside an "average."

Next time, have your mechanic use a hydrometer to verify the coolant mix and then calculate the current ratio so you can add the correct amount for a final correct ratio. You got the redneck method and the redneck result it sounds.

Samples can either be taken from the overflow bottle at any time, or the surge tank when cold.

Also beware that the overflow container is vented to atmosphere. Water will evaporate from it over time. But not coolant. So, when you top the system off after checking the level in the overflow container, all you need to add is water. Not the mix.

What I would do in your case is sample your system with a hydrometer, and assuming it is too strong, extract the correct amount of the current mix and replace with water. And then after a few drives to mix it up, recheck.

[Camfab]

Good question. Regarding your experience at elevated hp levels and moderate results, versus others that have claimed superior results at lower hp levels, that film that likely remains could be a factor.

Did a quick look at thermal conductivities. Copper is 400 whereas calcium silicate is 0.05. Big difference.

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

I really like that chart, but Diamond is 1000! Could that be correct?

[Camfab]

I just read about it, crazy! The ultimate Viper radiator the 10,000 carat core!!!