Any thoughts for water pump upgrade for gen iv 6.2 yukon

[kaleburditt]

I have 08 yukon denali with the 6.2 and kept vvt. I stroked it and supercharged it. I got exactly what i wanted and that was to tow up hill and across country in converter lockup. Problem is overheating. Obviously 1600 rpms aren't enough to keep it cool enough. For that matter neither is 2200. I replaced the radiator with a monster. Added external transmission cooler and in the process of oil cooler as well. But it still overheats. I think I just need extra air flow or water flow and I would be good. My water pump outlet comes out the top of the pump and with vvt, its apparently a different mounting as well. Has anyone had success with aftermarket performance pumps that specifically work better at the lower rpm? I never go over 4000 rpms so even an electric pump or smaller pulley would work? Maybe use an LS3 pump and get a new water return hose?

Edelbrock claims they don't make one. March doesn't make pulleys for it. FlowKooler are currently out of stock and its only for an ls2, and meziere doesn't seem to have the appropriate application either.

With a L92 I am having a difficult time sorting through the applicable cross references on which water pumps I can use. OR even if i need one. There doesn't seem to be definitive answers to flow rates of oem and after market pumps especially at closer to the idle and cruise ranges. If I could get away with just upgraded electric fans I would take that option as well although I see unconfirmed that stock flows 5500 cfm already.

 

[Doubeleive]

I bought a used OEM dual 700w system (k5l) and then I put new 700w motors in it just to be on the safe side, I can't say it cools any better or not there is a difference the shroud is thicker and the motors are bigger, they are a smidge louder when running high speed but not excessive enough to hear it in the truck. none of the parts are swapable with the 500w fan system.
it's all plug-n-play no other changes are needed I confirmed with the dealer the relays are the same for the 500w and 700w system, electrical connectors are the same also.
https://www.ebay.com/itm/Radiator-C...AOSwgbdcG~8J:sc:FedExHomeDelivery!95219!US!-1

 

[ivin74]

I have 08 yukon denali with the 6.2 and kept vvt. I stroked it and supercharged it. I got exactly what i wanted and that was to tow up hill and across country in converter lockup. Problem is overheating. Obviously 1600 rpms aren't enough to keep it cool enough. For that matter neither is 2200. I replaced the radiator with a monster. Added external transmission cooler and in the process of oil cooler as well. But it still overheats. I think I just need extra air flow or water flow and I would be good. My water pump outlet comes out the top of the pump and with vvt, its apparently a different mounting as well. Has anyone had success with aftermarket performance pumps that specifically work better at the lower rpm? I never go over 4000 rpms so even an electric pump or smaller pulley would work? Maybe use an LS3 pump and get a new water return hose?

Edelbrock claims they don't make one. March doesn't make pulleys for it. FlowKooler are currently out of stock and its only for an ls2, and meziere doesn't seem to have the appropriate application either.

With a L92 I am having a difficult time sorting through the applicable cross references on which water pumps I can use. OR even if i need one. There doesn't seem to be definitive answers to flow rates of oem and after market pumps especially at closer to the idle and cruise ranges. If I could get away with just upgraded electric fans I would take that option as well although I see unconfirmed that stock flows 5500 cfm already.

Try asking the folks on performancetrucks.net those folks are very knowledgeable.

 

[thompsoj22]

Just a thought, I have the 08 same vehicle and have allways seen the front grill as obstructive to ram air effect. All those holes have got to disrupt the air flow and at a minimum slow it down. I have been looking at the stock GMC sierra grills that have the lateral bars and i believe the "ram airflow" would be improved at speed.Also noticed that on vehicles with viscous clutch fans when you are going downhill and off throttle the engine temp will drop but on electric fan setup it does not have the same effect, in fact going downhill and off throttle the temp gauge will not move. You are supercharged so a few HP to drive a viscous fan wont hurt your rig, Maybe eliminate the electric fan setup and determine if your temps would be more manageable. Moving the coolant more rapidly wont work, you have to reduce the temp of the fluid delivered to the engine, ie' more airflow through the radiator.

 

[kaleburditt]

I bought a used OEM dual 700w system (k5l) and then I put new 700w motors in it just to be on the safe side, I can't say it cools any better or not there is a difference the shroud is thicker and the motors are bigger, they are a smidge louder when running high speed but not excessive enough to hear it in the truck. none of the parts are swapable with the 500w fan system.
it's all plug-n-play no other changes are needed I confirmed with the dealer the relays are the same for the 500w and 700w system, electrical connectors are the same also.
https://www.ebay.com/itm/Radiator-C...AOSwgbdcG~8J:sc:FedExHomeDelivery!95219!US!-1

i went ahead and bought these. didn't know there were more powerful drop in fans available. and it seems to be about the best i can get before having to make drastic changes to install a mechanical fan.

Just a thought, I have the 08 same vehicle and have allways seen the front grill as obstructive to ram air effect. All those holes have got to disrupt the air flow and at a minimum slow it down. I have been looking at the stock GMC sierra grills that have the lateral bars and i believe the "ram airflow" would be improved at speed.Also noticed that on vehicles with viscous clutch fans when you are going downhill and off throttle the engine temp will drop but on electric fan setup it does not have the same effect, in fact going downhill and off throttle the temp gauge will not move. You are supercharged so a few HP to drive a viscous fan wont hurt your rig, Maybe eliminate the electric fan setup and determine if your temps would be more manageable. Moving the coolant more rapidly wont work, you have to reduce the temp of the fluid delivered to the engine, ie' more airflow through the radiator.

which brings me to this. i considered this but i would have to completely change my intake to accomodate the mechanical fan and shroud as the lsa supercharger TB is lower and points to the driver side. this is my last resort option. I was thinking of the front grill too and considered modifying it to include some sort of under bumper scoop to aid in air delivery. also changing to a mechanical fan would require replacing the water pump and now you are definately trying to find water pumps not made for the vvt application. also that goes back to a possible water pump upgrade.

it should be noted that GM states that up to 250 degrees is acceptable for towing and i am only allowing it to get to 240. but i tow so much that i can't help but think that if you run an engine during its entire lifetime at 240, it's not good.

thanks for the speedy replies guys.

 

[Doubeleive]

i went ahead and bought these. didn't know there were more powerful drop in fans available. and it seems to be about the best i can get before having to make drastic changes to install a mechanical fan.



which brings me to this. i considered this but i would have to completely change my intake to accomodate the mechanical fan and shroud as the lsa supercharger TB is lower and points to the driver side. this is my last resort option. I was thinking of the front grill too and considered modifying it to include some sort of under bumper scoop to aid in air delivery. also changing to a mechanical fan would require replacing the water pump and now you are definately trying to find water pumps not made for the vvt application. also that goes back to a possible water pump upgrade.

it should be noted that GM states that up to 250 degrees is acceptable for towing and i am only allowing it to get to 240. but i tow so much that i can't help but think that if you run an engine during its entire lifetime at 240, it's not good.

thanks for the speedy replies guys.

let us know if the 700w fans help any.

 

[randeez]

Fans wont do anything if your overheating while moving, theyre typically not even on if your moving.

I would start with assessing the condition on the stock parts, how many miles on radiator-is the coolant clean dexcool or just some brown slurry, verify thermostat is working, how is the belt routed with the supercharger? Does the water pump not have proper belt wrap to spin under load?
Check the tune also, a 1600rpm cruise shouldnt be stressing anything if there is too much timing in it under that much load itll heat the engine up also

Do some gears if you're only towing, itll help two fold

 

[thompsoj22]

Fans wont do anything if your overheating while moving, theyre typically not even on if your moving.

I would start with assessing the condition on the stock parts, how many miles on radiator-is the coolant clean dexcool or just some brown slurry, verify thermostat is working, how is the belt routed with the supercharger? Does the water pump not have proper belt wrap to spin under load?
Check the tune also, a 1600rpm cruise shouldnt be stressing anything if there is too much timing in it under that much load itll heat the engine up also

Do some gears if you're only towing, itll help two fold

Are you sure on the "fans arent even on if your moving" statement? Id bet those fans are on constantly while the op is towing? but the belt wrap on the pump is a good consideration. Read the opening thread, the post defines skills/knowledge so i doubt there is brown slurry in the new radiator. I dont know how much weight he is towing and the trans is definitley adding heat to the radiator. I agree with the K5L fans as the next logical part to throw at it. plug and play is no stress and no mods!

 

[randeez]

you have my word.

even if theyre on, they arent doing much. use a simple online cfm calc 34x22" radiator (duct size), call the stock fans 6000cfm rated. it shows as moving the air at >10mph
or try putting your hand behind your fans when theyre on high and feel the force, then drive 20, 30 ,40, 50mph with your hand out the window and which is more powerful?

 

[iamdub]

Any chance your thermostat could be stuck open?