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Smallest radiator for a turbo 5.3?

JohnnyJ--thanks, so it would seem that the length of the run plays an important part in how far a stock water pump can pump to keep the motor cool. Which is true for any pump but at least we have some tech here that shows what to shoot for in length.
 
csutton7 said:
JohnnyJ--thanks, so it would seem that the length of the run plays an important part in how far a stock water pump can pump to keep the motor cool.
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Not for a LS.

Plenty of people run rear mounted radiators with stock WP
 
Yes they do, but again my point is the stock water pump can only pump coolant so far with X amount of bends before it becomes inefficient in keeping the motor cool when idling. I think my run was 10-11' long for the lower hose(up, down, s turn,up) and 14'-15' for the upper hose(up, down,s-turn, up,over) and it wouldn't keep my engine in the range that I thought it should. I got differing results, but 208 was the best I saw and then a few days later it climbed past that and was going up until I pushed the rpms to 1500-1600 and then it would cool down to the mid 190's.
 
so what would be the max number of bends, slash degree of bends per run, and length max, and would smaller or larger hose make a difference?

or ball park max.
 
chaplinfj60 said:
so what would be the max number of bends, slash degree of bends per run, and length max, and would smaller or larger hose make a difference?

or ball park max.
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Don't overthink it.

People cool 600+hp LS engines with rear mounted rads with stock WPs all the time.

If you have cooling issues it's not from the WP.
 
Here's what I had for bends:
Bottom hose: eight 90's
Upper Hose: eight 90's and one 45
1 1/4" EPDM hose for both hoses
195* T-stat
Stock radiator with 2 stock fans
6.0 bored .030 with M122 supercharger
Holley Terminator x Max computer
Steam lines connected to all 4 corners

Again at idle, it would climb past 211-212 and I never let it get past that except at the initial start-up when it went up above 230 before I shut it off. Once I got all the air out of it the climb from 205-211 took time, but it was still climbing and I would turned if off. I changed the steam line hose runs like 3 times and bled the system a few times to make sure I had no air in the system. If I upped the rpms to 1500-1600 it would cool right down, so that leads me to believe that the pump couldn't overcome the amount of bends and length to keep the engine cool at idle. Now maybe there are other issues but I'm not sure what they are at this point. I had coolant in the steam lines and I could see coolant being circulated in the reservoir(was better when the rpms went up), so that's my saga with the rear-mounted radiator.
 
Don't get me wrong, I'm not disagreeing with Bebop, cuz he's right, many guys do have rear-mounted radiators, but my system was proving not to be successful. Maybe I would've topped out at 220 at idle, but that seems excessive and I'd really like to see 205 or so at most, but I never got to that point and am now moving stuff around and putting a smaller radiator up front with a Taurus fan to see what happens there.

Oh yea this in my Willys pickup.
 
csutton7 said:
Don't get me wrong, I'm not disagreeing with Bebop, cuz he's right, many guys do have rear-mounted radiators, but my system was proving not to be successful. Maybe I would've topped out at 220 at idle, but that seems excessive and I'd really like to see 205 or so at most, but I never got to that point and am now moving stuff around and putting a smaller radiator up front with a Taurus fan to see what happens there.

Oh yea this in my Willys pickup.
Click to expand...

What size rad ?
Airflow ?
Model of fans ?
 
Should be absolutely plenty. I agree you had another issue.
 
I have no idea what the other issue would've been at this stage. So to me, my final thoughts were too much friction, too much length, and to many bends for the stock pump to overcome at idle because once the rpms went up there was no problem. It's a brand new motor that has yet to see over 3000 rpms and is on jack stands.

Could air still have been trapped in the motor or somewhere? I don't know, but I was pretty sure there wasn't, but again I ain't got no water bug to shove in the system to swim around & diagnose & report back an issue and I bled and bled and ran lines differently and plus I thought if there was air in the system then there was no way it would cool down regardless of the rpms the water pump was seeing. Am I wrong in that thought?

I've left the radiator in the back for now just in case I have to go back to it using some electrical conduit or exhaust tubing instead of the EPDM hose, but I'll still have the same amount of bends if not more due to the flexibility of the hose vs pipe, but the friction part of it should be way less.
 
I would have tested a smaller pulley before anything else in that case.

I know of at least one other buggy that has a similar "issue" and it has never been a problem since you don't drive around at idle.
 
I could never find a smaller pulley for the LS water pump and I looked. but that doesn't mean they don't exist somewhere, cuz you can look and look and then one day out of nowhere you run across what you couldn't find before. The other option was an aftermarket hi-flow water pump or an electric water pump, but that meant forking out $750-$1000 and I just can't afford that right now. And I know you are off and on the pedal, but my luck runs in a circle that no one wants to be in, so I don't want to chance it. I want it to idle cool enough that if the outside temp goes up or in elevation that I have some leeway and don't have to rely on more pedal/rpms at any given point to get it to cool down.
 
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