CK5
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Wes's Burb build/update/maintance
- Thread starter Wes Harden
- Start date
Yeah right about the same 53-57ish mph will stick the go pro down there good idea.
good to know. I use that app too. I be sure to up date with my results. I do have a set of 5 degree shims at home. Will do the camera and then maybe the 5's see if improved or moved
Well after modifying the correct temp sender to fit my late model heads, I have much better read on engine temp, I have compared the gauge to infrared temp gun. 180 degree is just at the center line of gauge.
On my trip over Cajon summit I needed to turn off the A/C temp climbed to the 3/4 mark. Temp stabilized after that, I soon crested the summit and turned the a/c on temps stayed in the middle.
I drove I40 to Az, towing a Harley Bagger on aluminum single axle trailer, in the evening temps stayed good till a long steady climb. When I noticed needle was over 3/4 approaching the red, turn a/c off, heater on temp dropped. Left the a/c off the rest off the way. Ambient temps were high 90's.
Next day enclosed single axle trailer, full of house hold stuff. Driven 1.1 miles 100 degree day up hill 20-25 mph 2nd gear mostly. A/c on temps back near red, from cold engine.
A/c off heater on temps normalize quickly. Drive back a/c off no problem, down hill thou. Second and 3rd loads no a/c temps climbed but just over the half way mark.
All of those trips where with 160 degree thermostat. Saturday I swap it out for 180, thinking the coolant is moving to fast through the radiator. Test drive to gas station a couple miles up the highway, 45 and 55 mph 4th gear a/c on, no trailer, temp creeping up the red. Same routine, a/c off heater on added a little more rpms cools less than minute. Fuel it 8.6mpg for that tank. Drive back no a/c temps good, notice slight climb at stop signs, up hill. Parked in garage temp needle at half turn a/c on 1000 rpm temps stays good.
With the 180 tstat the infrared says upper 180's to low 200's at various times, 179 at Rad inlet. 165 midway up tank on outlet side.
I didn't get any temp readings when the needle was near the red, nor did I get any condenser temps. My condenser is original, best guess. I my self have put a compressor on this truck, the compressor didn't grenade, clutch did, was expedient to do whole compressor. Flushed the system new orifice tube, and accumulator, that was 2005.
A/c gets dam cold thou. Dilemma if the condenser is blocked, I am having trouble finding a replacement. Everyone is out of stock it seems. Know any sources ?
My next thought would be air flow. I have a severe duty fan clutch with 5 blade factory fan, and shroud . A/c condenser has 10" electric pusher that is on when the a/c is on.
In April radiator was re-cored 4 row brass high fin per inch, block flushed, new stat, heater core(brass) and all hoses.
option for more air flow I can get a six blade fan. I can wire the 10" electric to also run off temp sender( won't help while a/c is on ) I can do windstar fans.
What am I not considering ?
Could the winch be altering the air flow ? Maybe leaking around the core support instead of through the rad?
On my trip over Cajon summit I needed to turn off the A/C temp climbed to the 3/4 mark. Temp stabilized after that, I soon crested the summit and turned the a/c on temps stayed in the middle.
I drove I40 to Az, towing a Harley Bagger on aluminum single axle trailer, in the evening temps stayed good till a long steady climb. When I noticed needle was over 3/4 approaching the red, turn a/c off, heater on temp dropped. Left the a/c off the rest off the way. Ambient temps were high 90's.
Next day enclosed single axle trailer, full of house hold stuff. Driven 1.1 miles 100 degree day up hill 20-25 mph 2nd gear mostly. A/c on temps back near red, from cold engine.
A/c off heater on temps normalize quickly. Drive back a/c off no problem, down hill thou. Second and 3rd loads no a/c temps climbed but just over the half way mark.
All of those trips where with 160 degree thermostat. Saturday I swap it out for 180, thinking the coolant is moving to fast through the radiator. Test drive to gas station a couple miles up the highway, 45 and 55 mph 4th gear a/c on, no trailer, temp creeping up the red. Same routine, a/c off heater on added a little more rpms cools less than minute. Fuel it 8.6mpg for that tank. Drive back no a/c temps good, notice slight climb at stop signs, up hill. Parked in garage temp needle at half turn a/c on 1000 rpm temps stays good.
With the 180 tstat the infrared says upper 180's to low 200's at various times, 179 at Rad inlet. 165 midway up tank on outlet side.
I didn't get any temp readings when the needle was near the red, nor did I get any condenser temps. My condenser is original, best guess. I my self have put a compressor on this truck, the compressor didn't grenade, clutch did, was expedient to do whole compressor. Flushed the system new orifice tube, and accumulator, that was 2005.
A/c gets dam cold thou. Dilemma if the condenser is blocked, I am having trouble finding a replacement. Everyone is out of stock it seems. Know any sources ?
My next thought would be air flow. I have a severe duty fan clutch with 5 blade factory fan, and shroud . A/c condenser has 10" electric pusher that is on when the a/c is on.
In April radiator was re-cored 4 row brass high fin per inch, block flushed, new stat, heater core(brass) and all hoses.
option for more air flow I can get a six blade fan. I can wire the 10" electric to also run off temp sender( won't help while a/c is on ) I can do windstar fans.
What am I not considering ?
Could the winch be altering the air flow ? Maybe leaking around the core support instead of through the rad?
Fan shroud is in place, intact, and proper fan depth?
To me it sounds like radiator cooling is handled about as good as can be. Radiator is obviously working, 15* drop across seems to be nearly the standard, and you are there.
Could get exotic and try a fancier high flow water pump I suppose, but I've not seen any data that has proven it's effective.
You certainly wouldn't hurt anything by going to a stock fan with more blades, although I'm not sure that is the answer if the coolant is losing 15* through the radiator already. Fan shroud may be the same, but at speed maybe the airflow needs more channeling.
1977 had no air dams stock either I assume?
Probably least likely to be a factor, but not running any more than 50% antifreeze?
To me it sounds like radiator cooling is handled about as good as can be. Radiator is obviously working, 15* drop across seems to be nearly the standard, and you are there.
Could get exotic and try a fancier high flow water pump I suppose, but I've not seen any data that has proven it's effective.
You certainly wouldn't hurt anything by going to a stock fan with more blades, although I'm not sure that is the answer if the coolant is losing 15* through the radiator already. Fan shroud may be the same, but at speed maybe the airflow needs more channeling.
1977 had no air dams stock either I assume?
Probably least likely to be a factor, but not running any more than 50% antifreeze?
Shroud is in great shape. To me the fan looks deep, the rear of the blade are even with the edge of the shroud.
No air dams, I did block some 1/2" diameter and smaller holes in the top of the core support. no test yet. The bottom is wide open. Maybe I can rig up something up for a test there.
50-50 mix.
No air dams, I did block some 1/2" diameter and smaller holes in the top of the core support. no test yet. The bottom is wide open. Maybe I can rig up something up for a test there.
50-50 mix.
That is your problem.
Fan needs to be half way in
Yeah what I was thinking, got to figure out how to move it back @ 1 "
Later this evening I am going to test the fan clutch, make sure it works. I didn't test it before be cause it's only 6ish months old.
Usually a fan helps if you're below about 55, above that a fan gets in the way. Looks like a lot of your speeds were 55 and below so that may be something to look at. Also are you running a fan clutch, and if so, are you sure it's working properly?
You beat me to the punch.. lol
I know this is not apples to apples comparison, but it does have similarities.
I have a 77 GMC Jimmy SBC 400, 415 ish hp, TH350, 3.73 gears running 35's.
Since the rebuild, I have not had ANY engine coolant problems whatsoever. I am also running a 3 core aluminum, 180 Fail Safe T stat, flex fan, no clutch with a HD high flow water pump from VatoZone. Fan is probably halfway into the shroud which is not in the greatest of shape since I cut it in half so I could get it out easier. Splice with screws at the top and bottom sure makes it easier to get it out. My 2002 Chevy Astro has a 2 piece shroud and it is awesome. I also have a Warn 8274 in the front of the Jimmy and am running about 6400 lbs with all my crap in it. With my water temp sensor at the bottom of the radiator, the hottest I have seen was 170ish. Stock gauge is still hooked up and reading way down on the temp. Slightly above C. Hottest oil temp I have seen is 160 and that was today with ambient at 85 to 90 degrees going uphill. Engine oil temp is measured at the aftermarket cooler before it goes back to the engine. So all of my temps are pretty close to what the Jimmy should be running. Except the tranny, but that is another story. I am not running the AC though since I still have to get that fixed, but it shouldn't cause it to jump that much given the temps I have now.
My vote is HD high flow water pump, 180 T stat, and get your fan to about halfway in the shroud. first 2 being the most important, I think.
Joel
norcal
I have a 77 GMC Jimmy SBC 400, 415 ish hp, TH350, 3.73 gears running 35's.
Since the rebuild, I have not had ANY engine coolant problems whatsoever. I am also running a 3 core aluminum, 180 Fail Safe T stat, flex fan, no clutch with a HD high flow water pump from VatoZone. Fan is probably halfway into the shroud which is not in the greatest of shape since I cut it in half so I could get it out easier. Splice with screws at the top and bottom sure makes it easier to get it out. My 2002 Chevy Astro has a 2 piece shroud and it is awesome. I also have a Warn 8274 in the front of the Jimmy and am running about 6400 lbs with all my crap in it. With my water temp sensor at the bottom of the radiator, the hottest I have seen was 170ish. Stock gauge is still hooked up and reading way down on the temp. Slightly above C. Hottest oil temp I have seen is 160 and that was today with ambient at 85 to 90 degrees going uphill. Engine oil temp is measured at the aftermarket cooler before it goes back to the engine. So all of my temps are pretty close to what the Jimmy should be running. Except the tranny, but that is another story. I am not running the AC though since I still have to get that fixed, but it shouldn't cause it to jump that much given the temps I have now.
My vote is HD high flow water pump, 180 T stat, and get your fan to about halfway in the shroud. first 2 being the most important, I think.
Joel
norcal
Thanks for your input Joel, I am looking at a fan clutch hayden 2947 hd but seem to be @ 1/2" shorter than the severe duty on the truck now. I will go full electric before i go solid fan. Just don't need to listen to that 
. I suspect the newish clutch is bad will find out soon.
. I suspect the newish clutch is bad will find out soon.
Just a stupid idea here, but is the electric fan blocking or disrupting airflow on the highway? If it is on at all times with the A/C, I have heard that airflow at higher speeds can suffer if the fan is on. I have no personal experience with this though.
Could you disconnect the fan and try to see if there is any difference at all?
Now what I DO know, is that my Edelbrock water pumps work well. Pricey, yes. But both of my old trucks have good cooling.
Could you disconnect the fan and try to see if there is any difference at all?
Now what I DO know, is that my Edelbrock water pumps work well. Pricey, yes. But both of my old trucks have good cooling.
Got the truck nose in the garage let it idle for 30 mins a/c on. Temp gauge rock steady at center line. Infrared gun shows 198 at stat. Outlet of radiator is 165.
Condenser inlet is 185, out let is 120. Far left vent is blowing 50.
Shut a/c off stat is 188 rad outlet is 160.
I think fan clutch is good. Being severe duty it seems to be on 90 percent of the time. I can't hear a difference in the fan noise. When I shut the engine off the fan stops in place, no free spin, but I can turn it by hand with lite resistance.
Time for road test.
Condenser inlet is 185, out let is 120. Far left vent is blowing 50.
Shut a/c off stat is 188 rad outlet is 160.
I think fan clutch is good. Being severe duty it seems to be on 90 percent of the time. I can't hear a difference in the fan noise. When I shut the engine off the fan stops in place, no free spin, but I can turn it by hand with lite resistance.
Time for road test.
I cant hear my fan over the SBC 400, the 24" glasspacks and my stereo...Thanks for your input Joel, I am looking at a fan clutch hayden 2947 hd but seem to be @ 1/2" shorter than the severe duty on the truck now. I will go full electric before i go solid fan. Just don't need to listen to that
I have a better handle on the temps at upper range of my gauge now.
Half way between the middle line and 3/4 is 205 at the stat 190 at rad inlet. Just touching the red line is 220.
91 degrees ambient, up hill mild grade slow speed 3rd gear 1500 rpm a/c off gauge goes to 5/8th's and stays there. Up hill little steeper a/c on gauge will go to bottom of red. a/c off coasting down hill slow speeds returns to middle 30-40 seconds. This is at 91 degrees ambient.
Stopped got a burger, headed back I used the highway 45ish in 4th a/c on crept up to 5/8ths. Turn off the highway side streets got up to 3/4.
For whatever reasons the cooling system can't deal with the heat under load. I ordered the 6 blade fan I will probably get the shorter fan clutch I found.
For the time being I will retard the timing a couple of degrees and retest
Half way between the middle line and 3/4 is 205 at the stat 190 at rad inlet. Just touching the red line is 220.
91 degrees ambient, up hill mild grade slow speed 3rd gear 1500 rpm a/c off gauge goes to 5/8th's and stays there. Up hill little steeper a/c on gauge will go to bottom of red. a/c off coasting down hill slow speeds returns to middle 30-40 seconds. This is at 91 degrees ambient.
Stopped got a burger, headed back I used the highway 45ish in 4th a/c on crept up to 5/8ths. Turn off the highway side streets got up to 3/4.
For whatever reasons the cooling system can't deal with the heat under load. I ordered the 6 blade fan I will probably get the shorter fan clutch I found.
For the time being I will retard the timing a couple of degrees and retest
Preach it brother....
