Hot Summer; Hot, Overheating V-8 Radiator Setup., Hot Summer; Hot, Overheating V-8 Radiator Setup. Options

[Chris H.]

That really sounds like your t-stat was not open. If the fans work and they didn't kick on, then warmer coolant isn't flowing completely to reach the sensor that kicks them on at X temp. Definitely worth removing it and running without it for a bit. It won't hurt anything. Just might take a bit longer to warm up. Keep it under 100mph until it gets warm (IMG:style_emoticons/default/biggrin.gif) .

I had something similar happen to my car but it didn't overheat, I shut it down before it got above 190. The lines were cold up front and the fans didn't kick on even though they were set for like 165. This only happened a couple times when I was just starting out and the car was cold. That's when I decided to take the thermostat out. No problems since. Takes an extra 5 minutes to fully warm up but that's fine with me.

[Mike Bellis]

When is the last time you replace your water pump? V8 conversions us a big block Mopar pump and they do go bad. Most of them are stamped steel impellers and I've seen these blades break off and or corrode.

Are the high quality electric pumps good enough to remove those big block Mopar pumps?

Almost all electric water pumps are made for V8 applications.

[bulitt]

Put one of these powering a 12ga wire and a relay to control your fans. Put the probe in the radiator fins.


https://www.amazon.com/gp/aw/d/B00K75QRZA/r...&ref=plSrch




You need to have the system purge a couple times in order for the expansion tank to functuon correctly.

Thats awesome Andrew (IMG:style_emoticons/default/smilie_pokal.gif)

[BRAVE_HELIOS]

I understand that the probe you point to gets attached to the radiator. Would it not be better to place the probe/controller closer to the engine for a more exact reading? I have my sensor connected to a port next to the t-stat, into the intake; which is also connected to a controller where I can set the fan switch on temp.

Put one of these powering a 12ga wire and a relay to control your fans. Put the probe in the radiator fins.


https://www.amazon.com/gp/aw/d/B00K75QRZA/r...&ref=plSrch




You need to have the system purge a couple times in order for the expansion tank to functuon correctly.

Thats awesome Andrew (IMG:style_emoticons/default/smilie_pokal.gif)

[Chris H.]

Your temp sensor should be close to the engine. Is that also your fan controller? If that's the case you could leave it there. You MIGHT have an air pocket by your thermostat which will work its way out eventually, but try it with the thermostat removed. The coolant will flow a LOT better and you'll eliminate one thing from the list. The air should purge out much faster. If you still have issues then look to your water pump.

[BRAVE_HELIOS]

Took the t-stat out. Gutted it and stuck it back in. Will let you know how it turns out.

BTW... Looking at the picture... sensor to the right of t-stat (facing towards front of car) is for temp gauge and sensor on left side of t-stat is for temp controller.

Your temp sensor should be close to the engine. Is that also your fan controller? If that's the case you could leave it there. You MIGHT have an air pocket by your thermostat which will work its way out eventually, but try it with the thermostat removed. The coolant will flow a LOT better and you'll eliminate one thing from the list. The air should purge out much faster. If you still have issues then look to your water pump.

[veekry9]

https://www.youtube.com/watch?v=aa1yG-fntRk


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https://www.youtube.com/watch?v=XKNab4MUUjg


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[Andyrew]

I understand that the probe you point to gets attached to the radiator. Would it not be better to place the probe/controller closer to the engine for a more exact reading? I have my sensor connected to a port next to the t-stat, into the intake; which is also connected to a controller where I can set the fan switch on temp.

Put one of these powering a 12ga wire and a relay to control your fans. Put the probe in the radiator fins.


https://www.amazon.com/gp/aw/d/B00K75QRZA/r...&ref=plSrch




You need to have the system purge a couple times in order for the expansion tank to functuon correctly.

Thats awesome Andrew (IMG:style_emoticons/default/smilie_pokal.gif)

You can easily insert it by the hot side of the radiator. Thats the reason. Also its close to the fans, thus making wiring easier. You wont loose but 5 deg between the engine block and the hot aide of the radiator.

[BRAVE_HELIOS]

Took it a drive after gutting the t-stat.

I think it is getting better; although towards the end of my short drive in stop and go and at speed; the temp crept up towards 200. It must be because there continues to be air pockets in the system. Still no coolant coming out of the rad petcock. Lines in and out of heater core are warm and less warm respectively.

I included a picture of my bumper opening which is 4.5 inches x 21 inches or 94.5 square inches. I did my measures when I first installed the conversion and thought it to be sufficient.

I will continue to drive and monitor the engine temp and hope all the air will eventually get purged from the system with the continued run cycles.

[speed metal army]

Shrouding the rad and intake towards the rad will help a bunch. Air is a real PITA and creates all kinds of hot readings.. I also pulled my thermostat, as I had a sticking one. Ive had zero cooling issues with mine once I bled it properly , even when I had BUBS and a really small amount of intake cut out..Good luck!

[Chris H.]

That's good. Sounds like you're heading in the right direction. Keep cycling it. You want to get the RPMs up some to get that coolant moving well and purge the air. I'd keep the system totally closed so you don't let any air in. Try not opening the blue cap or the purge valve for a while. I could never get a thing out of my purge valve either. Make sure the system is well pressurized by checking to see if the coolant level in the pressurized tank with the blue cap rises when the engine warms up. Probably is fine but that's easy to check.

[914forme]

are you running a heater core? Looks like you are from the pictures, and it looks like it might be a high point of the system. they way the hoses run. Little confused from the picture. If that is the case, you will want to put a bleed at the highest point, even Tee with a bolt will work. Look at the Honda Civics, they did this on the engine to get all the air out of the system.

Since it is a gas engine you will produce enough heat to get your coolant tips up even at idle. Let the thing sit, your bread end rolled up on ramps to make it the high point. And keep the water flowing, make sure your heater is on full hot also. Or cap it off and remove it from the equation right now. Let it run and burp all the air out.

With the Hondas we started using a vacuum system. You pull the entire cooling system down with vacuum, and then, hit the valve and suck a ton of coolant into the system. I always used a five gallon bucket and had extra ready, just in case. The Vacuum will also pull air in if you let it. (IMG:style_emoticons/default/headbang.gif)

Here is a YouTube Video for your pleasure on how it works. GT40 or Pantera, it seems that a V8 914 might be close to those two vehicles.

[veekry9]

"Still no coolant coming out of the rad petcock."
?
All the air and a squirt of coolant should come out of the petcock.
If not,there is a problem,like a closed line,that would be bad.
Ensure the pump you have has the correct rotation,impeller and flow rates.
The Edelbrock ally pump has an impeller with actual vanes,that flow better at lower rpm,doesn't cavitate at high revs.
Make sure you have the flows going in the correct directions.
An actual flow test is filling a 55gal drum in 60 secs at 4k rpm,use 2 drums.
A question about the engine is the condition,and whether the heads have ever been off for reconditioning.
(IMG:style_emoticons/default/idea.gif)
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A test of the flow the rad can handle,is also a good idea,at this point,it may be plugged.
Your heater core is properly oriented and also vented,otherwise,a vapour lock will exist.
(IMG:style_emoticons/default/idea.gif)
A remote cooling torus for a nuke generator is also tested.
(IMG:style_emoticons/default/biggrin.gif)
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[914GT]

If you're not getting coolant to run out of the petcock on the top of the radiator, then that definitely means there's air trapped in the system which will cause you problems. I was looking at the photos and I don't see where the pressure cap is located. That should be at your highest point in the system and higher then the top of the radiator, and also be your initial fill point in the system.

I've seen several ways to plumb this up for a working system. What I used was a Dedenbear ET1K expansion tank that places the pressure cap about 5"-6" above the thermostat and bolts directly onto the intake manifold. On initial fill I pour the coolant into the expansion tank with the radiator petcock open until all the air bubbles run out and I get a steady stream of coolant. I have a small piece of clear tubing on the petcock to collect the coolant and check for air bubbles. Once I'm at this point I turn on the electric water pump to begin circulation, and also have my heater core valve open. I let the air burp out of the expansion tank until it's topped-off, and periodically check the radiator petcock to make sure no more bubbles are there. At this point the job is done. I finally connect tubing from the expansion tank over to the bottom nipple on the overflow tank, and make sure the overflow is about full of coolant.

From this point on the expansion and overflow tank take care of any remaining air in the system and purge it out automatically. I never have to mess with it again. The electric pump does make the process a little easier as I can run it without the engine running, but the process would be similar with a belt-driven pump and just idle the engine. I do have a bypass hole in the thermostat as well as a coolant bypass for the block to allow circulation around the water jackets with thermostat closed. This was built-in to the stock Chevy water pump.

Hope this helps with your problem as I'm sure you're getting frustrated with it. If you need any photos let me know. It's a very straightforward setup and quick and easy to get going.

[BRAVE_HELIOS]

Youtube is great, isn't it!

I saw a video of this old time mechanic that made his own air purging 'system' and all it required was a collateral rad cap that he gutted so it held no pressure but kept the coolant flowing from the engine to the expansion tank, to the overflow tank without any spilling. Eventually; the air makes its way to the overflow and as long as there is coolant in the overflow; it will get drawn back in the system when replacing the air.

So I took an extra cap I had laying around; gutted it and ran the car for a while with it (kept it parked for now). Also kept the car level. Noticed that the heater core lines were now hot and I had a bit of air then coolant coming out of the rad petcock.

I'll run it a bit more with the dummy cap then take it out for a drive (with the std cap) and see what happens!

are you running a heater core? Looks like you are from the pictures, and it looks like it might be a high point of the system. they way the hoses run. Little confused from the picture. If that is the case, you will want to put a bleed at the highest point, even Tee with a bolt will work. Look at the Honda Civics, they did this on the engine to get all the air out of the system.

Since it is a gas engine you will produce enough heat to get your coolant tips up even at idle. Let the thing sit, your bread end rolled up on ramps to make it the high point. And keep the water flowing, make sure your heater is on full hot also. Or cap it off and remove it from the equation right now. Let it run and burp all the air out.

With the Hondas we started using a vacuum system. You pull the entire cooling system down with vacuum, and then, hit the valve and suck a ton of coolant into the system. I always used a five gallon bucket and had extra ready, just in case. The Vacuum will also pull air in if you let it. (IMG:style_emoticons/default/headbang.gif)

Here is a YouTube Video for your pleasure on how it works. GT40 or Pantera, it seems that a V8 914 might be close to those two vehicles.

[BRAVE_HELIOS]

Well... here we are. Expansion is in, t-stat is out, I have done many driving cycles and yet my temp still creeps up towards 200. At least I can most definitely say that the temp goes up driving at speed... constant velocity; 50-60 mph and higher. At idle; it will stay at around 180 (fan comes on but maintains 180).

So I think this will be my last attempt at purging air out of the system. If this does not work; I think the next step will be to go electric.

I rented a radiator pressure testing kit from O'Reilly's and of course they did not have the correct fitting for a VW expansion tank. So I made my own with a sink stopper and it works. I pressurized the system to around 14 psi and bled the system from the rad petcock located on the upper corner of the rad. I also lifted the front end of the car to make sure the petcock was the highest point of the coolant system. I bled the system this way around 6 times and I saw no air; only coolant coming out of the petcock.

Am I doing this correctly? Is this something I need to do (way) more than 6 times?

[speed metal army]

I know I should read the whole thread... But how big is the opening in front of your rad ? Is there a pic of the front setup?(just the bulkhead, and the holes in it) I ask because at cruising, it should be cooling nicely if there is air flow. Only asking cuz the car does stay cool at idle, fans work etc.. Is that rad super isolated from the front? I see foam...
One cool thing about the electric pump is that it makes it a breeze to bleed the system.
Just cycle the pump, no engine required. Mike Bellis found a pretty cool one that moves a ton of gpm.

[Rand]

Proper rad shrouding and mounting is going to make a huge difference. Using spray foam is a horrible hack. (IMG:style_emoticons/default/barf.gif)

[BRAVE_HELIOS]

I know I should read the whole thread... But how big is the opening in front of your rad ? Is there a pic of the front setup?(just the bulkhead, and the holes in it) I ask because at cruising, it should be cooling nicely if there is air flow. Only asking cuz the car does stay cool at idle, fans work etc.. Is that rad super isolated from the front? I see foam...
One cool thing about the electric pump is that it makes it a breeze to bleed the system.
Just cycle the pump, no engine required. Mike Bellis found a pretty cool one that moves a ton of gpm.

Good questions. The opening of the bumper to allow air in is around 92.5 square inches.The front bulkhead was completely opened up... from the headlight bucket area to the center hood latch/brace area, left and right sides. The chalon front bumper to bulkhead has around a 12 inch space which has been ducted from bumper to bulkhead. The foam around the rad is not spray foam but folded sheet foam and allows very little air to go around the rad.

[speed metal army]

Have you tried a different temp gauge? Wouldn't be the first time a gauge was reading nonsense... Just trying to eliminate some obvious stuff (IMG:style_emoticons/default/biggrin.gif)