Combating Shutdown Heatsoak- I finally did something about it

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If it is that much an issue I would remove some of the hood seal near the windshield. All the heat really needs is a small crack and will readily convect up out cooling very quickly. The wifes old G8 I removed the plastic fake scoop covers and it cooled down significantly faster. The old 73 Corvette 454 i would lift the hood and put a .5 inch spacer.

I can appreciate the High Tech approach to the problem but a low tech solution would be far superior IMO.

What I've done successfully in the past is spacer the hood hinges.

I got VERY tired of everyone saying the hood would snap off in a head on colission and decapitate me so I had to get rid of the hood hinge spacer.

This vehicle never sees more than 15 MPH unless it's on a trailer --- in which case I'm not in it anyway! Of course I should be VERY worried about a head on collision.
 

SammyChevelleTypeS3

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I just realized something easy to overlook. ALL of the cars of the past (before fuel injection) had a cowl vent at the base of the windshield that ran the full width of the hood. Slotted 3-4 inch vent lines ran from fender to fender across the hood. These were there for two things. Fresh cool source of air to the carbs and cooling in general was a benefit while driving and after, Cars of today do not have this anymore. I suppose the builders feel there is no need with fuel injection.
 
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I just realized something easy to overlook. ALL of the cars of the past (before fuel injection) had a cowl vent at the base of the windshield that ran the full width of the hood. Slotted 3-4 inch vent lines ran from fender to fender across the hood. These were there for two things. Fresh cool source of air to the carbs and cooling in general was a benefit while driving and after, Cars of today do not have this anymore. I suppose the builders feel there is no need with fuel injection.
That cowling had nothing to do with insuring air for the carbs and in fact it wasn't connected to the engine bay at all. It was and still is used for providing air to heat/cool the cabin however the air does come from the engine bay.
 
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I've never considered heat soak on any car I've ever owned. I've also never had a car overheat, no engine failures, nothing. Coincidence or proof this is a non-issue?
Generally speaking it's a non-issue. Turbochargers today are typically oil/water cooled and continue to circulate at engine shutdown.

The one potential issue is parts longevity due to the constant heat cycling of plastic components within the engine bay. Automakers striving for max efficiency want their engines to run as warm as possible.
 

SammyChevelleTypeS3

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That cowling had nothing to do with insuring air for the carbs and in fact it wasn't connected to the engine bay at all. It was and still is used for providing air to heat/cool the cabin however the air does come from the engi
 

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SammyChevelleTypeS3

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That cowling had nothing to do with insuring air for the carbs and in fact it wasn't connected to the engine bay at all. It was and still is used for providing air to heat/cool the cabin however the air does come from the engine bay.
you are correct. very sorry. I forgot it was only used for inside cabin except for special applications.
 
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I have a fan that blows air into the grille on all 3 of my vehicles, after I park them. My garage is also evaporator cooled. In the hottest weather I'll run them about an hour. You can feel the hot air blowing out of the wheel wells. I think this really helps. Especially with battery life.
 
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Or you could just aim a high powered fan at the grill and the temps would drop faster. At first I thought you was building a actual heat soak coolant pump/cool setup but what you have done a simple fan aimed at the grill could do in less time.
After writing this I finished the thread so understand you want a portable setup.
 
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Some of you guys might have noticed I like to partake with the topic of engine shutdown heatsoak. I tend to have what EricTheCarGuy describes as excessive mechanical sympathy. This project has been almost a year in the making, and I finally got the system working, after a lot of thinking, design, mock ups, searching and online shopping, and lots of Youtube video learning.
Before I start , I want to stress that I suck at electrics and electronics especially the electronics bits. But I do have soldering experience thanks to my RC Car hobby. I have to repeat to myself several times which wire goes to where, and had to search on forums and Youtube videos to get ideas and understand concepts.

The system consists of :
1. A remote control relay, 12V powered.
2. A Programmable temperature controller with wire probe, max detect temp 120C, also 12V powered.
3. Automotive 40A 4 pin relay.
4. Three 80mmx38mm Ball bearing brushless fans, load draw 1A.
5. Many lengths of 20ga and 16ga wires, in black, red and yellow.
6. Tiny Switches
7. Compact fuse holders
8. Tight fit connectors 2 different types
9. Small Diameter cable trunking.
10. Own designed fan brackets and 3D printed housings and air ducts.

First the system inside the car. I pulled a + and - from the radio adapter connector which is always live and fused to the radio. Soldered a XT30 connector. Plugged the Wires to another XT30 connector which supplies power to the system. The Heart of the system is the 12V remote control relay. The 12V power mentioned earlier goes to this relay. Before it reaches the Remote control relay, it goes through a 1A fuse and a tiny switch, so I can cut power to everything when I dont want the system to be misused (car at mechanic or in some one else hands). The remote control relay will send 12V power to the Temperature control relay when I want it to , namely by pressing button A on the remote. The reason I used a remote control is so that I can turn on/off the system without opening the doors.
The temp controller then has its own relay which activates when the temperature detected (in this case the rocker head surface ) is above the set temperature. This temp relay also has a tiny switch wired after the relay so that I can cut power to the fans and use the system merely to detect the head temp.
Both these electronic modules are housed in a 3D printed plastic housing which is taped on the right side below the steering wheel, and It allows me to see the temp controller target temp and actual measured temp, as well if the relays are turned on.
The temp probe and the 16ga + wire from the temp relay is routed into the engine bay. The + wire is attached to pin 86 on the 4 pin relay, and pin 85 will go to ground. The + from battery goes through a 3A fuse to pin 30, and pin 87 powers the 3 fans in parallel. The fans then take each ground from the best ground point nearby. The fans are attached on brackets I designed that mount on the best available space I have. One fan is under the turbo and is the lowest placed fan , so it sucks in relatively cool air from below and blows it up to the hood surface. One exhaust fan is placed on the opposite end near the fire wall which will suck out and eject hot air through the small gap between hood and fender, I designed my own vacuum cleaner type ducting made with 3D prints.
One more fan is mounted ahead of the power steering pump and blows underneath the front turbo towards the fire wall. I am not too happy with this fan position so I turned it last night to suck hot air out and eject it through the radiator. I have not tested this latest configuration . The last 20+ cycles I tested was in the previous configuration, but what I didnt like about it was it was forcing the hot air out towards the lower part of the windscreen , heating the localized area of the windscreen to nearly 60C.
Overall the system works well and is not a terrible drain on the battery, but I am still doing some fine tuning. The system achieves its intended goal of quicky lowering peak shut off temperature under the hood which otherwise stays hotter for way longer. Now I am able to bring down a 91C head surface temp down to 57C in 1hr 30 mins. I chose 57C as it is a temp that isnt damaging to the wires and rubber hoses, and if I go much lower I would be running the fans for too long and may drain the battery too much. Initially I set it to 45C but finally settled on 57C.
For now I give a sneak peek of the brain of the system ,I will post up the youtube video by tonight.
View attachment 74188

View attachment 74189
Excessive mechanical sympathy, **** I guess that's what I have lol.
 
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My 74 Fiat X- 1/9 had a thermostatically controlled fan That would run on/off after the engine was turned off and blow air on the carb.
 
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on my 2001 jetta 1.8T + i always opened the hood after a long hot drive to work because its said to help preserve the timing belt as well as other under hood stuff prone to drying out. my replacement car since retiring an audi TT 225Q ++roadster has a factory after run water pump to help cool downs + both cars have factory oil cooled turbos + they got real synthetic oils with meager 4.25 qt sumps. most modern vehicles use thermostatically controlled electric fan-s
 
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some of the 80s cars with the first electric fans would run them 5 minutes after shutdown.
I wonder if liability of having mechanics or owners fingers in the fan blades got rid of this, or if sticky relays were running batteries flat.

With all that said, you can get a self grounding fan switch for, say, a 1984 Chevy Celebrity. Jam it in the head or block somewhere, doesn't even need to be a water jacket, and run it to one additional relay that works in parallel with the factory setup, albeit not with the ignition key required to be on.
 
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Strangely enough the lack of a heat soak is a problem with an EV. In the winter my garage never gets the heating from a shut off engine, so excess humidity from a wet vehicle becomes a winter problem.

I have a de-humidifier that I run periodically but never had to do that before.
 
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I wonder if liability of having mechanics or owners fingers in the fan blades got rid of this, or if sticky relays were running batteries flat.

With all that said, you can get a self grounding fan switch for, say, a 1984 Chevy Celebrity. Jam it in the head or block somewhere, doesn't even need to be a water jacket, and run it to one additional relay that works in parallel with the factory setup, albeit not with the ignition key required to be on.
My 280ZX had a blower just to cool off the fuel rail 🤣

My Touareg will run the fan if I mistakenly shut it off during a regen. DPF gets hot hot hot
 
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my s60 volvos, if you ran them hard, would run the under hood fan by design after turning them off.
Are you certain you're not confusing this with the ventilation blower fan which can continue to blow to dry the evaporator?

Were your S60 vehicles turbocharged? I've only owned 3 V70 non-turbos.
 
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Are you certain you're not confusing this with the ventilation blower fan which can continue to blow to dry the evaporator?

Were your S60 vehicles turbocharged? I've only owned 3 V70 non-turbos.
Correct. The “afterblow” would run on the interior after the car was off for an hour, IF the AC had been used in a temperature above…. Some point which I don’t remember.

The radiator fan would remain on upon turning the engine off if for instance I’d just done steep hill climbs in third close to WOT and then shut it down at the top. It’s not a very loud fan but could move gobs of air.

i had two NAs and 1 turbo. afterblow worked in one of each, and I never heard the turbo’s radiator fan run after the car was off, but that’s probably more to do with how I was using it.
 
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I don’t recall now the original post by now, but it seems that a “turbo timer” sort of thing connected to just the radiator fan and set for 3-5 minutes would be an elegant solution here - but then the guys who live in the electrical sub-forum will freak because the battery will never be at rest with a full charge! (Also more difficult to do with newer PCM/ecu controlled fans.

could mount a smaller 6” fan behind a grate in a lower dust shield to move air at less power.
 

Al

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Obviously you were bent on a high tech solution that required mega amounts of your time....to fix a "problem" that can be avoided by avoiding something like running at higher power (turbo) , stopping and then shutting off the engine. I get that and obviously you are more than smart enough to get it also. Glad you enjoyed the task..kudos.

An asid.... my Forester has a gauge that shows boost and also oil temp, which is nice. During around town driving the turbo might run at a few pounds of boost less than 20% of the time.
 

alcyon

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Since this thread has some new likes, I am making an update
I added a programmable module that cuts off power to the fans if the battery voltage drops off below 11.6V, and will restart if battery voltage reaches 12V. It gets its power from the 87 pin of the relay which used to power the fan. So now it goes through this module, and if the voltage is 11.6V and above the fans will run until cut off temp which is now 54 C.
1650243714655.jpg
 
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Under the Hood
Lots of ASE and others tell me they actually open their hoods after parking in the home garage to let out heat anytime its convenient after long trips. They say its a simple attempt done to prolong life of heat affected parts / wires / connectors under the hood. Seems logical yet I am certain some will say idiotic and foolish.

My 2021 Ford Escape is (3) cylinders and of course has a turbo.
When I park in the garage on a hot day, after 10 minutes the fender is so hot, you can't keep your hand on it.
I open the hood and a blast of heat hits my face.
You also can not touch the battery.
So, what about ALL the hoses and other components?

I have started to open the hood (when in garage) after any long drive.
 
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