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[JOP33]

I'd been thinking for sometime now how I could dress up the cuts around the hinges in the body. I believe Tim Whittaker sold some billet pieces at one time to install around them, but after seeing them once, I never came across them again. So I ventured out on my own trying to come up with something simple, easy to install and low cost to make...here is the result of that...

https://youtu.be/LYnF0s_LMug

[JOP33]

Last week when I hit 2000 miles on the car, I put the car up on the lift to just eyeball the underneath and make sure nothing looked out of sorts. I also re-torque items that need to be. Something I caught was some heating up of the heat sleeve I had placed around the starter wires. They pass extremely close (and in fact were laying right against) the header pipes. The heat protection was doing exactly what it was suppose to be, but in an effort to avoid an issue later down the road, I re-wrapped the wires with some new wrap. I still wasn't too happy with the way the wires were laying, so I also fab'd a small bracket to pull the wires away from the headers allowing a bit more air flow between...

Before re-wrap and bracket...
Marked Up - B4.jpg

Heated area...
IMG_8352.jpg

After re-wrap from above and below...
Marked Up - Top View.jpg

Marked Up - Bottom View.jpg

Bracket...
IMG_8354.jpg

IMG_8353.jpg

[JOP33]

Yesterday I drove the car back to work after lunch - I am blessed (or burdened ) by the fact that I only live about 10 miles away from work. So on my trip back home after work as I was testing the AC for coolness and watching the engine temp for cooling as well, as luck would have it on my 10 mile trip, I was held up by three trains, construction & car wreck. This turned the normal 15 minute drive into a 50 minute drive or maybe more appropriately a continuous start and stop. During the span of this time the engine temp was running pretty consistently 210-220 moving with the AC on and jumping to 220-230 at stop. This seems just a bit high, but I have read many post on some of the 302 forums that these engines typically run between 200-210 and a bit higher with the EFI. I reached out to the guys at Engine Factory for their thoughts on this as it was only 95 yesterday, so we are a good 10 degrees from what we could see at times. I do have some ideas on helping to cool, but have not pressed forward with them as of yet. Will update as I get some more info on this.

[sread]

I am in the process of hanging my grill/rad assembly right now and I have noticed a couple of possible issues. First is the laid back angle of the the rad - that can't be the optimum set up for airflow thru the core. Not much you can do about it other than switch to the more vertical 32 grill.
Second, is the spacing between the condenser and the radiator. It really needs to be at least an inch or it really reduces the efficiency of the rad also. One other thing that comes to mind is I am pretty sure the FF supplied electric fan is probably not the top of the line either when it comes to cfm air movement.
Just some things to consider.

[sethmark]

I’ve always been taught that overheating at speed is not enough radiator and overheating while going slow is not enough fan. Kind of obvious if you think about it. With that said, at slow speed you need to get the heat out as well.

If you’re not running a shroud, that would be the very first thing to add. The second thing, as mentioned in the previous post is more fan....look up SPAL fans. Figure out What fits in the hole and get one with as much power as possible. I hate overheating issues and have fought them on a number of projects over the years. Unless there is a issue that is greater, such as thin cylinder walls or some sort of mechanical blockage, it usually boils down to airflow.

[JimLev]

I used a shroud on mine plus I added a PWM speed controller so the fan runs all the time at whatever speed I set it too.
If the engine ECU wants more cooling it bypasses my PWM controller and sets the fan speed to 100%
It's easier to keep an engine cooler if air is always moving thru the radiator than it is to try to bring the temp down after it's hot.
This is very helpful in stop and go traffic.

[progmgr1]

I used a shroud on mine plus I added a PWM speed controller so the fan runs all the time at whatever speed I set it too.
If the engine ECU wants more cooling it bypasses my PWM controller and sets the fan speed to 100%

Hey Jim,
That sounds like a great idea. I'm just getting ready to do the wiring, so a schematic and parts list of your setup would be very helpful.
Thanks,
Keith HR #894

[JimLev]

Keith, I'll probably have to redraw it and add more notes to it.
The top part of the page is the way it was wired using the GM ECU (temp switch in the head) to control the fan.
The temp switch in the bottom of the radiator is not used.

The fan was grounded and the ECU relay would switch 12v on or off as needed.
Using a PWM controller most of the ones I've used in the past did the switching on the ground leg, not the + side.
This requires a DPDT relay (Magnacraft W388COX-6) to switch both fan wires.
When the relay is not energized the fan runs off the PWM controller.
When the ECU wants more cooling the ECU fan relay energizes the Magnacraft relay which switches both fan wires.
Any 12 volt relay that can handle ~15-20 amps will work.
Here's the PWM controller I used. You set it to the % of speed you want, not the actual RPM.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

JOP, sorry to hijack your thread.
Keith, if you need more info let me know and I'll post it on your build page.

PWM Fan Circuit.jpg

DSCN3529.JPG

[JOP33]

Actually what ya'll are saying is the feedback I am getting...running heat = not enough radiator, idle heat = not enough fan. Engine Factory has come back and suggested changing from the installed 180 Tstat to a 160 an from the FFR stock 2800 cfm fan to a 3300 fan. BTW, I am using a fan shroud and also have the hood vent. It appears the stock fan is about1-1/4" to 2-1/2" deep by ~16" in diameter...anyone happen to have a part number on a 3300 cfm fan that might fit nicely?

[sethmark]

https://www.spalusa.com/products/fans/16/

Your engine is not overheating at 160°. Nor is it overheating at 180°. The way that the thermostat works is that the number is where it begins to open. It is then fully open 20° later. So a 180 is fully open at 200°. Still not overheating.

The best remedies I found in the most stubborn of cars are high-quality water pumps and strong puller fans with good shrouds. I had a 53 Chevy pick up I put a small block Chevy in and it would not run cool. I eventually had to put in a new radiator, fan, shroud and water pump to keep the temperature south of 220 while idling with the air conditioning on in South Florida heat. With all those components installed, it never got hot around town.

[JOP33]

Good information Seth...and what I have uncovered from comparing part numbers and information is that Tony Z thought the cfm on the FFR fan was 2800...it is actually 1900 cfm max! So getting to even a 3000 cfm fan will help significantly (I think). However, getting the fan off (bolted from inside of shroud that is riveted on to radiator) might be bit of a challenge in itself!

[sethmark]

A 3000cfm fan is a hurricane.

[JimLev]

A 3000cfm fan is a hurricane.

^_and will sound like one too. If you go the 3000cfm route better check how many amps it will draw. A fan with S curved blades is a little quieter than straight blade fans.
No room to add a bigger radiator, a fan with more CFM will help however the on/off control will still have the temp go up and down.
A fan that is only running when the ECU signals it to be on vs one that is always running at a slower than max speed is something to consider.
I have pretty much this same PWM circuit in my other car (4.4L V8) with a Flex-a-Lite 116 16" 1450 CFM fan.
Last summer it hit 102º here, I had the AC set to 65º and was stuck in traffic many times. I can read the engine temp in deg C in the cluster. It always stayed below 100ºC. I also built a delay off circuit the will keep the fan running for 5 min after you turn the engine off.
Another easier alternative to a PWM controller is to put a 100w resistor across the fan relay contacts, a value of a few ohms should keep the fan spinning around 1/2 speed and then go to full speed if the ECU wants more engine cooling.

[JOP33]

So I got the fan changed out - went from 1900 CFM to 3000 (what a pain) and the thermostat - went from 180° to 160°. I ran the car for about 10 minutes yesterday after everything was buttoned up (fluid added, everything tightened) and fan engaged as it should. Today I took it out for a road test..not crazy hot outside 82°. AC on full blast was running about 190°-205° for most of the drive. Stopped for gas and then got back on the road at that point it traveled pretty quickly to 230° - I now know that although the fan came on yesterday, it never came on today. Drove back to the house and here is where I am at right now (still need to chase down the fan issue, but I had to do a sanity check on some temps)...

After 15 minutes of running, with AC on @ idle (taken with infrared temperature gun)...
Speedhut Gauges Reading - 245°
Drivers Side Engine Block (behind Alt) - 155°
Passenger Side Engine Block (behind AC Comp) - 197°
Thermostat Housing (just at the base of the gauge temp sensor) - 190°

My first question is, where is the best location to get an accurate reading of the engine temperature? Then secondly, more of a statement, the gauge temperature reading seems to be the big discrepancy.

It would be great to hear some additional input on this, thanks

[sethmark]

Top and bottom of radiator. You need to know how hot the water is going into and coming out of the radiator. The differential will tell you how effective the cooling of the rad is. Where is the water temp gauge plumbed?

[JOP33]

It’s in the thermostat housing.

[sethmark]

Out of the gate, it sounds like the system is not bled. Open the radiator cap with the car cold, turn on the heater and let it idle until it’s fully up to temp. I would expect to see a couple of good burps.

The gauge should be accurate in the thermostat housing, but there should be fluctuations... With a 160 therm the tstat should be wide open at all temps above 180 (remember, it opens at 160and is fully open 20° later).

[sread]

If bleeding the air out of the system doesn't help I have a feeling you may find it a challenge to keep the car cool without opening up the engine compartment some more to allow all of that hot air to escape. I doubt that the the vent you have currently in the hood is going to be sufficient. ( I know not something you want to hear). It should be pretty easy to test by just removing the side panels and see what effect it has.

[JOP33]

ALL extremely helpful information. I haven't had a chance to check the temp on the upper and lower radiator hose inlets and compare or bleed the system. I did remember that the EFI is controlling the fan cut-in and cut-out and it is on a separate thermo sensor from the gauges. It is installed in the top left side of the engine block (where the temp is registering on the outside of the block @ 155°). If the temp there is even remotely close to actual, the fan is set to not cut-in until 170°. The gauge thermo sensor is installed in the top of the thermostat housing (where the temp is registering just the below the sensor 190°) - this is far cry from the 245° that is registering on the gauges on the dash though. So I am wondering if there is something wrong with this sensor...if it is just a bad sensor and the system is cooling properly and I just need to replace that sensor, I would feel a lot better knowing that. How accurate should I expect the temps shot on the outside of these engine locations to be relative to real temps inside?

Thanks again for all your help and I will keep you updating as I work through this.

[wrp]

I do not have any pictures but after rebuilding my motor and putting it back in I could not get it to burp. I jacked the front end up to the highest point I could get the jaqck stands to hold it. The car was at a steep front to back incline. I let it sit overnight. Seemed to solve the problem.

[JOP33]

Although I am not completely satisfied, I think I am satisfied enough to get the ole' bird back on the road for a test. Today, between a few drives through the neighborhood and (mostly) idling (~30 minutes), the max temp reading I saw on the Holley Temp Sensor (installed as shown in pic A below) with the AC on was 207° (ambient 87°). Now during this time I was still seeing the Speedhut Dash Gauge reading 230° (installed as shown in pic B below)...so I'd much rather those numbers be a little closer, but Engine Factory has advised the EFI sensor should be the most accurate. I did (at the suggestion of a few of you here on the forum) burp the system and there was some air that came to the top. So the fan has been upgraded and is engaging as programmed, the thermostat was changed from 180° to 160°, system has been bled and it appears the only real issue is the dash gauge is off (to the hot side) by +20° or so. I can replace the thermo sensor for about $20 and hope that corrects the issue, but I am absolutely dreading chasing down the lead, disconnecting and re-running on a "hope" that the issue will disappear. I think I am going to play it by ear, confirm temps over the next few drives with the Holley Sensor (I can view the handheld out of my console) and if the discrepancy is consistent (especially when it may only truly matter at stop & idle), I may just decide to live with it until winter.

Holley Temp Sensor Pic A
InkedIMG_8440_LI.jpg

Speedhut Temp Sensor Pic B
IMG_8441.jpg

[sethmark]

That 230 number scares me. The gauges use turd sensors. Temperature up/resistance down. You should be able to check the sensor as it warms up by pulling the leads off the sensor and recording the numbers. If you pull the offending sensor and record the resistance in a cup of room temp water, then boiling water, you can then check the sensor installed in the intake,with the gauge installed and determine accuracy. If you’re really can hook up the gauge to a battery in the house and do your accuracy checks with the gauge. I also have auto meter gauges and sensors,from the kit I didn’t use. If you want them.

[narly1]

OK Jamie, you're in my wheelhouse now. I sell sensors for a living.

The sensing element used in these types of coolant temperature sensors is a device called a thermistor.

The characteristic of the thermistor that is used to infer temperature is the fact that it's resistance changes with temperature. Apply a stable, known voltage to the sensor (like 12Vdc, look at the voltage drop across it (with respect to ground) with a voltmeter (which is what your coolant temperature gauge is) and your off to the races.

Refer to https://en.wikipedia.org/wiki/Thermistor and you will be an expert on the subject, LOL.

So what does all of this have to do with checking to see if your sensor is good or bad? A couple of things:

1. Remember I said apply a stable, known voltage? If you're not doing this due to lack of input voltage regulation, or a bad/poorly connected +ve, output, or negative (remember the case of the sensor is the ground connection) electrical connection the results could be off. Start there.

2. Then the next thing you can check is what values of resistance the thermistor outputs at various temperatures. There are charts out there you can look up, but this is where the car OEMs and sensor companies do a poor job of documenting what's what. Due to reasons of economy, they're not that consistent in resistance output at a given temperature from unit to unit.

Armed with this knowledge you can still go poking around and check the resistance across all of the coolant temp sensors in the system (with a digital multimeter set to ohms) to see how they compare, both to the published chart(s) and each other.

I hope this helps.

[sethmark]

OK Jamie, you're in my wheelhouse now. I sell sensors for a living.

The sensing element used in these types of coolant temperature sensors is a device called a thermistor.

The characteristic of the thermistor that is used to infer temperature is the fact that it's resistance changes with temperature. Apply a stable, known voltage to the sensor (like 12Vdc, look at the voltage drop across it (with respect to ground) with a voltmeter (which is what your coolant temperature gauge is) and your off to the races.

Refer to https://en.wikipedia.org/wiki/Thermistor and you will be an expert on the subject, LOL.

So what does all of this have to do with checking to see if your sensor is good or bad? A couple of things:

1. Remember I said apply a stable, known voltage? If you're not doing this due to lack of input voltage regulation, or a bad/poorly connected +ve, output, or negative (remember the case of the sensor is the ground connection) electrical connection the results could be off. Start there.

2. Then the next thing you can check is what values of resistance the thermistor outputs at various temperatures. There are charts out there you can look up, but this is where the car OEMs and sensor companies do a poor job of documenting what's what. Due to reasons of economy, they're not that consistent in resistance output at a given temperature from unit to unit.

Armed with this knowledge you can still go poking around and check the resistance across all of the coolant temp sensors in the system (with a digital multimeter set to ohms) to see how they compare, both to the published chart(s) and each other.

I hope this helps.

I like turd gauge.

[narly1]

I like turd gauge.

I know eh? Cheap crap.

I was surprised to see that there isn't a standard resistance vs temp curve/spec that coolant sensors are supposed to conform to within some tolerance.

Thinking the best thing to do might be to pre-calibrate the sensor & gauge together by immersing the sensor in a pot of heated water while comparing it to an accurate thermometer. If you put a trimpot in series with the sensor output you could then adjust it and make the gauge read dead on.

[sethmark]

​I think you said what I tried to say....better

[JOP33]

Whewwww! Guys this is way too much discussion & knowledge being fed to me this early in the morning! I don't even know if I can digest this all...I feel like someone has just explained to me how to do brain surgery. It may take me a day or two to even begin to know where to start here...but thanks again for ALL the information, I will update as I (gulp) work through this...

confused.png

[sethmark]

Toughen up,Jamie. You built a car.

[JOP33]

I get it! Thanks again

[JOP33]

Toughen up,Jamie. You built a car.

I might add Seth...Just cause I can buy a lottery ticket, doesn't make me a millionaire!

Ya'll have a great day!

[JOP33]

Have not checked thermistor as of yet. Did get the car out for about a 20 minute drive, tale of the tape below...

88° Ambient Temperature
AC on
Mostly Highway driving with a few idles

Dash Gauge - 210° max / Thermostat Housing - 168°
Holley EFI Handheld - 183° max / Top Driver Side of Block - 167°
Radiator Inlet (Upper) - 168°
Radiator Outlet (Lower) - 140°

[sethmark]

I would be far more inclined to believe the Holley than the auto meter. If you’d like for me to send you another temp sensor, send me a PM.

[FF33rod]

Have not checked thermistor as of yet. Did get the car out for about a 20 minute drive, tale of the tape below...

88° Ambient Temperature
AC on
Mostly Highway driving with a few idles

Dash Gauge - 210° max / Thermostat Housing - 168°
Holley EFI Handheld - 183° max / Top Driver Side of Block - 167°
Radiator Inlet (Upper) - 168°
Radiator Outlet (Lower) - 140°

Everything seems pretty normal/consistent except the dash gauge

[JOP33]

I would be far more inclined to believe the Holley than the auto meter. If you’d like for me to send you another temp sensor, send me a PM.

I would agree, and I also need to go back a few post and edit, as for some reason I had Autometer on my mind, but the gauges I have are actually the Speedhut Legends 6 in 1 Elliptical Cluster.

EJJF1195.JPG

[JOP33]

Taking the car across town a bit today, so it will be a better test. Keeping the Holley Handheld visible just for some reassurance.

[narly1]

Everything seems pretty normal/consistent except the dash gauge

And the sensor it's connected to....those two seem to be the "odd man out" components in terms of the temps being read/observed.

So how to troubleshoot:

1. Easy but not definitive approach: Swap out the existing temp sensor on the engine for a new one. If all measurements agree then safe to say that was the problem. If they don't you may have another wonky sensor or the gauge is somehow off.

2. More involved but definitive approach: Hot plate/pot of water/ accurate thermometer, dunk the existing temp sensor into the pot while still connected to the dash gauge and powered by the car to see how they compare as the water heats up.

[HVACMAN]

And the sensor it's connected to....those two seem to be the "odd man out" components in terms of the temps being read/observed.

So how to troubleshoot:

1. Easy but not definitive approach: Swap out the existing temp sensor on the engine for a new one. If all measurements agree then safe to say that was the problem. If they don't you may have another wonky sensor or the gauge is somehow off.

2. More involved but definitive approach: Hot plate/pot of water/ accurate thermometer, dunk the existing temp sensor into the pot while still connected to the dash gauge and powered by the car to see how they compare as the water heats up.

You don't even need a thermometer (another variable). Boiling water is exactly 212 degrees.

[narly1]

You don't even need a thermometer (another variable). Boiling water is exactly 212 degrees.

Altitude and barometric pressure will affect that figure slightly but yes, you're correct boiling = 212 F would be close enough for the purpose of checking the accuracy of the temp sensor & gauge.

[JOP33]

So still nothing definitive on the sensor yet, however I do feel much better about the cooling system in general. Today I was out for about 3 hours, probably 2 hours of that driving - some highway and some in town. With an ambient temperature of 90° and the AC on, I was seeing a max of 225° on the Gauges and 200° on the Holley Handheld. It is interesting that no matter what, throughout the day the difference between the two was usually 20° - 25°. I also want to mention that I reached out to Speedhut on the gauge sensor and they very promptly sent the ° to ohms conversion (below) for the Legends 6 in 1 Gauge Temp Sensor, they also stated that if in fact I found an issue they would send a new one at no cost. I have actually asked them to just send another one out as that should be the most definitive check.

To another subject for a moment, as I know I have spent a significant amount of time the last week on on the whole "cooling dilemma of 2020". After today, I do believe the AC is working pretty efficiently, I also believe that I am getting a significant amount of heated air from the engine compartment coming in around the firewall, trans tunnel, etc. This is just m theory, so don't consider any of this gospel..ya'll that have the removable engine side covers or louvers (or some kind of opening in the side panels) have a place for this heated air to escape. For me, the path of least resistance seems to be any slight or not so slight gap at the firewall or around the trans tunnel. I probably should have expected this and done a bit more with regards to that to help things out (instead of being so focussed on the thermal transfer of heat - or at least been just as foccussed)...by no means is it a sauna, but I think the cool air being generated by AC is just being slighted by the forced heated air. My first plan on this is to try and fill any gaps with some of the high temperature, batted insulation. Something similar to an Owens Corning that can be tucked into the gaps...I was able to find some high temp rated at Grainger and will try that first. Plan B will be to create some vents for the side panels. I have been working on a few designs that ultimately I would have 3D printed out of aluminum, just like the hood vent.

Speedhut ° to ohms conversion...
Capture.PNG


Here are a few of the Plan B designs if things have to go that far. The drawings are 2D for now, but they would be functional vents with opens on the back side that flow toward the door...
Circles.png

FFR_33.png

Fi-vent.png

Tri-Vent.png

Tri-Star.png

Tri-Star_no_border.png

WM!_33.png

[JimLev]

To be honest those small side vent openings won't do that much.
While your driving the majority of the air flow will be out the bottom of the engine compartment, that opening is much bigger, the air will take the path of least resistance.