GCrites said:KentF said: So, the guy in the video was using an oscilloscope. Remember the oscilloscope? I bought an oscilloscope for $120. Have not used one in 40 years. They used to have cathode ray tubes and were the size of a restaurant coffee machine.Haha, I totally thought they were still like that.
Some still are, I guess they have a grassroots friendly version now too.
Jacking Rails
Last Christmas my #2 son got me a $50 gift certificate to Summit. So, I bought some $80 Jacking Rails. Been wanting this for years but never got them. Last spring while waiting for other parts I installed them.
You are supposed to weld them into the floor pan and the raised seam. This would require dissembling much of the interior so as not to set fire to it. I was still recovering from a knee replacement and did not feel up to that much climbing around inside the car. The rails came punched with 5/16” holes every six inches. Yes – it would be stiffer and better if they were welded. My goal here was to make the car easier to jack up at an event. I bought bolts…
First order of business after removing the plastic rocker covers was to fix the damage to the raised seam holding the body panels to the floor pan. Years of raising the car with various jacks and shop lifts had left its toll. Much of the damage was actually done by mechanics who did not pay attention to the exact placement of their equipment and did not have lift pads with grooves. I remember coming back from some crap @#$% mechanic and discovering part of a seam had been perfectly flattened. The car was still new then! Come-on man! I never went back to that shop.
In later years it did not help that the Spintech side exhausts make hitting the rear lift points more difficult. It is almost impossible to get a jack and a jack stand in that small space. Since putting sub frame rails on several years ago I have avoided using the OEM lift points because they were slowly crushing up into the body of the car. They are made to support the car at these specific positions. But just barely. And if you flatten them they have no strength at all.
After a lot of hammering and pulling and a little cutting I had the seams fairly straight. I then primed and painted everything and finished if off with black truck bed spray. Luckily this car has not been driven in winter for several years now or all of this would have been rotted out. The metal is still good, just a bit bent up. I also sprayed the frame rails with truck bed spray.
Next came drilling through the pre-punched holes in the jacking rails through the standing seam joint. This was a bit tedious and awkward since I still could not fully bend one knee. Then I started wrenching them together. The strong straight jacking rails pulled in the body seams nicely. They never looked better.
Now the plastic rocker panel facia. It also was bent and permanently deformed by abusive lift management. Nothing a heat gun and some wide face pliers could not fix.
This turned out to be a much more rigid assembly than I expected. Yes, it would be stiffer if welded. But the bolts really pulled together the seam and got it back to the original engineered shape. And no more damage from sloppy people with lifts.
Kent: We haven't heard from you in 5 months. Are you and the family OK? Any new updates on the Mustang?
In reply to Mustang50 :
Hi Mustang50. We are doing OK thank you for checking. I had the last post written (in the can so to speak) and then published it from the hospital. I had my wife proof it because i was on some "pretty good" pain killers at the time.
I had a bad infection in my left knee. Long recovery but doing fine now. Pretty much October through mid December were a lost cause.
Have gone to part time at work and liking it. Mistress almost has a new radiator and I just finished replacing all the mangled brake lines. Will have that all written up soon.
The Radiator turned out to be a lot of work! Currently it is removed (again) to make access to the brake lines. Now that that is done I can do final assembly. Some progress photos below.
So how are you doing?
KentF (Forum Supporter) said:It is a ratcheting cable clamp that opens/closes the spring clamps on hoses. Works great. $50 at NAPA. Hose Clamp Tool
They're 92 bucks now. Dammit.
In reply to rdcyclist :
Ha! Keep searching. I am seeing a lot of very cheap versions (too cheap junk) online. However, this one looks better than mine for $64:
Thank you for that! Yes, Lisle tools are pretty good. I've not broken many of them over the years so I'll get that one.
I'm doing OK health wise. But a little depressed over my decision to cease auto crossing due to heart issues. I still love driving my Mustang.
In reply to Mustang50 :
Hang in there Mustang50. I learned one of the secrets to life is how we "let go" of things we love. I have not mastered it either.
New Radiator - Part 1
I used to be cool. Then I had kids. The kids grew up. I got a little bit of cool back. Just a wee bit. It is harder to be cool when you are old.
My car, however, has only gotten hotter. And that is cool. This summer Mistress got so hot I could not keep it cool and had to delay some runs while I frantically used the tire sprayer on the radiator and intercooler. That was not cool. And it is not fast either. I already hold the car back. Even more so if I spend time between runs thinking about the car rather than where I left some time out there.
To get through the summer I switched out the coolant to Stay Frosty water-based coolant (water has better heat transfer than glycol). I also removed the air conditioning to allow better air flow (never use it anyway).
The little OEM single pass cross flow radiator could not keep up with the additional load. So… How much radiator do I need?
I started writing up a Long Sciencey physics answer to that question with heat transfer calculations and such. Then I realized I could not “close” the discussion because I had no actual data on temperatures and fluid flows.
So here is the intermediate answer:
For any given “system”: Energy Out = Energy In + Energy Stored. For this discussion I am defining the “system” as the engine in Mistress with the fuel line as “Energy In”. The Radiator, Exhaust & Crankshaft are “Energy Out”. We are going to assume the car is all warmed up, battery is charged up, etc. Therefore, Energy Stored is roughly zero. We are also going to hold this discussion to full throttle maximum inputs and outputs. Basically like a dyno run.
Energy Out: From the factory the engine in Mistress was rated at 193 HP. That is the mechanical power (energy/time) coming out of the crankshaft. That can be converted to more universal units of kilowatts or 144 kW. Today, I estimate the supercharged 4.2 ltr version of that engine generates about 390 HP or 292 kW.
Reference Point: In the US, a 120 VAC household electrical outlet can supply about 1500 Watts or 1.5 kW. So, the engine in Mistress can create about the same power as 292 / 1.5 = 195 electrical outlets at full throttle. Get some extension cords…
Energy In: A modern automobile engine turns about 35% of the chemical energy in the fuel to mechanical power.
Hold on – If you google that you will find numbers more like 20% to 25%. Those lower numbers include the whole car with losses from the drive train, tires, wind, etc. We are interested in waste heat from just the engine (the “system” defined above, not the whole car). If you google the energy efficiency of an Otto Cycle Engine you will find a lot of serious calculations and deep study papers.
After a lot of webbernet gleaning you may find that the ideal efficiency of an Otto Cycle engine with a 9.5:1 compression ratio is around 55% to 58%. That ideal engine is not real and exists only in spreadsheets, graphs, and physicist’s dreams. In the real world of steel, aluminum, inertia, friction, combustion, and heat transfer the things are about 20% less efficient than “ideal”.
So – Let’s, say Mistress turns 55% Ideal – 20% = 35% of the fuel energy from the fuel line into mechanical power. But the engine in Mistress was designed in the late 1970s. It barely qualifies as a “modern” engine. Let’s round that down to 30% efficient for this exercise. So -30% of the energy in the gasoline comes out the crankshaft.
Working the math backwards the 144 kW original factory output would require about 144 / 0.30 = 480 kW of chemical energy in the gasoline. Today the estimated 292 kW of output would be 292 / 0.30 = 973 kW input from fuel.
Wasted Energy Out: The original wasted energy was about 481 kW – 144 kW = 337 kW. Today it is 680 kW.
More interblag gleaning will likely net you that the wasted energy on an Otto Cycle engine is split at about 40% exhaust and 60% radiator. This works out to 202 kW of radiator heat rejection on the factory engine and 408 kW today. So, I need a radiator that will reject in the neighborhood of 408 kW of heat energy. That is equal to 272 plug in 1500 W electric heaters.
It makes sense in that, all other things equal, the available power at the crank has increased by a factor of two so the heat rejection has also increased by two. So – I need a radiator that can “reject” over 400 kW of heat from a 202 degF coolant fluid to 95 degF air (a hot day in the Great White North).
As a tangent: All things are not quite equal in this case. The engine at high RPM and WOT is now being fed an air/fuel mixture at around 12 psig (almost two atmospheres). This is a higher energy density than the original design and in physics it is always easier (more efficient) to convert from one form of energy to another at higher energy densities. This engine is more efficient than the original. On the other hand, most, if not all, of that efficiency gain is lost again by the parasitic losses running the supercharger. We have more power, but not more efficiency (still ~30%).
All of the above is theory and rough numbers. Your mileage may vary. Mine might also.
The Short Answer to how big a radiator should I install: As BIG a radiator as will fit in the damn car! That is what I did. It did not really fit. Width and height and mounting points match but this thing is much thicker (four pass verses the original one pass). This is an aftermarket radiator meant to fit in a 500+ 4.6 SVT.
Mods to make it fit:
The rework was a little more extensive than expected!
Speaking of the fan: The tune for the car has a low speed and high speed temperature settings. I have always gone for about 202 and 212 degF. The GT has the same fan (they are interchangeable). However, when rewiring the fan I discovered only two wires in the harness to the fan (the fan plug has three wires). Going through the wiring diagrams I found that only the GT has the high-speed circuit. But the programming is still there! And the high speed windings are in that fan. They saved a relay and a wire on the V6 car.
That is the set up for what I have been doing all winter. Next posting will run through the details step by step.
More to come...
WOW! That analysis was way beyond my ability to comprehend. Please allow me to ask a stupid question. What temperature thermostat are you using? When I was autocrossing my V6 Mustang I changed to a 180 Deg. thermostat and that helped my heat soak issues between runs. My car is obviously not putting out the HP yours is.
In reply to Mustang50 :
Thanks. Just messing around.
I believe my thermostat is 190 degrees. I have not thought to change it. I don't think the extra ten degrees would buy much time on a one minute course and it would still take a long time.to get back down for.the second run. At the rate it was cooling it would take 20 min to get back to 180.
I can watch the temperature on my phone from the OBDII link transmitter as well as the analog water temp gauge. It would be fine unless the air temperature was 80 degrees or more. Then it would take a long time to come down and shut the fan off at 203 degrees. The thermostat is still wide open above 198 or so.
More Messing around: A gallon of gas contains about 114,000 BTUs of energy.
973 kW (full power input to Mistress today) is 922 BTU/second.
So at full power Mistress burns something like 922 / 114,000 x 60 = 0.48 gallons of gas per minute.
Something like a half a gallon per minute. That is why people starting out the autocross day with 1/4 tank are on fumes by the end of the afternoon.
New Radiator Part 2 – Cut to Fit. Bump to Suit
The radiator I bought theoretically has four times the surface area as the stock unit. However, each successive “pass” of coolent is downwind of the one before it. The air is heated as it flows through the thing making the last row much less effective than the first one. Also, this car generates more power than a stock GT of the same generation (2 or 3 row radiator). So, as noted before, I went for as much radiator as would fit in the car for about $220. As noted earlier, it did not really fit. Side to side was great. Right in the same mounts on the frame. Front to back: Not good.
Note there is no radiator cap on the thing. A GT has a plastic pressure/overflow tank with the cap on it. Mistress had the cap right on the radiator and an overflow tank down by the fan (old school). I needed to duplicate that arrangement and did not have room for the GT configuration. That is why I also bought a little 1.2 quart aluminum expansion tank with radiator cap mount. More on that in the next entry.
The Intake Cowl
Clearance issues started with the first test fit. The new Radiator core is 3” thick while the old one is only about ¾ inch thick. The front of the radiator is in the same position but the extra thickness is towards the engine.
The supercharger intake cowl (air filter to supercharger inlet) conflicted with the fragile radiator by about 1/8”. At his point I was at a loss on what to do. A week after it arrived I had gotten very sick with an infection in my artificial knee. It was now three months later and I could not return the thing.
I contemplated cutting the mounts off of the car and rewelding them ¼” forward. Or cutting the mounts off the radiator… Hmmm….
I have learned (and often advised) in this situation just pull up a chair, get copmfortable, and sit and stare. The solution is there. It just takes time to see it. This one took a couple of days of staring (on and off). And there it was – Just trim the hard plastic cowl on the supercharger.
This yielded just enough room.
With this I was able to mount the radiator into the factory mounts. Then I tried to start fitting the new fan in front of the radiator where the air conditioning condenser used to be. It is 16” in diameter which matches the radiator top to bottom. There is room for another 10” fan but I do not expect to need it.
Intercooler and Towel Bar
I had bought a fairly narrow fan but not a super low profile one. The lower profile fans do not push as much air as a regular fan and I expected this to fit since the AC Condenser was already removed. I was wrong. Not enough clearance to the intercooler by about an inch. A big fat inch. A whole inch. And I also had the thing for three months at this point and could not return it easily.
I worked out that the intercooler could be mounted forward on spacers if I replaced the bumper with a racing tubular bumper. This would also provide better air flow to the intercooler. Bought one.
Did not like it. This is a piece of 1” tubing that is supposed to provide some semblance of reinforcement in a crash. I could flex it with my bare hands. It would make a good towel bar for the shop (no, really)! Returned it.
More sitting and staring and thinking each evening. A couple more days went by…
Move the intercooler forward an inch on spacers. Make spacers and move the OEM bumper forward an inch. Trim a fat inch off the back of the dense Styrofoam insert that serves as the low speed crush zone in front of the bumper. It should all still fit behind the plastic outer cowl.
Bumper Modification
And while I am at it trim the bottom of the bumper on an angle to allow better air flow into the intercooler. In the photo below the black stripe on the intercooler is overspray from some sloppy spray painting (the cardboard slipped). The top of that stripe is where the OEM bumper sits. The bumper blocks the top 1/3 of the intercooler.
If I cut and bevel the bottom of the bumper the strength would be minimally reduced and I would have much better air flow.
Modern steel technology is phenomenal. This material is similar to tempered blue steel that springs are made from. It dulls and breaks drill bits. The stamping is prestressed and wants to unfold when you start cutting it. It is a royal pain to work with.
Clamping it alone has no effect on the material. It springs right back to where it wants to be. I had to heat it red hot with Mapp gas while clamping it in the vice and C clamps to get it to fold in for the bevel. It was a lot of work (You will YEILD damn you! Bend!!).
With this modification the bumper retained most of its strength (as opposed to the towel bar) and now the intercooler is fully exposed to the air stream.
Bumper Relocation
The bumper had to move forward about 1-1/8 inches in the car and needed to be solidly mounted. I fabricated box sections from 1 inch angle and welded them together in an “H” pattern to match up with the bumper support tubes on the car.
To mount them to the car I tapped these fabrications so they could be bolted on without welding (and so I could change my mind). Painted them up and mounted them.
They are sandwiched behind the bumper (mounted with longer Grade 8 bolts).
Next up Radiator Part 3 - Metal Fab, Fan Frustration and Expansion Tank Madness
Radiator Part 3
Fan Frustrations, Metal Fab, Expansion Tank Madness
Fan Frustrations:
I did a fair amount of sitting and staring at the fan to figure out how to mount the thing. The 16 inch Spal fan has four mounting holes on the rim so you can bolt through to supports in front of it.
However, the bolt heads would be perilously close to the fragile radiator fins. Things vibrate, things twist, things shift. The radiator itself is on rubber mounts and can move a millimeter or three on its own. The further away the fan shroud is from the surface of the radiator the more air will short circuit and not flow through. I bought some foam gasket material from the hardware store… Nope, not going to stick to the rather narrow edge on the fan shroud.
I was thinking about trying to return the fan and was searching Summit for alternatives. By sheer chance I discovered Spal Fans has special gaskets for the things. They also have mounting clips of various lengths. There is no hint of either part as a “Required Part” or “Recommended Part” on the fan page (or any Spal fan page). Unless you are really “into” aftermarket automotive fans you would never know these parts exist.
Even worse, the mounting clips come in various lengths. But no dimensions are given (even on the Spal webpage). So, you have no idea which ones you want even IF you know they exist.
This is basically negative marketing. I bought the gasket and had to pay shipping which would have been avoided if it had been purchased with the fan. Very frustrating. I expect better from Summit.
By the way, the gasket works perfectly. If you buy one of these fans – You want the gasket. It can be touching the radiator core and should not damage it.
I ended up just using some pan head bolts rather than what is shown above. The pan heads sunk down in the zig-zaggy gasket a little giving better clearance.
Using two aluminum angle pieces I did some test fits and figured out how to mount the fan. Note the photo below does not have the fan gasket installed.
I drilled mounting holes in the frame being careful not to drill through the radiator (that would be a bad day).
That brings back a memory from about 1972ish – Patching radiators… I remember soldering a thin piece of copper patch on the top tank of my 1968 Mustang. Blow torch, steel wool, solder, flux in a little tin, and a little piece of copper strip about the size of a penny. We were on a ski trip up north. It was snowing. It took a couple of attempts to patch the radiator. But we got home from the trip. Yeah, we used to do stuff like that. Did not think twice about it. I think I went back later and brazed it to make it permanent. I think when I brazed it I got it too hot, melted a bigger hole, and had to start all over. One thing I absolutely remember though: We did not buy a new radiator. We fixed it. We fixed everything (eventually).
Here is the completed fan assembly. The fan is mounted on 2” long spacer couplings (hardware store) with the gasket barely touching the radiator. The spacers are mounted to the angles. Everything has some blue thread locker on it. There are some little nylon spacers where the angles mount to the frame. All the fasteners are ¼-20.
I noted in the last post the car was not wired for the two speed OEM fan even though the fan was two speed (as well as the programming).
For grins here is the OEM fan and plug:
And the OEM harness (note the missing connector in the center):
I still think it is comical that the car came with programming for a feature it did not have. And that I have had it for 22 years and never noted that the fan never went to high speed even on the hottest days.
I cut the plug that came on the Spal fan off and used one from Amazon. Apparently Spal and Summit carry matching plugs but I could not find them and did not want to pay shipping again anyway. Negative marketing. No sale.
Metal Fabrication
The OEM radiator was fairly well “boxed in” both with factory parts and some additional parts I made some time ago. Boxing in forces air coming in the front of the car through the radiator rather than spilling out around everywhere under the front cover. I used some flexible plastic storage dividers and gorilla tape to do this work. Gorilla tape is great stuff and you can fold it on itself to make flexible gaskets and seals for this purpose.
The OEM set up used a large electrical harness to keep air from running between the top of the radiator and the frame. It worked well and is an efficient design. It would work again for the new radiator but for two things:
Thing 1 – I needed something to mount the expansion tank on.
Thing 2 – I wanted to direct some cold air onto the engine air intake. The filter is right behind the top of the radiator. It galls me a bit that I lost my cold air intake with the supercharger kit.
So, after some sitting and staring and messing around with cardboard I came up with a plan ( I would know later if it was a good plan or not).
The Plan:
My Neandertal metal working skills would be put to the test!
I started with making a template with some card stock. After a few false starts I was able to come up with a simple “bendiment” about 6 inches wide and 30 inches long.
I bought a piece of aluminum and while it was shipping made a crude brake on my workbench out of some angle iron. One angle was screwed to the bench top and the other screwed on top of that with the aluminum clamped in between. It is an old bench – Just drive screws into it.
The brake was a bit too crude. I had to score a groove on the underside of the bend to get a sharp edge. Most of the trimming was with a vibrating multi-tool. It was not perfect but serviceable.
The hole to direct some cold air into the intake was made with a hole saw and multi-tool.
To dress up this pig: Burnishing little spin circles in a pattern with the drill press. Little sander disks are from Harbor Freight. Easy to do and covers up a multitude of sins.
And the lipstick on the pig is to put 1/8” rubber edging (Bushwacker Fender Gimps 000040-01 from Summit) around all the cuts that are exposed (the multi-tool is not a precision instrument). You can see it around the cold air intake hole here:
Expansion Tank
The OEM radiator on the V6 model has the pressure cap mounted directly to it. This radiator is from a GT and does not have a cap so it needs an expansion tank and place to mount the cap. I wanted the expansion tank as high as possible. The OEM radiator cap was about 3 inches below the high point in the engine. This made filling and venting somewhat tedious. Raising the tank would help with this. But how high without getting into the hood?
With the car on the lift, I used a broom handle poking up through from the floor. I lowered the lift slowly until the handle was about to hit the closed (but unlatched) hood.
With the hood opened I marked the handle so I would know what height to set the tank.
With the tank height known I set about with new cardboard templates and made a support plate. The top of it is mounted on some 1 inch spacers from the radiator cover made above. The bottom is supported directly from the (now unused) OEM fan mount that came welded to the new radiator. I had to cut this down and then drill and re-tap it. A little trepidation clamping the new radiator to a vice and taking a hacksaw to it.
In for a penny?
And this would work well and look good. Hopefully I would not need to remember how to patch a radiator.
This fabrication was much smaller and easier.
The plate has a bend along the diagonal edge to add rigidity. This time I just used my wood vice and a ball pean hammer.
It is serviceable, does not block air flow, holds the tank properly and you really can’t see it anyway. In fact, once installed it almost disappears. I can’t even get a good photo of it.
Reassembling the front of the car required a few more "cut to fits" and "bumps to suit" to get everything to match up. The fiberglass assembly that mounts the headlights had to be trimmed in several places.
Nothing a little flat black paint won’t hide.
More Tank Madness
If your engine holds 2 gallons of water then the water expands about to about 2.2 gallons when heating from 60 degF to 204 degF. That is almost one quart. That is about 800 ml.
When shopping for aftermarket expansion tanks your choices appear to be limited to 800 ml, 1 liter, or 1.2 quarts (1.1 liter). After the first warm up I found the little tank would empty itself out the radiator cap to the floor. Fluid expansion on my engine is about 1.2 quarts. I must run with a non-pressurized overflow tank that siphons fluid back into the pressure tank through the cap on cool down. That means ALL of those overflow tanks on the market are too small unless you have a little four banger. All of them…
I ended up reusing the overflow tank that Procharger provided with the super charger kit. I think it is not quite 2 quarts. Works fine. I think it is actually meant to be a vacuum tank. It is mounted between the fan and the bumper next to the intercooler.
Summary observations:
I love your updates! This car is turning out really cool.
Kent should be writing DIY articles for GRM.
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