Sunday, November 18, 2018

Harvest Time Celebration

The title of this update was chosen without any consideration of calendar position.  I can only sometimes answer correctly when asked what day of the week it is, and that's usually only because I had been told or overheard the right answer within an hour beforehand.  If your expectations include me being able to come up with a play on words that's reliant on me knowing where the big hand is on the year clock, you may want to adjust them down.

No, the title is about my harvesting images that relate to what's been happening in the shop lately so I can share with you an ocular feast of shitty pictures recorded by shittier camera software!  Let us give thanks.

So first off, the baseplate/Helicoil situation is still awaiting resolution, and has been a real bastard every step of the way.  Trying to extract the Helicoil from the other hole that needed repair took a lot of time, work, a previously-usable drill bit, and a t-handle.

I chucked an ez-out in that to extract the coil, as I had done with the other.  Just using my hands resulted in one twisted-to-hell tee and an indifferent Helicoil.  I eventually got it out by abusing the hell out of a drill bit and turning parts of the coil out of the threads, using a drift to hammer it in spots, and pulling it with needle nose.  Here's what it looked like when it was over.

After filling that hole with alumiweld,
I got as far as getting one of the holes redrilled and the heli installed.  It seemed to go well, but test fitting to verify the hole was drilled square to the surfaces turned out to be where the bad times were hiding.

After getting one of the hole to where I presumed it to be good and coiled, I threaded bolts through it and the two good holes, compared them, and found that the new hole was wonked.  Somehow.  I ran it on the drill press, made sure the travel of the bit was square with the table, etc., but it just wasn't enough.

If I had to guess, it looks like the drift occurred because the center point was near the edge of the alumiweld and the "whatever the hell kind of crap cast alloy" Redline uses when they half-ass these plates out.  As the bit plunged the materials, a much greater portion of the flute was in the potted meat metal than it was in the alumiweld (which is a fair degree stronger and harder than the other stuff), and cut through it with less resistance than the alumiweld, causing it to drift into the softer metal.  This maybe could've been prevented by feeding the bit even slower than I had been, but that's hindsight for you.

At that point, I thought I had plenty of reason to cuss. So I did. And continued to, as I removed the bolts I had threaded in, as well as one of the inserts that decided it would rather piggyback on the bolt and take a ride out of there instead of staying in its damned hole like it was supposed to.  Guess the red loctite wasn't good enough reason for it to stay put. . .

So I put the baseplate aside to work on stuff that would at least drive me crazy in a different way.  I guess I chose wisely when I went with the throttle cable, as I managed to get that sorted out without any real hassle to speak of.

The factory cable is fine, but there's not a lot of length to it once it passes through the firewall and into the engine bay.  Since I've still got to at least dry-fit the carb to see how much length I'll need for sure, I may still end up using it.  Judging by how things look already, though, I'm going to need a bit more reach.  Luckily, I have a cable from a ('98, I think?) XJ that needed only a little bit of modification to act as an alternate option.

The Gremlin and XJ cables match in just about every way that's critical; firewall and throttle pedal retainers, end clips for the carb/tb linkages, and that sort of thing are all the same.  The XJ cable is a slightly heavier gauge, is significantly longer, and has more substantial sleeving, though the position of the cable stops give it a longer throw.  If you install it without altering it, the gas pedal will drop to the floor because of the slack in the line.  Easy enough to fix, though!

All you have to do to set the length of the XJ cable to where it'll work with the Gremlin is take the stops off the pedal end, cut the cable to length, and braze a new stop to the cable.  I didn't think to get a picture of removing the first stop (the one that is farther away from the cable end), but what I did was carefully cut a groove down the length of it and slowly crush it with a pair of pliers, while making sure not to pinch or bend the cable.

You pull the cable all the way out on the pedal end on both the old and new cables, compare the length, and wrap the XJ cable with tape behind the cut point.  Using a cutoff wheel and the tape will prevent fraying.  Slip the plastic retainer piece back on the cable as far down as you can and secure it in place.  You don't want to have it get too close to the other end when you're brazing the new stop to the cable.

Once that's done, take a #10 pan head machine screw and drill a hole down the center.  You want the hole to be just large enough for the cable to closely pass through, but not snug.  A slight amount of extra space is needed to let flux and filler flow through when you braze the screw to the cable end act as a stop.  Braze the very end to hold the stop and cable together, then do the section by the screw head.  Don't use too much filler or the screw head won't seat in the plastic retainer, and don't use too little or the brazed joint could give under load.  Either too much or too little may create a bend point that could cause the cable to wear and fail prematurely.

Add a note to your service and maintenance records to check that joint periodically to confirm that it's holding and that the cable isn't wearing out until you're reasonably sure that all is well.  DO NOT just slap it together, install it, and forget about it.

Crimping a cable stop on is an option, provided you can find one that will fit to the plastic retainer.  I couldn't find anything like that when I checked at the hardware store and didn't feel like hunting for one.  Regardless of the method you use, just make sure the cable remains tightly wound, and doesn't get kinked.  Both will cause weak points that will eventually work-harden and break.

For my next trick, I'll need an old oil filter, the box for a new oil filter, and a plain old, ordinary, empty 1 liter Arrowhead water bottle.  Be amazed as I. . .  Store the old oil filter without making it wear a nitrile glove as a hat.

Ta da.

Since you've all been good enough to read through all this mess up to this point, I'll throw in this last trick I came across when getting starting fluid on myself as I was figuring out a way to light a cigarette with a dead lighter.  And a can of starting fluid.  So I guess that's two tricks.  I'm sure you can figure out the rest of how the cigarette one goes.

What I discovered is this: if you have jeans that are oil stained to the degree that no amount of washing will get the stains out, starting fluid will knock that dirt in the dick.  Either that, or my jeans have ringworm.  Check it out:

I could return these to the store for a refund and no one would ever know.

Saturday, November 17, 2018

The Hell I Coil, Pt. 2: Hell Comes to Coil Town

I had a vision in the night.  In the course of my fitful sleep, I was visited by an entity.  Formless and empty, this absence of being was devoid of tone, feeling, or impression.  It was defined by nothing, save the message it had been charged with delivering to me.

I woke with no regard towards how little time I had spent resting through the six hours of sleep, and words fell from my mouth.

"Fuck.  I'm gonna have to get Helicoils."

Discovering you need Helicoils for a task is like going to an old man who's spent more time fine-tuning his craft than you've even been a member of the "things residing on Earth" club, asking him his expert opinion on what to do for a given situation, and waiting as he silently leans back in his chair.  After his feels-like-hours pause, he dryly opens his mouth.  Following the sound of his lips cracking apart you hear,

"Well. . .  I've got an answer for ya, but you're not gonna like it. . ."

The base plate that fastens to the adapter plate provided in the Redline Weber kit for the AMC 258 is made of some flavor of cast aluminum.  The cast part is okay-ish.  Not bad enough to be bad, and useful enough to not totally hate it.  The problems with it seem to stem not so much from the casting process as much as the lack of obvious finishing work done once the part is demolded.  The biggest pains in the ass I've had from working with it have all been directly related to the threads in the holes for the mounting studs.

While some grades of aluminum can provide threads that can withstand the torque needed to secure a carb to an intake (not to mention the stress of thermal expansion and contraction delivered by engine operation and cool-down periods), the mystery meat used to make these plates doesn't hold such a distinction.

I guess whoever was calling the shots figured "Why bother?" when determining manufacturing and QA processed for these parts, since the quality of the threads themselves are about as up to the task as the material.  And to clarify: I've been heckled on more than one occasion for my insistence on taking great care to make sure fasteners are torqued appropriately.  Like anyone else, I've stripped, broken, and rounded off my share of hardware, but it's not because I'm a reckless mongo that hamfists every threaded object I come in contact with.

The entirety of yesterday was spent doing the finishing work on a roughout of a phenolic spacer that's needed to give some clearance for linkage components, and to make sure the carb isn't just dumping fuel onto the floor of the intake from being too close.  The phenolic is some sort of horrible shit used to make lab workbenches, and can be a serious bastard about being worked in some respects.  So as I'm sure you know, I fucked up parts of it that will let it be alright to use with break-in, but doesn't really belong on the road.

The spacer is relevant here because I hadn't (and haven't) reached the point of even trying to install the carb to the intake before three of the threads were stripped.  It was the stress of dry fitting the plates to the carb and torquing the bolts only as much as required to confirm things lined up that was too much for the plate to handle.

As I made my way back to the house, I thought I would be fine sticking a bolt in the holes and flowing alumiweld into the gap to recreate the threads.  I had been up for 30 hours at that point, so cut me some slack.  It was a terrible idea, and it took me having The Ghost of Fuckups Future visiting me in my dreams for me to realize why.

I think alumiweld is kinda neat.  Not a bad thing to have around.  Kinda limited in its range of use, though, and a little fussy compared to brazing ferrous metal.  It's not really up to the task of flowing through passages as narrow and having as long a run as the mangled crap in the bolt holes without ending up as porous as spray foam.  It's also not an enchanted glue stick that will magically ensure a bolt will sit and remain centered in the worst of the three points that needed attention. 

The idea of having the threads give out for good while on the road was entirely unacceptable, so these threads needed to be fixed for good.  That meant threaded inserts.  The piss-poor supply of this kind of thing in a storefront here means the threaded inserts were going to be Helicoils.

After looking for a kit that I could buy for less than $30 (and failing), I got my kit and went to the shop.  It was at this point that the bad points of the baseplate really got their chance to shine. 

Depending on the location, material, drill size needed, and so on, I'll use the original fastener to fully strip the threads out and then turn a drill bit by hand that's equal to the thread diameter to clean up before tapping.  The reasoning behind this is that doing this will prevent me from making a bigger mess by drilling a drifting oval hole.  If I take my time, pay attention, and use good cutting oil when tapping the hole, the tall should be good with cutting through the extra material.   This should result in a clear, straight, threaded hole.  After today, I say "should" and not will.

For whatever reason, the godawful threads don't run completely through the bore.  There's a gap about 3 threads thick towards the bottom surface of the plate that interrupts the run.  It's this gap that gave my tap a chance to get distracted and wander off.  The result?  Two holes out of four are straight through.  The other two were so bad off that I had to get the easy out to extract the Helicoils, and then fill the holes with alumiweld so that I can drill new holes and start over again.

So to be perfectly clear, I went to go install the carb two days ago and am hoping that tomorrow doesn't end before I actually get it on there.  Here's hoping for a spirit-free sleep.  I don't need any more wise ideas.

The Hell I Coil

I'll be upfront with you here -- writing the last update left a bad taste in my mouth.  Not because I was sleep deprived and ended up getting a fine carpet of old tobacco all over my tongue from letting the mouth-end of my cigarette unravel worse than the cohesion of the text I was laying down.  Because I wrote about being successful when I tried coming up with a way of hacking something together.  If you dare read through the entire run of this log (fat chance that I'll do that), you'll probably find that it was a landmark event.  The first post in finding a good solution, but even more than that, terror and failure were nowhere to be seen.

Today I'll be making up for that.

I will post q second update before my day is done to cover specifics and details, but first, I think we need to do some stage dressing.

Take a minute and clear your mind.  Visualize yourself in a wide, open field.  The sun shining, the wind gently blowing ripples like those on a the surface of a placid pond across the grass expanse that radiates around you.  Imagine the warmth that bathes you from the sun, tempered and complimented by the coolness from the breeze.

Now, as you are in the field, imagine a garage.  A garage packed with trash, tools, and farts.  This garage was birthed in cosmic chaos, formed in the blink of the eye of the deepest, coldest, most malevolent core of space, then was fired out at a speed far exceeding anything that should be physically possible.  It's screaming in rage as it rips through the cosmos.  You stand in the field.  Happy.  Content.

Burning past photons emitted by stars that have been dead and gone for millennia, the garage howls as it passes through emptiness and galaxies.  You see a grasshopper jump over a rabbit to land on a smooth, flat stone.

The garage sees a dot of light in the distance, distance that is made meaningless by comparison to the expanses it has traversed to arrive here. It's destination.  You lie back on the soft ground and take off your shoes, spreading your toes and sunning your soles.

The garage bellows, not in the agony it should feel from Earth's atmosphere rending the ever-regenerating exterior from the garage's inadequate and warped frame, but of bellicose bloodlust.  The moment draws near.  You are picking out animal shapes in the stretched weave of clouds spanning the entire expanse of powder blue skies.

A screaming garage lands on you.

Still unsure whether you've unwittingly drifted off sleep and are now in the middle of a dream, you make no effort to wonder how you could possibly survive being crushed under the now-silent garage that surrounds you.  You look in front of you to see what has to be a workbench under a twelve foot long, three foot thick slab of rust, tools, and empty plastic jugs that once contained black coffee.  In the center of this is a piece of cardboard with a message, deliberately marked in black ink from a blunt felt marker across the middle of the surface.

S T E P  1:  I N S T A L L  C A R B .

And so it begins.

Wednesday, November 14, 2018

Report Card Time

 If you like reading what I write about resistance wire, then you're in for a treat.  Kinda.  While some people spend years and careers working on and writing about many types of vehicles, nearly none of them ever end up writing about resistance wire.  Despite that, I somehow have managed to make the subject a recurring feature -- and I have a feeling this probably won't be the last time it comes up.

Today I'll be covering how I dealt with a segment of resistance wire that is used in the factory harness, what it does, and considerations to have in mind when planning a new harness and/or alternator upgrade.

The original harness used a run of resistance wire unrelated to the starting circuit I covered previously.  It is spec'ed to 15 Ohms, and links the wire that delivers battery voltage to the ignition switch with the wire from the alternator to the idiot light.  The functions of this wire are current delivery to the light when the ignition switch is in "RUN", and a redundant source of resistance in the event that the bulb burns out.  The reason the latter is important is because the alternator's voltage regulator isn't designed to receive full battery voltage on that pin, and can end up getting cooked if run for very long in that state.

I've personally yet to find a local source of resistance wire that doesn't include a junkyard, so I planned on using a resistor I had laying around to get the job done.  Before I could hop to it, I needed to do a little research on what resistance value I should aim for, on account of the upgraded alternator I'm using.

The factory alternator was a model 10si, which allows for a pretty simple upgrade to a CS130, which has a rated output of 105A, is usually cheaper than a 10si, and will charge at lower RPM.  Another difference appears to be the light circuit resistor value needed to keep the alt from scrambling it's insides.  I found  a million opinions on what size resistor is needed, but the Delco service manual for the CS130 clears that up a little in the section on bench testing.

"Use a resistor of any value between 35 ohm, 5 watt, and 500 ohm, 1/2 watt between battery and "L" terminal.”

So now we're looking at a 15R value in the factory harness, while the CS130 needs 35R, minimum.  Since I'm not tied to the factory harness, I decided to go ahead and change the resistor value to something inline with the Delco manual.  All I had in my immediate vision was a 50W 150R resistor, so I figured I'd cut it open and trim the resistance down a little.

This is pretty much the same as what I started with.  First thing I had to do was peel it.  To do that, I sawed the base away from the bottom, then sawed from as close to the top side as I could, through the aluminum, down to the outer edge of the black circle.  Couple of hammer taps to a cold chisel later, and I was able to strip the aluminum away from that black core of epoxy.

The epoxy was surprisingly easy to remove.  I just gently clamped it in my pliers a few times and it crumbled away.  It's worth mentioning that this didn't take much force at all, which is great in avoiding damage to the wire the epoxy covers.

After shelling the epoxy, I cut the wire away from one end of the resistor core and stripped the wire away, periodically checking the resistance of the wire still wrapped on the resistor frame.  I got tired of dealing with tiny wire after a while and called it good at 41R.  Here's what it looked like at that point:

Then I wrapped the free end back around the post at that end, dropped a dot of super glue on it to hold it in place, then stood it up in a plastic tube and potted the whole shebang in some 2 part resin I had handy.  No pictures of that, but you'll see the finished product in a future update.

So with that, I finished doing what was required to be done with the base electrical system.  I've now got all wires to start and run, so here's where things are at now:

Gotta get up in 3 hours to get back at it, so I hope you'll excuse me ending this abrup

Wednesday, November 7, 2018

Directing traffic

Work has been focused on showing electrons who's bigger.  They may have me on numbers, but I can run wire.

I had to rebuild the starting and ignition circuits in the engine bay, as I mentioned before, though I'm glad I did.  Doing that gave me the opportunity to not only clean up my harness and make it more serviceable in the future, but also let things click as far as what I had been confounding that made things a mess in the first place.

If you start making changes to a Duraspark ignition system to replace the hot aluminum lunchbox tasked with controlling spark with a moderately more reliable, but easier to replace HEI module, you might find yourself in a situation where wires start getting jumbled up pretty quick.

I'm going to explain where I was getting mixed up in a sec, but to do that I'll need to give a quick rundown of how the start and ignition circuits work in their stock form.

The Duraspark setup uses a starter relay/solenoid (pick your desired level of pedantry) that has a total of 4 posts (5, if you have a torqueflite with a functioning neutral start switch.  This fifth post just gives you a path to ground when engaging the starter, assuming you're in neutral or park.  I may cover pros and cons to this system in the future, but that's all he need to know about it here). 

The two posts on the sides are for current delivery to the starter, while the two smaller posts on the front are for control and power distribution to ignition circuits ("S" and "I", respectively).  The "S" post, when activated by current being delivered from the ignition switch in the "START" position, closes the relay and engages the starter motor, while also acting as a terminal for delivery of full battery voltage to the ignition coil until the ignition switch has been moved to a different position.

The "I" terminal is a junction that serves to provide current to ignition components after the engine has started and the ignition switch is in the "RUN"/"ON" position.  The coil used in the Duraspark system is not designed to receive full voltage from the battery outside of when the engine is starting, so current is delivered to the coil from this post via a ballast resistor or (in our case) a length of resistance wire that is bundled in the harness -- presumably to keep the rest of the harness warm and comfortable during the colder seasons and to make your life miserable if you are forced to perform a factory-correct replacement.

There are several details I'm simplifying or skimming past in that description, but they're what's important for the purposes of this post.

When you start making this modification, you'll find a ton of helpful diagrams that mostly deal with bare minimum changes to make to get rid of the lunchbox and slap in an HEI module.  This can get kinda confusing, depending on how thorough a change you intend to make.  In all cases I came across, the diagrams either left the "S" terminal disconnected, or had a note that read something to the effect of "Not used with HEI".

That's all well and good, unless you find that your car won't start.  If you're really unlucky, like me, you'll find that your car is all too happy to start, but clearly unwilling to stop, regardless of what position your ignition switch is in.  If you end up in that spot, you may just say to hell with it like I did and throw a diode inline with the "START" wire, to keep it from being energized when in "RUN".  That'll work, at least for a while, but it's not really ideal because it's another point of failure.  You know as well as I do that the point will be made when it's most problematic and a 100V 6A diode is least-readily available, unless you happen to have a time machine to make runs to a Radio Shack.

Since you'd still be screwed, because they'd be out of stock even if you did bend time and space to get to a rad sack, eliminating the diode and wiring things better than a monkey would is your best bet.  How to do that?  Simple.  After you've set your wiring up as shown by the aforementioned diagrams, just run the damn starter wire to the "S" post and stop making things difficult for yourself.  See, the reason those diagrams probably leave this out is because,

  1.  The diagrams are focused on IGNITION SYSTEM wiring and not STARTING SYSTEM wiring, and
  2.  The people drawing them up probably expected you to have a modicum of sense and be able to figure this out without much effort.
I sure showed them!

I'll post up my diagrams after confirming that my wiring actually works.  In the meantime, I need to finish up with this power distribution board I started making.  The resin should be cured by now.

Monday, October 29, 2018

Wrapped tight in my plastic jacket, I'm rotting from the inside

Putting the finishing touches on the enclosure for my HEI module required that I pull out the engine wiring harness to get an idea of what needs to be done to allow access for the connections to terminate.  As I picked at the harness, it dawned on me: I have no damn recollection of what terminates where.

I then set out to check my notes.  Given that it was a fairly hectic and somewhat emotionally taxing point in time for me when they were written, I wasn't at all surprised when I discovered that they took off for parts unknown.  "No big deal," I said to myself.  "I wired it up before, and I'll do it again."

I found that the quality of work I did when wiring the ignition circuits was a direct reflection of my state of mind.  That is to say, after I finished peeling away the multi-layer insulation armor I had made with silicon tape wrap, heat shrink, and asphalt sleeve, I was greeted by wiring that looked like pure, unmitigated crap.  From excessive heat shrink covering inexplicable butt-joints, to using marine wire not suitable for the conditions I intend to protect against, I was left dumbfounded, embarrassed, and finally relieved.  Relieved that no one else would see what kind of half-assed work I was apparently capable of.

Situations like this are good opportunities to learn, though.  When cutting out the diode that I decided should be in (instead of putting connectors on each end and securing it in a place where it could be serviced without hacking into the harness), I discovered what my lesson would be.

The improvised "butt-connector" was used to join the diode lead to the wire shown in the picture.  Despite my propensity for doing stupid things, I'm certain that the wire didn't look like a urinal penny when I smashed that joint together.  I'll skip over the details of my investigation into the cause -- which are too boring for even me to cover -- and let you know what the cause was: solder.  Specifically, the flux in the solder.

See, I prefer to double up on my wiring termination by crimping, then soldering my joints.  The reason for this is mainly to serve in preventing corrosion.  The crimp provides the mechanical joint (reminder: except for when it is, solder isn't a mechanical component!), while the solder ensures that the components in the joint maintain continuity and are sealed against moisture ingress to the stranded wire core.

When soldering these joints, you always use electrical solder.  Not acid-core plumbing solder, or whatever the hell else.  Trial and error led me to discover that the best solder to use for my wiring is actually low-temp soldering paste used to solder SMD components to circuit boards.  It comes in a syringe, you can squeeze out just as much as you need, where you need it, and you don't have to spend a hand on holding solder wire.  You can also get it to flow easily with a pocket torch, which makes it great for field repairs.  All in all, it's fantastic -- so long as you use it right.

Electrical solder uses rosin flux to strip away metal oxide layers, wet the components, and allow the fluid metal to flow.  While rosin isn't an acid flux in the way the term is used to describe flux, it is still acidic.  Because of this, best practice when building soldered circuits is to wash the board or whatever with a cleaner (alcohol or some mild solvent) to remove residual flux.  Even though I had cleaned this joint after soldering, this still happened.  What gives?!?

Well, it's pretty simple: this was a result of what was basically a cold joint, meaning I didn't cook it long enough.  The flux used in SMD paste is actually designed to neutralize once it has come up to soldering temp and stays there for a duration roughly equal to what it should take for you to do a properly-flowed solder joint.  Since I didn't let it cook long enough, the remaining flux wicked into the wire core (probably even aided by the solvent wash I gave the joint after the fact), made itself at home, and proceeded to eat everything in reach.

At this point, you may be thinking that it'll be a huge pain to fix any other joints like this, but that's not actually the case.  Like I had mentioned, the flux is supposed to strip corrosion away from the base metal when it's heated.  If you re-heat it and reflow your joint, not only does the flux remove the corrosion, but everything should be neutralized after the joint is properly done, meaning the fix is as simple as hitting it with a torch for a moment.

It's pretty refreshing to find a screw up that is actually simple to fix, for a change.  I'm going to get back to work so I can make others that are closer to my comfort zone.

Saturday, October 27, 2018

Words words words, coolant, transmission, words

I went down a rabbit hole here recently that ended with having to redo the trans cooler lines again.  The biggest problem was fan blade clearance, since the fatty wagon came equipped with electric or hydraulic fans, as opposed to the belt-drive fan that's fixed to the shaft of my water pump.  Whoops.

A bigger whoops was closely avoided when I started to take the alleged need to route through the integrated cooler in the radiator at face value.  I almost ended up plumbing things to run through it until I actually sat down and thought it through.  Here's the deal:

A lot of sources say that running the trans fluid through the integrated cooler is a necessary step to ensure the trans fluid is warmed by the coolant in the radiator.  Bypassing this cooler will have the effect of shortened life for the bands in the transmission, as a consequence of stress put on the steel through excess expansion and contraction.  Let's think this through a little bit. . .

As your engine is warming up and working to reach op-temp, your cooling system is closed. This is so you aren't constantly pulling heat away from the engine and delaying it from reaching the temperature range where it performs most efficiently.  This is why it's necessary to replace a thermostat that becomes stuck in the open position, as you'll be inviting a slew of problems if the engine runs cold for excessive periods of time (loss of power, guzzling fuel, overly-rich exhaust that can foul cats, and so on).

Once the coolant in the engine passages reach the temperature needed to allow the thermostat to open fully, coolant will pass through the thermostat opening and cycle through the cooling circuit (i.e., the radiator), allowing the engine to run while keeping it from overheating.  Generally speaking, an AMC 258 thermostat will be rated to be fully-open at 185°F, which means it will actually reach that point around 170-175°F.  Keep this in mind, as we'll be coming back to it.

While the thermostat doesn't go from fully-closed to fully-open like an electrical toggle switch, the duration of travel doesn't appear to take so long that the cooling circuit will be providing coolant of sufficient temp to warm the transmission oil during the earliest point of the engine's warmup period.  Really, until the thermostat is fully open and all coolant has cycled through to reach roughly the same temperature, the coolant in the radiator has the lowest temperature out of the entire cooling circuit.

Then there's the warmup procedure itself.

The way of warming up an engine that is least efficient and causes highest wear to an engine is to let it idle until op-temp is reached.  Best practice is to start the vehicle, let it idle for a couple minutes, then put the engine under light load until it's fully warmed.  During these first couple of minutes, the thermostat will be closed (or close enough to it to where any warm coolant that would be introduced to the radiator will have negligible effects on the radiator coolant temperature), which will be sucking away any heat in the trans fluid.  Since this will continue to be the case until the radiator coolant warms sufficiently, at what point does the overlap of the transmission oil being at a lower temp than the coolant occur?  If you have an answer for this, please post a comment to enlighten me, because I'm at a loss.

Up to this point, there's been a key detail that's gone without attention: the proper operating temperature of the transmission fluid itself.  This is where things get really confusing to me, as I'm of the understanding that the proper temperature for the oil in these torqueflites should be around 180°F, which is warmer than the temperature at which the thermostat can be expected to be fully open.  Now, an unmodified torqueflite will not be pumping fluid while in Park, so it's conceivable that you could be delivering warmed fluid to the system if you remained in Park until the point where the thermostat is fully-opened, the coolant temperature has reached equilibrium throughout the circuit, and it has transferred the heat to the transmission fluid in the integrated cooler, then put the transmission into gear.  Leaving the details of inconvenience and bad practices aside, isn't this kind of extreme heat fluctuation exactly what the cooler/"warmer" is supposed to be preventing in the first place?  If you've installed a shift kit that allows the fluid pump to be engaged while still in Park, the thermal shock in this scenario could be mitigated, though the fluid is still going to suffer from it's heat being wicked away by the coolant.

Following this reasoning, the ideal configuration seems to be one where the fluid is pumped while in Park, which will serve in getting it warm as it flows through an external cooler that has minimal airflow over it during those first couple minutes of warmup.  The best way to accomplish that would be either by having a thermostat-triggered fan mounted to the cooler, or a water pump fan with a clutch.  I have neither, so I'll be making due with being mindful in my cooler placement.

If you're still awake, you might be wondering why the hell any of this even matters in the first place.  Honestly, for most people it really doesn't.  In my case, I need to be reasonably sure that I'm not going to be causing damage to my transmission that will cause me trouble as I'm on the road, and I needed to weigh confidence levels.  See, I've already had one transmission die from the radiator cooler allowing coolant into the trans fluid circuit, so I'm already very distrustful of the design.

In doing research on the issue, I found that it transcends manufacturers, models, years, OE or aftermarket parts, and so on.  Coolant will, at some point, cause that barrier to corrode through.  That's a dead-in-the-water show stopper, right there.  Now, if you believe what some people say when they assert that the integral cooler is necessary, you'd suspect that bypassing the cooler in favor of an external unit will lead to equally calamitous results.  This may be true if you're towing tons of material through mountain passes or whatever, but in my case it doesn't seem that it's something to worry about.

A cheap radiator causing the inside of my transmission to be filled with strawberries and cream?  That's something I'll be making damn sure I eliminate as a potential reality.

Saturday, October 20, 2018

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