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I've read numerous posts on other boards of people raving about how great the 3.8L Taurus electric fan is.
So I picked one up for $25.
Installed it. Played with it. Hooked up two 30amp relays in parallel to switch it on, and used a manual override under the dash, and a keyed-on temperature switch to automatically operate the fan.
I can report that it did an fine job cooling my built 392 around town, and did OK for the first hundred or so miles of mostly flat towing.
It didn't do well in Yellowstone on long slow climbs, or Wyoming on the other side of the park.
This, with a freshly recored 3-row rad, RS 180 stat.
At Willy C's, I removed the air conditioning and auto trans coolers from the grille area (AC doesn't work, and the front clip is from an auto truck, now installed on my stick truck).
Don't think that made much improvement, but propping the rear of the hood open did seem to help. I did this by adjusting the hood hinges on the '74 pickup as far as they'd go, pushing the rear of the hood UP.
Definitely improved hot air flow out of the engine bay.
Still liked to get hot climbing hills with 90-100 deg ambient temps.
I killed the 392 on the second day, just before RMIHR.. after RMIHR we swapped in a stock 392.
The Taurus (and cocked-open hood) did MUCH better with the stock motor, with similar temps.
I only stopped once to let the engine cool, pulling Fremont pass into Leadville, CO.
Otherwise, the motor ran 200-220-ish (lost my mechanical gauge when swapping motors) at 65-75mph (3000 to 3500rpm) at 14-15,000lbs with ambient temps between 90-105 (Moab, UT was in the "low 100s".. )pulling grades and on the flats for 900 miles through the Rockies.
I need to get the correct tranny mount into my truck, and then I'll look at using the deep 74/75 shroud I have and put my clutch fan back on.
I might keep the Taurus fan at the same time, for use when idling in traffic, or for cool-down at fuel stops, but I think I need to go back to the mechanical for primary cooling purposes.
I don't want to put the fan in front of the radiator (pusher), because I need the room for the A/C stuff.. and with the 74/75 engine set-back, I can JUST get the Taurus fan AND clutch fan in place.
If I upgrade to a 4-row, I'll have to have the mounting flanges offset to put the rad forward a bit, to keep the clutch from hitting the electric fan motor.
Note that the Taurus draws ~40amps when running.. I upgraded to a Delco 12si 94amp alt at the same time, and 4-gauge charge wire, just to make sure I could keep up.:D 8/5 --------------
Some progress
Finally had a moment to pull the driver's side head from the 392 last night.
The head gasket seems to be "OK" to my untrained eye. It tore just a
little when removing the head, and the headgasket and dowels both came off
with the head, leaving just a spot or two near water jackets of torn
gasket.
I haven't pulled the gasket from the head yet. I need to get the digi-cam and get pictures of what I have thus far.
On the head, the front chamber (#1) looks a little "drier" or cleaner than
#3/5, which look dull and carbon'd, while #7 has a streak of "wet" across
both valves.
It could be coolant from tearing it down, though the stand leans with the
front down. #7 and #3 had coolant in them, with less on #1/#5, but those
were closer to TDC, too.
No obvious signs on the head of the valves hitting anything or being
nicked or anything else.
On to the block.
No obvious (to me) signs of headgasket failure. I'll get pictures.
All 4 pistons are carboned. #1 is at TDC. The other three all have a
black carbon ring about 3/8" thick (going Up/down the bore), and then
another ring, about 3/8", that's discolored ("gold"-ish color), before
going to the rest of the bore, which is roughly uniform.
I see little black lines in this discolored area, that might be carbon
deposits. I see some in each bore I can see. #7 has a couple lines at 6
o'clock, within 1/2" "grouping" - I presume these lines are from the top
ring gap, and it's walked a little. The other bores have a slight
variance in the location of the lines as well.
Nothing looks obviously scratched to me, and there's no hole (visible) in
the #7 piston.
I still need to drain and pull the pan, and then see about pulling the #7
piston out, for a closer inspection.
But thus far nothing LOOKS bad.. at least, not like my spun con-rod did
("Black.. hmmm..")
8/6 -------------
Here's the brain-dead move of the month..
When rebuilding the 304C race motor over the winter, I was disassembling each lifter, and along the way lost one of the spring-clips that holds the "cup" into the lifter.
Since I had a full set of NEW lifters for the 392, I borrowed a spring clip from one of the set, to put the racer together. To remind me, I turned the "cup" part of the plunger assembly upside down, so I'd KNOW not to just throw this lifter in when I got to the 392.
Apparently, I remembered to put the clip in, but somehow completely blew off flipping the "cup" back over.
This is why the "left" #7 lifter reflects the flash so well. IT'S FLAT ON TOP.
I had the same theory as (Ed Sohm on the IHC Digest, and others) for the first day or five about the problem being valve/valve-train related, but just couldn't see how it could continue to be valvetrain.. but it sure made sense, since it seemed to work fine until I pulled the rocker shaft off and put it back on.
So I have two theories thus far.
1) Somehow I managed to get the pushrod n' such installed in such a manner that the valve actually worked when I left home, but on the roadside in Colorado I couldn't reproduce such luck.
2) It didn't matter what I did, that lifter just took a while (900 miles?) to pump up, and when it did, it kept the exhaust valve open (since the lifter is "taller" than it should be)
Either way, it seemed to not have a vacuum issue until after the pushrods broke. It never audibly BOUNCED before then, so I'm leaning towards "I just didn't put it back in the right magic way.."
I remember trying to put that pushrod back in, and I couldn't "feel" the lifter like all of the others.. just felt "off" and "vague".. I wanted to look at the lifter, or pull it, and see why it felt so funny, but the brake booster was in my way, and of course once we pulled the engine out, we'd already decided to SWAP IT, not rebuild it before heading for home.
The pictures of the carbon deposits here and there, and the light "scratches" - which I think are just thin carbon lines left by the top ring - were mostly taken before Michelle started asking questions.. "Why are the pistons at different heights?" "See the other crank over there, with the offset journals.. blah blah.. " "What are these?" "Those are lifters." "Why does this one look different?" "Hmm.. uhh.. D'OH!.. Let's take a look..."
So.. I think I'll clean everything back up, try and re-RightStuff the valley and everything, and put the engine back together.
I still have one or two extra head gaskets (same brand), should have one more tappet gasket.
First I'll CC the #7 chamber and then let it sit overnight and check for any leak-down that might indicate a bent valve or poor valve seating, just in case it hit - though I see no sign.
Motor won't go back in for a while though. I have a shop to get ready for this winter (as in, paint floor, wire, bring gas/electric to it, insulate, sheetrock, etc) and a wedding in October, right before hunting season.. etc. Good news is, my front end might be ready by then (only a year late..) and the new shop should be big enough to put the Travelette inside and work on it.
I have the new-to-me 5spd w/ PTO to install at the same time, so the front clip'll come off and I'll swing it all in together.
-Tom