SECOND in a series of CJ-5 defroster problem solving tips!!!

Re: FIFTH in a series of CJ-5 defroster problem solving tips!!!

OK, I'll just go back and sit in my corner and be quiet!

 

SEVENTH in a series of CJ-5 defroster problem solving tips!!!

When time allows I'm going to attempt to draw some illustrations, shoot them with my digital camera & make them available in a future post as attachments.
This is the last post regarding the blending plate modifications. Tho OTHER PROBLEMS exist in the over all defrost system the blending plate modifications as I have described them cure about 70% percent of the defroster problem. The other problems will be discussed in the following posts.
This last modification to the blending plate tho inexpensive is also time consuming & can test the patience a little. Patience & keen observation here gentlemen, plus a tight but not to tight fit makes a REMARKABLE difference in defroster out put. Testing by "feel" the volume of forced air blowing out of the defrost penetration with the two metal spacers installed & no gasket was still impressive tho. It was the forced air that was still blowing by around the plate & exiting out the heater penetrations that convinced me to "gasket" the blending plate.
I would truly say at LEAST 95% of the forced air is being directed into my defrost chamber when the gasketed blending plate is in full defrost position, as a feather I held in front of the heater exit penetrations with the fan on full power barly showed movement.
The gasket I used was puchased at Home Depot as were all material I used in the blending plate modifications. The gasket I choose to use is manufactured by FROST KING & is labled as "Tubular Vinyl Gasket". It's dimensions are listed as 1/2" wide, 1/4" thick & 17' long. On the lower right side of the front of the package is a part number, "V18W.
This gasket I installed, started from the LOWER edge of the now mofdified ENTRANCE ramp on the blending plate. I installed this gasket on TOP of the blending plate edge that rides against the SYNTHETIC wall of the heater box. I continued up that side of the blending plate, BENDING/FORMING it around the EXIT ramp corner & continuing it across the length of the top of the MODIFIED/EXTENDED exit ramp part of the blending plate. I cut the gasket at the EXIT ramp top corner that meets the corner of the synthetic heater box material & sheet metal covering plate, leaving about a 1/32 of an inch overhang.
At this point I installed the blending plate/rod assembly & quickly realized that there was NO room to install the gasket down the other side of the blending plate that rides against the sheet metal cover plate. Installing the sheet metal cover plate & tightening it down I discovered I could not even BUDGE the blending plate rod for defrost/heater position.
I removed the blending plate assembly & using "Kentucky windage" snipped of the hollow tube part of the gasket to where it extended past the blending plate edge ABOUT 1/8th of an inch. The part of the gasket I snipped of with scissors started at the lower edge of the ENTRANCE ramp UP to the EXIT ramp corner. I snipped off NONE OF THE TUBULAR GASKET THAT MAKES CONTACT WITH THE DEFROST CHAMBER CEILING.
The round hollow tube gasket that was snipped off looked more like a "shallow C" shaped gasket now. After assembling the unit again, the blending plate rod moved from defrost to heater position "stiffly" but not totaly unreasonable. This is where I tried the "feather" test & found preciuos little air ESCAPING out the heater exit penetrations when the blending plate was in full defrost position.
I did NOT gasket the back edge of the blending plate at all as the performence of the defrost chamber had far exceded my wildest expectations. The forced air, when in full defrost position did'nt just blow out of the ONE defroster penetration, it BOILED out!!! That squirrel cage when running on high puts out some serious cfm!
I used a piece of aluminum purcased from Home Depot & called a "seam binder" with a part number of 78121 as the securing agent for the tubular gasket. Simply cut it to fit & pop rivit it over the flat tang of the tubular gasket. I used pop rivits about every inch or so to enhance the sealing/longevity capability of the gasket. The corner of where the synthetic defrost ceiling/wall meet, is where you need to take TIME to make sure it all FITS & is rivited correctly for seal. Don't get impatient here gentlemen as you need a tight seal here!
My next post will describe a MODIFICATION that will further increase the heating capability of you heater/defroster output regardless of the heat range of the thermostat you choose to use. AND, it all takes less than an hour in time & is so simple even our next president, Hillary Clinton could do it!!!
Stay tuned gentlemen as you'll like it!

 

EIGHTH in a series of CJ-5 defroster problem solving tips!!!

Seven posts to get here regarding a simple blending plate modification? And you wonder why my handle is SLOW bear? WHOOOO!
Anyways, If you followed me to this point(God bless your patience!) & have made these modifications as I described, you have undoubtably found out that your ole heater box in your pre 76' CJ-5 has some REAL potential!!!
Like REAL heat during those below zero day's? Ever wonder why the cabin in your ole J-5 stays static in temperture, even when the ole "max heat" knob is pulled all the way out? Embarressed that your new date thinks your keeping the cabin cold as a "suggestive" suggesstion?
Ole slow bear has a trick up his sleeve for any model year J-5 owner! Look under that ole dash board & a quick visual will tell you that ALL air that feeds into the heater box comes from OUTSIDE your beloved J-5. At zero degrees F. that outside air does a GREAT job of COOLING that little "radiator" inside your heater box. If you would like to quit dressing up like a Eskimo living at Point Barrow in a full force ten williwa, read on!
While that ole heater box is out of you J-5 receiving the "slow bear" treatment, add even more "DIGNITY" to your J-5 cabin by performing the following! To the right(PASSENGER SIDE) of your heater box oval shaped fresh air inlet is a flat spot. You will need to drill out two penetrations to receive two seperate ABS plumbing connections. I will get the part numbers/names & specifications of the ABS pieces needed that I purchased from Ace Hardware for this installation in the next post(s).
Next, I drilled a penetration 2.5 inches in diamiter dead center on the passenger side VERTICAL HEATER CORE CHAMBER WALL about one inch above the chambers floor. Over this penetration I installed aluminum screen mesh with pop rivits for an anti mouse barrier. This aluminum mesh was installed on the inside of the heater core chamber wall.
NOTE; this 2.5 inch penetration I found out is too SMALL in diamiter for maximum fan inhalation. I had installed the heater box with out TESTING this modification & found the fan motor "straining" with the fresh air plate in closed position & the fan motor on the high setting as it was putting out more cfm than it could bring in. Bore a three inch penetration instead! This modification allows the heated cabin air to be recirculated when the fresh air plate is in closed position. Dos'nt take a rocket scientist to calculate the increased BTU capability here regarding the cabin heat!!!
In the next post I will describe pecuiliarities with the pre 76' fiberboard duct/plenum & windsheild frame plenum.

 

NINTH in a series of CJ-5 defroster problem solving tips!!!

When the heater box was fully modified I installed it in my J-5 with the highest of expectations! I was well aware tho, from previous visualization of the fiberboard defroster duct/plenum & windsheild plenum that the heater box modifications, even the blending plate modification may well be insufficient as to cure the TOTAL JINX with the defroster problem.
The fiberbord duct/plenum's SMALL diamiter inlet penetration REALLY had me concerned even before I removed the heater box assembly for it's first visual inspection. A veteran of many a high performence carbureted induction systems I am acutly aware of ANYTHING that can pose even a minor restriction problem with air/liquid flow regarding intake manifolds/carburetors/air cleaners etc.
So with the heater box installed in my J-5 I hooked up the two inch aluminum flex pipe that I had purchased at NAPA(the same pipe used as the stove pipe between the exhaust manifold heat box & air cleaner for warm air start up) & turned the key to the "on" position. I flipped the heater motor switch to the high position & immediatly heard the strain on the fan motor, which I had previously expected due to exhaust restriction.
Forced air was DEFFINANTLY in evidence tho for the first time thru the defrost vents in the windsheild frame due to the aluminum flex pipe making a PERFECT SEAL between the defrost exhaust penetration & the receiving end of the fiberboard duct/plenum! The velocity/volume of forced air was way short of what I would have prefered, as expected due to the fiberboard duct/plenum's small intake penetration. While I was repairing the fiberboard duct/plenum, during the heater box removal/modification I was shocked at the flimsy/shody engineering/construction of this piece.
I was able to duct tape/spray glue it to a leak proof condition plus rivit on two new home made mounting attachments. I even used silicone caulk to seal the lip between the underside of the tub sheet metal & exhaust lip of the fiberboard duct/plenum. Simply put, there is just NO easy solution to increasing the diamiter of the intake penetration leading into the fiberboard duct/plenum.
GPin, a fellow forumist informed me that tho the installation of a plastic duct/plenum helped his J-5's defroster performence. He also informed me that the intake penetration was "about" the same size as the original fiberboard unit. A good assumtion may be that the plastic units, which I have seen digitals of, have a superior mating surface to the sheet metal tub surface thus causing a leak proof seal.
When i disconnected the aluminum flex duct from the fiberboard duct/plenum with the fan motor running on high, a WHOOSH of pent up air jetted from the flex tube & the fan motor quit labouring & picked up speed. The RESTRICTION here is all to OBVIOUS!!!
Worse yet, the cone shape of the fiberboard housing that inserts a inch or so into the two inch flex duct causes turbulence due to back flow around the exterior of the fiberboard cone(where else can this air go but BACK down the flex pipe!) further restricting the already restricted air flowing into the fiberboard duct/plenum's undersized penetration.
I beleive that the use of a post 75' CJ ABS duct/plenum with the OVAL shaped intake(ebay lists them by the bazillions!) is more conducive to the performence we all desire. The intake surface area of the 76' & later oval shaped duct/plenum looks to be more on par with the surface area of the defrost exhaust penetration. This would cause a "next to nothing" restriction with the same volume of air entering the windsheild plenum as is exhausted out of the defrost exhaust penetration, WHICH IS SUBSTANTIAL!!!
Tho I have not been able to get to this part yet, I'd place a dollar on your dime this is the NEXT "cure" to the defroster nightmare. Anybody with experience regarding installation of these 76' & newer abs duct/plenums in 75' & older J-5's, your information would be much in appreciation by me, & I'm sure many others!
The last of the defrost nightmares I can see, lays inside the cavernous windsheild plenum. This unrestricted & cavernous windsheild plenum is the ONLY place in the entire defrost system where one WANTS A CALIBRATED RESTRICTION! The engineer that designed this defrost system had it all bass ackwards. With these two problem area's solved me & my fellow J-5ers otta have defrosters second only to Boeing's 747!!!
I'll post more on the duct/plenum problem as I gather more info or have time to actually work on the project.

 

Hey Slow Bear!
Just want to let you know how much I appreciate this information! I was considering replacing my heater with an aftermarket unit, until I read your write-up. When I get to the point in my rebuild that it's time to install the heater, I'm going to give your suggestions a shot.
Thanks again for taking the time to share your improvement project. Rick

 

:iagree:
When I have time to work on the mods as you've lined out, I will try to take pictures of the mods described. (At least as well as I can interpret them!) Great write-up BTW!

 

You won't be unhappy Rick! I'm going to try, as soon as time allows to get some sketches drawn & add them as aeeachments in a future post. Keep your eyes open for it!!!
Slow Bear.

 

Lost Dawg; My time is at a premium right now. I'm shooting for next week end to sketch & attach the drawings to the next post, IF OVERTIME dos'nt run me ragged at work! With the drawings as a helpful visual guide you'll probably get thru with the whole project in a week end if not sooner. As I said previously...I'm not a journalist...& knowing me as I do I probably over complicated the instruction process if no other way than redundency!

 

No problemo, Amigo! I can relate to the OT... with the weather the way it was, there was no shortage. Then a 2 day jury trial this week (I was on the jury, not in front of it!R) )... I haven't had time to finish my TFI/HEI Duraspark upgrade, either. (But it's almost done!)
Look forward to seeing your next posts.
Mike

 

Your installing fuel injection on your J5?

 

No, a TFI/HEI Duraspark upgrade is where I replaced the old Delco points distro with a '80 distro from a 360 Wagoneer, used a ignition module from a 350 chevy, and the distributor cap/rotor/adapter and high output eCoil from a Ford. It appears (from everything I've researched) to be the best combo to provide a high output electronic ignition. There are threads in this forum, as well as other forums/articles that give weight to the argument. Trust me tho, there are easier upgrades . But where's the fun in doing things the easy way?
I will be posting the upgrade once it's completed and running well, so if anyone else is thinking of it they can see what was involved.
Now fuel injection, that's something for down the road, when Momma forgets what everything is costing me now!R)

 

I mistook the TPI you mentioned as Tuned port fuel injection(TPFI), sorry! I'm trying to get the scans loaded now for the blending plate mods. Should be up & running in a few minutes along with my next post.
Slow Bear.

 

Tenth in a series of CJ-5 defroster problem solving tips!!!

Gentlemen, I got the drawings ready to go & scanned them into the H/P program. Unfortuantly, I am either too "green", or my mighty Hewlett Packard PSC 1400 All-in One series printer/scanner is to complex for me to be able to figure out how to add the attachments to my post.
If any of you can offer technical assistence to me about adding the attachments to the next post I'll get them on line to you as soon as possable. These schematics are not of C.A.D. quality & NO attempt was made to put them into scale. I've got six "primitive" free hand schematics but they should be more than enough to quide you thru the process.
My heater/defrost fan quit working when in the "high" position three days ago, bringing down the defrost performence more closly to the non functional mode of previous. I suspect it is the switch it's self that is faulty. I can not find a replacement two speed switch any where's, Napa, Auto Zone, dealership or even on ebay. Any body know if the three speed switch is applicable in my case?
The switch that is in my J-5 at present is of a three position toggle switch configuration, off, low & high position. It may or may not be factory installed so input from my fellow forumist would surely be appreciated by me!
Sorry about the attachment problem, will get them on line as soon as possable!

 

Re: Tenth in a series of CJ-5 defroster problem solving tips!!!

My switch died years ago, so I installed a three position toggle switch. Looks factory but has low all the way down, off in the middle, and high in the full up position. I got it out of a parts bin at work probably 15 years ago, but I think any heavy truck headlight, mirror heat, jake brake, ect. switch would work and are pretty easy to get. I think you want the one with 6 terminals on the back. PM me and I could probably find one at work that we no longer have trucks that match the switch. Looks like you live close by!

 

Eleven in a series of CJ-5 defroster problem solving tips!!!

Well I got five of the six schematics added on as attachments before I realized there was no more room for number six. I would imagine the best course for all who are interested in the schematics is just to copy/download the five I have available as attachments. I'll keep the attachments posted for about a week then delete them so I can add attachment number six.
I will also add another schematic showing the location of the two "cabin air recirculation" vents I added, just to the passenger side of the oval shaped fresh air intake located on top of the heater box. It will also pin point the location of the 2.5" penetration I bored into the passenger side of the heater core chamber wall to increase cabin air circulation.
With that all done & posted for your viewing it will be the end of the heater/defrost box modifications part of the series. I will post again in the future, WITH DIGITALS no less, of the installation of the 78'& newer ABS defrost duct(s)/flex tube(s) & possable windsheild plenum problems. Till next week! View attachment 16006

View attachment 16007

View attachment 16008

View attachment 16009

View attachment 16010

 

Last in a series of CJ-5 defroster problem solving tips!!!

I tried to scan the last three defroster modification schematics so I could offer them as attachments for your viewing, but, my H/P scanner/printer is completly dead. I will post again AFTER I have completed the installation of the post 78 defrost ducts/plenums & any windsheild plenum modifications that I come up with along the way.
I had no idea when I posted my first post that the series would drag on this long. I had envisioned three to four posts but with out digitals this quickly got out of control. Hey, I meen it's my first attempt at trying to offer advice regarding a forum on the net. My next post will be complete from start to finish with digitals so you all can view it all in one or two posts.
Tho my printer/scanner is kaput at present, I did get the names & SKU numbers from Ace Hardware of the pieces I used for the two cabin air recirculation vents that I installed just to the passenger side of the oval shaped fresh air intake. The SKU numbers are international meening any & all Ace Hardware stores will have the items I list under the same SKU numbers.
After drilling out the two penetrations along side the fresh air intake I installed the 1.5 inch A.B.S. threaded adapters(SKU# 41810) into the penetrations. I installed them so that the threads were on the OUT SIDE of the heater box.
This was done so that I could reach thru the glove box door penetration(I removed the glove box liner for good!) so I could screw on the two A.B.S. caps(SKU# 48500) when not in use. The caps may not be needed by you, but for me they serve as an anti mouse/rodent device.
Once the two threaded adapters are in place I pushed a pair of 1.5 inch A.B.S. clean out adapters(SKU# 41808) from inside the heater core chamber into the threaded adapters that protrude into that chamber. Of course I used A.B.S. glue to secure the two pieces together. Work FAST here as the glue dry's FAST!
The penetration I drilled into the passenger side heater core chamber wall should be positioned so that the bottom of the penetration is up off the floor about an inch or so. The penetration is centered depth wise on the wall so that air coming thru this penetration & into the chamber flows right into the lower middle of the heater core.
Even with the two 1.5 inch diameter A.B.S. vents located in the ceiling of the heater core chamber, I feel this 2.5 inch penetration is to small in diameter to allow the squirrel cage to draw maximum cfm. Play it safe & drill out this penetration for a 3.0 inch diameter!
Other small mods I made include a Frost King brand solid foam weatherstrip wrap of the heater core. When I removed the ole leaky core originally, there was NO trace of a gasket left. I meen the core just fit in loosly. This weather strip I used as a gasket(sorry no SKU#) was purchased at Home Depot & is light grey in color & comes in a roll. It's dimensions are ABOUT one to one & a quarter inch in width & 1/8th of an inch thick. I used a double wrap around the core & it fit VERY snug into place.
This serves two purposes, one of which is to force all incoming air to go thru the core fins for max temperture, the other is to stop heater core movement when driving. This step ELIMINATED THE RATTLE NOISE FROM THE HEATER BOX while driving. I also gasketed the FRESH AIR intake plate with an inexpensive self adhering open cell weatherstrip. I purchased this weatherstrip from Ace Hardware. It is listed as poly foam & it's dimensions are listed as 3/16" thick & 3/8" wide. It has a item or SKU# of 51272 on the upper left of the package.
In retrospect, I don't even know if it pays to keep the fresh air box/assembly. I meen with my Kayliner top & non carpeted floor boards I got enough "fresh air" coming thru to keep even the EPA/OSHA happy!!! With a new Bestop & a floor liner/carpet installed it might come in handy tho. If you do not want the fresh air option you can disconect the duct from the heater box. This oval shapped penetration has enough "surface area" to allow the squirrel cage to function at max capability, plus you dont need to drill out the additional penetrations I listed above as the oval penetration would now be your cabin air recirculation vent.
I did install aluminum screen mesh over the penetration on the heater core chamber wall. Tho VERY close to the passenger side sheet metal when installed, I did this not only for rodent protection but insect protection as well. Were LOADED with yellow jackets, wasps & the dreaded "white eyed(bald faced!) Hornets out here. If these bald faced hornets got any bigger I'd be bringing em down with a scatter gun! I really don't want em nesting in my J5 & the aluminum mesh is cheap protection.
Once again, sorry for the lack of the last three attachments. I will post them with the digitals of the defrost duct(s)/windsheild plenum project when I can get to that project.
SB

 

Am I the only one getting an invalid attachment message when I try to download the five that are listed? My impression is that these attachments are good, and we'll get three more at a later time. Is this correct? :?

 

Sparky, The attachments are indeed invalid. I have the whole series, including the five attached drawings, modified (only to clean up) and saved as a Word Document if that would help until SlowBear reposts his info...
Mike