MCI 102-C3 coach to RV - Engine Bay

[CarterKraft]

On to the second Dart PWM controller. Accidentally hooked up the first controller to the wrong battery posts last night. POW! Couldn't find any evidence of anything being burnt besides the cable lug, but the controller smells burnt and isn't cooperating.

Running smooth on the second controller. Wife and I went over the amperage and adjustments. The top speed current draw will still drop to 1 amp and if crank the max speed adjuster all the way up, but doing so causes the speed pot to be more an on/off switch. Backing the max speed down a little causes the speed pot to become stable and the top speed current draw floats between 9 and 12 amps which.

All in all, everything looks good to use two larger fans. I've got to decided on what to connect the radiator cores with so I can start slapping all this stuff in.

Something doesn't sound right there.
A normal Spal cooling fan draws much more than 9-12 amps.
Is this with no fan blade or something?

 

[JNHEscher]

Something doesn't sound right there.
A normal Spal cooling fan draws much more than 9-12 amps.
Is this with no fan blade or something?

Measured with a fan attached and all eight blades. Running on 24 volts...ish.

It's weird as hell. I've checked it at least a couple dozen times now, which is reaching the definition of insanity because I get the same result every time.

My current guess is that this has mostly to do with fan speed and blade type. This wouldn't be considered cavitation, but perhaps the aerodynamic equivalent. I can feel pressure being emitted from the inner and outer diameters of the fan. Per Multi-Wing's explanation, this is what an airfoil blade does - Airfoil Fan Blades - Multi-Wing America. Hoverhawk being a hovercraft business, it makes sense that they choose the airfoil blade. I'm wondering if there's a point in the RPM band that the blade length, pitch, and type cause it to become "neutral" and that the neutral point is right at my max RPM allowed by the controller. My tach battery died so I haven't been able to check the RPM with the fan attached yet.

From the looks of it, I need the PressureMAX blades - PressureMAX High Pressure Fan - Multi-Wing America
The airfoil blades seem to be designed with energy efficiency in mind to move a craft across water.

From an electrical standpoint, only the fact that this is running on pulse width modulation makes some sense. I looked back at the numbers I had jotted down when I hooked this directly to batteries. They were well over the rating of the motor. I'll see about getting my tach going so I can graph this for a better visual. It's still really odd how the current draw peaks and tanks within the last increase of RPM.

Edit: Forgot to add that we tested the neutral point idea. Nothing scientific. Just held a sheet of plywood a couple inches from the fan running full speed to see if the resistance changed the pressure enough to change the current draw. A difference of a 1 amp increase is all it made.

 

[CarterKraft]

Measured with a fan attached and all eight blades. Running on 24 volts...ish.

It's weird as hell. I've checked it at least a couple dozen times now, which is reaching the definition of insanity because I get the same result every time.

My current guess is that this has mostly to do with fan speed and blade type. This wouldn't be considered cavitation, but perhaps the aerodynamic equivalent. I can feel pressure being emitted from the inner and outer diameters of the fan. Per Multi-Wing's explanation, this is what an airfoil blade does - Airfoil Fan Blades - Multi-Wing America. Hoverhawk being a hovercraft business, it makes sense that they choose the airfoil blade. I'm wondering if there's a point in the RPM band that the blade length, pitch, and type cause it to become "neutral" and that the neutral point is right at my max RPM allowed by the controller. My tach battery died so I haven't been able to check the RPM with the fan attached yet.

From the looks of it, I need the PressureMAX blades - PressureMAX High Pressure Fan - Multi-Wing America
The airfoil blades seem to be designed with energy efficiency in mind to move a craft across water.

From an electrical standpoint, only the fact that this is running on pulse width modulation makes some sense. I looked back at the numbers I had jotted down when I hooked this directly to batteries. They were well over the rating of the motor. I'll see about getting my tach going so I can graph this for a better visual. It's still really odd how the current draw peaks and tanks within the last increase of RPM.

Edit: Forgot to add that we tested the neutral point idea. Nothing scientific. Just held a sheet of plywood a couple inches from the fan running full speed to see if the resistance changed the pressure enough to change the current draw. A difference of a 1 amp increase is all it made.

Are you exceeding the amp draw of the BMS in the battery?
skip the controller for the full power tests, full power is full power.

 

[JNHEscher]

Are you exceeding the amp draw of the BMS in the battery?
skip the controller for the full power tests, full power is full power.

Not that I can tell. BMS allows a continuous 100 amps. I did full power tests before on the 8D batteries. Might give it another go with the lithium batteries and new clamp meter.

 

[JNHEscher]

My post on the fan motor mystery with video. The electrical sub gets so little traffic.

DC motor current draw

Curious what others' thoughts are on the amp readings of what I'm setting up as a radiator fan. I put the component descriptions in the video. Didn't bother with showing the fan motion in the video as all you would see is a stroboscopic effect. You can hear what the motor and fan are doing...

irate4x4.com

 

[JNHEscher]

Paid for two of these buggers. Almost exactly what I was after. The alu blades might be a little heavy.

 

[JNHEscher]

Back on machining the pump adapter. Had to swap the 3" chuck on to hold the pilot and face the other side. The chuck jaws hold stuff so out of round that I can't bore the adapter out. Now I remember why I took that thing off and swapped the 4" chuck on right away.

 

[JNHEscher]

Swapping on the new studs from Diesel Pro. I was stoked to see that they're plated. I did see that the stud holes protrude right into the water jacket. The studs come with thread sealer on them, although it doesn't feel very snug.

 

[JNHEscher]

Still lacking a few parts to finish up the blast cabinet install. Went at it anyway. Turb parts glass blasted. I'll be painting them in the same cabinet. Can't wait to see the Glacier Black on them. I think I'll blast the compressor housings and paint them white. I absolutely hate the silver paint that machine shops always use on aluminum parts. Bare alu looks better than liquid sprinkles.

 

[JNHEscher]

Blast/paint cabinet is working out well. Have to clean out the turb parts and mask them off. Pulled out my Sata to lay the paint on these.

 

[JNHEscher]

Got some fittings in for the radiator ports to mess with. The nut threads are not as large in diameter as the 1.75"-12 threads on the nuts of the other fitting I had considered using. I need to somehow measure the internal threads with what tools I have on hand. Clay was the first thing I tried. It worked surprisingly well, but is still too rough to get a good measurement. As far as I can tell, it is 1.625"-12. Gotta keep looking for my thread pitch gauges.

Edit: I should add that this fitting is a Matco-Norca NT-100 tailpiece.

 

[Provience]

can you make the clay solid and thread/screw the nut onto the clay stud fully, then unscrew it? might need to lube the nut with some soap to keep it from sticking, but a gentle taper lead in and tight packed clay should take a pretty good thread and be more accurate than trying to reform it from a hollow piece.

also, use a ruler once you have the threads formed on the clay rod, set the nut on and count however many full turns make an easy to count ratio, then just do the math to get turns per inch.

 

[JNHEscher]

can you make the clay solid and thread/screw the nut onto the clay stud fully, then unscrew it? might need to lube the nut with some soap to keep it from sticking, but a gentle taper lead in and tight packed clay should take a pretty good thread and be more accurate than trying to reform it from a hollow piece.

also, use a ruler once you have the threads formed on the clay rod, set the nut on and count however many full turns make an easy to count ratio, then just do the math to get turns per inch.

I may try that. Tried packing a solid chunk in today with some dish soap to keep it from sticking. Didn't work all that well. Maybe like you suggested, form a solid rod and then I can turn it gently in the lathe to size so it's as accurate to start with as possible.

I haven't used my thread gauges in years. Almost always have a dial caliper with me and that's what always use to measure thread diameters and pitches, but I can't fit the caliper inside the nut or correctly measure what diameter rod to use. I saw my thread gauges maybe last week and can't remember where

 

[bgaidan]

If you're going to fire up the lathe, why not just turn a scrap 1.625-12 thread and see how it fits?

 

[JNHEscher]

If you're going to fire up the lathe, why not just turn a scrap 1.625-12 thread and see how it fits?

Mostly because of expense and timing. Have to order the tooling which won't get here before we leave for Missouri. Stoner Enterprises has the bar in several metals in stock. I'll see about grabbing some cheap aluminum in the next few days. Wanted to try copying the threads with stuff I have sitting around before I spend the rest of my dough on the real parts.

Edit: Or better yet. Found somebody with the steam valves - 1" FIP x 1" MIP Union Steam Angle Radiator Valve 82647083837 | eBay
About the same price as me making test threads on bar and I get another tailpiece with the purchase.

 

[JNHEscher]

Machined the NT-100 into what I'm after. These fittings have more meat on them than the 1-TPKXL.

Left: 1-TPKXL with the FNPT threads bored out. Now $24 each through Supply House
Right: NT-100, stock nut, one stock tail, and the tail that I just faced and bored. $4.94 each at Mr. Supply.

I'm figuring out manifold logs for the end of each radiator core stack. The NT-100's will thread into the logs and I'll machine the brass bar to fit onto the radiator core ports for the NT-100 nut to thread onto. Square-cut o-rings for sealing. This assembly will allow me to slip any of the cores out for repair or replacement without having to disassemble the whole thing. Overkill as always.

I thought about using cord grips to slip onto the radiator ports so that I wouldn't have to modify the cores in any way. A total of 24 ports will be on this. Going with the NT-100's is the most cost-effective route I could come up with.

 

[CarterKraft]

Machined the NT-100 into what I'm after. These fittings have more meat on them than the 1-TPKXL.

Left: 1-TPKXL with the FNPT threads bored out. Now $24 each through Supply House
Right: NT-100, stock nut, one stock tail, and the tail that I just faced and bored. $4.94 each at Mr. Supply.

I'm figuring out manifold logs for the end of each radiator core stack. The NT-100's will thread into the logs and I'll machine the brass bar to fit onto the radiator core ports for the NT-100 nut to thread onto. Square-cut o-rings for sealing. This assembly will allow me to slip any of the cores out for repair or replacement without having to disassemble the whole thing. Overkill as always.

I thought about using cord grips to slip onto the radiator ports so that I wouldn't have to modify the cores in any way. A total of 24 ports will be on this. Going with the NT-100's is the most cost-effective route I could come up with.

Have you thought about just using the OEM seals and having logs laser cut to mimic the original mounting system.
I think it would be much simpler for you to replicate with less leak sources, it would also be more robust with vibration dampened cores.

As usual I am your Debbie Downer lol

 

[JNHEscher]

Have you thought about just using the OEM seals and having logs laser cut to mimic the original mounting system.
I think it would be much simpler for you to replicate with less leak sources, it would also be more robust with vibration dampened cores.

As usual I am your Debbie Downer lol

You're no Debbie Downer at all, man. One of the most resourceful dudes on my threads, honestly.

I've been tempted to use to OE gaskets many times. They're pretty cheap and available. What I'm trying to accomplish with this, though, is the ability to unscrew the nuts at the ends of one core and pull it straight out without having to separate the logs from all six cores to access just one core. The flat face sealing of the unions make that possible. I think the worst of it is having to silver solder some threaded bungs onto the cores for the unions to thread to. Sometimes I have make it hard on myself now in order to make it easier on myself later on.

I was throwing some pipe fittings into Fusion the other night to figure out sizes, quantities, and costs. 2x2x1 tees, 2" nips, etc. Didn't seem like the most ideal way to go about it. I'm going to sketch up some logs for Precision Laser Tube Las Vegas to cut ports in that I can weld 1" NPT bungs to for the NT-100's to thread into.

Edit: Meant to add the pic of the cast fittings.

 

[JNHEscher]

Somebody else found the Detroit paperwork that I had hunted for many times. I need to edit one of the beginning posts of each of the threads with a full list of tech specs for quick reference. Putting another slice of it here for now.

8V92TA requires 22,000btu of heat dissapation. The water pump flow 180gpm at above 2,000rpm.

 

[JNHEscher]

Ran the other seven pieces through the machine and ordered a radiator valve for threads to measure.

 

[JNHEscher]

Confirmed. 1-5/8"x12. Picked up a 6" section of 1-5/8" brass bar from Stoner Enterprises while in town today.

I need to order some lathe goodies. A thread cutting tool, maybe a steady rest, and possibly a chuck. I keep wondering if I should try something like a hole saw on this to cut the ID of the fittings to their rough dimension while coring out a smaller bar from the middle so that I'm not turning so much material into swarf. About 1-3/8" diameter will be drilled out of the bar otherwise. I could make quite a few more pieces of something with that much left over.

 

[bgaidan]

Trepanning is the word you're looking for. You can make a tool from HSS if you have a piece laying around. Hole saw or annular cutter may work if you're not going super deep.

 

[JNHEscher]

Trepanning is the word you're looking for. You can make a tool from HSS if you have a piece laying around. Hole saw or annular cutter may work if you're not going super deep.

Yup yup. I knew it as face parting. I do have several pieces of HSS, but those won't go deep. I found an annular cutter that'll go 3" deep. I'll have to turn the shank down to a diameter that will fit in my tailstock chuck. Gonna give it a try. I'm making mountains of swarf lately and it all goes in the trash. Might as well try to get some solid, usable chunks out of the waste.

 

[bgaidan]

Definitely worth it on higher priced stock if you can do it quickly and efficiently. Annular will be way better than a hole saw in brass. Just keep your ear plugs handy! I have piles of random HSS if you need anything weird or want to try trepanning. Probably even have a few already ground to close to the right profile.

Which piece are you actually going to make from that pic?

 

[JNHEscher]

Definitely worth it on higher priced stock if you can do it quickly and efficiently. Annular will be way better than a hole saw in brass. Just keep your ear plugs handy! I have piles of random HSS if you need anything weird or want to try trepanning. Probably even have a few already ground to close to the right profile.

Which piece are you actually going to make from that pic?

Did a quickie sketch. The fitting will basically be a threaded sleeve that slips onto the rad core ends.

Trepanning is doable if I part off one fitting at a time. Thread the whole bar, make the OD parting cuts for the width of each sleeve, face part a sleeve, back the carriage off to remove the sleeve, then face part each remaining sleeve off of the bar core. I could definitely face part each sleeve to the final ID, but these radiator core ports vary in size a little.

I'm searching some more to see if there's any brass pipe or fitting that the sleeve could be made from. Still nothing that isn't some combination of too small of an OD, too large of an ID, or too thin of a length.

 

[bgaidan]

If you can find an annular cutter that gets you close, it wouldn't be so bad to just check the parted off piece back in a 3 jaw later and skim the ID to size. If your chuck through hole is smaller than your bore size, make a spider out of aluminum to keep it square space the part off the face of the chuck to give you enough room to bore it.

Hell, you could even take a scrap piece of al and thread a shallow blind hole to thread that part in while your bore it out.

 

[JNHEscher]

Parts are masked. I picked up a box of little gen II PPS cups, a gen II adapter for my Sata 4000, and some fresh tape last week. The humidity is nice and low in the mid afternoon every day. I'm going to go ahead and order one more bottle of Cerakote, just so that I know I have enough. Two coats on this much surface area is probably stretching 16 ounces.

 

[JNHEscher]

Hot side parts are coated. Did two coats on all six parts with only 2 ounces. This stuff is interesting and awesome. Sprayed at 30psi with a 1.3mm tip restricted and and medium fan.

Being used to spraying cars, I was hesitant to start spraying with only one pint on hand. Guess I've got plenty for other parts. I could almost spray the entire engine with what I have now.

 

[JNHEscher]

Have to let the paint set up more before I proceed any further. Looking pretty sweet otherwise. Might have to touch up a spot or two due to very little adhesion after 24 hours.

 

[JNHEscher]

A friend got the ball rolling on some exhaust manifold bucks. One side is being printed as I type this. They took the port inserts off the printer bed to bring to me for test fitment. All I had to do was file a little of the roughness down to a smooth taper to get one to tap in nice and snug.