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MCI 102-C3 coach to RV - Engine Bay

I always apply RTV in a manner that won't squeeze into any engine cavity. I've had to scrape and clean a ton of it out of engines that other people worked on using way more sealant than should have used and clogged stuff like oil pumps and coolant ports.

Once we get the bus up to our house in Colorado Springs I might start pulling parts off to modify for O-rings. It's always really nice to have a reusable gasket that stays in place and completely seals up. Probably doing the same for another Detroit two-stroke. I was up in Springs helping a friend on his 1957 GMC PD4104 that has a 6V92TA swapped in it and he and I got to talking about all the oil leaks and we both want our engines tight.
 
Well, that won't work. Ports are only about 1/8". It'd take like 15 of these to make a bypass. So, an external pilot valve will be the way to go in conjunction with this thermo valve.

428.jpg
 
aczlan said,
JNHEscher said:
Well, that won't work. Ports are only about 1/8". It'd take like 15 of these to make a bypass. So, an external pilot valve will be the way to go in conjunction with this thermo valve.​
Found this PDF from Alpine Coach: http://www.alpinecoachassociation.com/chassis/Radiator FanMotor Sauer-Sundstrand c.1996.pdf
It looks to be the Sauer-Sundstrand book on sizing the components for the system and it includes part numbers for motors with the control valves, a standalone electric or hydraulic control valve and pumps.

Aaron Z
 
[486] said,
Mr. Mindless said:
Finally, something more expensive than Loctite thread locker :laughing:

Even so I may have to give that a try.​
they buy it from the winzer guy at work, so I'd bet it's like $40 a tube

it is worth it though
orange shit that gets hard real good
ETA: as said, the tube can be left open and it stays good and goopy for years and years now
 
aczlan said,
[486] said:
they buy it from the winzer guy at work, so I'd bet it's like $40 a tube

it is worth it though
orange shit that gets hard real good
ETA: as said, the tube can be left open and it stays good and goopy for years and years now​
Chrysler has their own anaerobic sealer as well, got a tube back when we had a Grand Caravan that had a transmission cover rust out and 4+ years later, its still not hardened.

Aaron Z
 
Back on. That was a bitch to do in a hurry when a winter storm hit just as soon as I stuck Permatex on the plate. Had snow and dirt blowing in on me and the open gear case. Letting the sealant tack up a bit before I torque it all down.

429.jpg
 
aczlan said:
Found this PDF from Alpine Coach: http://www.alpinecoachassociation.com/chassis/Radiator FanMotor Sauer-Sundstrand c.1996.pdf
It looks to be the Sauer-Sundstrand book on sizing the components for the system and it includes part numbers for motors with the control valves, a standalone electric or hydraulic control valve and pumps.

Aaron Z​
This is perfect. I really needed all the info presented here. Pilot-operated valve is definitely the way to go. The manual explains all the operations within it which includes a maximum fan speed control by limiting pressure. I was wanting the fans to be able to spin at full speed without having to wind up the engine. This way, I can size the pump to supply plenty of flow to do so.

Fan HP draw is as you stated. 16.1-16.3 HP at 2500 RPM. I didn't know if cross multiplication was all it took or not.
 
aczlan said,
JNHEscher said:
Eh? https://www.surpluscenter.com/Hydrau...9-7073-100.axd
Looks like I can get about 19HP out of that motor and it has a relief valve for coasting when engine/pump gets shut off.​
That should work up to 3000RPM and 22.7HP with 13GPM flow at 3000PSI.
JNHEscher said:
Next up would be this - https://www.surpluscenter.com/Hydrau...66-9-12157.axd
I'd have to pull up Parker's catalog info to find out more about it. Serious output, though.​
No outboard bearing though, so you would need to setup a bearing between the motor and the fan (possibly a thrust bearing as well?).

Aaron Z
 
No matter which motor I use, I think I'll be mounting the fans on a length of shaft that passes through the rads and rides on pillow bearings for axial stability. The motors don't offer much shaft for the fan hubs to ride on unless I get a K shaft. 3/4" is the minimum shaft size for the fans and I'll probably use jaw couplers. I have to ask how much shaft length the fan hubs occupy.
Cross motor specs - https://crossmfg.com/assets/images/s...and-Motors.pdf

Next up is figuring system pressure. I'm assuming running motors in series stacks the HP and increases pressure between the pump and first motor. Don't wanna exceed max pressure. If I run only one pump, T-ing pump output between pairs of series motors sounds like the better way to go, but fan speed between pairs could differentiate. Two pumps would be great if I can come up with a stackable pair with sufficient output. I have to call Cross about backpressure on the motors in series. Shouldn't be any problem, but their specs sheet doesn't mention it.
 
Throwing this in here in case anyone else is browsing pumps for this project as it has appeared that a few gentlemen know right where to look for some items that I scour profusely for. The pump(s) will have to be counter-clockwise rotation when view from the shaft end. This picture shows the gear train rotation at the flywheel end. The blower drive is the smallest gear at the very top.


2913178-690c8e622f6379bda18edc767e9aa980.jpg
 
Been poking around a rotary flow dividers for a few days and can't up with anything without having to order from overseas or make a business account aside from this one from Surplus Center - https://www.surpluscenter.com/Brands...E-9-8405-2.axd
For 2,500 fan RPM, the 1.0 cu.in. motors need 10.8 GPM. The divider knocks the fan RPM down to 2,100 which is about 14 HP with blade pitch at 50 degrees. The 0.75 cu.in. motors would spin up to 2,800 RPM.
 
Disregarding the thermostatic and pilot valving, here's what I have going on for plumbing options.

Upper left is the most straightforward, but I'm not sure how much pressure that will put against the pump to push four motors in series. Each downstream motor would receive heat from the upstream motor and I'm sure a pressure drop from each motor would effect the next motor.

Lower left is two motor circuits with a flow divider for series-parallel.

Right is two stacked pumps each running a pair of series motors.

I have the GPM listed going to each motor circuit. Thoughts on running all four motors in series? I'd like to go that route, but don't want to smoke the pump or motors doing so.

431.jpg
 
aczlan said:
From what I have found (mostly from discussions like: https://talk.newagtalk.com/forums/th...splayType=flat ) it shouldn't hurt the motors to run them in series as long as you control your heat (hydraulic cooler on the way back into the tank?), and you will be better off if you can run case drains on all of the motors that run back to the tank.


Aaron Z​
I'm mainly concerned about excess heat from the pressure between the pump and first motor. Seems to me that pressure would be quite high with one pump pushing four motors drawing about 16 HP each. That is, if the blade pitch is set to 50 degrees. I'll definitely have an oil cooler on the return lines. The Cross motors have drains that have to be ported if the back pressure is over 250 psi. Easy enough to go with the simpler series circuit and start testing from there.

I don't think any of these parts will be ordered until we're moved to the new house. Wife is watching all spending until after closing. Until then, I will have compiled another expensive parts list for her to rant about lol.
 
aczlan said,
JNHEscher said:
I'm mainly concerned about excess heat from the pressure between the pump and first motor. Seems to me that pressure would be quite high with one pump pushing four motors drawing about 11 HP each. That is, if the blade pitch is set to 50 degrees. I'll definitely have an oil cooler on the return lines. The Cross motors have drains that have to be ported if the back pressure is over 250 psi. Easy enough to go with the simpler series circuit and start testing from there.

I don't think any of these parts will be ordered until we're moved to the new house. Wife is watching all spending until after closing. Until then, I will have compiled another expensive parts list for her to rant about lol.​
If you need to extract 44HP from the circuit at the usual 80% efficiency (running 4 x 11HP fans), you will need 55HP from the engine. That works out to 30GPM at 2830PSI (per the Surplus Center calculator).

So, if you size your pump to make 30GPM (with a single pump, 15GPM with dual pumps) and at least 2830PSI at whatever RPM you are looking at, and size your motors to be able to handle either 30GPM if running 4 fans in series, or 15GPM if running 2 sets of 2 fans (with dual pumps, or a flow divider) at at least 2830PSI continuous it should be fine.

As long as the motors are bi-directional and have a case drain, they should be fine with as much backpressure as forward pressure.

I cant remember, how many RPMs will the pump need to handle?

Aaron Z
 
At average cruising speed, the pump will see around 4,000 RPM. At redline, the pump will see around 5,000 RPM. At idle, it should see around 1,300 RPM.

I always forget about SC's calculators. I'll punch in the numbers there, but I'm a tad lost on the 30 GPM with all motors in a single series run. The motors would have to spinning pretty damn fast to consume that much volume, wouldn't they?

Edit: Just realized I made a typo last night saying the motors would draw about 11 HP each. At 2,500 RPM, the fans take the 16.2 HP each. That comes up to about 78 engine HP.
 
vetteboy79 said,

Just watching some of the numbers creep here...

Is that geartrain/coupler/keyway/shaft/etc sized to deliver an additional 55 HP from that point on the engine? Seems rather large...at that point I'm thinking of the additional gear separation forces acting on the bearing of the blower assembly.

Also that's about twice as much as any of the pumps linked so far...granted some can be stacked, but that single connection to the drive gear still needs to deliver the total combined HP of the pumps.

A typical 50 HP electric motor has a 1-7/8" (3600 RPM) to 2-1/8" (1800 RPM) shaft diameter, for comparison.
 
[486] said,
vetteboy79 said:
A typical 50 HP electric motor has a 1-7/8" (3600 RPM) to 2-1/8" (1800 RPM) shaft diameter, for comparison.​
and a typical 200hp automotive engine's trans input shaft is 1-1/8"

thinking it has to do with hardened steel splined coupling rather than soft steel single keyway
 
vetteboy79 said,
[486] said:
and a typical 200hp automotive engine's trans input shaft is 1-1/8"

thinking it has to do with hardened steel splined coupling rather than soft steel single keyway​
It's partially that (note that the pump drive in this case is just that single keyway), and also the fact that automotive stuff in general is ridiculously undersized compared to industrial stuff.

You can probably count on two hands the number of times that a typical 200 HP auto engine actually develops 200 HP in its lifetime, and even then for any extended period of time. Also by nature (and unlike an electric motor) you can't just turn it on and instantly get hammered with 3x your rated torque.
 
As stated before, I'm not opposed to boring the coupler to fit a larger shaft. The blower drive assembly is pretty stout. Accessory pump drive might need some help. IMO, keyways aren't for anything more powerful than a lawnmower engine and I don't think any of the coupler is hardened. Had to put it in there so I could measure it for pump shaft fitment ideas. There looks to be a lot more splined shaft pumps out there which would be sweet to install here. Stackable is preferred. Dunno where to find splined, stackable pumps at.

The HP ratings I'm getting figured out are for maximum output (Thirty two 50 degree pitched fan blades spinning at 2,500). I haven't a clue yet if I really need the blades titled that hard or the hubs spinning that fast. Gotta make sure everything can handle it all, ya know? I might run the numbers on the power steering pump for comparison since it's on an identical drive but spinning counter-clockwise.
 
aczlan said,
JNHEscher said:
At average cruising speed, the pump will see around 4,000 RPM. At redline, the pump will see around 5,000 RPM. At idle, it should see around 1,300 RPM.
I always forget about SC's calculators. I'll punch in the numbers there, but I'm a tad lost on the 30 GPM with all motors in a single series run. The motors would have to spinning pretty damn fast to consume that much volume, wouldn't they?​
Most motors are rated for around 2800PSI continuous, to get 44HP in that pressure range, you would need 30GPM. At 4000RPM, that would take a 1.73 cubic inch pump.

Then you use a larger motor (such as 3 cubic inch motor) to get the RPM you want on the fans.
When they are in series, every motor in the series needs to be able to handle the full output of the pump, but every motor will not draw use the full output in normal usage.
If you could find higher pressure motors (such as: https://www.surpluscenter.com/Hydrau...tor-9-8915.axd which are rated for 3600PSI continous) and a high pressure pump, you could reduce the flow, but very few of the pumps on Surplus Center are rated for more than 3600RPMs continuously.
JNHEscher said:
Edit: Just realized I made a typo last night saying the motors would draw about 11 HP each. At 2,500 RPM, the fans take the 16.2 HP each. That comes up to about 78 engine HP.​
At 3600PSI, you would need about 33.5GPM to get 78HP used by the pump.

If each fan needs 16.2HP, that means that you need a total of 64.8HP to run all four.
With 80% efficiency, that should be 81HP engine HP which would be about 34.7GPM at 3600PSI, or 41.7GPM at 3000PSI.

Aaron Z
 
That makes more sense. I still need to study this some more. Feels like I'm missing something with the correlation between flow and pressure to calculate horsepower. Understandably, I'd need to add the HP requirement of all four fans and have a pump that would output the equivalent or near the full sum. What throws me off is that you can't compress a fluid and cramming 33.5-41.7 GPM through the 1.0 cu.in. motor spins it at 7,739-9,633 RPM. 33.5 GPM still spins a 1.53 cu.in. motor at 5,058 RPM. Although HP ratings match up with those pressures and flows, in my head, the fixed displacement of the motors would govern the flow volume given a certain pressure to create a certain speed. Kinda turning into Hydraulics 101 here. I'll figure it out lol. I'm all over vane and axial pumps with steering cylinders. This motor and pump banter is a little different, it seems.
 
aczlan said,
JNHEscher said:
That makes more sense. I still need to study this some more. Feels like I'm missing something with the correlation between flow and pressure to calculate horsepower. Understandably, I'd need to add the HP requirement of all four fans and have a pump that would output the equivalent or near the full sum.​
To run the motors in series, you would have to look at the HP requirements for all 4 fans (so, 64.8HP) and size the motors such that EACH fan motor in the series can handle that much HP.
As such, if all 4 fans are in series, the fan motors will each be rated for 4 times the HP that the fan needs to spin it in your worst case, full power scenario.
JNHEscher said:
What throws me off is that you can't compress a fluid and cramming 33.5-41.7 GPM through the 1.0 cu.in. motor spins it at 7,739-9,633 RPM. 33.5 GPM still spins a 1.53 cu.in. motor at 5,058 RPM. Although HP ratings match up with those pressures and flows, in my head, the fixed displacement of the motors would govern the flow volume given a certain pressure to create a certain speed. Kinda turning into Hydraulics 101 here. I'll figure it out lol. I'm all over vane and axial pumps with steering cylinders. This motor and pump banter is a little different, it seems.​
That is why I said that you would need a 3 cu in motor with 30GPM.
I should have been clearer when I linked to the 1.53 cu in motor, to use it, you would need a flow divider, or dual pumps.

Aaron Z
 
That was blatantly stupid of me. I guess I wasn’t reading all of your first paragraph. On the same page now, so I’ll find the corresponding motors for the pump output required for the fans. Holy hell I must’ve been stuck in major brain fart last night.
 
aczlan said,
JNHEscher said:
That was blatantly stupid of me. I guess I wasn’t reading all of your first paragraph. On the same page now, so I’ll find the corresponding motors for the pump output required for the fans. Holy hell I must’ve been stuck in major brain fart last night.​
No problem, lack of sleep makes brain farts happen just like eating tacos causes non-brain farts... :grinpimp:

Aaron Z
 
Punching in data on notepad for quick editing. I've been playing around with pump RPM's at their respective engine RPM's to figure out what speed I would like the pump to output its max flow to spin the fans at 2,500 RPM without having to rev the engine to redline. So far, not one pump is capable of withstanding one of the given RPM or pressure attributes in any scenario. Particularly anything that will fit an SAE A pattern. I would include some flow regulation so as not to over spin the motors when the engine is revved high enough.

I've started entering data for 20" fans as well. No more luck there than 22" fans. On the Vickers vane pump data sheet, some pumps are listed to spin up to 7,000 RPM at lower pressures. I would assume about any other pump could do the same without cavitation, provided it has proper inlet flow. I can make some calls tomorrow to verify this.

Here's my current notes copied in text for quoting and adding in $0.02.
22" T4 8-B = 16.2HP @ 2.500 RPM
408.4 in. lbs. / 34 ft. lbs.
x4 77.76HP pump req. @ 80% eff.
x4 74.52HP pump req. @ 85% eff.

Pump 3000PSI/44.35GPM = 77.625HP
3600PSI/37.03GPM = 77.776HP
Engine Pump 1:2.05 drive ratio 3000 3600
650RPM - 1333RPM
1200RPM - 2460RPM
1300RPM - 2665RPM
1400RPM - 2870RPM 3.57cu. 2.98cu.
1500RPM - 3075RPM 3.33cu. 2.78cu.
1600RPM - 3280RPM 3.12cu. 2.61cu.
1700RPM - 3485RPM 2.94cu. 2.45cu.
1800RPM - 3690RPM 2.78cu. 2.32cu.
1900RPM - 3895RPM 2.63cu. 2.20cu.
2000RPM - 4100RPM 2.50cu. 2.09cu.
2100RPM - 4305RPM 2.38cu. 1.99cu.
2400RPM - 4920RPM 2.08cu. 1.74cu.
2500RPM - 5125RPM 2.00cu. 1.67cu.
 
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