4106 fan clutch drive control

Jim Blackwood · January 25, 2021, 10:24:01 AM

If it helps any, that torus should function in a similar way to any other fluid filled clutch... like a torque converter for instance. In which case it will only work if it has oil, because the oil transfers drive from the input to the output.

Jim

chessie4905 · January 25, 2021, 06:28:03 PM

Thats right. Exhaust is blocked to cause fan to run full speed instead of temp modulated.

Bobert · January 25, 2021, 06:56:45 PM

I am much smarter on this then when I began and I appreciate everyone's help!

chessie4905 · January 27, 2021, 11:19:24 AM

Correction. Keyser or Kysor of Cadillac made the vernatherms. The manual shoes correct orientation.

richard5933 · January 27, 2021, 11:55:52 AM

Quote from: chessie4905 on January 27, 2021, 11:19:24 AM
Correction. Keyser or Kysor of Cadillac made the vernatherms. The manual shoes correct orientation.

Makes sense - Kysor made the Shutterstat as well.

Friday1 · February 03, 2021, 06:54:50 AM

On our 4106, I blocked off both ends and disabled the vernatherm. I have a 9 bladed plastic fan on ours and it made the engine run cooler but took a bite out of the fuel "economy". So I put the line back in the system and think about controlling the flow with a 12VDC valve. Tha is way down the list of things to do as long as it is not running hot.

dtcerrato · February 03, 2021, 07:28:41 AM

@ Friday1
I was glad to see you say it & wanted to note it. Seems like lots of especially vintage bus owners go for lighter weight fans (plastic) and some mention the word "efficiency. IMO efficiency is an obscure word to use about a fan. The more air a fan pushes the efficiency pertains to the cooling it does but as far as taxed HP - more air is more work! If not, what am I missing here?

Utahclaimjumper · February 03, 2021, 08:04:20 AM

You CAN improve the efficiency of the shroud without penalty,, in many cases a needed improvement.>>>Dan

Friday1 · February 03, 2021, 11:51:25 AM

Quote from: dtcerrato on February 03, 2021, 07:28:41 AM
@ Friday1
I was glad to see you say it & wanted to note it. Seems like lots of especially vintage bus owners go for lighter weight fans (plastic) and some mention the word "efficiency. IMO efficiency is an obscure word to use about a fan. The more air a fan pushes the efficiency pertains to the cooling it does but as far as taxed HP - more air is more work! If not, what am I missing here?

You are correct. I changed my fan because the original looked like a propeller from a B-17 after a landing without landing gear extended. With that much weight way out of balance, it had to be much less efficient. It takes a lot of horsepower to spin the fan fast and pull a lot of air through the radiator. Another trade off you have to weigh any benefit to see if it is worth the expense and if your original goals are met.

Friday1 · February 03, 2021, 11:53:27 AM

Quote from: Utahclaimjumper on February 03, 2021, 08:04:20 AM
You CAN improve the efficiency of the shroud without penalty,, in many cases a needed improvement.>>>Dan

Good point. My next metal project is to make the shroud work better and look into making the belly pans.

chessie4905 · February 03, 2021, 04:24:45 PM

Make sure you have the full width flap right behind rear axle attached to bottom of bulkhead.

richard5933 · February 03, 2021, 04:35:55 PM

Quote from: Friday1 on February 03, 2021, 11:53:27 AM
Good point. My next metal project is to make the shroud work better and look into making the belly pans.

I've thought that the belly pans do a lot for improving air flow through the radiator. The ones on my bus have rearward-facing louvers which should create a negative pressure pulling air out of the engine compartment, and since the radiator door is the only real opening for air to enter it's got to increase air flow through the radiator as long as the bus is in motion.

Friday1 · February 03, 2021, 08:24:06 PM

Quote from: richard5933 on February 03, 2021, 04:35:55 PM
I've thought that the belly pans do a lot for improving air flow through the radiator. The ones on my bus have rearward-facing louvers which should create a negative pressure pulling air out of the engine compartment, and since the radiator door is the only real opening for air to enter it's got to increase air flow through the radiator as long as the bus is in motion.

Richard, Are your belly pans OEM or you made them. I would like to know any info about them. What thickness are they? Thanks in advance

richard5933 · February 04, 2021, 04:17:59 AM

Quote from: Friday1 on February 03, 2021, 08:24:06 PM
Richard, Are your belly pans OEM or you made them. I would like to know any info about them. What thickness are they? Thanks in advance

Definitely OEM. Not sure of the thickness, but IIRC about the same as the other non-structural panels around the bus. I'll try and measure next time it's not snowing/icing outside and get back to you.

There are two pieces for mine on the 4108 - one main piece under the bulk of the engine and another smaller one driver's side under the radiator. There are a few u-channels running front to back to stiffen the belly pans, and they are both louvered over most of their surface with rearward-facing louvers. These are key, IMO, to making the belly pans do their job of sucking air down and out.

This photo is taken through the curb side transmission door looking at the main belly pan. You can see a couple of the spring-loaded mounting points from above and the circular depressed area built into the pans where they mount. I believe that these circular depressions are just tack welded into holes. You can see the spring end of the mounting points above the cradle, and down below they have about 1" diameter loops sticking down. These loops rotate and go into slots in the pans to lock them in.

Where each of the mounting points are there is about a 3" diameter depressed area where the spring-loaded mounting loop goes, resulting in the belly pan being about 2" offset from the mounting points. The OEM mounting loops go through slots in the belly pans and then turn 90 degrees to hold the pans in place. If you are making the pans from scratch and don't have mounting points, it would probably be possible to use some type of stand-off spacer and mounting bolts instead, but whatever system you create for mounting should enable you to remount the pans easily. You'll be holding them in place with one hand while fastening them in place, so simple is better. If I didn't have the OEM spring mounted loops I'd probably consider tacking 1" studs under the cradle which the pans could be raised onto, then you'd only have to put on some wing nuts to fasten. Hopefully you still have the OEM mounting loops.

chessie4905 · February 04, 2021, 06:52:06 AM

they use the same loops below ac condenser