Coolant Pressure Control Cap

[Leroy Eckert]

Yes, that is what I am testing. The 180 degree engine thermostats operate
between 180-197 degrees. The 170 degree engine thermostats operate between
170-187. You are absolutely correct in your statement.

However, based upon the tests I have made I cannot under any circumstances
force the engine thermostats to cycle so to speak, so in my opinion, based on my
documented testing, if they are going to cycle they will do so in winter. They
are either closing gradually, or they are fully open. The fact of the matter is
this, the Alarmstat pushes the temperature to the high limit before the fan is
exercised. ( restricted air flow vs. hp, I will guarantee that was the original
theory) Hey, this thing is not a race car.

If on a hot day the fan comes on at 195 degrees, there is a lot of residual hot
water in the lines intended to cool the tranny, engine oil, retarder
etc.(remember they are working and they are hot) If the Alarmstat has a 8-10
degree operating range, and it does, then the average cooling water temperature
used to cool the drive train components is to hot in my opinion. Remember,
there are several feet of cooling hose in the compartment. Frankly, I think
that is crazy. There simply is not enough fan operating time (air flow) to cool
the water flow to the components.

My Alarmstat is located on the water jacket next to the water pump on the left
hand side (looking at the engine from the rear) adjacent to the temperature
sender. It is a bulb looking sensor with two wires. The original connections
were screw connections. Replacement units are slide on connectors which I
filled with epoxy.. If the part has not been painted it should have Alarmstat,
or Medallion Instruments on it. On the hex portion it should have 195 stamped.
It is a BB part, currently manufactured by Medallion Instruments and comes in a
box stating standard OEM BB parts. I could not order it from another supplier.
About $80.00, and 30 minutes of time to change.

This whole issue came up over a radiator cap at 7-9-13 psi. The higher the
rating the higher the boiling point. I'm thinking , reduce the operating
temperature, and to hell with worrying about the cap pressure. 7-9 should be
good.

I will say this again. I have a Royale Conversion. I would not think that has
anything to do with the DD, but you should be certain that you understand how
your system is set up before you change anything. So far, I'm good.

Leroy Eckert
1990 WB-40"Smoke N Mirrors"
Niceville, FL



----- Original Message -----
From: Don Bradner
To: WanderlodgeForum@yahoogroups.com
Sent: Monday, March 05, 2007 7:04 PM
Subject: Re: [WanderlodgeForum] Coolant Pressure Control Cap


My 195-degree alarmstat runs the temp between 189-197, with the engine
thermostat at 180. If the 185-degree alarmstat ran 179-187 (big IF), that would
appear to have the potential of turning the fan on at 187 and then never turning
it off, as the temp would rarely drop to 179. Now it is quite possible my 189 is
undershoot after the alarmstat has turned the fan off, in which case it won't
matter.

Where is the alarmstat, physically? I think someone asked where you were
getting it, but if there was a reply I did not see it.

On 3/5/2007 at 6:12 PM Leroy Eckert wrote:

>Thanks: I have not experienced overheating problems, I am picking at it,
>and I just do not yet understand why BB and their engineers specified an
>Alarmstat fan controller which pushes the water temperature to the upper
>limit. That is why I changed my Alarmstat to a lower temperature. I may
>yet try a 185 degree just to see if it interferes with the engine
>thermostat operation. I have a feeling that it will not. If I can get my
>coach to run on the flat in the mid-range of DD specifications, an average
>of 185 degrees I am going to do it. As always, thanks again for the input.
>
>Again, I am posting what I am doing and do not suggest any one else try
>this unless you understand how your particular system works. So far mine
>is doing fine. If I blow my engine up that is my problem. If my theory
>works, I'm happy and I will report.
>
>For those who do not know, the Alarmstat, funny name for a part that
>actually forces the water temperature up, is the part that cycles the
>hydraulic fan on and off, assuming your chassis a/c is off and the fan
>override is off. That is how mine works on the WB-40
>
>I am going to install a supplemental water spray system, just in case I
>need it.
>
>Leroy Eckert
>1990 WB-40"Smoke N Mirrors"
>Niceville, FL
>
>
>
>
>
> ----- Original Message -----
> From: Pete Masterson
> To: WanderlodgeForum@yahoogroups.com
> Sent: Monday, March 05, 2007 12:55 PM
> Subject: Re: [WanderlodgeForum] Coolant Pressure Control Cap
>
>
> I had some overheating problems with my Series 60 powered unit on my
> homebound trip after taking delivery in Texas...
>
> Upon opening up the radiator, it was found to be 2/3 filled with oily-
> dirt pulled into the radiator. This could not be seen from the
> outside due to the charge air radiator that's located in front of the
> water radiator and it could not be seen from the inside due to the
> metal shroud around the fan. The area under the fan was open and
> clear -- it was everything else that was blocked up.
>
> Although a simple cleaning of the radiator could have resolved the
> problem -- I elected to replace the radiator core with a more
> efficient design (since about 1/2 the cost was the labor to pull the
> radiator).
>
> My current temperature readings are quite similar to yours -- except
> the water temperature has yet to go much above 180 -- and my retarder
> is exhaust based, and doesn't have a temperature gauge.
>
> When the radiator was replaced, the radiator service replaced the
> cap ... it's rated at 15 lbs.
>
> I do lose about 1 quart of radiator water each trip while using the
> chassis heat. There's a minor leak somewhere, but I haven't found it
> yet. When the chassis heat isn't used, then I don't seem to use any
> radiator water. (I carry a couple of spare gallons of premixed
> coolant along...)
>
> Pete Masterson
> aeonix1@...
> '95 Blue Bird Wanderlodge WBDA 42'
> El Sobrante, CA
>
> On Mar 4, 2007, at 6:09 PM, Leroy Eckert wrote:
>
> > <Snip>
> > I like my drive train component temps now.
> >
> > Engine Oil-215
> > Water Temp-Cycles between 180-190
> > Transmission Temp- 170
> > Retarder Temp- 220
> > All recorded in flat conditions at cruise speed of 68 mph, pulling
> > a 20ft trailer w/car.
> >
> > I do not suggest you try anything unless you fully understand your
> > system, I'm simply reporting what I did.
> > The foregoing presumes that all system components are in proper
> > working order.
> >
> > My next project is to install MH's water injection system so when I
> > climb the mountains next summer I'll have a water flood just in case.
> >
> > Alright, fire away, I have Redneck engineering paperwork on this
> > one. LOL lol, lol
>
> [Non-text portions of this message have been removed]
>
>
>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>
>
>Yahoo! Groups Links
>
>
>

Don Bradner
90 PT40 "Blue Thunder"
Eureka, CA





[Non-text portions of this message have been removed]