Running the onan in hot weather

[ron preston]

Now that you all have soothed my RPM worries . I've always been reluctant
to run the onan for hours when driving in hot weather 100 ° + to run the
AC (my brother always said I was a worry wart)
I have the 6k power drawer , meter says 79 hrs. Sure it's more like 1079
it's always run well and I just changed the oil/filter. It's probably no
problem but wanted any feedback about what I should/shouldn't do? Watch
for etc.
Thanks
Ron Preston,
San jose ,CA
75 Glenbrook Headers, flowmasters
Soon to get auxiliary AC from Jim K?

 

[Carl Stouffer]

> Now that you all have soothed my RPM worries . I've always been reluctant
> to run the onan for hours when driving in hot weather 100 ° + to run the
> AC (my brother always said I was a worry wart)
> I have the 6k power drawer , meter says 79 hrs. Sure it's more like 1079
> it's always run well and I just changed the oil/filter. It's probably no
> problem but wanted any feedback about what I should/shouldn't do? Watch
> for etc.
> Thanks
> Ron Preston,
> San jose ,CA
> 75 Glenbrook Headers, flowmasters
> Soon to get auxiliary AC from Jim K?
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

It's NOT a problem Ron. I have run mine all day on the road with the roof AC running. The only issues you need to worry about are having enough gas
in the tank (it will 'run out' if the main tank gets below 1/4) and make sure the crank case is full of oil.

Running mine last Summer for several days worth of travel, I managed to run it low enough on oil that the low oil protection kicked in as I was
backing into a space and the generator quit. I checked the oil and it was two quarts low. After refilling it, it ran the whole next day on the last
leg of the trip, from Payson to Tucson, AZ without a hitch.

I DO have a Fire Fight Halon extinguisher in the compartment just in case. Always a good idea.

--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

 

[jim kanomata1]

Hope you have the outer rubber air seal around the oil filter, as it aids
in keeping the engine cool.
You should also have the air deflector to keep the unit from pulling in the
heated air.
I seldom carry spare parts, but a new board and a 5 amp fuse is always good.
Oh, keep our phone # should you need help on the phone.

> Now that you all have soothed my RPM worries . I've always been reluctant
> to run the onan for hours when driving in hot weather 100 ° + to run the
> AC (my brother always said I was a worry wart)
> I have the 6k power drawer , meter says 79 hrs. Sure it's more like 1079
> it's always run well and I just changed the oil/filter. It's probably no
> problem but wanted any feedback about what I should/shouldn't do? Watch
> for etc.
> Thanks
> Ron Preston,
> San jose ,CA
> 75 Glenbrook Headers, flowmasters
> Soon to get auxiliary AC from Jim K?
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502

 

[Ken B]

I'm not nuts enough to head south in the summer, but last summer I went to Branson, which I do not consider south, and the temperatures were running
100 to 104 during the heat of the day with 90's at night. My Onan quit due to vapor lock problems several times during that trip. An hour of parking
in the shade with it pulled out to cool and it would run OK for the next 1/2 hour or so on the road. My main 455 engine was not experiencing any
vapor lock problems at the time. My immediate solution was to hide out in an air conditioned store that allowed me to bring my dog inside with us.

My long term fix was to remove the fuel line from the carb to the base of the generator cabinet and cover it with aviation "fire sleeve" and
reflective aluminum tape. I figured that is where the gasoline was picking up the most heat. I also covered the fuel pump with reflective tape. I
have since then run into two days on the road at 100 degrees on other trips and have not experienced any vapor lock problems. A second solution might
be to install or move the fuel pump back to the fuel tank. That is what I'll do next if this ever happens again.

As far as fire extinguishers go, I use to plan installations and sell Halon systems for large computer rooms. Halon works well in enclosed areas, but
in areas of high air flow it is almost useless. It needs to be configured and installed way over capacity to keep the area protected if there is air
flow occurring during a fire.

Part of our halon installation was electric an shut down of all forced airflow and automatic door closers in the protected areas when the system went
off.

There is a lot of air flow in and around the Onan.

Also I notice people are installing these extinguishes on the front cover of the Onan which is away from the probable fire sources which are on the
side where the carb fuel pump and gas lines are located, the top of the cabinet where the heat is radiated from the exhaust, and the generator itself
which is located on the rear of the unit. So I have my doubts that the halon systems being sold an installed for our Onans are a good solution. I am
waiting for an actual Halon deployment in the Onan cabinet to be reported to prove me wrong.

Halon would be a good solution in the refrigerator or propane cabinets where air flow is minimal.

I do have the deflector on the Onan that blows the hot air away from the coach. It was installed when I had the vapor lock problems.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[Matt Colie]

A year or two back, I ran the Onan for three days straight. The power was out and the missing part for the Honda generator was waiting in the blacked
out post office. I did shut it down twice a day to check the oil. In sprite of the high enclosure temperature, I have never had a vapor lock issue.

During that last long outage the Fire-Fight put it out in the second hour (this was the third and I just don't bother any more).

I got the unit with an unknown history and have put another 290+ hours on it in the last 12 years. Yes, it has needed love and attention, but that is
a small price for the convenience and dependability.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[Ken B]

Matt,

Are you saying that the Fire Fight went off three times and there really was no fire?

Also when it went off did it have enough Halon concentration to kill the running engine?

Was it mounted to the outside of the front cover?

What did it cost to recharge the extinguisher?
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[Ernest Dankert]

Two things I do for Onan peace of mind. Amsoil (air cooled engines run hotter).
Fire Fight remote head installed inboard/forward of the generator compartment.
Yeah the Halon solution may be imperfect, but better than nothing.
--
1977 Eleganza II
Ogden NY

 

[Ken B]

> Two things I do for Onan peace of mind. Amsoil (air cooled engines run hotter).
> Fire Fight remote head installed inboard/forward of the generator compartment.
> Yeah the Halon solution may be imperfect, but better than nothing.

Only if it actually puts the fire out. You only get one shot at it and then you walk away if it does not work.

I like the idea of the remote head.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[jim miller]

> Only if it actually puts the fire out. You only get one shot at it and then you walk away if it does not work.

Are there any documented examples of Onan fires in our GMC coaches?

—Jim

Jim Miller
1977 Eleganza
1977 Royale
Hamilton, OH

 

[Rdenney]

I recall at least one coach that burned, starting at the generator
compartment. But who owned it and other details have escaped me.

My own Onan had a crack at the exhaust connection that had charred the
compartment above it, so it wouldn't have taken much to fan that into
flames. That's one of the reasons I switched to the Generac.

Rick "whose generator compartment is now lined with sheet metal" Denney

>
> > Only if it actually puts the fire out. You only get one shot at it and
> then you walk away if it does not work.
>
> Are there any documented examples of Onan fires in our GMC coaches?
>
> —Jim
>
> Jim Miller
> 1977 Eleganza
> 1977 Royale
> Hamilton, OH
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com

 

[johnny]

Swapping an Onan for a Generac strikes me like swapping a VW for a Yugo

--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased

 

[jim miller]

> My own Onan had a crack at the exhaust connection that had charred the compartment above it, so it wouldn't have taken much to fan that into flames. That's one of the reasons I switched to the Generac.


Thanks Rick. I can see where an exhaust jet from a compromised manifold might set off the insulation ala the Challenger’s SRB failure.

My coach had similar crusty insulation above the Onan exhaust manifold; however unlike yours my manifold was intact.

I was curious about what was really going on at that area of the compartment and after re-insulating the area with Reflectix I instrumented the compartment with thermocouples to see what was really happening. To my surprise the area above the manifold stayed barely above ambient *while the Onan was running*. It was only after shutdown that the area peaked to around 200F before cooling down. This is documented at: http://www.jcmco.com/gallery/album29 http://www.jcmco.com/gallery/album29

—Jim

Jim Miller
1977 Eleganza
1977 Royale
Hamilton, OH

 

[Rdenney]

I have spent about two hours working on the Generac in 130 hours of use, to
replace a failed shaft speed sensor.

I spent about 80 hours fiddling with the Onan in 30 hours of use. And still
it leaked oil and exhaust. The oil dripped onto the muffler when stopped,
and covered the back of the coach with oil at speed.

I am happy with the reversal of the ratio of fiddling-to-operating, no
matter what the reputation of Generac.

Rick "there were no other solutions at the time" Denney

On Sun, Jun 18, 2017 at 4:33 PM Johnny Bridges via Gmclist <

> Swapping an Onan for a Generac strikes me like swapping a VW for a Yugo
>
> --johnny
> --
> 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga
> "I forgive them all, save those who hurt the dogs. They must answer to me
> in hell" - ol Andy, paraphrased
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com

 

[Matt Colie]

> Matt,
>
> Are you saying that the Fire Fight went off three times and there really was no fire?
>
> Also when it went off did it have enough Halon concentration to kill the running engine?
>
> Was it mounted to the outside of the front cover?
>
> What did it cost to recharge the extinguisher?

Ken,
That is exactly what I am saying. (At least three.)

It sure did. Think about it, everything is copacetic and BANG the electric plant stops HARD. (Yes, the A/C was running the first time and it took out
the bridge.)
So, you run out there only to find . . . Nothing....

It was initially mounted as directed inside the front cover of the Onan. The second time in was inside horizontal over the battery and the last time
it was standing up outboard of the battery. Remember this is a 73 23 so things are different.

Recharge was 25$ all but the last. It is still empty as I have given up.

I may have lost count, the logs are out in the coach and I think Mac gave me a new one for one of the times. I did buy two recharges.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[Ken B]

What you are telling me is good news in a way. Properly placed, It will dump enough halon to stop the engine and it's associated high volume cooling
fan that is moving some of that fresh air into the area.

Since the air intake, carb, and fuel pump are all located together, that tells me that properly placed, halon might be effective in a gasoline fire in
that area. I still do not know what would happen in a cabinet fire (overhead) or a fire in the actual generator itself. Every coach I have checked
has had some scorching or melting in the overhead portion of the generator cabinet.

Most people never look overhead to see what has happened there, because they have to lay on the ground and look up to see it. This is the reason I
installed an aluminum shield up there and down the side to reflect and absorb some of the excess heat from that area.

Matt, they make extinguisher triggers with several different melting temperatures. Have you tried one with a higher temperature?

BTW, For Halon look-a-like enthusiasts, Have you looked at this VW solution for use in the generator compartment:

https://jogrusa.com/products/blazecut-fire-suppression-system?variant=16369324485

They make them in 3', 6', 9', and 12' lengths. They do not take much room and could be run all over the sides and top of the cabinet. It will only
trigger where the actual heat is. Then it dumps the entire contents at that trigger point. Each longer size contains a proportional amount of
additional extinguishing liquid which turns to gas on deployment.

I have seen one and the only drawback is the pipe is fairly rigid but it will bend. I do not know what the smallest bending radius is. Installing it
around tight corners might be a problem. If I ever had the generator removed from the cabinet so I could easily work inside, I think I would install
9 or 12 feet of this stuff around the generator cabinet and inside the battery enclosure that is next to the generator.

In their demo they only used a 6 foot one and the engine was not running moving air.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[chris tyler]

I understand the concern for engine temps, but remember ther are a lot of air cooled engines used in very hot climates without problems

You can run a heavier oil if you dont experiance lower temps- I never really get outside FL

I suppose you could get a cyl head temp and/or oil temp gauges to monitor it if you want to worry about it.

Regarding fire issues: I have become a foam fan for anything involving flamable liquids. Dry chemical is effective but leaves a huge mess and ruins
electrical components

real halon seems to be getting hard to find
--
76 Glenbrook

 

[RJW]

> Now that you all have soothed my RPM worries . I've always been reluctant
> to run the onan for hours when driving in hot weather 100 ° + to run the
> AC (my brother always said I was a worry wart)
> I have the 6k power drawer , meter says 79 hrs. Sure it's more like 1079
> it's always run well and I just changed the oil/filter. It's probably no
> problem but wanted any feedback about what I should/shouldn't do? Watch
> for etc.
> Thanks
> Ron Preston,
> San jose ,CA
> 75 Glenbrook Headers, flowmasters
> Soon to get auxiliary AC from Jim K?

I just returned from a 2 week GMC trip from Michigan to Austin, Texas for my son's wedding. Even though I lived in Dallas for a couple of years back
in the 70's, I had forgotten how hot it can get in Texas. Because there was no way the dash air would keep up with the 95-100 degree temps (and this
was June) I had to run my Onan to power the house air to keep half way cool while driving. Now I know why people down there have 2 air conditioners
because 1 does not cut it. At any rate, we ran the Onan for a total of 27.7 hours. If I started it cold, it would run just fine until time to get
gas. But when I shut it down for refueling, it would not start again until it cooled, which took a few hours of driving which was annoying because it
got hot in our GMC without house air running. Apparently, vapor lock was the cause.

During the trip, I used my IF thermometer to measure Onan temps. I found that when it is running, everything stays relatively cool, which must be
because of all the air being moved by the Onan's cooling fan. Upon shut down, things start to get hot (~200 degrees on the exhaust) which to me
explains the vapor lock because of the proximity of the fuel system to the manifold.

As Ken B. has suggested, I might move the fuel pump and wrap the fuel line with some sort of insulation. I am also thinking about installing a 2nd air
conditioner and a second evaporator for the dash air.



--
Richard
76 Palm Beach
SE Michigan
www.PalmBeachGMC.com


Coop Roller Cam 455, Howell TBI + EBL, 3.42 FD, Quadra Bag, Macerator, Manny Tranny etc.

 

[mark sawyer]

> > Now that you all have soothed my RPM worries . I've always been reluctant
> > to run the onan for hours when driving in hot weather 100 ° + to run the
> > AC (my brother always said I was a worry wart)
> > I have the 6k power drawer , meter says 79 hrs. Sure it's more like 1079
> > it's always run well and I just changed the oil/filter. It's probably no
> > problem but wanted any feedback about what I should/shouldn't do? Watch
> > for etc.
> > Thanks
> > Ron Preston,
> > San jose ,CA
> > 75 Glenbrook Headers, flowmasters
> > Soon to get auxiliary AC from Jim K?
>
>
> I just returned from a 2 week GMC trip from Michigan to Austin, Texas for my son's wedding. Even though I lived in Dallas for a couple of years
> back in the 70's, I had forgotten how hot it can get in Texas. Because there was no way the dash air would keep up with the 95-100 degree temps (and
> this was June) I had to run my Onan to power the house air to keep half way cool while driving. Now I know why people down there have 2 air
> conditioners because 1 does not cut it. At any rate, we ran the Onan for a total of 27.7 hours. If I started it cold, it would run just fine until
> time to get gas. But when I shut it down for refueling, it would not start again until it cooled, which took a few hours of driving which was
> annoying because it got hot in our GMC without house air running. Apparently, vapor lock was the cause.
>
> During the trip, I used my IF thermometer to measure Onan temps. I found that when it is running, everything stays relatively cool, which must be
> because of all the air being moved by the Onan's cooling fan. Upon shut down, things start to get hot (~200 degrees on the exhaust) which to me
> explains the vapor lock because of the proximity of the fuel system to the manifold.
>
> As Ken B. has suggested, I might move the fuel pump and wrap the fuel line with some sort of insulation. I am also thinking about installing a 2nd
> air conditioner and a second evaporator for the dash air.


Have you tried sliding the genny out when you shut down to refuel? I am in Texas as well, (and have been fighting some vapor lock on the onan) and
have found that can help when only shutting down for a short time...

--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX

 

[Ken H.]

Richard,

You might consider adding a supplemental fan like Johnny's been promoting
or like this one of mine (since permanently mounted):

http://www.gmcmhphotos.com/photos/troybilt-generator-installation/p31703-140-cdddooling-fan-temporarily-mounted.html

That one works very well supplying air to the ToryBilt I've been running,
with NO problems, since 2009.

With such a fan rigged to run with the Onan shut down (perhaps on a
thermostat or a timer?), you might easily alleviate your vapor lock problem.

Oh yeah, it's installed to blow INTO the compartment.

Ken H.

> ​...
>
> During the trip, I used my IF thermometer to measure Onan temps. I found
> that when it is running, everything stays relatively cool, which must be
> ​
> because of all the air being moved by the Onan's cooling fan. Upon shut
> down, things start to get hot (~200 degrees on the exhaust) which to me
> ​
> explains the vapor lock because of the proximity of the fuel system to the
> manifold.
> ​...
>

 

[RJW]

> Have you tried sliding the genny out when you shut down to refuel? I am in Texas as well, (and have been fighting some vapor lock on the onan)
> and have found that can help when only shutting down for a short time...

I did not try sliding it out during gas stops. In retrospect, it seems like that would help cool it during a fuel stop. Good tip!
--
Richard
76 Palm Beach
SE Michigan
www.PalmBeachGMC.com


Coop Roller Cam 455, Howell TBI + EBL, 3.42 FD, Quadra Bag, Macerator, Manny Tranny etc.