Air Cooled Heat Exchangers

Ara Klujian

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:AddEmoticons04259:
Exhaust and air intake is one of the most important factors one must consider when operating an air cooled Truckmount. Put a load on your engine and run the exhaust though a box or what have you. :AddEmoticons08024:
This is a risky attempt in my opinion. Air cooled motors need to running as cool as possible. If you use an engine specifically to heat water than your cookin. Which is one of my designs I am sharing with you. With a hurricane fan in front of it. I think that would be such a cool setup. And to have the setup in the back of the van with vaccuum hook ups on the side as well as in the back.
 
Jun 23, 2008
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Air cooled engines are designed to run hotter than liquid cooled engines; that's just how it is.

Running a HX system on an air cooled engine is not risky if it is designed properly, i.e., measuring engine back pressure, hot spots, etc.. Any reputable Truck Mount manufacturer will have the engine manufacturer do an Application Review to ensure that the engine is not being prematurely destroyed by the design of the truckmount. This also helps to protect the end-user's warranty on the engine.

As long as your air cooled engine is in a position in the van (close to a door) to pull cool air then you will be ok. Also, make sure the exhaust clears the van interior so that the engine won't pull hot air.
 
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My friend who is certified to work on Briggs, Kohler, Honda, Kawasaki, Robbins and others told me yesterday about a fan made of nylon that mounts to the drive shaft and provides additional cooling. He's going to show me one next week.

Should be interesting.
 

Ara Klujian

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I would actually like to see that Duane.
OK Chris, You make some good points. What happens if you buy the unit and then find out that the recovery tank must be mounted right next to the motor? Allowing no adequate airflow. Kiss it good by because its not gonna last. That recovery tank aint no refridgerator. The engine will crack recovery tank side all the time.
 
Jun 23, 2008
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Again Ara, if the TM manufacturer got an application review they would more than likely catch a flaw like that.

There shouldnt be a problem with mounting a recovery tank on the side of an engine because the cooling air is pulled in by the engine fan at the front of the engine and directed through the engine and out of the back of the engine. So as long as the engine has a source of cool air of which to pull and a means of exhausting out of the van there shouldn't be a problem. This is why it is so important to put back all of the sheet metal on your engine when you take it apart for repair. The sheet metal is actually ducting for the cooling air and without it your engine will not properly cool itself.

And it is always a good idea to have the side and rear doors of the van open while running a TM.

Ara, what TM are you referring to that has the tank butted-up against the engine?

This is a good discussion Ara, thanks for starting the thread!
 

Ara Klujian

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Ive seen old units like that. Ive seen L-head plates crack. I can't say what units because I don't want to say for certain reasons, if you understand. It happens!
And I think back pressure in the exhaust system on a hx is less of a concern than how long it takes to leave the system to atmosphere. Some manufactures keep that exhaust trapped way to long. And if can't keep the doors open because its a bad neighborhood you cook.
 
Jun 23, 2008
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Any engine will cook if you run it with the van doors closed; air cooled, liquid cooled, whether it has HX or propane/kerosene heat.

Ara, back pressure is a major concern and can cause major problems to your engine/TM. Engines need a certain amount of back pressure but too much can be problematic.
 

Jeff Ellis

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Closed doors on a van is never acceptable with any slide-in TM. If you are in a bad neighborhood than post a guard if you must but do not shut the doors.
 

Ara Klujian

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I agree with you about too much being problematic. In general it should never exceed 1.75 psi WOT (wide open throttle) at full load.
We always keep a door open. But Chris said to keep side and rear doors open, which is a good idea but not always feasable.
Liquid cooled engines are less likely to overheat than an air cooled engines.

The thread was started based on an opinion. I'm sorry you feel so strongly about air cooled hx. I on the other hand don't recomend them for the long haul.
 
May 6, 2008
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Any reputable Truck Mount manufacturer will have the engine manufacturer do an Application Review to ensure that the engine is not being prematurely destroyed by the design of the truckmount.
Hey, Chris:

You're right.

That review is virtually a requirement these days. Any manufacturer who buys direct from an engine manufacturer will find this is part of the requirement to do so.
 

Larry Cobb

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Ara;

We have been thru warranty certification with both Honda & Kohler factory technicians with our HX design.

They have verified that engine back pressure thru our HX is well within their specs and actually lower than some muffler systems that they have tested.

Since our exhaust system is all stainless steel, it will maintain that low back pressure for many years.

We also have tested it on a liquid-cooled 31 HP Kohler with Electronic Fuel Injection.

Larry