View Full Version : OT----Onan 6.5 Genset Operating Temps?

09-17-2007, 09:27 PM
Recently installed a new genset in somewhat cramped quarters, very similar to earlier installations. Candyass employees now want 1/2 inch or so of noise isolation material glued to inside of genset enclosure, hopefully leaving clearance for sufficient, incoming cooling air. Heated air exhausts downward through a plenum to exterior of van.

Question: Any experiences on maximum air temps not to exceed, for the discharged air?


09-17-2007, 10:17 PM
It's no problem as long as the engine cooling system works properly and you keep the proper oil level, engine oil temp should exceed 180 deg, coolant temp 195. As long as there is some type of air induction system into the enclosure you should be ok.

J Tiers
09-17-2007, 10:39 PM
1/2 inch or so of noise isolation material glued to inside of genset enclosure Is unlikely to do any good if applied.

The ONLY right way to do the job is to discover what is causing the noise.

OK, it's obvious that an IC engine is making the noise, that's not what I mean......

The source of the noise determines the solution

Some possibles are:

1) is the sheetmetal vibrating and "amplifying" noise?

2) Is the noise coming from the enclosure at all? Or may it be exhaust noise, or structure-borne vibration?

3) If it IS from inside the enclosure, can you characterize it at all? What does it sound like?

3A) is it a clatter etc typical of IC engines?

3B) is it airflow noise from cooling fan?

3C is it noise from belt driven accessories?

For "'1", damping the vibrations will do a lot, and "some noise isolation " stuff probably won't do squat, except incidentally.

for "2", the solution might be a better muffler, or a change to the mounting.

For items listed under "3", a combination of noise absorbing stuff, and some attention to the source is needed.

09-17-2007, 10:51 PM
I have an Onan 5.5kw in my motor home. It is really tight but the fan air is ducted out of the enclosure. That is the key. You have to move the air in and out. As long as you have a good input/output for the air the tightness around the unit should not matter. Is it designed for tight quarters use? Meaning does it have a ducted fan unit for cooling. JRouche

09-18-2007, 12:47 AM
I got this from my 6.5 Onan manual:

A 1.00" min. clearance required around set and .50" min. above carb to compartment walls or sound insulation (Oil filter may protrude into 1.00 clearance).

The required free air intake must be at least 120 square inches.