dktool
Well-known member
- Joined
- Apr 3, 2015
- Posts
- 269
I also did complete the insulation and exhaust quieting project on this.
Started with an obvious thing, putting rubber cushioning washer between the bottom pan and the mounting rails on the 4 bolts.
Then I lined the enclosure (sides, back and top) with 1" egg crate type sound dampening foam.
I also used some 80 mil Kilmat (comparable to Dynamat for less $) to cover the outside of the cooling fan cover and various sheet metal areas on the exterior of the enclosure.
For the exhaust I was concerned about potential increased back pressure by extending the exhaust to move the exit toward the front of the coach.
I teed a vacuum gauge into the source for the choke pull off to get a reading as it was originally, then went on to experiment with what became an overall net increase of 5-1/2'
There was no noticeable increase in back pressure on the gauge.
These engines are such low spinning, small breathing units that I wasn't expecting the increased length to cause an issue.
I used the original 1.5" o.d. 90 degree pipe the was connected to the muffler as the exit piece, moved forward with a 5.5' length of 1.5" o.d. flex exhaust tubing.
Overall the improvement in engine and exhaust noise is HUGE.
Started with an obvious thing, putting rubber cushioning washer between the bottom pan and the mounting rails on the 4 bolts.
Then I lined the enclosure (sides, back and top) with 1" egg crate type sound dampening foam.
I also used some 80 mil Kilmat (comparable to Dynamat for less $) to cover the outside of the cooling fan cover and various sheet metal areas on the exterior of the enclosure.
For the exhaust I was concerned about potential increased back pressure by extending the exhaust to move the exit toward the front of the coach.
I teed a vacuum gauge into the source for the choke pull off to get a reading as it was originally, then went on to experiment with what became an overall net increase of 5-1/2'
There was no noticeable increase in back pressure on the gauge.
These engines are such low spinning, small breathing units that I wasn't expecting the increased length to cause an issue.
I used the original 1.5" o.d. 90 degree pipe the was connected to the muffler as the exit piece, moved forward with a 5.5' length of 1.5" o.d. flex exhaust tubing.
Overall the improvement in engine and exhaust noise is HUGE.
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