Chinook RV

I have a 1975 Concourse and a tremendous amount of heat is generated through the engine cover (dog house) making it difficult to even keep my foot on the accelerator. I assume I need to remove the cover and replace the insulation inside the cover. With that much heat I want to make sure I purchase the correct insulation. Any recommendations and tips for a novice as this is my first motorhome.

Thanks in advance. I am so happy I found this forum. it has already provided me with a tremendous amount of reading material. Only wish I could find a 1975 owners manual

I haven't done the one on my Chinook yet, but I did a friend's 2003 Ford cutaway (same exact doghouse as my '99 Ford). Yours will likely be different but maybe the same idea.

So, we started by choosing and ordering products. For his we went with (IIRC) Second Skin Damplifier (which he already had on hand) and then Dynamat Hoodliner. Again IIRC, the Damplifier helps vibration and the Hoodliner was for heat (which was a problem, as you mentioned).

A note is that it is also important to have a good seal between the doghouse and the cab. In his RV the builders had left some carpet strands in a place that compromised the seal. We cleaned all that up so there were no gaps and the factory seal was actually a seal.

Then we tackled the doghouse cover. All of this was on the back side that faces the engine.

There was a Ford layer of shiny foil stuff that was on some kind of lightweight backing. We removed that. Oh, interestingly, his original doghouse (gas engine) had nothing under this shiny layer. The people who built his RV had sawed off the knobs that hold the console (cupholder) on, so he had bought another doghouse from eBay to actually use for this project. Based on the smell (before we cleaned it) it was from a diesel version. That one had something just like the Damplifier under the shiny foil molded sheet. So now that I think about it we didn't use his Damplifier, because it was already on the new doghouse (but we would have if it had not been there).

Next we made patterns and cut and fit the HoodLiner. We found that in order to use the thick hoodliner, he would have to not put the stock Ford "foil thing" back on. (He could also have used a thinner liner product and kept the factory foil liner.) The HoodLiner does have a foil face and is meant for high heat. I think we might have removed a couple of the "buckles" that hold the doghouse in place in order to fit the HoodLiner (and then reinstalled them). I can't remember for sure because this was three years ago. We were also very careful not to obstruct the metal-to-rubber doghouse seal area.

Once we had that all done we reinstalled. IR thermometer confirmed that it was cooler on the cab side. Yay! We couldn't tell as much about the noise abatement in a stock rig as he had the Banks Pack (which makes it "throatier"). Also I didn't drive it (I measured temps right after we stopped, but I was driving my own RV), and he's kind of hard-of-hearing.

That RV has since been driven cross-country three or four times, and no issues noticed from leaving the stock Ford "foil thing" off in favor of the thick HoodLiner. Not sure if I will do that or will use a thinner liner. That project is back-burnered at the mo'.

BG

Hi Conk - I used the Dynamat Hood Liner under my hood but went with "regular" Dynamat for the doghouse. As Blue mentioned its important to make sure that the doghouse seals properly. I'd recommend that you have a friend help you put the doghouse back in place to make sure the seals are mating properly on both sides of the unit before you latch it. If I had it to do over again I would add another layer of Dynamat to help with both heat and sound reduction.

Oh, that reminds me of a tip for re-seating the doghouse. I had done it a few times but with some struggle when I read the (for me, counterintuitive) tip to fasten the UPPER buckles first. Darned if that didn't make it seat easier so now I do it that way each time.

Hey Blue - thanks for the tip. I noticed that when I got my rig back from the guy who had insulated the dog house for me that there was a large gap where the seal was sort of bent from being latched down before it was properly aligned. If you have any gaps at all it will defeat the whole purpose of insulating the doghouse.