TL-DR: added an insulated muffler heat shield, but probably could have done something simpler with two pieces of aluminum heat shield above and below the muffler. Something like a 150-200F drop in temperature around the muffler.
Update: I did put in the insulated muffler heat shield. I will admit up front not to being a sheet metal whiz. The sane way to do this is probably to remove the muffler and do this off the tractor. I didn't, and I do regret that decision.
I made a series of templates in paper, then cardboard, then cutting the insulation, fitting it, trimming it more to fit, then transferring it to the aluminum, with an extra perimeter to fold over the ends. I decided to put the seam on the engine side to allow some airflow between the intake and the muffler where the Deutz routes some airflow.
The hard bit is that on the BF3L2011 there are three exhaust headers from the Deutz that go into the combined header/muffler. So, you have to get the cutouts for those aligned with the ends, and then manage the muffler end covers. Fiddly doesn't begin to describe it as you have to compress the heat shield around the circumference while keeping the cut outs aligned at the exhaust header tubes. I ended up using four large hose clamps, and I should have planned for two or three inches of aluminum overlap to make fitting things up easier.
Does it help? Well, I ran the tractor for a bit and the exhaust was measuring 390F, and the outside of the heat shield was reading 90F. That's probably not totally accurate as the IR thermometer that I used does need to be adjusted for highly reflective surfaces, but in the past the adjustment has only been 20F or so. You can touch the heat shield.
This may adversely affect the intake air during cold weather (no warming from the exhaust), but time will tell.
I used the Design engineering Muffler Heat Shield 10529. I broke the first stainless zip tie that they supplied trying to use their fancy tool. I also used a stainless hose clamp to hold parts of one end to the exhaust pipe by way of a lateral anchor. I will probably replace it with stainless safety wire in a few days.
I am not happy with the wrinkles, but I think it results from my not having several inches of excess aluminum heat shield to slide over each other. You can see the aluminized fiberglass wire loom that I used above and below the muffler.
Let's just say that this took more effort than I thought it would. If I were doing it again, I might just curve a piece of aluminum heat shield from above the air intake down to the level of the exhaust, and put a heat shield over the starter and solenoid. Much less fiddly, and probably would also help route cool air up to the hydraulic cooler, as this does.
I liked the heat shield products; the Deutz exhaust is just a bit of a jungle.
All the best,
Peter
