My air throttle servo is a little closer to the turbo pipe on my DD than I'd like, so I was looking for options to protect it- I can make a heat shield, but I was also curious about the "header wrap" products. Advance Auto localy has a roll in stock for $45. The info on the package says that wrapping the exhaust increases HP. I was more thinking that wrapping the ehxust components make keep the exhaust hotter and burn up more of the gook thats generated when the engine idles.
The wrap is significantly cheaper on ebay. Any thoughts?
I have seen a number of race cars with heat wrap on the headers and it does keep the heat in the exhaust system and out of the engine compartment both of which help HP. Downside is shorter exhaust piping life; the mild steel headers are eaten away from the outside in.
I have been running wraps and blankets for quite a while..On my street car ,manifold and hot side of turbo wrapped was good for 20 hp..used blanket on my bus,gets a lot hotter than gas motor,will really trap moisture under wrap,but not much of a concern on cast iron manifold,just coat with good high temp paint before applying. Drops under hood heat a bunch..
I use a header wrap on a Corvette I own where the exhaust gets too close to the body. I also use it on my Generator in the bus It sure keeps the area close by cooler. Any speed shop sells a product from DEI lots of width choices.
Hi Chuck.
Any effort to put a heat shield of some sort on a bus exhaust is a great step forward. First of all, the common wisdom is that it does make more HP - at least on turbo engines. Next, it keeps your bedroom a bit cooler. Lastly, and most importantly in my opinion, is that it is a SAFETY FACTOR. The exhaust can easily be the ignition source if a liquid "fuel" line breaks/leaks. In this case, "fuel" is fuel, oil, trans fluid, PS fluid, etc.
DD engine exhaust manifolds do not permit wrapping, because of their configuration. The exhaust pipes can be wrapped with the material sold by speed shops.
The manifold can be insulated using a product that is formed when wet (like a cast). I used to sell the product, but now just refer folks to the primary source:
http://www.engineheatprotection.com/index.html
The material tends to be a bit "fragile" so I wrap it with high temperature foil tape such as NASHUA 617022 (Grainger number 6A068).
You can see how I did the installation on my 6V92 on the bus project pages listed in my signature.
When I did the Series 60 conversion, I cracked out for custom manifold and turbo blankets. The source there is:
http://www.atpwrap.com/motor_coach.htm
Hope that helps
I have read about bus fires that were caused by a leaking manifold, exhaust pipes and mufflers. I believe that wrapping them would also help prevent this type catastrophe.
Richard
I second what Jim Shepard said about the EHP blankets and wraps. I used them on my gen, cut the exh pipe heat down by 60-70%. I'm installing a new, quieter gen and will be using it again.
My 4104 w/671 really has no real need for it on the exhaust system and the space is so tight I can barely get the mufflers in as it is.
Chuck,
I wrapped my whole exhaust system and it made a BIG difference. My muffler is mounted above my engine and really had alot of heat in the engine compartment. I didn't bother with the manifolds, but I wrapped every pipe up to the turbo then the muffler. I also wrapped my intake to help keep the air cool.
I would do it again in a minute. Take your time and wrap it flat and tightwith about a 1/4" to 1/2" overlap.
HTH,
Dale
I used the wet blanket on my gen muffler and pipe. The muffler is in the bay along side the gen and after wrapping all the pipe and muffler with the wet blanket I can now put my hand on the muffler and hold it there after it has been running a couple hours. As soon as I have the money will use the same on the exhaust on the 8V92.
ED
MCI 7
Higher temperature air moves faster (less density/resistance) than lower temp air (higher density/resistance). If you wrap the headers, turbo and at least the first 4 feet of exhaust pipe - you should get a little better boost. Keeping the engine bay temperatures lower and the hot temps on the hot side of the turbo also means the cold side of the turbo won't inject as much heat into the intake air. Remember - most new turbo'd engines have an intercooler after the turbo to cool the air (and some older engines have an after cooler) - as cooler air has a higher density (more air in = more air to burn fuel/better compression = better combustion = more output power/fuel efficiency).
Also I think Richard had a mishap with hot exhaust and combustibles in his rig... It's a good safety improvement to reduce the hot surface exposure in a compartment full of oil, hydraulic fluid and/or diesel fuel. A wrap should also prevent direct out gassing towards plywood floors or rear-bedroom matresses... :o
Cheers!
-Tim
My gen exhaust and muffler happened to pass not too far from my propane tank when I got the bus. Even though the compartment was mostly open the exhaust got hot enough while parked to pop off the LP safety valve, pretty exciting on ones new bus! It was no problem while under way.
After I wrapped the exhaust, including the muffler, with EHP wet blanket the compartment wasn't even moderately warm. I wrapped the blanket with Al foil tape to keep the blanket clean and protect it from vibration. The blanket gets pretty hard and brittle when completely dry, but it sure keeps the heat in the exhaust system where it belongs.