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Hello guys and gals,
what is the best way to insulate a single header? I have trouble with engine bay temps causing my starter to fail. I have tried insulation wrap, it works but it falls apart in about a year. Do the coatings cut heat? They sure look good. Who would you recommend? Thanks!
Hartley
There might be a setting in your Apexspeed profile that allows you to see more previous threads. There's literally a thread that deals with this very topic right below your thread (at least on my view):
https://www.apexspeed.com/forums/att...d=110077&stc=1
IMHO, you should NEVER "WRAP" a starter to protect it from heat. You need to SHIELD the direct heat with some sort of 'heat blocker' - such as a trimmed Aluminum sheet formed to block as much heat as possible and catching enough air (wind) as you can manage 'end on to the wind' to keep the sheet from getting too hot. I do the same thing above the exhaust headers in my vee - works quite well.
Needs to be stout enough to endure the abuse of racing or you'll be replacing it every weekend.
Depending on how your starter is mounted you could also shield it from engine block heat, but that's not nearly as important as exhaust heat.
Header coatings seem to help extend the life of a header system, but don't do much to reduce radiated heat. WRAPPING the header will help block some heat.. but in turn that keeps it in the header - which if you are using regular steel headers reduces the life of the header.. which is generally way more expensive than replacing the starter. IMHO, see above - that is the easiest, cheapest way.
Another way to help is to 'catch some air' and direct it to the starter or between the header and starter, but takes a lot more air to perform the same as a physical Al shield.. maybe some 6061 x .060 sheet should do the trick nicely .. if you can fab it appropriately. 6061 works well but it tough to bend and shape. Make your first one out of softer Al (3003) and maybe go through a couple iterations, then make the last one from 6061.
Steve, FV80
The best way to deal with exhaust heat that I have found is to build a box around the header and feed that box with an air scoop. Also have a good exit to the box so the incoming air flows over the headers and out the exit area.
Dave Weitzenhof has a setup on his car that has worked great for many decades.
Wraps will retain the heat in the exhaust system and lead to early failure of the system.
Steve, could you share a pic or two of this please?Quote:
Originally Posted by S Lathrop
bt
I scrounged through old files and I cannot find pictures of how I shielded the exhaust systems.Quote:
Originally Posted by billtebbutt
If you look at pictures of the Citation engine covers you will see 2 large NACA ducts on both sides of the engine. Those were the inlet air source. If you look at pictures of Dave Weitzenhof's engine cover you will see an extension the engine cover to the end, in the shape of a tunnel. That is how he pulls the air through the engine compartment to cool the upper part of the exhaust and the intake manifold. The original engine cover had louvers down the back side but they were not all that effective compared to the tunnel.
When I had an issue with the engine compartment getting too hot, I made some shielding to separate the upper engine bay from the lower engine bay. The lower engine bay in my case contained the headers + exhausted air from aircooled cylinders. This all became necessary when I flat bottomed the car, which covered over the bottom of the engine and trapped hot air from escaping the engine bay efficiently, and I had an issue with the throttle cable sheath melting. Also added louvers along the bodywork next to the engine bay (where my newly made sheet metal directs the hot air) to encourage air to exit there. Lowered the engine bay temp from 200+ deg F to about 150, and it addressed the issue wtih the throttle cable
To help your overheating starter, how about putting some shielding between the starter and the heat source (presumably the headers), and duct cooling air directly to the starter. I might prefer option, if it's possible, to cooling the exhaust.