It's a myth and an internet stigma. As per some research I've been doing and been consulted about: the pressure build up that you get in your exhaust manifold can be so great, especially in a log-style, that when the exhaust valves open there is a conflict based on the pressures. It can get to the point where the exhaust from inside the manifold can actually seep back into the combustion chamber causing you to reburn exhaust gasses. When you use a cam like the ITR cams that have a good deal of overlap, you use your boost pressure to help keep that exhuast pressure out of the combustion chamber, but it needs to be tuned correctly. The ITR cams will also be tuned with the adjustable cam gears so if need be I can just tune out the overlap if it comes to that.

I've thought this out.

Oh, and Bumnah, because it's there. h: