An alternative to the hot gas method is the water heat method. A plate is fabricated to fit the cavity and plumbed into the engine cooling system.
I've heard arguments in favor of each. Some say with the exhaust set-up, since exhaust is coming into both ports, there is no flow. Thus, they say it would be slow to heat.
Then there are those who say the coolant method is slowest. The engine has to get the water hot enough to open the thermostat before there is any hot flow to the manifold.
Who wants to defend either position?
