Originally Posted by Tommy the Cat
The exhaust manifold is far more effective at combating this because it heats the intake much faster than waiting for water to heat up while the pooled up fuel hurts your emissions and sneaks past your rings when it gets to the combustion in liquid form thereby washing oil off the cylinder walls and contaminating the oil in the crankcase.
Vapor locking, by definition, does not occur to cold fuel. It is a result of hot fuel boiling and turning to "vapor". I'm not sure what you are experiencing when your truck is cold but it is not vapor lock. Perhaps you are experiencing an overly rich mixture caused by what I explained before.
If you simply must use a header (like I did before I knew better) the liquid heaters are better than nothing but it will never be as effective as a manifold and you WILL see increased wear from the overly rich condition before the water gets warm enough to have an effect. It may be academic but a fact just the same.
Sorry, but I don't agree with you. First off, every carbed V8 engine in the world relies on either the water heating up or thermal transmission via the metal to metal contact with the cylinder heads to warm up. They have many more intake runners and bends than a 2F does. They have no more issue with emissions or cylinder scoring from wash down than any other engine. Very few engines have the exhaust manifold bolted directly under the intake & carb.
Also, even if you do get a miniscule amount of liquid fuel in a cylinder, it only lasts until the first time that cylinder ignites. Any that does get into the oil usually evaporates out of the oil and is ingested into the intake via the crankcase vent valve. I routinely do oil testing via Blackstone on my 2F with a header and my fuel content in the oil is always less tha 1%, up to 3% is acceptable.
Ricardo is not saying his truck vapor locks when it's cold. He is saying that by having the liquid heat riser wick the heat away from the bottom of the intak/carb, it prevents it from ever getting hot enough to boil and cause vapor lock.