Originally Posted by iamtheari
I didn’t notice any improvement.
The symptoms suggest fuel heating and vapor generation. Although we tend to use 140F as a threshold value for vapor, the truth is that avgas is a mix of many volatile constituents, some of which have much lower vapor points.
No improvement with boost pump on says vapor formation is probably not happening prior to the engine driven pump.
Which brings us to Bryan's note above. The standard RV-14 firewall forward runs the servo feed line and fuel flow sender very close to the left side exhaust head pipes, in particular #2 (see attached). Personally I think that line should be shortened by an inch or more. Even if not a fuel heater, it would add some lifetime to the hose. For sure the pipes need heat shields.
In addition, there is an exhaust crossover under the rear of the servo. Do you have a heat shield on the pipe there?
BTW, the heat shields can be improved without much effort. A bare shield reflects some radiant energy. It absorbs the rest, and in effect divides it up. Some is carried away by convection, while some is carried to the other side by conduction, where it is re-radiated. Some of the re-radiated energy is reaching the servo. To reduce it, simply add an insulator to the servo side. Cut a patch of fiberfrax felt to match, and cover it with a wrap of aluminum tape. Done.