Intake manifold heater

[Bearleener]

Cold starts suck! One good solution is a block heater, but that doesn't work for the drive home (no outlet at work). A Prius-style Thermos for the coolant would be cool, but that's complicated and requires a mighty big Thermos (or several of them) if you want to heat the entire engine quickly, and the system would probably need to be under pressure.

How about only heating the intake manifold? I read that condensation of fuel on the cold manifold passages is one major reason for high gasoline consumption when cold. Indeed, my manifold has a small electric heater as standard equipment, but that's too ineffective. I'm thinking of something like a bag (hot water bottle) contacting (lying on top of) the aluminum manifold. This hot water (not under pressure) would be stored in a Thermos overnight and pumped into the bag right after a cold start.

Somewhere I read about a warm air intake. Is this for quicker warmup or for improved steady-state efficiency? What's the heat source?

Thanks!

[Daox]

I would think you would have much better results by dumping that hot water directly into the engine as coolant.

On modern cars with fuel injection there isn't much time for the fuel to cause condensation and cool the intake manifold. Thats IF the fuel even touches the intake manifold. Most designs have the injetors mounted in the head, so the fuel is injected after the manifold.

[RH77]

Originally Posted by Bearleener

Somewhere I read about a warm air intake. Is this for quicker warmup or for improved steady-state efficiency? What's the heat source?

For me, the warm air intake is both for warmup and FE. The air is sourced near the exhaust manifold -- in Winter, this helps keep the intake air within ranges that are more efficient, and gets that sensor input better suited for the ECU's decision for most efficient operation. I've found my engine to operate most efficiently at 90-110F IAT. Nearly all manufacturers (and sometimes between different models) react differently to this mod. It takes some testing...

As far as heating the intake, I'm not sure if that would net you significant gains, as the rest of the vehicle's components have to 'warm-up' as well...

RH77