318 MAX fuel economy builds?
Is there a stand alone spark control aftermarket unit for these engines? Something that advances spark just below ping?
No, this is something you set up on older rides. Computers have knock sensors.
I remember 30 years ago Jacobs energy team made something. Are they still available?
Not new, check eBay for Jacob’s ignitions.
IMO, exhaust heat is just not consistent enough to use to aid in vaporization. Coolant (heated coolant) would be much more consistent, although you wouldn’t get much help from it on cold starts until the engine temp came up.
Why not both?
The factory used both. EGR holes in the intake floor are opened up with a high vacuum. (I don’t remember what I tested the egr valve open up at, but it does close under a WOT condition.)
So the exhaust will heat up the floor of the intake first and the entire intake track very quickly. During warm up time.
Of course coolant temp takes longer and is more controllable than the egr gasses.
It works but only so fast and so well.
You yourself will have to be on point on this. Also, speaking from experience on this mileage hunt, and not a whole lot of it but when I was hunting for a as much as I could get and the ability to pass the tail pipe test, you can set it up really well for the time your doing it and have it fall off from target pretty badly in six months.
As mentioned and forgive the dead horse beating here, but truly the bottom line is the proper size carb for the job at hand that should be kept cool and have a reasonable primary size to allow a good cruise power without struggle. The fuel from leaving the bowl starts its journey into being mixed with the air. It starts there. Then through and out the booster. This path IMO, should have the fuel well mixed with the air and for throttle and mileage purposes, should leave a annular booster.
Once you find a good mix of air and fuel leaving the carb, the intake is the next part of the travel path that can bennifkt from a certain amount of heat. This is where the coolant temp will come into play.
After that, a multi spark ignition. Then pay attention to the spark plug gap and the ring left behind on the plug. Plug reading and style of plug as well as manufacturer will all come into play. This will be part of the experiment.
Open up the plug as much as practicable.
Many years ago N.Y. State had vehicles tested on a set of dyno like rollers the rear wheels would sit on and the car needed to come up to speed (55mph) and have the exhaust read. I had to run a catalyst and since I had dual exhaust…. Yup! I ran two cats. I grabbed a set of high flow cats from Summit.
Ran great, ran as clean as a newer car, still got 20 mpg’s.
Not awesome mileage, but not to darn bad from the kid tuner 30 years ago.