View Single Post
Old 07-31-2013, 10:24 AM   #8 (permalink)
It's all about Diesel
cRiPpLe_rOoStEr's Avatar
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 8,436
Thanks: 0
Thanked 917 Times in 812 Posts
Originally Posted by Aguila1 View Post
I did have some drivability issues when the temperatures dropped to near freezing - with 2.73 gears and overdrive, it would buck at low rpm. I suspected freezing, but never actually saw any icing. Keeping the engine and intake hot is the reason I went back with the excellent Pontiac cast iron manifold.
Getting the idle stability right after the start-up is still the biggest challenge while running on ethanol, and it will rattle a little more when it's still not warm enought. No wonder many Brazilian cars, either dedicated-ethanol or flexfuel, have an auxiliary tank which holds a small amount of gasoline to the start-ups at temperatures usually below 50F when automatically-controlled, altough older vehicles had the cold-start activated manually at any temperature. But nowadays some vehicles such as the Peugeot 308 with a 1.6L flexfuel engine have pre-heaters at the injector tips, not requiring the auxiliary gasoline tank.

We might throw a supercharger on the engine in the future, as the bottom end has been greatly strengthened, but more than likely a better candidate is the "Ford", which is of a magnitude stronger with all forged internals and NASCAR derived block.
When using the supercharger, a cam with a longer intake valves opening is good because it will emulate a longer power stroke and a shorter compression stroke, altough the supercharger will overcome the power and torque losses from the discompression generated by the longer intake valves opening.

I enjoy the insight into the Brazilian ethanol experience, which has led the world towards a more renewable and sustainable future.
Well, the Brazilian ethanol experience was not so great because the usage of compression-ignited engines was too much neglected during the ProAlcool era. Sure the prevalence of the indirect injection in light-duty Diesels at that time, and the requirement for some lube to be blended into the ethanol to avoid damages to the injection pump, made it harder, altough nowadays with the prevalence of the direct injection in Diesel engines the ethanol is easier to adapt to their current emissions-control requirements, actually even easier than biodiesel.
  Reply With Quote