Outer Limits 4x4 Board

Cj - Most older automotive textbook talk about 12.5 being the stoich.

the 14.7 comes up in newer data, a lot of vehicles run at this to meet emmisions i think true stoich is still at 12.5

Gwagen- lots of maths but i figured everyone reading could get a chance to see why a fuel with less energy can produce more power. Small building blocks that others may have missed when reading the link.

Another way of looking at it might be put that the 100cc E85 engine is the equivalent of a US 124cc engine as far as power and fuel economy

(Imagine If you could build a g13 that had the same power and fuel economy as a g16 with the option of switching back to petrol g13 economy on an off week. )

If you still believe you can make up the 30% fuel economy difference with compression and timing and still have a car that starts cold and is drivable, go for it.

It can't be done with LPG and that has a far higher octane than e85, even with factory development (Ford factory straight gas) because it's a less thermally efficient fuel.

Steve.

Lpg stoih is around 15/1

It can not benifit from the many hand make light work that ethanol can

As promised here's the PDF file.

http://www.environment.gov.au/atmospher ... soline.pdf

Its VERY comprehensive with lots of real research based data - I suggest reading the whole thing as its a complex subject with lots of swings and roundabouts.

However Pics of components are towards the end of the file and are very illustrative.

I'm not advocating one or the other fuels - I just suggest you consider the obvious impact on the fuel systems and engines tested.

Found the pictures - will post tonight or the engine report if I can find a file host for the PDF

thanks mighty mouse i will read it tonight

Left - Piston on Petrol, Right Piston on E20 - note staining and blowby evidence on skirt with E20



Left - Chanber Petrol, Right - Chamber on E20 - note deposits around valve guide on E20



Left -Valve on Petrol, Right Valve on E20 - note buildup on E20 valve



Valve undercut - Petrol VS E20 - note how much undercut on E20

Which page was that on?

I've been reading through the report supplied and can't find those pictures. I'd like to find out why they got a picture from cyl 1 for petrol and then cylinder 2 for e20

To clarify for those who haven't gone through the report the test is on E20 and its effect on unmodified fleet vehicles. The report had some carb vehicles in it too.

The pics are part of a separate even more detailed report that's not available online. I have extracted some of the pics.

Only the valve pics are from different cylinders and they are the worst situations for petrol and E20, not an invalid approach.....