Flex fuel question

[ranger450]

What makes the 3.0 a flex fuel motor? Heads?

 

[Earl43P]

http://www.enginebuildermag.com/Article/2179/rebuilding_the_ford_30l_v6.aspx

That link will answer SOME of the question.

They also use larger fuel injectors, the truck has a flex fuel sensor ($$$) on the frame rail and has different programming in the PCM.

 

[stmitch]

The primary differences are in the fuel system. Larger injectors, some special components, and ECU programming. The heads are slightly different, but that's mostly to make running e-85 easier. It's possible, to run a regular gasoline 3.0 on e-85 if all of the other components were in place.

 

[ranger450]

Are my valves bigger on my 3.0 valcun flex fuel motor?

 

[JP02XLT]

The valve stems on late model Flex fuel heads are 7mm, the others are 8mm

JP02XLT

 

[ranger450]

which are better to have 7mm or 8mm

 

[JP02XLT]

Not sure there is a true better choice, as for flow the 7mm stems are smaller & the stem takes less area in the port under the valve head, so if the ports (bowl area) are equal the 7mm stems would flow more due to the smaller stem (less impact on the flow stream due to smaller size) than the 8 mm stem. The late model heads also have the bee-hive valve springs which are also a better spring. However a 7mm stem is easier to bend than an 8 mm stem, guides are smaller etc etc.

JP02XLT