Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec 3.5L Duratec?

War, it's the other way around. They were experimenting with different strokes and using the stock bore size.

With 3.0L Bore size (89.0mm), the necessary stroke reduction to create a 2.0L displacent engine resulted in mean piston speeds of only 15 m/s. They would have needed a stroke of about 53.5mm to get down to 2.0L. As you know stock stroke is 79.5mm.

Using the 2.5L bore of 82.4mm, the stroke was closer to stock and piston speed was 17.7 m/s. According to the article, they used a 62.4mm stroke.

Thanks, I did understand that they had changed the stroke. However, I guess I interpreted the writing as if "they" were referring to the two engines having a different mean piston speed before the stroke was changed and that this was the driving force for their choice of bore. Thanks for pointing out that they were calculating what the effects of a change in stroke would have with the two piston choices.

It didn't make sense that the pistons could have a different speed when the stroke was the same.

I, as I said before, acknowledge the 2.3L MAZDA designed 4cyl is a new design. Can you show me these all new 2L duratec I4s??? All I see is the "zetec/duratec" 2Ls......

I just checked this out. I think he wasnt quite reading it right about the gas velocity thing. They are saying that reducing the stroke on the 3.0L (larger bore) to a 2.0 L made the mean piston speed slower (which makes alot of since) then how much they had to reduce the 2.5L to get the same displacement. The 2.5L`s piston speed would be higher. Because the stroke would be longer. The way he said it in the FCO forum it didnt come out like that.

Im really disappointed in the power the engine made... Im convinced better and wider LSA`s would help with the over scavaging and make more power... we need some adj cam gears on these engines. Its going to make a huge diffrence when the aftermarket cams come out. Im also convinced the 3.0L (larger bore and larger distance between the intake/exhaust valves) will make the overscavaging problem alot less of an issue. Give more increases at the top of the tach. Arhh so much work...

Kermit, here's 2 good articles on the media.ford.com web page:
Article 1
Article 2

There's one picture in there. Maybe I can find some other pictures later.

Travis,

The valve centers on the 3L are exactly the same as the 2.5L and with the larger 3L valves then the edges of the valves are actually closer together. This would make the problem worse instead of better. Not sure how that helps or doesn't help the cam choices, but better to know that up front.

So these new 2Ls you speak off aren't out yet, and really they're just a changed 2.3L,,, no wonder I haven't heard of them.

Yea they are the 2.0L duratec HE`s They are currently out in Europe. They have a shorter stroke then the 2.3`s which makes them VERY rev happy little engines. In essence a 2.0 is a stroke change away from a 2.3 from what iv been told. With the flow capabilities of the 2.3L head it could make an increadible combination. Cosworth is already releasing a head/cam/intake/header package for the 2.3L duratec I4 that puts it into the 200 whp range on pump gas. Not entirely torqueless either. Lots of spine from 3000 up. Should be interesting to see how the I4`s develope.