I agree, stopping and starting pistons is very costly. rotarys are a much better idea. just as jet turbans replaced piston engines in aircraft, not because they produce power or use less fuel, they will run 50,000 hours before you have to even look at them. pistons engines need top end jobs at 250 hours and full rebuild at about 2000 hrs.
Dave

 

I like rotary engines as long as they aren't in trucks. They require way too high of RPM's to be considered for practical truck use. Yeah you can spin the hell out of those things and produce some nice HP, but who wants to be running at over 7000 RPM's pulling a load. So anyways, lets get back to the thread topic.
How is 5 cylindars an oddball number for an inline motor, it's been done before by other auto makers, Mercedes diesel, or how about the old Geo 3 cylindar, ok, maybe not a good example. Although I did have a friend with one that had no problems, no power either, but that thing could go over 40 miles on a gallon of gas. I'm not saying the I-5 is an awesome motor, but it is respectable. AS far as inline vs V engines, I hear of problems with both all the time so I don't think you can say that one is superior to the other design. Some people claim that inlines make good low end torque, and then GM comes out with one that peaks in HP at 5600 RPM's. Others say OHC motors don't make any low end torque, but Fords 5.4 makes more torque per liter than anyother gas truck motor except for the DOHC Nissan Titan's 5.6, which further disproves that. There is so much more to an engine than just being an inline or DOHC or what ever.

 

Well, obviously each different design of a motor is going to have it's peaks and valleys. Yes, your V's are good for hp, due to the sheer design, this is why you don't see inline motors in drag racing. Inlines are better for torque, which is why almost all semi's have inline (most are inline 6's actually). And rotary motors, you can afford to have cranking at 7000 RPM, because it is all rotating in the same direction, which is a whole nother ballpark than a v or i. 7000 RPM on a rotary is like 3-4k on a v or i.

I do agree though on the "oddball". I mean, it's not really all that odd, it's been done before. In an I it doesn't matter how many cylinders you have, for the obvious reason being that they are in a strait line and dont have to push against eachother.

It's elementry physics.

 

the i5 came from a european design but, what the heck i'm a ford guy what can i say ford v8 and 6's have been around a coons age think i will go with the proven design