I have to disagree about the Toyota 7MGE and 7MGTE. Haven't you heard of the headgasket problems associated with these engines? These things blow headgaskets like they're going out of style. I should know since I'm currently working on a '91 Cressida (7MGE) which is in the shop for, you guessed it, a blown headgasket. I don't know how many Supra's I've encountered with headgasket problems. I do agree that the 7MGE can make good HP without too much trouble, but where are you going to put it? The Supra weighs about 1000lbs more than a 240Z, and it would be taboo to put a Toyota engine in a Nissan.
Also, I don't think you can compare the 7MGE to any Nissan RB engine. I think that the RB engines are much more reliable. I have not heard of any factory problems with the RB engines.
Also, where do you come up with fewer bearings on an inline engine? The L6's have 7 mains as opposed to the VG30 with 4 mains. I think a V4 would only have 3 mains.
Please don't think I'm trying to flame you or offend you. I just think that lots of people on this forum might be misled by some of the statements you made regarding this post.
Acura used to have a straight 5 as well, i belive they put it in the older gen Legend. As for the V4, I believe that some motorcycles use it (harleys? i may be wrong there), but the straight 4 is already fairly well balanced(4 pistons, with 4 strokes of the engine cycle), while keeping the size small enough to be used in most applications
The early 70s saab sonet had a v-4 that was made by ford. I guess a v-4 would made similar to a flat-4 except would be more upright. Just like a v-6 should be similar to a flat-6. I'm saying its 100% true, I might be wrong but it makes sense in my head.
My guess on why they dont make many of them is because a I-4 is alot easier to make, it has less parts(two heads vs one one), the I-4 is already small enough to be used in any car. I guess its almost like v-6 vs I-6.
This one responds to brian944t. The acure vigor had a straight 5 cylinder in it. My uncle owned one for about 5 years. Ran really smooth and tons of power he really liked it unfortunately he had about 250,000 kms on it so he got rid of it.
Several motorcycles run v4's, among them are some pretty fast bikes including the Honda VFR series, the Honda ST1100 and now ST1300, the Yamaha VMax, Yamaha Venture and Venture Royal. There are probably more but these are common. The v configuration is of benefit because it allows for a shorter narrower engine of a given displacement. Flat 4 is long (my Gold Wing flat 6 is bigger than my wife's Saturn engine), straight 4 is wide (remember the Honda CBX?) and vtwins shake like mad.
Yeap, Honda/Acura have a straight 5, my friend has one in his Accord Inspire.
Audi also made 5 cylinder engines, I think the early Quattros were 5s, and then turbo 5s which were very very quick. Landrover also make a 5 cylinder turbo deisel.
I read somewhere that Lancia used to make V4s?
VW has a interesting history, but school is in recess. The older flat fours had no counterbalances on the crank, and for those talking about rotaional mass... Porsche uses a similiar flat 6 some turbo'd. Theoritically this type (horizontaly apposed pistons) is far superior to any V or in-line. Infact the star pattern is very widely used in aviation with only one main connection rod, all others bolt onto this one rod. Talk about a weight and space saver!!!