Build on "the competition",......

clementine said

I admittedly am still learning but when I was building a nitrous motor it was explained to me that you are basically putting a lot of force on the crank pushing it out the bottom of the motor. Boost would be doing the same thing no? Not sure if you are saying why I would question a renowned builder or if you are agreeing. Im just a guy listening to what the guy said. He brought attention to the fact that they were choosing a motor that had fewer mains. RRR said it was no big deal. I believe you are saying the same. Great, its no big deal. Logically to me...Id probably go for more mains. Shed some light on me and explain how fewer mains is no big deal when dealing with those type of power levels. Im open to it.

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4 vs 7 mains in an inline 6 depends upon where the engine design group is placing more importance.
Inline 6 cylinder engines have excellent balance and a lack of secondary vibrations due to the crank throws being 120 degrees from each other. Two pistons at TDC two pistons at BDC and two pistons at mid stroke on every engine revolution. That helps the 4 main bearing design survive as dynamically the rotary motion is self balancing. The 7 main design has a shorter span between the crank supports so it will have greater stiffness and less flex at the crank. That is likely important when there are very large crankshaft loads as seen in HD large bore diesel long haul truck engines as all of those in line 6 cylinder engines are 7 main bearing designs.
So basically 7 mains are better than 4, but 7 is not needed in all applications.