Flat Crank V8?

[Paulster2]

Just wondering what any of you have thought about flat crank V8 engines? I understand most all of the European V8's run these (like Ferrari). In this video from Lingenfelter, they squeeze 621hp@9k rpm out of 358ci in an LSx block N/A.


http://youtu.be/HIxngbwE8jg

For those who are unsure what a "flat crank" is: instead of rod journals being 90o apart, they are 180o out. There are several things this does for the engine, the most important being the flat crank is naturally balanced. This allows for lighter flywheel/dampener. The harmonics of the crank are a lot better as well.

If the throaty V8 rumble is what you are after, this would not be something for you. It has a very distinct, Formula1 type sound to it. I'm more curious about if anyone on here has had any experience or have even thought about something like this? Wondering how this might work out in an LT1. I realize it takes more than a crank to make it happen. Would need a different cam shaft as well as tuning (or adjustment of crank timing/trigger). Anything else?

[Fastbird]

Call me crazy but there's a reason it hasn't caught on here yet. Not sure of what that is, but just thinking, cost maybe?

[firebird_1995]

I think its because automakers have a "if it ain't broke, don't fix it" or "that's how we've always done it" mentality. The other thing would be we have become accustomed to the throaty sound the american v8 puts out. If it lost that most people would think its broke. I for one love the flat crank sound. Let's go in half-seys and get some cranks made!
:D

[InsaneSpeed]

180 degree headers, problem solved for the sound part.

[Fastbird]

180 degree headers, problem solved for the sound part.

Doesn't kalecoauto sell those?

Posted from my Rooted and ICS'd Rezound

[InsaneSpeed]

Doesn't kalecoauto sell those?

Posted from my Rooted and ICS'd Rezound

LMaO..forgot about that place. The sad thing is, they are a real design, so no, they would not sell them.

[94Blackbird]

Call me crazy but there's a reason it hasn't caught on here yet. Not sure of what that is, but just thinking, cost maybe?

The reason it hasn't caught on here is because people want that deep rumble they've come to expect from a big American V8. A crossplane crank with counter weights also operates with less inherent vibration than a flat plane crankshaft. Flat plane crank engines promote better exhaust scavenging, higher rpm, and faster revving due to their even firing order and not having any counterweights on the crankshaft.

That being said, there is a displacement limit (generally accepted to be about 5 liters) on flatplane cranks without having to use balance shafts, that's why ferrari's never made a huge v8 for their cars, due to some pretty serious 2nd order harmonics that come into play with a single plane crankshaft and the fact that adding the balance shaft would negate the advantages of the flatplane crank.

[firebird_1995]

Ehh you just gotta order it without the whirlygig. NBD