Guest vvillium3 Posted June 6, 2005 Share Posted June 6, 2005 hello all, I was reading this weekend about some old engines and stumbled upon some old v-8's that used a flat plane crank??? I was just wondering what you guys know about this kind of engine. From what I learned that they are easy to tune but a bitch to balance. But theres get to be something good about them because ferrari's been using them since the eighties... also just wonder how they work because 720 degrees/8 doesn't work??? Do they fire more than one cylinder at a time??? Just slightly confunsed on this and plus just looking for more info on the subject.... thanks, jason Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted June 6, 2005 Share Posted June 6, 2005 some flat crank v8 engines fire two cylinders at a time, effectively making them an 8 cylinder engine operating as a 4 cylinder with two pistons firing at the same time, others fire in a similar manor to a typical v8 but not with the power strokes spaced 90 degrees apart but in 4 groups of two closely spaced power strokes , keep in mind the twin cylinder banks on a V8 or V12 do not need to be angled at 90 degrees, 60 degree,120 degree blocks exist you get a VERY unique sound at higher RPMS with these layouts Quote Link to comment Share on other sites More sharing options...
Guest vvillium3 Posted June 6, 2005 Share Posted June 6, 2005 So I wonder what is the most commonly used fire pattern???? So some really aren't 180 degree cranks, some are just really close to 180 (The ones that don't fire 2 cylinders at the same time) ... Quote Link to comment Share on other sites More sharing options...
Guest Phil1934 Posted June 9, 2005 Share Posted June 9, 2005 A flat crank makes each bank a 4 cyl so you get equally spaced intake and exhaust pulses. Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted June 19, 2005 Share Posted June 19, 2005 IIRC the new Ferrari F430(one that replaced 360 modena) uses a flat plane crankshaft. The flat plane cranks are generally said to give more power but more engine vibration. Quote Link to comment Share on other sites More sharing options...
Guest Will's Fiero Posted June 19, 2005 Share Posted June 19, 2005 A conventional V8 with 90 degree crank shaft is like 2 V4's put together end-to-end. Each bank is odd-fire, necessitating tricks like 180 headers to get ideal exhaust scavenging. Race V8's can have 180 degree cranks, which makes each bank an inline 4, and thus each bank is even fire. 180 degree headers are not necessary to get ideal exhaust scavenging. Flat crank V8's naturally vibrate more than 90 degree crank V8's. You know how much an inline 4 vibrates... now imagine two of them in a common block. The even fire pre bank firing order is one of the things that gives Ferrari V8's their sound. Quote Link to comment Share on other sites More sharing options...
Cable Posted April 15, 2008 Share Posted April 15, 2008 Digging up an old topic.... A buddy is interested in building a SBC with a 180 degree crankshaft. Does anyone know who would make/sell a crank like that? Thanks!! Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted April 15, 2008 Share Posted April 15, 2008 Crower makes alot of custom one off cranks. I don't know if hank the crank is still alive in AZ, but he would be another one. Digging up an old topic.... A buddy is interested in building a SBC with a 180 degree crankshaft. Does anyone know who would make/sell a crank like that? Thanks!! Quote Link to comment Share on other sites More sharing options...
bschiltz Posted April 15, 2008 Share Posted April 15, 2008 http://forums.hybridz.org/showthread.php?t=122238 I know it's kinda long, but there is a ton of great info in this thread especially towards the end. BRAAP posted some stuff that explains flat plane cranks very well. Quote Link to comment Share on other sites More sharing options...
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