Has Ferrari ever produced an engine that does not use a flat plane crankshaft?
Yes (Someone will correct me if I'm wrong, but....) I believe none of their 12-cylinder engines use flat plane cranks. I'm fairly certain the 6-cylinder engines also were not flat plane cranks. Or, are you only talking about the 8-cylinder engines ? Those were all flat plane I believe. I suspect, but am not certain, that the 4-cylinder engines were all flat plane, as well. .
^ That's interesting. I did not know that. I always thought it was just basically a slightly modified 308 engine.
Recent vintage Maser V8 use cross plane crank as well even though based on 430 engine I f I'm not mistaken
V6, V12 and Flat 12 are not flat planes, as there would not be possible to make a well working engine with such a crank. I don't believe any V8 Ferrari models have had a cross plane V8. A 12 cylinder crank 60+60+60 degrees is naturally balanced and a 60+60+60 degree V6 and I6 needs very little balance.
Because the desired property is "alternate bank firing" (i.e., having the exhaust pulses entering each exhaust manifold equally spaced in time) -- which allows sharper "tuning" of the exhaust flow = higher maximum torque/hp (but there are some trade-offs which is why they went the other way on a Thema 8.32). The "flat" crank shape gives that behavior in a 90 deg V8 block (with simple exhaust manifolds), but not in a 60 deg or 180 deg V12 block. On a 90 deg V8 with a cross-plane crank, you can still get alternate bank firing, but it takes routing some cylinder's exhaust in one bank over to the other bank's exhaust manifold (so those aren't simple exhaust manifolds).
Yes. They have made 12's of various degree "V" angles ---- 60, 65, 75, & 180 (e.g., the "Boxer" engine). All were cross plane. Here is a photo of an actual Boxer crank --- you can easily see the (3) pairs of crank arm angles each at 120 degrees from one another. Image Unavailable, Please Login
I had read about this and it said the decision was made to reduce vibration making the ride in the Thema "smoother".
you are confusing the issue. there are 2 types of v8 cranks for a 90 degree v8 block. the standard ferrari v8 crank is a flat crank- or a up- down- down- up drank pin. A standard v8 chevy ford etc has the crank pins every 90 degrees- or 12 oclock- 3 6 &9. I am told the 430 front engine v8 are 90 degree pin cranks because the long stroke caused too much vibration with the flat crank. I am told flat cranks will not work with long strokes (over 3 inch?) because they can only be balanced in 2 planes where as the other has 4 planes of balance. A 308 crank weighs more then a 454 chevy crank.When I asked about removing the counterweights like the 4 bike engines I was laughed at. Those cranks have no counterweights- they are flat. 1 of the new jap bikes uses a up- down-up- down flat crank. Bruce Crower tried that on a chevy engine at indy in the 60s- I am told it did not work well. Smokey chased it, so have nascar guys and a few pro stock guys- I believe they all tried the up down down up cranks. When you change the tri y headers on a 355 to aftermarket 4 into 1 headers the fuel curve must be re done. No stock v8 ferrari has ever used a 4 into 1 header. Tri ys appear to work on a flat crank and not on a standard crank. I believe no nascar or pro stock car now uses tri ys
308 was a stone age crank, have you looked at a 360 crank? Same engine family but greatly reduced crank weight. No stock Ferrari V8 has ever used a 4 into one???? What do you call the 360, 430 and 458 headers? 4 into one works fine, it all depends on what characteristics you are looking for. Tri Y doesn't work on a 90 degree crank? That's odd. Sure got used a lot for something that doesn't work.
I thought the issue was to do with breathing at high revs. With a 90 deg crank, you get even firing pulses, but some exhaust pulses happen on adjacent cylinders. That creates the throbby exhaust note that typical V8's make, but makes managing the exhaust gasses very difficult at high revs unless you have a cross-bank exhaust (like Ford GT40's and Repco V8's among others, had in the 1960's). If you want a V8 to rev, a flat-plane crank sorts the exhaust gasses out neatly, because the engine effectively runs as two 4-cylinder engines on a shared crankshaft. That is the solution Cosworth went for with the 1967 onwards DFV and derivative engines, and also the one that Ferrari opted for from 308 onwards with its V8 engines. I suspect that the decision to go with a 90 deg crank for the Maserati application of the 430 engine was mainly driven by marketing considerations (emphasising the GT nature of Maserati versus the sports nature of Ferrari), but may be being too cynical. I doubt it though...
Yes they did- we have a "268 SP," SOHC, 90 degree, V-8 engined sports prototype...its odd, it sounds like a "Buick or Chevy"...amazing low end torque, for such a small displacement engine. The crank plane issue has, in reality, little to do with exhaust pipes...this is more a byproduct issue, than a predicate issue, as it were...these issues are principally concerned with balance issues, "gross rotational" ...as well as harmonic/sympathetic... All the rest is conjecture not based engineering factors or concerns.
Generally speaking, one of the primary factors driving the 180 degree V8 crankshaft design (especially for a low-volume manufacturer like Ferrari) is capital cost management. The flat-plane crank can be forged with at least one less die set ($$$) and with fewer strikes than a 90 deg or 120 deg crank. If you're capitalizing an operation for a million or more units (e.g. domestic V8), you can afford to carry the additional tooling cost, but a small operation would be challenged.
cool discussion about cranks,also remember the term "boxer" is refering to type of crank,up and down,not shape of the block,from a enginering point of view
