I have an early sixties Ferrari; it now has a late model 456M 65-degree V12 engine six down draft Weber's etc I plan on adapting a Jaguar V12 distributor coming off the back of the right-hand cam shaft Actually, i already made up this configuration with and early V12 points distributor not knowing that the 456M fires 6 cylinders at 65 degrees and 6 cylinders at 55 only to find out that only some of the cylinders fired Durrrr Now the Jag fires at 60 degrees as does a Lamborghini has anyone out there any suggestions how I can make this Jag dist work I may have to design a new cam/reluctor and somehow build a new cap or modify the Jag one. Two six-cylinder distributors will not work either they are out of phase This is an odd firing V12
Surely would be but is not. The 65° refers to the angle between the cylinders on opposite banks and is designed to give more room for the intake tract than a 60° V12. The only odd thing about the 456M is that Ferrari tried a different firing order from the other 65° V12s. Timing is based around top dead center for each cylinder, just like any other V12, V8 or whatever, regardless of angle between banks. The crankshaft is designed to match up with the bank angle. She is effectively two inline sixes on a common crankshaft. The 65° angle theoretically does introduce a very slight secondary imbalance, but with that many firing events, not really noticeable. Ferrari has used up to 75° V angle on F1 engines.
You mean the magneti marelli jag distributor? It's very similar to the 400i one, in a more troublesome fashion... maybe you could retrofit the single coil 400i cap and rotor and use a proper ignition.
Here is what I came up with after carefully rotating engine with a degree wheel attach to crank and noting each and every cylinder at TDC At then end of day I found that 6 of the cylinders are at 65 degrees and 6 are at 55 degrees Example a 60 degree V12 you take 360 degrees divided by 60 and you get 6 hence the point distributor I have has a 6 lobe cam with two sets of points in other words on a complete rotation of distributor both sets of points open and close 12 times The Jag distributor I also have is a magnetic with a 12 point reluctor/cam Hear is my theory 360 divided by 65 equals 5.54 and 360 divided by 55 equals 6.55 now does one need a special reluctor/cam made and along with a distributor cap with off set terminals I feel the two x 6 cylinder distributors will not work no different than my Jag one
It seems very strange to me that this v12 is unevenly distributed. Ferrari does not cast their crankshaft, they machine them: why would they spend so much money to build something odd? Does your dist. have built-in rpm advance? is this the one meant to feed two separate coils?
I am going to try the Jag distributor maybe the 5 degrees Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
You are so close to the flywheel, why don't you just use two hall sensors and a pair of microplex from the 412/testarossa? Another approach would be to further dig into the 365/400/Jag ignitions: their magneti marelli distributor was upgraded over the course of two decades: two six cylinder distributors with point, same with low polution timing offset, same with booster, then single 12 cyl with reluctor, etc. The jaguar approach "one single dizzy for two coils" was the least reliable, I'd rather stick to single dizzy + single coil OR two dizzy + two coils. (If the outer carbon brush of your jag distributor gets damaged, your left bank could flood the hot exhaust with unburnt gazoline.) If all you need is to retard one bank by 5°, maybe you could use two HEI module as boosters and activate the 5° offset of one of the module (need to buy the modules that do provide this functionality). Given how cheap the modules are, this would let you easily know if your assumption is correct (without messing with the complex distributor).
You started 2 threads with the same name and same post. @mods is it possible to merge the threads. Neat project. Hope to see it come together
Wasn't exactly at you... there are 2 threads going, both with interesting information on them. I assume you didnt mean to post it twice, but ended up with different threads. Its quite the project... good luck! Here is your other thread... https://www.ferrarichat.com/forum/threads/456m.702861/
You have to remember one thing: 65° V12s have 12 equally timed firing pulses, just like any other V12. The crank is shaped differently, but you still fire the 12 plugs symmetrically.
