The firing order is also different on the 456 versus the 550 and 575M. 456 motors are pretty under stressed. Cheers, Geirge
George- The firing order has been the same for nearly all the V12 Ferraris, except the 456M. The 456 and Maranellos have the same firing order.
Okay, I think I remember correctly now: The 456 was a change from the 412. I can always count on you. Cheers, George
YES! The 456M is different from the 456/550/575. I did not comprehend your post. It seemed as if you were saying the 456/456M/550/575M all had the same firing order. I know my car is different, and that's what matters. Cheers, George
The 550 Ti rods were never designed for 650hp race engine but they could have been. Parts and part selection has to be looked at as a cohesive system and package. There are reasons for each part selected including cost. It is way cheaper to caveman a huge steel rod than push the limits in Ti or steel. OEM's take great pains to design, engineer, and test engines for their use. The Ferrari engineers proved the Ti rods in the 550 if it takes 650hp to break them. A 485hp 550 motor never will never be there and there is no routine failure of this part in the fleet. In racing we stress parts until they break. We redesign then find what breaks next. In low level club racing and even in the pros parts are often selected thinking they are a good idea. Then we find out what a mistake that was on track. That's racing. With all due respect I think people should look at these motors and the models "in context." The 456 is a 4 person lux people hauler, the 550 a grown-up executive's GT, and a 458 new young money. I think the motors as part of those packages reflect that.
John, to complete your table, I think you can safely put the 456 lift at 8.5 mm....But.... it's only about 8.2 mm if you subtract the valve clearance..... Just thought I'd drive you crazier than I have already.... Regards and Thanks......Mark
Mark, thanks for the update; yea the last go around with setting the valves really did my head in until it was pointed out that there was a temporary shim involved.
Taz, my body clock is permanently screwed up from the work I used to do, so even though I'm now semi-permanently stateside, my body still wants to be on GMT or GMT+1. I can't sleep past 2 or 3 AM no matter what time I go to bed .
John- Ouch. 20 years of flying at all hours on both sides of the pond taught me to sleep whenever I could. Still works and I spent 14 years arround the Greenwich Meridian + or - an hour or so.
Since I've read so many contradictions on this matter, I checked al the manuals again and found the following info: 456 GT until '96 Motronic 2.7 and firing order 1-12-5-8-3-10-6-7-2-11-4-9 456 GT/GTA after '96 Motronic 5.2 and firing order 1-12-5-8-3-10-6-7-2-11-4-9 456M GT/GTA after '98 Motronic 5.2 and firing order 1-7-5-11-3-9-6-12-2-8-4-10 The 550 and 575M have the same 'deviating' firing order as the early 456 models, so 1-12-5-8-3-10-6-7-2-11-4-9. So, for the 465M Ferrari actually returned to the 'traditional' firing order they used for most of the cars in the past. Natan
Natan- A common misconception caused by Ferrari changing the numbering system on the cylinders. On the 60 degree V12s, cylinders 1 and 12 are forward. On the 65 degree V6 for the Dino, cylinders 1 and 4 are forward. For the 65 degree V12s, the Dino numbering system was adapted and cylinders 1 and 7 are forward. If you do a drawing and draw all the lines, you will see that the 60 degree and 65 degree V12s have the same firing order, except cylinders 7-12's numbers are reversed. The 456M deviated from this firing order and was a one-off for the V12s, an experiment Ferrari did not repeat.
How can 1 & 12 be forward on the 65 degree V12 engines, if 1 & 12 are also forward on the 'old' 60 degree V12 engines as seen in the picture? Natan Image Unavailable, Please Login
If 1 & 7 are forward on the 65 degree engines, then the numbering system is not a 'horse shoe' as stated by many, but then I see your point of both engines firing in an identical pattern with only the actual cylinder numbers being different. If 1 & 12 are forward on the 65 degree engines, then the numbering system did not change compared to the classic 60 degree engines, meaning that the firing order on the 456 is different... Natan
Natan, you appear to be interested in learning about the why's and where'fors of Ferrari's numbering & firing sequences. Our engines are descendants of the famous "Dino" engines, and the firing sequence reflects this as well. Ours are firing like six V-twins linked by a common crankshaft, and this is the way Vittorio Jano and Ferrari's son Dino designed "their" V6 back in the day. The 456M, as Taz said, was a one-off departure from this. You might be interested in picking up a copy of a book called "The V12 Engine" by Ludvigsen. It's a great book in its own right, but there's a very interesting Annex at the back with a technical analysis of all the known V12's and their cylinder numbering and firing orders.
So this is it then... Left: 60 degree Colombo as used from 1947 to basically 1989 in the 412. Middle: 65 degree as used in the 456, 550, 575, 612 and later F 140 powered models Right: one time only combination as used in the 456M Natan Image Unavailable, Please Login
I bought that book a while ago, but it doesn't mention cylinder numbering for the specific engines and engine generations. That is one of the reasons why I dug into this. With many people stating many different things, it became unclear as to what is the actual 'truth'. After checking a few other forums I even found contradicting statements from the same person... Natan
And I may have been that person, because I was on the same quest as you back in 2010 and was getting a lot of conflicting info. I never did figure out whether the people who knew just didn't want to share, and all the rest were propagating BS, or what Fortunately, Brian Crall came to my aid back then, and he's been a friend and a great resource ever since.
I just wanted to say thank you, this is a very interesting thread, for a zero-tech person like me, in awe of this mechanical and historical knowledge.
I think I recall that I read somewhere the order was changed in the M to smooth out idle and provide better low end drive-ability - but I don't think I've ever read any followup or head-head comparison on such... If they switched back it would seem perhaps it didn't accomplish that goal...
Glad it all worked out. It surprises me though, that some people have issues sharing (technical) information with others. Specially in a forum like this. Natan
