456, 456M, 550, 575M, and 612 Cambelt Tension - Ferrari Life
 
LinkBack Thread Tools Display Modes
post #1 of 11 Old 09-24-2011, 06:30 PM Thread Starter
Owner
Elite Member
 
tazandjan's Avatar
 
Join Date: Aug 2011
Location: Albuquerque, NM
Ferrari Life Posts: 11,871
456, 456M, 550, 575M, Superamerica and 612 Cambelt Tension

For owners, there are two very important Assembly Numbers in the history of the 65 deg V12s with twin rubber cam timing belts. The first of these is Assembly Number 28614 for the 456 and possibly the early 550. At this Assembly Number Ferrari updated the cambelt tensioner pulley bracket to a newer model. This tensioner bracket remained unchanged throughout production of 65 degree V12 cambelt engines and through the 612.

Ferrari Parts : 171060 : 171060 PULLEY BRACKET

The second important Assembly Number is 43847, very early in 575M production (all US cars were later and the Geneva Autoshow car was Assembly Number 43148), when an improved cambelt was introduced that allowed cambelt change interval to be changed to 5 years or 50,000 km (~30,000 miles). When this belt was introduced in late 2001, it superceded the old belts for the 456, 456M, 550, and a very few Euro spec 575Ms.

The point of all this is that all of the 65 deg V12s with a recent belt change have the latest belts. If owners of early 456s (and possibly early 550s) change out their tensioner pulley brackets, they will have exactly the same cambelt hardware as the 575M and 612, which have a five year belt change interval. From there, draw your own conclusion on what belt change interval should be.

Now that we have looked at a little history of belt hardware, time for a bit of history on belt tension numbers. For the 456, 456M, and 550, the recommended tool was the Staeger FST 50 Tensiometer. This tensiometer measured the acual tension of the belt between the pulleys using a depression of the span to calculate tension. Results of this type of tensiometer were not particularly precise and not very repeatable.

For the 575M, a new type of tensiometer was recommended that used the harmonic frequency of the belt span to measure tension. This method of measuring belt tension proved to be very precise and repeatable. The recommended tensiometer was a Seems Tensiometer Type Diapaz, which cost around $2K. The nearest equivalent was the Gates 507C Sonic Tension Meter, which retailed for $800 and could be occasionally found for a bit less. Both of these tensiometers were way more complicated than necessary since they were designed for multiple applications, and not just automotive belt use.

Luckily, the Ducati folks found a much simpler tensiometer just for automotive or motorcycle belt applications, the MotoReva MT-112, that only costs $249.99.

MotoReva - Ducati Tools and Supplies

So now down to the real meat of this thread for anyone who would like to do his own belt change on one of the 65 deg V12s. These V12s all use the same belts and the same tensioner hardware, so the harmonic frequency for all the cambelts is the same and we know what that is from both the 575M and the 612 workshop manuals. From the 575M WSM, the frequency when the longest span is struck is 126 hz. The 612 WSM expressed it differently and wanted measurements of both the spans on one cambelt added together and the sum of those frequencies should be 335-360 hz. Logically, the 612 frequency was more than twice the frequency of the 575M WSM single span because the shorter cambelt span has a much higher frequency.

Note that this tensiometer can also be used to measure the tension of the auxiliary belts, and the 575M numbers should suffice for the 550, too, but I am unsure of the 456 and 456M applicability. 612 owners have numbers in their WSMs.

Here are the applicable pages from the 575M and 612 WSMs.

Any pros jump in here if I have gotten any of this wrong.
Attached Images
         

Taz
Terry Phillips

Present: 575M 135171
Past: Dino 246 GT 02984, 365 GTB/4 14009, 308 GTS 25125

Every day I look around, and if nobody is shooting at me, it is a pretty good day.

Last edited by tazandjan; 09-24-2011 at 06:35 PM.
tazandjan is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 10-31-2011, 02:53 PM
Owner
 
Join Date: Oct 2011
Ferrari Life Posts: 22
Yo Taz

I like reading what you post like Mr Goodwrench could learn from you.
Deke is offline  
post #3 of 11 Old 10-31-2011, 02:56 PM Thread Starter
Owner
Elite Member
 
tazandjan's Avatar
 
Join Date: Aug 2011
Location: Albuquerque, NM
Ferrari Life Posts: 11,871
Deke- I am just an amateur. If you have real questions on Ferraris, ask Brian Crall. He actually works on the cars.

Taz
Terry Phillips

Present: 575M 135171
Past: Dino 246 GT 02984, 365 GTB/4 14009, 308 GTS 25125

Every day I look around, and if nobody is shooting at me, it is a pretty good day.
tazandjan is offline  
 
post #4 of 11 Old 05-05-2013, 12:47 PM
Owner
Sponsor
 
David @ FluentInFerrari's Avatar
 
Join Date: Feb 2009
Location: Sarasota FL
Ferrari Life Posts: 966
Anyone looking for a mint Gates 507C belt tension meter, please drop me a note...

Sarasota Italian Garage, LLC
Sarasota, FL
www.fluentinferrari.com
[email protected]

**An independent facility with no affiliation with Ferrari SpA**
David @ FluentInFerrari is offline  
post #5 of 11 Old 05-11-2013, 06:06 PM
 
Join Date: Mar 2013
Ferrari Life Posts: 5
Thank You, for researching and posting this. It's really important.

Am now looking at ZFFWP50AXV0106***. Will let you all know what happens, in the near future, stay tuned . . .

CD05001
CD05001 is offline  
post #6 of 11 Old 05-11-2013, 07:46 PM Thread Starter
Owner
Elite Member
 
tazandjan's Avatar
 
Join Date: Aug 2011
Location: Albuquerque, NM
Ferrari Life Posts: 11,871
Good luck.

Taz
Terry Phillips

Present: 575M 135171
Past: Dino 246 GT 02984, 365 GTB/4 14009, 308 GTS 25125

Every day I look around, and if nobody is shooting at me, it is a pretty good day.
tazandjan is offline  
post #7 of 11 Old 06-07-2013, 05:11 PM
 
Join Date: Mar 2013
Ferrari Life Posts: 5
Oh, bother, Someone beat me to it.

Oh, bother, Someone beat me to it. It's gone. Still looking . . . .
CD05001 is offline  
post #8 of 11 Old 06-07-2013, 07:51 PM Thread Starter
Owner
Elite Member
 
tazandjan's Avatar
 
Join Date: Aug 2011
Location: Albuquerque, NM
Ferrari Life Posts: 11,871
New one for ~$250. Used successfully by Ferrari owners.

MotoReva - Ducati Tools and Supplies

Taz
Terry Phillips

Present: 575M 135171
Past: Dino 246 GT 02984, 365 GTB/4 14009, 308 GTS 25125

Every day I look around, and if nobody is shooting at me, it is a pretty good day.
tazandjan is offline  
post #9 of 11 Old 10-01-2013, 12:47 PM
Owner
 
Join Date: Nov 2011
Location: France (previously Maranello)
Ferrari Life Posts: 48
thanks for the thread.
henri66 is offline  
post #10 of 11 Old 01-18-2020, 03:40 AM
Owner
 
Join Date: Sep 2006
Location: Ratarossa HQ - Wokingham UK
Ferrari Life Posts: 40
Garage
Quote:
Originally Posted by tazandjan View Post
For owners, there are two very important Assembly Numbers in the history of the 65 deg V12s with twin rubber cam timing belts. The first of these is Assembly Number 28614 for the 456 and possibly the early 550. At this Assembly Number Ferrari updated the cambelt tensioner pulley bracket to a newer model. This tensioner bracket remained unchanged throughout production of 65 degree V12 cambelt engines and through the 612.

Ferrari Parts : 171060 : 171060 PULLEY BRACKET

The second important Assembly Number is 43847, very early in 575M production (all US cars were later and the Geneva Autoshow car was Assembly Number 43148), when an improved cambelt was introduced that allowed cambelt change interval to be changed to 5 years or 50,000 km (~30,000 miles). When this belt was introduced in late 2001, it superceded the old belts for the 456, 456M, 550, and a very few Euro spec 575Ms.

The point of all this is that all of the 65 deg V12s with a recent belt change have the latest belts. If owners of early 456s (and possibly early 550s) change out their tensioner pulley brackets, they will have exactly the same cambelt hardware as the 575M and 612, which have a five year belt change interval. From there, draw your own conclusion on what belt change interval should be.

Now that we have looked at a little history of belt hardware, time for a bit of history on belt tension numbers. For the 456, 456M, and 550, the recommended tool was the Staeger FST 50 Tensiometer. This tensiometer measured the acual tension of the belt between the pulleys using a depression of the span to calculate tension. Results of this type of tensiometer were not particularly precise and not very repeatable.

For the 575M, a new type of tensiometer was recommended that used the harmonic frequency of the belt span to measure tension. This method of measuring belt tension proved to be very precise and repeatable. The recommended tensiometer was a Seems Tensiometer Type Diapaz, which cost around $2K. The nearest equivalent was the Gates 507C Sonic Tension Meter, which retailed for $800 and could be occasionally found for a bit less. Both of these tensiometers were way more complicated than necessary since they were designed for multiple applications, and not just automotive belt use.

Luckily, the Ducati folks found a much simpler tensiometer just for automotive or motorcycle belt applications, the MotoReva MT-112, that only costs $249.99.

MotoReva - Ducati Tools and Supplies

So now down to the real meat of this thread for anyone who would like to do his own belt change on one of the 65 deg V12s. These V12s all use the same belts and the same tensioner hardware, so the harmonic frequency for all the cambelts is the same and we know what that is from both the 575M and the 612 workshop manuals. From the 575M WSM, the frequency when the longest span is struck is 126 hz. The 612 WSM expressed it differently and wanted measurements of both the spans on one cambelt added together and the sum of those frequencies should be 335-360 hz. Logically, the 612 frequency was more than twice the frequency of the 575M WSM single span because the shorter cambelt span has a much higher frequency.

Note that this tensiometer can also be used to measure the tension of the auxiliary belts, and the 575M numbers should suffice for the 550, too, but I am unsure of the 456 and 456M applicability. 612 owners have numbers in their WSMs.

Here are the applicable pages from the 575M and 612 WSMs.

Any pros jump in here if I have gotten any of this wrong.


Taz, I really appreciate your help on the other 456 suspension issue I have.

New topic here: Been researching belt change on the 456 this morning and found this superb thread you wrote. Very interesting to read and totally makes sense.

Question is after 9 years since writing it has anyone added to this or questioned it in any way ?

I'm planning to shoot another step by step video again such as I did on the 360 timing belt change to show the 456 service. The 360 uses frequency and the harmonic tension tool (or app) works perfectly. Ideally I want to use and show this method again as it is by far the most simple and cost effective ($free) way of doing so.

The 360 video has had over 25000 views and I regularly get questions and viewers telling me they follow it to do their own belt change and major. Hence I want to be sure if I use the frequency method on the 456 video it is done right.

Any input would be greatly appreciated

Scott
spiderscott is offline  
post #11 of 11 Old 01-18-2020, 07:50 AM Thread Starter
Owner
Elite Member
 
tazandjan's Avatar
 
Join Date: Aug 2011
Location: Albuquerque, NM
Ferrari Life Posts: 11,871
Scott- Since this thread was written, the actual hardware on the V12s has not changed and everything remains the same. What has changed, though, is there is now software available for I-Phones and Androids that can do the frequency tensiometer job. I am not familiar with the software, but others have used it with good results. There are threads in the other forum which can give you more info on the software they used. My techs have a frequency tensiometer.

Your 456GTA already has the upgraded bracket and undoubtedly has the new belts, since the old ones have not been available for nearly 20 years. If you do a belt change, I would definitely use the Hill Engineering pulleys/bearings.

Incidentally, I would bet your GTA came originally with the shock ECU she has in her. The shock ECUs do not have a high failure rate.

Taz
Terry Phillips

Present: 575M 135171
Past: Dino 246 GT 02984, 365 GTB/4 14009, 308 GTS 25125

Every day I look around, and if nobody is shooting at me, it is a pretty good day.
tazandjan is offline  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
Copyright 2012 ONE Media, Inc.
FerrariLife is independently run with no affiliation with Ferrari SpA
Ferrari for Sale | Maserati for Sale