The 'Definitive Guide to Rollerisation'

[pete roper]

The 'Definitive Guide to Rollerisation'
 

This is something I've been meaning to do for a while as, despite the very youngest flat tappet bikes being nine years old now there are still a large number of them out there and in this post I'll try and cover both the procedure and pitfalls liable to be met during the rollerising process.

 

Firstly let's cover which bikes need rollerising.

 

Most importantly it is ONLY the four valve per cylinder, (8 valves all told so I'll refer to them henceforth as 8V's.) engines that were subject to the Flat Tappet Fiasco. None of the CARC bikes that use the venerable two valve per cylinder pushrod operated OHV engine suffer from chronic cam and lifter problems. 

 

Next, don't be fooled by the fact that some 8V models were referred to by the factory as '4V'. This nomenclature has been the source of some confusion but the easy way to identify an 8V motor is to simply look at their rocker covers. 8V motors have the 'Quattro Valvole' logo cast onto them and the back of the cover has a black plastic shroud over it.

 

Like so.

 

 

Both the 1200 Sport and the 'Small tank' Stelvio, (2008-2011.) were designated as 4V but use the 8V motor. Grisos and Norges were all designated 8V from the outset. No, I have no idea why either.

 

Moving along from that we should look at which flat tappet 8V's need rollerising? The answer is simple. All of them. I know that some people are still in denial. Their engines don't make any unusual noises therefore everything is OK? Sadly, no. If people want to believe through magical thinking, or good luck, or using some special oil that "It isn't going to happen to them"? Well, good luck with that but the only person you'll be kidding is yourself. There is some anecdotal evidence that the last iteration, (There were at least three.) of the flat tappets will last longer than some of the earlier ones. I personally have seen no evidence of this. The problem is also very varied in when it manifests itself. Engines have been known to fail in a couple of thousand miles. Some soldier on for tens of thousands! Invariably though they will, all, eventually fail.

 

With one notable exception all 8V's changed over to roller tappets and cams by the middle of 2012. The factory's engine numbers for the changeover point are listed as;

 

Stelvio- Motor#AC12596 Build Date 12 March 2012

GRiSO - Motor#A813524 Build Date 12 April 2012

Norge - Motor#AA12214 Build Date 18 April 2012

 

The exception to this is 1200 Sports, none of which were ever made with roller engines at the factory. It's my belief that this is because the last of them were built before the advent of the roller top end and although they continued to be sold and plated as 'Current model' up until at least 2015 in the Australian market they were in fact 'New Old Stock' manufactured prior to rollers.

 

We'll now move on to which 'Kit' will be required for any given bike.

 

Due to changes made to some parts of the top end over the period of production of flat tappet bikes not all of them require the same parts to convert them from flat to roller tappets. For this reason Piaggio produced four different kits to perform the operation on the various engines. Which one you will need and the cost involved can vary enormously and not getting the right one means you can end up with a costly 'White Elephant' on your hands that may be hard to on-sell or can only be done so at a substantial loss. So let's look at this firstly with a timeline.

 

The earliest 8V motors were made using chilled cast iron flat tappets, these were in 2007 through to early 2009. It quickly became apparent that there was a problem as the tappets started to fail. At this point, from memory around the end of 2008 or the beginning of 2009 the factory DID issue an actual recall but not to fit roller tappets as these hadn't been manufactured yet. The first attempted fix was to replace the chilled cast iron tappets with forged steel ones with a 'Diamond like carbon', (DLC.) coating on them. This was supposed to be 'The Fix' and as with all recalls was supposed to be publicised by both factory and dealers and, to their credit, most owners were so notified and in my experience it has been very rare to find a cast iron tappeted bike in circulation after the recall.

 

The problem was it didn't fix the issue. 8V's, the 'Great White Hope' of the Guzzi range was self destructing at an alarming rate! Some geographical locations it seemed to be worse than others, (I for instance long remained skeptical about the problem because I just wasn't seeing it in bikes I'd serviced from new. My problem was I wasn't looking in the right place!). Then in 2012, after the launch of the porcine California 1400 which had the honour of being the first roller tappetted production engine the new roller top end was adopted across the 1200 range with the aforementioned exception of the Sport.

 

This left though all the bikes manufactured before this time with wonky, failing top ends. 2007 to 2012 was a five year window when it should of been fixed but wasn't. Not only that but issuing a full blown recall would of been poisonously expensive. So they didn't. They fudged it. Instead of a recall there was what was described as a 'Technical Update' released on the Service Motoguzzi web portal laying out how the factory would handle it.

 

Firstly it was stated that failures were a rare and unlikely event. They aren't. The attrition rate is 100%. There would be no pre-emptive replacements, the tappets had to fail before a claim would be accepted and the claim for a roller conversion kit was dependent on the owner having a full service history completed not just on distance but also on time, (So if you only did 5,000km a year you were still expected to get a full 10,000km service performed annually and recorded in your log book.). No service history? No kit! The inspection for damage had  to be performed by an authorised dealer or service agent and provision of the kit was entirely discretionary. The owner was responsible for the labour component of both the inspection and, if the claim was successful, the installation of the kit. In certain markets with stronger protection laws there was a bit more wriggle room but for most people trying to negotiate a kit was and remains a nightmare. One not helped by the fact that even to this day many dealerships remain seemingly woefully ignorant of the whole sorry affair!

 

So let's look at the four kits and what needs to be done to install them. Needless to say there is no sense at all in their identification as A, B, C and D kits don't follow any sensible timeline!

 

First cab off the rank is bikes built from 2007 through to early 2010. These will all need to be fitted with the C kit. The C kit includes new camboxes, shims for under the inlet valve spring seats, valve guide oil seals for those valves, inlet and exhaust manifold gaskets, tampons, plug tube o-rings and rocker cover gaskets along with the hemispherical 'Pads' that go on top of the tappet towers in the rockers and all three thicknesses of head gasket.

 

For reasons I won't go into here the larger inlet valves require shims under the spring seats. This means the heads have to be removed to fit them. Since you won't know what thickness head gasket you will require until the head is off the kit contains all three gaskets and this adds substantially to the price. There are ways to get out of this cheaper than purchasing th C kit but I'll cover that later.

 

While removing the heads isn't that bothersome per se it can, on some models, most notably the Norge and Stelvio add substantial time to the whole rollerisation operation.

 

Next up in the timeline are bikes built from early 2010 through to late 2011. These bikes require the B kit which doesn't contain manifold gaskets or head gaskets because during this period there were changes to either valve springs or the way the valve spring seats were machined rendering the shims under the spring seats redundant so on these bikes the heads do not have to be removed for rollerisation. From this point on on all models except the 1200 Sports the lack of need for the head to be removed is identified by a drill mark in the paint on the head on the side facing the valley of the engine adjacent to the manufacturing date stamp.

 

From late 2011 through to the changeover to roller tappets at build in mid 2012 there were a number of revisions to the top end that I will cover in the next section. These bikes require the A kit which is similar to the B kit as it doesn't require the heads to come off so no head gaskets, or manifold gaskets are included.

 

Finally, there are the final run 1200 Sports. These use the stand alone and stupidly expensive D kit. This contains all the gaskets as the heads have to come off to shim the inlet valve seats but, unlike the earlier Sports which were confusingly labeled 4V they use the later type heads and camboxes I'll cover in the next section.

 

OK, having listed the kits we'd better work out what the differences are to the top ends of the motors and I'll explain why it is so important to get the correct type of kit for your engine. There are some traps for new players so it is important not to get it wrong as expensive damage can result if you get it wrong.

 

There are basically two versions of the single spark 1200 Hi-Cam top end. The early versions that use the C and B kits and the later versions that use the A and D kits.

 

Let's look at the differences.

 

 

Most notable is the way the plug tunnel is sealed. On the right you can see the early system. These motors have a long plug tube that passes through the rocker carrier/cambox casting that is sealed at either end with an o ring. One in the head casting and one in the rocker cover. This system uses what is known as a 'Non floating' rocker cover.

 

The later system can be seen on the left. On these machines the *Tube* is much shorter. It is still sealed at either end by an o ring but now it seals in the actual rocker carrier/cambox casting and the top of the tunnel is sealed by a neoprene gasket of the same cross section as the rocker cover gasket itself. This means that the rocker cover is not solidly indexed to the head or rocker carrier and 'Floats' relying on the comparatively light compression of the four cover bolts and their tampons to keep it in position. Note also that there are two different types of tampon and it is important to use the right ones if leakage is to be avoided.

 

So let's first look at the rocker cover of the early type. Here you can see the plug tube and how it inserts in the cover.

 

 

Note that when the rocker cover is lifted the tube may remain in the head or it may lift with the cover. Damper climates will tend to encourage the tube to rust into the cover and it will lift. Drier climates the tube will tend to remain in the head. Since it is a lot more bothersome to replace the o ring in the head it's a good idea to use some rubber grease on the top, rocker cover, o ring to encourage the rocker cover to come off the tube easier next time and leave the tube in the head.

 

When removed from the rocker cover the pipe reveals the o ring and the groove in which it sits. Note there is no o ring in the groove on this cover.

 

 

The later versions with the short tube have a similar groove machined into the bottom of the tunnel in the cambox casting.

 

 

And the top of the plug tube is sealed between the carrier casting and rocker cover by the neoprene gasket.

 

 

Which in turn fits into a groove in the inside of the rocker cover.

 

 

Moving on to the two camboxes/rocker carriers there are notable differences here as well. By comparing the two side by side it is possible to see several reasons why they are not interchangeable. In the picture below you can see the later type at the top and the old type at the bottom.

 

 

See also from looking at the pic above the hole in the casting of the old type is larger to accommodate the passage of the tube. The long tube simply won't fit through the 'New' casting.

 

 

By looking at them from the side you can see the substantial difference in height of the plug tunnels. The shorter one being the old type as the plug tube pokes up through it to seal with the o ring in the rocker cover. The later one uses the casting itself to act as one of the mating surfaces for the circular gasket used with the 'Floating' cover. Note again new on the left, old on the right.

 

 

And now we come to one of the, if not the most important difference between the two different assemblies and the reason one must make absolutely sure you choose the right one.

 

During the time when the factory was thrashing around feebly trying to find a solution to the problem of the flat tappets self destructing one thing they tried is deepening the weirs in which the cam lobes actually spin. One assumes that this was in the hope that keeping more lubricant on and around the lobes and tappets would save them. Sadly this was another bit of magical thinking that didn't work but these deeper weirs were added at the same time as the swap to the late type plug tube and rocker cover sealing system in 2011.

 

To accomodate the slight extra depth of the weir castings in the camboxes the actual cylinder head on these later motors is machined under the weir to provide extra clearance. Earlier model, 'Long' plug tube heads do not have this machining. Since all of the roller conversion kits are manufactured using parts cast for the California 1400, (Hence the extra, redundant, plug tunnel.) which also have this machining to the head the weirs are all of the 'Deep' type. Now woe betide you if you try and fit one of these later type camboxes from an 'A' kit to an early bike! While the difference in depth isn't great if you try it you will be rewarded by a 'Clink' noise as you torque the main head/cambox retaining studs down. That'll be the sound of the weir cracking and costing you a considerable sum of money! You can probably guess how I found that out? :oops: 

 

Anyway, the way that this issue is addressed with camboxes for the early motors is very simple. Rather than machining the head to give more clearance it is simply the bottom of the weir that has a chamfer machined onto it to give the required clearance. See below the weir on an A/D kit cambox with no chamfer.

 

 

And a B or C kit cambox.

 

 

Side by side you can see the difference more clearly.

 

 

So make SURE you know what you need to order before ordering. I've had several enquiries in the last year from people who have been sold or bought the wrong kit and as I say, this can be a very costly mistake.

 

It is also quite possible for people who need a C or D kit to make substantial savings by buying a B or A kit and adding the other bits required. I've already listed them elsewhere so I'm not going to do it again here.

 

Also, if anyone isn't sure of what they need or would simply like the required parts organised I can happily do it for them. I order direct from Europe and the parts are despatched from there direct to the customer. It'll not cost the customers a cent more than if they buy them direct but I get a substantial trade discount as I put tens of thousands of € through my account every year. I can also guarantee that the correct parts are supplied and can advise on other sensible preventative maintenance at the same time.

 

I hope that has been useful. If people would like further details of what else changed in the top end on the change from 'Old' to 'New' I can continue that later.

[KINDOY2]

Awesome Pete!

 

[al_roethlisberger]

This is extraordinarily helpful information for anyone looking at this generation of bikes!

Thanks 

[p6x]

check your knowledge:

Is the Stelvio shown in the video below equipped with the flat or roller tappet?

 

[pete roper]

Rollers.