8V cam Pt 2: follow-up

[belfastguzzi]

I've put a higher res pic of the cam on Flickr, though I'm not sure if Flickr down-samples it when it is uploaded:

http://farm4.static.flickr.com/3597/348008...553f74147_b.jpg

 

This is a smaller version of it

[luhbo]

....

However, from the photos, I think we can agree that the tappet foot isn't quite what it should be!

 

It's not looking fresh, indeed.

 

The problem with pics is that things which appear to be scratches, dents or the like, especially on spherical surfaces, in fact might be very hard to measure. A real big fat scratch might in fact just be a few microns deep (compare it with turning marks on valve shafts e.g.). The question of course is not how deep a scratch is, it's more what is the reason for it, was it already there before the shit happened or not.

To me this camshaft, the journals - not the cam itself, seems to be in perfect condition. I can see nothing that would worry me (again, I'm far away with a nicely running bike, so that's easily said, I know).

Perhaps this topic could be run a bit less emotional if you or Pete could mark on one or more of these photos the damage you see or think to see.

 

As far as I know you will never get parts that were replaced under warranty. The dealer has to send them back to proof that he has really done the work and to enable the factory to further examine the problem. It has nothing to do with "split party theories" or the like. Probably the dealer likes you more than he likes Guzzi.

 

Regarding the mounting mark on the plungers: the kinematics at each end are completely different. The bottom end goes mostly only up and down with nearly no relative movement between the surfaces, the upper end sees heavy friction compared to the one mentioned first. At least theoretically they must be different, if not in shape (well, some have sharp eyes <_ then in surface treatment or whatever. just case some need a possible reason to follow the advice given officially>

 

Hubert

[Greg Field]

Belfast:

 

It is impossible to inspect the pump from inside the sump.

 

At very least, have them flush the cooler system. This requires removing it because the thermo valve will be close until the engine gets hot.

[macguzzi]

I've been reading through these posts on this subject it strikes me that with very little effort you could drop the sump and remove the conrod caps to check for wear. Looking at the damage to your top end lack of oil looks likley BMW had this same problem when they went 8 valve. I was talking to people in the club in mandello last week they are all very aware of the problem and worried this will cost Guzzi it's already tarnished reputation. All the test bikes leaving the factory were Stelvios and they were screwing the nuts off them I also noticed lots of 8v in bits in the workshop. I also notice that Agostini did not have one 8v for sale or in the shop. What really surprised me was the club members I met saw no reason for the Aprillia to be badged Guzzi, they have done this with Gilera in this years moto gp it's an aprillia 125 ,but Gilera are 100 years old this year thats the excuse

[belfastguzzi]

Hey Mac, I know you've been out of touch with things recently. so

psst, do you wanna buy a Griso: just been, er, serviced?

[macguzzi]

What really pisses me off is I fancied one, put the battery in the Scura today started first hit

[belfastguzzi]

What really pisses me off is I fancied one, put the battery in the Scura today started first hit

Oh, haven't I mentioned: the Griso doesn't start either.

I have to hold the starter button down and then, maybe after 3 seconds or after 5 seconds or after another 5 prods, it decides to send lectrikery to the starter.

I'll not mention it again.

[macguzzi]

Are you sure it's not a Griso Le Mon!

[pete roper]

Belfast:

 

It is impossible to inspect the pump from inside the sump.

 

To-whit;

 

 

Note the previously mentioned twin vane construction.

 

But what would I know? I'm a scaremonger. Guzzi probably have 'Secret Spectacles' available only for the annointed few which allow you to look through metal from the sump

 

Pete

[macguzzi]

Question Pete what about removing con rod caps? to look at big end wear

[pete roper]

Well, you could, but that will require removing the sump again and getting new rod bolts.

 

I've been trying to find a way to post the 'Lubrication' pages from the manual but I'm too stupid. The long and the short of it is that both the cooling and lubrication pumps are filtered..... by strainers. These will take out bigish lumps until they clog but they won't take out bits anything like small enough that they won't do serious damage to the oil pump,

 

The front rotor in the pic above is the cooling rotor. It delivers oil to the oil cooler which doesn't appear to have a thermostat so oil is being pumped through it ALL the time. The rotor closest to the wall of the case delivers oil for all the bearings, including the cam bearings, via the replaceable cartridge type filter. From the look of it this supply will also be responsible for the under-piston jets.

 

So, theorretically, the bearings should be protected UNLESS the filter goes into bypass mode. Whether this happens, even when the oil is cold, I'm not sure as all the filters I've ever cut open show no deformation of the ellement but whether this will happen depends on the design of the filter. Time for me to cut another one open for a good squizz methinks.

 

This doesn't alter tha fact that the pump will of been sucking shit and articulate matter will of been flung all through the motor by windage and cyclonic forces from the spinning crank.

 

I maintain from the look of the cam cournals on BFG's cams that there is SUBSTANTIAL damage to that engine. We won't know for sure until it is stripped and inspected but I would be almost certain that mos of the bearings are toast. If the cam bearings have been recievingcontaminated oil so have the mains and big ends.

 

Pete

[pete roper]

Here are some of my comparatively undamaged bits for comparison.

 

http://farm4.static.flickr.com/3640/348146..._df8fd42133.jpg?

 

http://farm4.static.flickr.com/3331/348143..._a4ab5b6e6b.jpg?

 

http://farm4.static.flickr.com/3617/348220..._5c419c1044.jpg?

 

http://farm4.static.flickr.com/3347/348215..._35f8b0034d.jpg?

That one is of one of the new tappets to try and show the differences, it isn't very clear, sorry.

 

http://farm4.static.flickr.com/3602/348217..._43a54ea3c9.jpg?

 

For some reason I can't actually get the pics to load so you'll have to click on the links

 

Pete

[Mark909]

A question please.

 

How would someone know that the bike they are buying has had the work done? Also will there be some list of engine numbers to indicate which bikes have been delivered from the factory with the good parts in them? In other words, at what engine number do the bad parts stop and the good bits start? Without knowing this I imagine potential buyers would be very wary of handing over the cash.

[Guzzirider]

A question please.

 

How would someone know that the bike they are buying has had the work done? Also will there be some list of engine numbers to indicate which bikes have been delivered from the factory with the good parts in them? In other words, at what engine number do the bad parts stop and the good bits start? Without knowing this I imagine potential buyers would be very wary of handing over the cash.

 

From what I can gather, all 8V bikes are being recalled. When I got my recall work done there was no paperwork but I assume the work has been registered on Guzzi's database, so I guess a dealer could tell you whether a particular bike has had the modifications done.

[Greg Field]

So, theorretically, the bearings should be protected UNLESS the filter goes into bypass mode. Whether this happens, even when the oil is cold, I'm not sure as all the filters I've ever cut open show no deformation of the ellement but whether this will happen depends on the design of the filter. Time for me to cut another one open for a good squizz methinks.

 

 

The filter doesn't deform when it goes into bypass. Rather, a valve opens, dumping the oil around the filter element. It's non-destructive and repeatable without consequence to the filter.