Not really a new topic. Cam failures 8V.

[Dick]

So what we have here is a flat tappet Guzzi 8V  converted to roller tappet? Excuse my ignorance but an 8 valve has pushrods and cam in the V valley ? And the rollers run on the existing flat tappet cam?

I'm pretty sure the conversion kit comes with a newly designed cam, for roller use. Someone,(Pete), can confirm.

[Dick]

Oh... Like the 60-70's Opel 4 cylinder?  So there's a rocker with a cylinder shaped tappet running directly on the cam?....The reason  I asked is a roller cam has different lobe profiles than a flat tappet cam....replacing a typical round tappet with a roller will shorten cam duration  quite a bit

I believe there's a stubby length pushrod between the lifter and rocker. I saw an exploded view once or twice, so not an expert.  :)  Absolute zero familiarity with the Opel.   

[Vasco DG]

Oh... Like the 60-70's Opel 4 cylinder?  So there's a rocker with a cylinder shaped tappet running directly on the cam?....The reason  I asked is a roller cam has different lobe profiles than a flat tappet cam....replacing a typical round tappet with a roller will shorten cam duration  quite a bit

The roller cams are completely different to the flat tappet cams but their two profiles produce identical lift and duration figures at the valve. Hence the fact that they run the same mapping. The exception to this is the 1200 Sport which had 'Stand alone' flat tappet cams but the conversion kits use the same cams as all the rest of the models. The factory has released a 'Stand alone' map for converted 1200 Sports which they insist is for that model alone. This is quite funny as if you look at it with Tunerpro you find its the 2008/9 Stelvio map re-badged.

I've posted up the parts diagrams for both roller and flat top ends before but can do it again if you can't find them.

Pete

[Rough Edge racing]

 So you're also replacing the cam... I missed that part...

[Vasco DG]

When you do a conversion you swap everything North of the cylinder head bar the rocker cover, the rockers themselves and camchain sprocket. The kits consist of various parts, some engines needing shims installed under the inlet valve springs to add preload as the roller tappets are appreciably heavier than the flatties and their pushrods.

The major components though are the camboxes which are delivered to you as an assembly. It is essentially the same set-up as the Cali 1400, it even uses the same cambox casting with the extra spark plug tunnel. It's just machined so it doesn't interfere with the single plug 1200 rocker covers. The roller cams are also pre-loaded by a Belville washer assembley on the front of the cam that acts against the front of the cambox casting rather than the older internal shimming or, on the early engines, nothing to stop the cams lashing around and making a ghastly noise! :D

Here's a couple of pics of the early flat tappet camboxes which include the rocker supports and various other bits.

Cambox on bike.



Off bike and being reassembled after the early cam/tappet swap.




Eeny-weeny pushrod. (Just for giggles I got our local Jewler to turn a pair of these now redundant items into ear-rings for Jude. They're a bit heavy mind but you wouldn't wear them every day! ;D)



Roller cambox on engine.



And off the bike and showing the location of the 'Pads' that sit atop the 'Pusher' on the roller tappet. This fits into the cup on the rocker and mimics the top of the eeny weeny pushrod.



Pete

[pauldaytona]

So you're also replacing the cam... I missed that part...

 to show how it was made at first:

[molly]

I've haven't been here for a while because I sold my 1200 2v Sport and bought a Triumph Tiger Sport in November but I'm missing the Guzzi already so If I can find another I'm back in the fold pronto.

Before the Triumph I went to my local Guzzi dealer and we had what can be described as a honest and frank discussion about me buying a 8 valve Sport.
The discussion came down this. He believed the 8 valve flat tappet motor has a design fault that can only be solved with a roller conversion. He offered to sell me a Sport and straight away put in a warranty claim for roller cams because he had no faith in the existing design. Even then he would only be happy when the roller motors had racked up some decent mileage without problems.
The guy had boxes of old cam assemblies and talked me through what he beieved was the cause he was even fitting roller cams at cost to keep his customers on side.
I just couldn't bring myself to buy a new bike and then go through a warranty claim without even riding it hence the Triumph.

The Triumph is a good bike but the soul is missing. If Guzzi had not shot themselves in the foot with the 8 valve motor I would still be amongst a great bunch of people on this forum, a crying shame for me.

[Wayne Orwig]

There are a LOT of working higher mile 8V flat tappet motors out there to be THAT paranoid.

[Vasco DG]

Interestingly Mark III who posts here had his go out. His was an interesting case because his bike was sent from the factory with a Japanese market header pipe on the RH side. This pipe had an extra catalytic converter in and one of the things he noticed with it was that the RH head always ran substantially cooler than the left and, especially in cooler weather, was always full of Mayo.

When the tappets went tits and I rollerised it it was interesting to note that LH tappets, although showing damage were nowhere near as worn as the RH ones which were totally trashed.

No, it's not a definitive proof but it does correspond with my belief that the problem is related to over-cooling and moisture in the oil.

Until this spring I had NEVER had a Tappet failure through my shop. This year I've had half a dozen. Last winter was very cool and damp. Coincidence? I think not!

Pete

[pauldaytona]

I've haven't been here for a while because I sold my 1200 2v Sport and bought a Triumph Tiger Sport in November but I'm missing the Guzzi already so If I can find another I'm back in the fold pronto.

Before the Triumph I went to my local Guzzi dealer and we had what can be described as a honest and frank discussion about me buying a 8 valve Sport.
The discussion came down this. He believed the 8 valve flat tappet motor has a design fault that can only be solved with a roller conversion. He offered to sell me a Sport and straight away put in a warranty claim for roller cams because he had no faith in the existing design. Even then he would only be happy when the roller motors had racked up some decent mileage without problems.
The guy had boxes of old cam assemblies and talked me through what he beieved was the cause he was even fitting roller cams at cost to keep his customers on side.
I just couldn't bring myself to buy a new bike and then go through a warranty claim without even riding it hence the Triumph.

The Triumph is a good bike but the soul is missing. If Guzzi had not shot themselves in the foot with the 8 valve motor I would still be amongst a great bunch of people on this forum, a crying shame for me.

If there wasn't internet you would have the 8V.  And if there wasn't internet there had never been a roller kit.

[molly]

I'm not sure about that Paul I may have bought a 8V Sport in ignorance but with the problems the bike has suffered in the U.K. I probably wouldn't have kept it long.
My local Triumph dealer will no longer take Moto Guzzis in part exchange the last 8V Griso they sold cost them a lot of money in cam repairs under their own warranty scheme.

I'm doing my best not to be negative and I certainly would buy a roller cam model but Guzzi did not offer the 1200 Sport with rollers for some daft reason and it is no longer available anyway.

Guzzi should have recalled all problem engines for roller conversions, suffered the financial pain but kept their reputation intact. But like other manufacturers unless it is safety related they bury their heads in the sand. This isn't unique to Guzzi but the 1200 8V motor is a big proportion of the model range so the brand suffers more as a consequence.

[molly]

What I like about Guzzis is there always a bit of enigma about them. I have been phoning round U.K. dealers to see what 1200 2v and 8v Sports are available and had some interesting conversations.

One guy who was on the phone 30 minutes talking about 8v engines swore blind that by using Motul 7100 he has had no cam failures on any bike he has sold. He had no 1200 Sports left and was 300 miles away so he had nothing to gain from me. He was convinced  the ester in the Motul oil made all the difference. Keeps the mystery going a bit longer I suppose. http://chemlube-malaysia.blogspot.co.uk/2012/11/the-benefit-of-ester-based-synthetic-oil.html

 Still looking for a 1200 2v with low mileage though.

[Vasco DG]

Given the fact that the 1200 Sport hasn't been manufactured since early 2013 none of them were ever made with the roller top end. They all require the 'C' kit to convert to rollers as the Sport used a 'Stand Alone' cam profile for some reason and then the map needs to be updated to a 'Special' map for the rollerised motor. Only thing is it isn't a 'Special' map, it's just the 2008 Stelvio map re-named ::). None of the Sports have shimmed valve springs either.

Oh, and on the oil issue? Yes, using a full ester synthetic is vital. It's obvious if you understand how the engine cools itself.

Pete

[nikwax]

I don't want to flog a deceased horse here, and, there was a question about warming up the motor by idling. Now this is something I never do with vehicles, and I have no idea how this would play out with an oil cooled Guzzi, but I can relay a story from my BMW days:


An owner of an 1150 GS purchased the BMW official factory shop manual and was preparing for an oil change. The factory service manual specified warming up the motor for 20 minutes by letting it sit idling, which the owner did unattended in his driveway. He came back after 15 minutes to find his bike on fire, the motor had gotten so hot that the oil site glass had popped out and hot oil dumped on the exhaust manifold and ignited. BMW NA eventually replaced his bike. I don't know if they ever corrected the service manual. My experience with the oil cooled BMW was that it got hot really quickly when idling, so much so that a large fan was recommended to keep it cool if a throttle body sync would take more than a minute or two. Certainly the bikes overheated in traffic and had to be shut down if stopped for an extended period. No fan on the oil cooler. Worse in the summer but still an issue in the winter.



Back to the dead horse: no idea if this applies in Guzziland.



And a question about the living horse: is the warmup (or winter overcooling) issue specific to the Griso, or does it also apply to the Norge? Different radiator and air flows involved.

[Vasco DG]

All the 8V's over-cool in weather below about 15*C and if it's wet? Forget it, the oil temp won't get much above 55-65*C. Perversely, there are points in the motor, most specifically in the cooling galleries around the exhaust valves, where the oil temperature will momentarily reach very high temperatures. Hence the need for a full ester synthetic oil.

If you leave any air/oil cooled engine idling for a long period it will overheat. I have a customer who cooked his Griso this way. There was surprisingly little damage to it though inside the engine.

Pete

[pauldaytona]

Given the fact that the 1200 Sport hasn't been manufactured since early 2013 none of them were ever made with the roller top end. They all require the 'C' kit to convert to rollers
Pete

Pete one half of the 1200 sports 8v needs the C kit, other half the D kit. Depending on production date and easy to see on head cover.

[Vasco DG]

I'll have to double check the bulletin. I thought they all needed the 'C' kit.

I stand corrected. The later ones need the 'D' kit. Apologies.

Pete

[molly]

Oh, and on the oil issue? Yes, using a full ester synthetic is vital. It's obvious if you understand how the engine cools itself.

Pete

That's interesting you agree on the ester content Pete because it's the first time I have heard of it here or anywhere else.
I also didn't realise not all fully synthetic oils contain ester.

[Vasco DG]

Well I've been very vocal about it for years Dave.......

[gsf12man]

From what I've seen, the 'full ester' oils will say so on the bottle; other full synthetics tend to be a bit coy about base stocks. I have a 2V engine so I don't think the ester bit matters as much (although I run a full ester oil—it's my baby!).

[youcanrunnaked]

New slogan for Moto Guzzi:  If you don't want your engine to take a siesta, make sure when you buy oil, on the label you see ester.

[molly]

Or even: ester la vista baby.
https://www.youtube.com/watch?v=Q73gUUr8Zlw