The fall and rise of a works SFC engine
- Thread starter sfcpiet
- Start date
Laverdalothar
Hero member
- Location
- Germany
Don't be so Deutsch Lothar, a bit of bar banter doesn't hurt...
No problem with that, Piet, you know I am guilty for going off topic myself uncountable times. this was just sooooo far away, I thought I might make you post some more pics to get the thread back on topic. Success...
Other forums are way more strict on this. The most strict one I know is the Tesla Freunde Forum (German - what else...). After the 3rd just slightly off topic post, there is always someone screaming for moderators to remove the content or move it to the "off-Topic"area...
anoying...Oh - and you need new leathers, Piet. They really don't match the color of the bike...
Not going to happen. The Nürburgring oganisers have already forced me to buy a new helmet, newest ECE 22.06 specs only allowed. I now have enough helmets to see me out...No problem with that, Piet, you know I am guilty for going off topic myself uncountable times. this was just sooooo far away, I thought I might make you post some more pics to get the thread back on topic. Success...
Other forums are way more strict on this. The most strict one I know is the Tesla Freunde Forum (German - what else...). After the 3rd just slightly off topic post, there is always someone screaming for moderators to remove the content or move it to the "off-Topic"area...
Oh - and you need new leathers, Piet. They really don't match the color of the bike...
Friends of Tesla???
Surely you mean Nicola Tesla, the inventor/physicist? piet
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If you were around when Paul started this forum, after the Guzzi Forum imploded with a sudden bout of Mass Insanity and the desire to be able to post pictures, this place was moderated with an iron fist, not by Paul or the current admin someone else, I think, long gone. That lasted for appox 5 minutes, closer to a month actual, till the members rioted. Lots of talk about Adults not needing supervision. And it's by far worked pretty well MOSTLY. On occasion, the big stick comes out, and people apologise or, in some cases, walk away with all their toys. It's sad when that happens, but it's always their choice. To me, most of the big dust-ups come from people insisting it's their way or the highway. Nobody is right all the time, especially me.
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chrisk
Hero member
- Location
- Brisbane, Australia
Don't be so Deutsch Lothar, a bit of bar banter doesn't hurt...
Starting to look like a complete bike again.
View attachment 106243
Currently waiting on a couple of brake line fittings to rectify the last-minute sins of 2016 in readiness for the not-the-Barry 2017.
Next on the list is replacing the modern rear shocks with a pair of period Ceriani GP items that I have been able to source. The shocks were in a sorry shape and require a total overhaul, of course seal kits are no longer available, so these will need to be made up. The shocks are the De Carbon type with a floating piston separating the damper oil from a gas charge. As I don't anticipate finding anybody capable of re-charging these, they'll be rebuilt as simple oil dampers. Reckon they should be fine for a couple of demo laps here and there.
piet
Just a curious question Piet, what stops the seat/tail unit from falling off? Looking at the undressed picture and Marks pictures, I can’t see any telltale fixings?
There's an angled bracket laminated under the seat that snuggles up to the end of the top frame rails. These have a thread at their blunt end into which the angled brackets are bolted. Front of the seat is held by the ubiquitous Laverda hook system. Quite clever and invisible.
piet
chrisk
Hero member
- Location
- Brisbane, Australia
That’ll do it, can see a thread hole now that you explained it….. 
I reckon I’ll borrow that idea, but with 3C type seat slots in the angle so it lifts off the loosened screws
I reckon I’ll borrow that idea, but with 3C type seat slots in the angle so it lifts off the loosened screws
As previously described, I've found and now overhauled a pair of Ceriani GP rear shocks. One was leaking and devoid of damping oil, the other hardly budged...
They're pretty crude and hold less than 75ml of oil, stock Cerianis on 750 Laverdas contain 100ml, maybe there's a reason they're so rare these days! The one-piece rubber oil seal was substituted with an alloy collar with an o-ring at its' circumferance running in the damper tube and an oil seal together with a dust seal for the damper rod. Rather straightforward actually. The dampers only started showing anything like dampening action when the 10W fork oil I started off with was replaced with straight 50W motor oil! I omitted the floating piston originally seperating the damper oil from a gas/air charge, the oil content would then be less than 50ml and the piggy-back chamber would contain only gas,usually nitrogen. For now, they will rely on oil alone as I have no idea how they are pressurised, nor do I know of anybody that is capable of doing so. There is only a simple plug on the chamber, no Shrader valve or aperture allowing charging with a needle.
Anyway, I'm pretty chuffed how nice they came out, even if they're probably far from top-notch equipment. They will at least give the bike a further period touch and I can finally return the YSS that my mate Dirk graciously lent me 10 years ago...
I also replaced a couple of brake line unions that were more-or-less last-minute fittings back in January 2017. The calipers have a rather uncommon 3/8-24 thread, not much of that to be found in a workshop dealing mainly with M10x1 hydraulic threads. M/C on the other hand, has M10x1, wtf was Signor Fontana drinking that day? Front lines now have a far more pleasing flow, rear no longer snakes around the swing arm pivot and also looks a lot tidier. Unfortunately, the Fontana front M/C no longer creates/holds pressure, new seals are on their way. This stuff is thankfully still readily available as Fontana based their caliper and M/C dimensions on the established Lockheed hydraulics of the day and the seals are found in an assortment of '70-'80s brit bikes such as the Norton Commando and Triumph Tiger and Bonneville. Just a shame the available seals are of crap quality and don't last longer than a season or three...
The new head stud nuts arrived yesterday and will be fitted tomorrow, almost ready to roar!
piet
They're pretty crude and hold less than 75ml of oil, stock Cerianis on 750 Laverdas contain 100ml, maybe there's a reason they're so rare these days!
The one-piece rubber oil seal was substituted with an alloy collar with an o-ring at its' circumferance running in the damper tube and an oil seal together with a dust seal for the damper rod. Rather straightforward actually. The dampers only started showing anything like dampening action when the 10W fork oil I started off with was replaced with straight 50W motor oil! I omitted the floating piston originally seperating the damper oil from a gas/air charge, the oil content would then be less than 50ml and the piggy-back chamber would contain only gas,usually nitrogen. For now, they will rely on oil alone as I have no idea how they are pressurised, nor do I know of anybody that is capable of doing so. There is only a simple plug on the chamber, no Shrader valve or aperture allowing charging with a needle.Anyway, I'm pretty chuffed how nice they came out, even if they're probably far from top-notch equipment. They will at least give the bike a further period touch and I can finally return the YSS that my mate Dirk graciously lent me 10 years ago...
I also replaced a couple of brake line unions that were more-or-less last-minute fittings back in January 2017. The calipers have a rather uncommon 3/8-24 thread, not much of that to be found in a workshop dealing mainly with M10x1 hydraulic threads. M/C on the other hand, has M10x1, wtf was Signor Fontana drinking that day? Front lines now have a far more pleasing flow, rear no longer snakes around the swing arm pivot and also looks a lot tidier. Unfortunately, the Fontana front M/C no longer creates/holds pressure, new seals are on their way. This stuff is thankfully still readily available as Fontana based their caliper and M/C dimensions on the established Lockheed hydraulics of the day and the seals are found in an assortment of '70-'80s brit bikes such as the Norton Commando and Triumph Tiger and Bonneville. Just a shame the available seals are of crap quality and don't last longer than a season or three...
The new head stud nuts arrived yesterday and will be fitted tomorrow, almost ready to roar!
piet
piranha-bro2
Hero member
- Location
- Melbourne
Splendid resurrection, Piet. Did Fontana make their own calipers or just rebadge Lockheed or Girling (I think that's the name, as used on early 70s pommie bikes, Rickman etc). Thought the TPI imperialismo thread was a bit odd for Sig Fontana.
Definitely their own design and manufacture, Quentin.
All piston diametres are the same as in Lockheed and Girling, as are the seal fitting dimensions. Possibly a cost-cutting measure. Using imperial threads may have been a part of that as well as a wide variety of fittings would have readily been available off the shelf, instead of re-inventing the wheel.
Bike is equipped with Fontana hubs and brake discs as well. Hubs and disc carriers are magnesium alloy.
piet
Nope.
As there are/were no signs of corrosion whatsoever, I haven't any reservations using the stuff.
Magnesium alloys can fail once exposed to serious oxidation. The hubs weren't even painted when the bike was first dismantled, just the natural oxidation layer caused by exposure to the atmosphere, more like anodised than rusted... a lick of paint to protect them should see them out for decades to come.
Just look at all the G50 Matchless and Manx Nortons, 70-year-old Mg cases holding up just fine, not to mention all those gearbox casings of 1950's VW Beetles! Haven't heard of a beetle spitting its' gearbox guts because the casing fractured. Lots of irrepairable ones that were left in a moist barn to rot for 40-odd years though.
piet
Are there many original Manx or G50 out there being used for anything other than demos?
Paul
You might want to visit the Goodwood Revival or similar events, real take-no-prisoners racing. Where else can you observe an original Ferarri GTO or Lister Jaguar being totalled?
Goodwood seems to be quite bike-friendly, didn't see a single bike crash. Belgian TT at Gedinne attracts a bunch of original bikes, the riders go all-in, sort of a micro-IoM TT on country True, lots of replicas amoungst them, but a surprising amount of originals.
piet
I have quite a few friends who ride at Gedinne, and some organising, just up the road from here.You might want to visit the Goodwood Revival or similar events, real take-no-prisoners racing. Where else can you observe an original Ferarri GTO or Lister Jaguar being totalled?roadslanes.
True, lots of replicas amoungst them, but a surprising amount of originals.
piet
Neither at Gedinne nor Goodwood, is the majority of machines engaged in year long championships.
I believe that original classics were pulled out of those years ago. Why run a valuable fragile old nail when an expensive modern replica can run circles around it?
Paul
Pretty sure older Honda Elsinores and Husqvarnas used it in Case Covers; dont know about full crankcases other than what's referred to as Mag Huskys, but there were issues in erly water cooled Huskys with internal corrosion; the fix, from memory, was painting the engine internally. I just remember early Ducati bevel wheels. I like to learn what I can. Looking forward to an engine start video, please.
Alzero
Hero member
- Location
- DaNang Vietnam
IIRC, back in the Troy Corser and Doug Polen days Ducati ran and sold bikes with magnesium crankcases that had a service life of 300 hours. A customer from San Francisco brought one in to be measured and aligned that he bought for track days.