Snapped Rod

They also break because they're old.
And quality control half a century ago in a small rural semi industrial factory wasn't what it is today.
Geds photos are on his Facebook page.
Paul
 
I wish the failure of the rod in the engine of my second SFC1000 had only caused that amount of damage. Unfortunately, it created an explosion like a grenade going off, bits going everywhere and destroying quite a bit of the engine in the process. The guy following me, Dave Madsen-Mygdal, on an ex works RG500 wasn’t too happy either.
 
Andy J said:
I wish the failure of the rod in the engine of my second SFC1000 had only caused that amount of damage. Unfortunately, it created an explosion like a grenade going off, bits going everywhere and destroying quite a bit of the engine in the process. The guy following me, Dave Madsen-Mygdal, on an ex works RG500 wasn’t too happy either.
Click to expand...
How old and what mileage did your SFC detonate at?
 
Back in the '80s, when from April till October was Track Day season, I was at a Goodwood session when a Triple spat its right conrod.
It smashed through the back of the crankcase, chopped the starter motor out and, for an encore, punched a two inch square section out of the front of the crankcase.
This caused great consternation among several of the Laverda owners present.
One of the neophytes asked Phil (Todd) "Will mine do that?"
Phil replied "Don't worry, yours will be fine. That's a really old one."
On checking, it was two numbers earlier than mine!
"Thanks, Phil."
 
Last edited:
Interesting failure. I've not seen a rod all crumpled up like that before. I reckon the bottom of the rod being all scrunched up against the flywheel is what limited the damage. There's not enough rod end poking out to bash bloody great holes in everything. At what engine revs did it let go?
 
Dellortoman said:
Interesting failure. I've not seen a rod all crumpled up like that before. I reckon the bottom of the rod being all scrunched up against the flywheel is what limited the damage. There's not enough rod end poking out to bash bloody great holes in everything. At what engine revs did it let go?
Click to expand...
Last one I saw like that was a flooded cylinder and it did it at cranking speed.
 
Andy J said:
It was in 1987. I don’t remember the mileage off hand, but it wasn’t a lot. I’ll post a photo of it a few miles before it went bang and of the aftermath showing the damage.
Click to expand...
Reason I ask is it appears to have happened on a two year old bike (?) with low miles indicating a problem with the design/ quality of the rod not an age/ mileage thing. Are they all ticking bombs waiting to let go?
 
Dellortoman said:
Interesting failure. I've not seen a rod all crumpled up like that before. I reckon the bottom of the rod being all scrunched up against the flywheel is what limited the damage. There's not enough rod end poking out to bash bloody great holes in everything. At what engine revs did it let go?
Click to expand...
No idea Cam, Ged bought it like that.
 
This topic always brings me out in a cold sweat. A few years ago i had a fuel in the cylinders episode. I detected this on observing unleaded pissing out of the collector join as she attempted to fire up. A set of neoprine float valves from Paddy cured the problem. It sinks to the back of my mind over time but then somebody posts a pic of a snapped rod and it all comes rushing back 😱
 
Dellortoman said:
Interesting failure. I've not seen a rod all crumpled up like that before. I reckon the bottom of the rod being all scrunched up against the flywheel is what limited the damage. There's not enough rod end poking out to bash bloody great holes in everything. At what engine revs did it let go?
Click to expand...
750 this time, rod remained intact... well, at least in one piece. ;)

piet234.jpg.JPG
 
Exmoor beast said:
Reason I ask is it appears to have happened on a two year old bike (?) with low miles indicating a problem with the design/ quality of the rod not an age/ mileage thing. Are they all ticking bombs waiting to let go?
Click to expand...
I was fibbing, it was in 1989, but still only 4 years old. I bought it off Richard Slater, who had just bought it and was heading back to Collington with it and he offered it to me on the way. After it blew up, the engine was completely rebuilt by Steve Winterton and the bike sold.
I’ve told this story a few times, but always worth repeating, many years later, 2013 to be precise, the year of the infamous attempt by Piero to ride the V6 around the mountain course, I had collected Piero, Fernando and Sandro from the airport and taken them back to my place. I left them chatting in the garden whilst I went inside to call Bob Dixon to find out where he was as he was supposed to have followed us to the house. When I went back outside the three of them were starring at a smashed set of triple crank cases, I’d forgotten I had placed them on a wall as a garden ornament. I said the first thing that came into my head, ‘Laverda rods don’t break.’ They all immediately turned around and walked away in silence.
The first photo was taken a few miles before the blow up and the second after the bike had been recovered. If you look closely you can see some of the damage it inflicted to the hydraulic clutch casing among other things and the amount of oil all over the back wheel. About a year ago I posted a picture of the crank cases on another thread about holes in crankcases. I’ll see if I can find them.
 

Attachments

  • A98D471A-0F71-40CD-8929-1CD1A7F28E47.jpeg
    A98D471A-0F71-40CD-8929-1CD1A7F28E47.jpeg
    123.7 KB · Views: 44
  • BEB35EEF-AFC7-48EB-A5E6-54FC6C3E4690.jpeg
    BEB35EEF-AFC7-48EB-A5E6-54FC6C3E4690.jpeg
    166.4 KB · Views: 45
You must log in or register to reply here.
Back
Top