3
3patC
Guest
I've sent you an e-mail. All is not lost.implamentor said:
4 row primary Drive & Power outputs, Crank balancing, Con Rods, Alloy casting.
- Thread starter Jota Rob
- Start date
Rusty Spokes
Hero member
- Location
- Decatur, Ga. USA
Have never found out why the stock rods let go, more triples than twins, too. Unfortunately, the battered bits don't give much of a hint why the bloody things fail, haven't come across a rod that showed signs of giving up. What's puzzling is that they usually let go in mid-range, very seldom at high revs or heavy loads.
My opinion is, somewhere in the engine's history, the fuel cocks were left on overnight and the engine experienced some hydraulic lock. The operator got the engine running and one of the rods now had a very slight bend in it. After a couple of million revolutions/loads and thermal soaks...bang.
Breaking in the mid range? Could be the rods are heavily loaded at 3/4k even if the engine is not being thrashed. Seems like most sick engines give up internals at the end of many fast runs when just coming back into the mid range, or at red line.
I always turn off the petcocks while still riding and about 1 minute prior to parking my bike. Once on the center stand, I just listen to the engine and as the idle begins to slow up, then turn the key off. Not much fuel left in the lines or floats. Little chance of fuel locking up the engine later and keeps the float needles off the needle seats too. I think that helps.
My opinion is, somewhere in the engine's history, the fuel cocks were left on overnight and the engine experienced some hydraulic lock. The operator got the engine running and one of the rods now had a very slight bend in it. After a couple of million revolutions/loads and thermal soaks...bang.
Breaking in the mid range? Could be the rods are heavily loaded at 3/4k even if the engine is not being thrashed. Seems like most sick engines give up internals at the end of many fast runs when just coming back into the mid range, or at red line.
I always turn off the petcocks while still riding and about 1 minute prior to parking my bike. Once on the center stand, I just listen to the engine and as the idle begins to slow up, then turn the key off. Not much fuel left in the lines or floats. Little chance of fuel locking up the engine later and keeps the float needles off the needle seats too. I think that helps.
G
Grant
Guest
I guess every case is different but mine was comprehensively Donald Ducked.
The flailing rod cut through the liner and barrel, and took a massive chunk out of the upper crankcase half. The Piston destroyed the head.
Mine too was under moderate acceleration in mid range.
The flailing rod cut through the liner and barrel, and took a massive chunk out of the upper crankcase half. The Piston destroyed the head.
Mine too was under moderate acceleration in mid range.
G
Grant
Guest
In my case I was 'making progress' in third gear on a twisty back road, but not hammering it. There was a sudden bang, then the bike was running on 2 cylinders with a woofling sort of noise. No lock up at all. Because the hole in the cases was obscured by the starter motor it took me a few minutes to work out what had happened.
Then it was game over.
Then it was game over.
Nick, yes I whipped the clutch in but its akin to doing 100 mph and having someone step out in front of your car, you'd process, brake and then survey the damage 100 metres behind you, contemplating why you've also gone from Imperial to metric in the process ???nick7 said:
No the wheel didn't lock, the gearing probably takes care of that!
Tippie
Hero member
- Location
- Dr?bak, Norway
That is lovely work Piet.
I?ll wait to hear how your twins go vibration-wise before thinking too hard and it looks like a very costly exercise. The vibration on my racer is quite liveable as well as I can keep hard on the power and that is the general idea however it still occasionally cracks off brackets on the frame. As a road bike it was very smooth to around 5000rpm then got steadily more annoying.
Rob the triples don?t have an oil drain plate like the twins so I doubt my magnet would be an option for them.
I?ll wait to hear how your twins go vibration-wise before thinking too hard and it looks like a very costly exercise. The vibration on my racer is quite liveable as well as I can keep hard on the power and that is the general idea however it still occasionally cracks off brackets on the frame. As a road bike it was very smooth to around 5000rpm then got steadily more annoying.
Rob the triples don?t have an oil drain plate like the twins so I doubt my magnet would be an option for them.
Thanks, Tippie.
I too am very curious as to how the engines will behave. We're doing 9 cranks, 3 lightened 180? triples, a stock 120? triple, 2 lightened 360? twins, a stock 360? twin, a lightened 270? twin and a heavy(as in GT) 270? twin, more or less simultaneously.
Judging from the amount of time the project is consuming, crank lightening and balancing certainly is not a cheap enterprise. Reckon once we've got it all together, consecutive cranks will be able to be done quicker.
The stock 360? crank will probably be the first to run again, the engine is coming together nicely and will be ready when the snow disappears. A 180 as well as the 120 triple and the heavy 270 twin are for my own projects, hope to get them ready for next season as well. Going to be a busy winter......
piet
I too am very curious as to how the engines will behave. We're doing 9 cranks, 3 lightened 180? triples, a stock 120? triple, 2 lightened 360? twins, a stock 360? twin, a lightened 270? twin and a heavy(as in GT) 270? twin, more or less simultaneously.
Judging from the amount of time the project is consuming, crank lightening and balancing certainly is not a cheap enterprise. Reckon once we've got it all together, consecutive cranks will be able to be done quicker.
The stock 360? crank will probably be the first to run again, the engine is coming together nicely and will be ready when the snow disappears. A 180 as well as the 120 triple and the heavy 270 twin are for my own projects, hope to get them ready for next season as well. Going to be a busy winter......
piet
Per Rusty Spokes question about what causes the rod failures,long ago after putting the 4th crank in my Duc 900 bevel race bike a Yamaha racer friend told me that roller bearing cranks need to be loaded [either on power or on overrun] otherwise the rollers skid on the crankpin and will eventually flatspot and wear through whatever hardening and deteriorate rapidly.Feathering the throttle at high speeds allows the rod to float a bit and unloads the bearings causing them to skid and the clearance,if enough also allows the bearings to hammer both rod and pin further distorting the races.This all made sense to me as all the failures I had occured when letting off the throttle a bit at higher revs.Come to think of it most rod failures on plain bearing engines happen under the same conditions too.I guess the solution is to never let off! I did experience better reliability after changing my riding style by either being on the gas or off with no in between.Went a little faster too!
Piet,
Your Twin cyl crank phasing work sounds very interesting. Will you keep us informed how they compare with each other please. Obviously different tunes but vibration wise and power take-up would be very interesting.
Referring to the general post.
Regarding the use of old parts etc the theory is only for things like blocks etc and is thus. Metals over time go through what is funnily enough called and "Aging" process, this is where the Austenite ( roughly speaking un-uniformly layered molecules) slowly turns to Martensite (uniformly layered molecules) over a fairly long time period. This process can be speeded up in some materials with moderate heat processes.
Leaving blocks and castings etc to "Age" is quite common and beneficial.
Rods however are under repeated stress and can be, and most have been "Over stressed" at some point in their long working life so using "Old" rods in a performance engine would always be a risk and not an advantage.
Nice thread,
Julian
Your Twin cyl crank phasing work sounds very interesting. Will you keep us informed how they compare with each other please. Obviously different tunes but vibration wise and power take-up would be very interesting.
Referring to the general post.
Regarding the use of old parts etc the theory is only for things like blocks etc and is thus. Metals over time go through what is funnily enough called and "Aging" process, this is where the Austenite ( roughly speaking un-uniformly layered molecules) slowly turns to Martensite (uniformly layered molecules) over a fairly long time period. This process can be speeded up in some materials with moderate heat processes.
Leaving blocks and castings etc to "Age" is quite common and beneficial.
Rods however are under repeated stress and can be, and most have been "Over stressed" at some point in their long working life so using "Old" rods in a performance engine would always be a risk and not an advantage.
Nice thread,
Julian
Julian,
Work is steadily progressing, up to my knees in swarf......
Have since made an axle to balance the 750 starter freewheel, about 8gr. imbalance there too! No use going to all those lengths getting the crank right and neglecting the peripherals.
Going to take a bit till the cranks are installed and tried out.... 30cms of snow here at the moment and no signs of any change. Probably have the crap lying around till February at least!
piet
Work is steadily progressing, up to my knees in swarf......
Have since made an axle to balance the 750 starter freewheel, about 8gr. imbalance there too! No use going to all those lengths getting the crank right and neglecting the peripherals.
Going to take a bit till the cranks are installed and tried out.... 30cms of snow here at the moment and no signs of any change. Probably have the crap lying around till February at least!
piet
LAVERDA54
Full member
- Location
- LORRAINE FRANCE
Some additional photos of my engine " 1000 Endurance ". If you want more information, do not hesitate to contact me.
Hi Laverda54
The picture didn't open, but I found the link so I've posted it here, hope thats ok and thank for showing us your pictures, lots of work there !!
Rob
http://picasaweb.google.com/111038958788921866795/1000EndurancePhil?authkey=Gv1sRgCLDxg5XhxcWULA&feat=directlink#
The picture didn't open, but I found the link so I've posted it here, hope thats ok and thank for showing us your pictures, lots of work there !!
Rob
http://picasaweb.google.com/111038958788921866795/1000EndurancePhil?authkey=Gv1sRgCLDxg5XhxcWULA&feat=directlink#
laverdakeith
Hero member
Great pics, thanks.
Keith
Keith
