the proper way to measure roundness is with a dial and a fixture. .5mm variation is... ah... no offense intended, but you might as well be eyeballing a measuring tape from six feet away.
get thee to a machinist, I'd say.
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Over revved '80 1000 SP... What Is Likely Damaged?
- Thread starter K2Guzzi
- Start date
get thee to a machinist, I'd say.
Ha! Ha! Ha! I obviously used the wrong caliper... as stated.
I burned 20 hours changing the clutch and other things a couple months before this occurred. Then put 1,000 miles on her... and even by Ducati standards... it is ludicrous! If she was a helicopter... it would be wonderful!
She has been most sitting for years... and obviously that is exactly what she wants to keep doing. Hmm? When did the stereotypes about Italians begin?
Dropping the engine and splitting it may be the final decision but this is ancient 70's technology on a tractor engine and not even a high performance 70's engine.
She did a mile or so while damaged as it happened right by my exit.
Now after letting my "fingers do the walking" I've seen plenty of half explanations on how to measure the crankshaft journal for roundness.
I need a 1" - 2" micrometer to get an accurate reading. Once I do that an informed decision can be made. Maybe ill need to get a dial and set it up
Obviously need to exam more closely the journal and the connecting rod for something surely must have been damaged to that piece of bearing pop out.
Thank you and hopefully this is a short thread... meaning it gets fixed easily! Off to find proper tool for job!
I burned 20 hours changing the clutch and other things a couple months before this occurred. Then put 1,000 miles on her... and even by Ducati standards... it is ludicrous! If she was a helicopter... it would be wonderful!
She has been most sitting for years... and obviously that is exactly what she wants to keep doing. Hmm? When did the stereotypes about Italians begin?
Dropping the engine and splitting it may be the final decision but this is ancient 70's technology on a tractor engine and not even a high performance 70's engine.
She did a mile or so while damaged as it happened right by my exit.
Now after letting my "fingers do the walking" I've seen plenty of half explanations on how to measure the crankshaft journal for roundness.
I need a 1" - 2" micrometer to get an accurate reading. Once I do that an informed decision can be made. Maybe ill need to get a dial and set it up
Obviously need to exam more closely the journal and the connecting rod for something surely must have been damaged to that piece of bearing pop out.
Thank you and hopefully this is a short thread... meaning it gets fixed easily! Off to find proper tool for job!
Vagrant
GT Reference
for less than $10 you can get a digital vernier caliper at harbor freight that reeds both metric and US. use the larger flat area and turn it around the crank.
Vagrant,
Thank you! So that is what the tool I used is called! But it wan't digital.
The one I see at Harbor Freight only goes to hundredths (0.00) but not thousandths (0.001). I have been looking at micrometer and noticed that. Do I need something more exact? I learning on the job but the parameters John said the journal needs to meet... probably.
Either way you confirmed what I thought... that a micrometer may be best but a vernier caliper can work.
The chilly weather hear kills motivation and has been delaying the work. Was so aggravated flew out to Florida... though the tentative plan was to ride.
Seems the perfect time with less traffic everywhere and it's the best way to distance. Only thing is were to sleep if hotels are closed and you just rode 800 miles... with 400 to go.
Thank you! So that is what the tool I used is called! But it wan't digital.
The one I see at Harbor Freight only goes to hundredths (0.00) but not thousandths (0.001). I have been looking at micrometer and noticed that. Do I need something more exact? I learning on the job but the parameters John said the journal needs to meet... probably.
Either way you confirmed what I thought... that a micrometer may be best but a vernier caliper can work.
The chilly weather hear kills motivation and has been delaying the work. Was so aggravated flew out to Florida... though the tentative plan was to ride.
Seems the perfect time with less traffic everywhere and it's the best way to distance. Only thing is were to sleep if hotels are closed and you just rode 800 miles... with 400 to go.
I think perhaps the units are getting confused, your previous measurement was in mm, so if you're still dealing in metric units you'll be looking for a measuring tool accurate to hundredths, not thousandths. no hand held tool could be accurate to .001mm.
Tobinh,
Well... I have been chasing my tail but found them... for hundred of dollars! Real professional tools for precise work.
There is no confusion. It's started in mm and is continuing.
44.013 to 44.033 mm is the range John indicated. That means 1000th should be measured to do properly. 100ths likely can get it evaluated... but obviously not preferred.
Again... those who have done know. Those learning to do can only use previous knowledge and assume.
Thank you for your statement.
Well... I have been chasing my tail but found them... for hundred of dollars! Real professional tools for precise work.
There is no confusion. It's started in mm and is continuing.
44.013 to 44.033 mm is the range John indicated. That means 1000th should be measured to do properly. 100ths likely can get it evaluated... but obviously not preferred.
Again... those who have done know. Those learning to do can only use previous knowledge and assume.
Thank you for your statement.
Though I have several tools with adequate resolution, I am rather curious to see such an accurate tool, as when I've had to measure things to that level of accuracy gauge blocks and fixtures were required
Also, be sure to note the temperature when you take your measurements, lest your precision suffer
That is understandable! Even when age or alcohol hasn't ruined the steadiness of hand you have to think about limitations.
Temperature? Yeah! Been mostly around 50. Colder should contract and vice versa.
I figure I am looking for consistency across the journal. But since one somehow partially tore apart from over revving... there should be a gouge somewhere. It just wouldn't be right and too easy if there wasn't.
20 hours must be added to this since accessing the crank is so easy and normal since we do it every time we change the oil filter.
While getting the accurate measurement I'll exam and photograph and rub my nail across every part of the journal. Something had to be damaged to let the shard of bearing out.
Temperature?
Yeah! Been mostly around 50. Colder should contract and vice versa. I figure I am looking for consistency across the journal. But since one somehow partially tore apart from over revving... there should be a gouge somewhere. It just wouldn't be right and too easy if there wasn't.
20 hours must be added to this since accessing the crank is so easy and normal since we do it every time we change the oil filter.
While getting the accurate measurement I'll exam and photograph and rub my nail across every part of the journal. Something had to be damaged to let the shard of bearing out.
Vagrant
GT Reference
https://www.harborfreight.com/6-in-...sae-and-metric-fractional-readings-63731.html
to .03MM use the 20% off coupon. I suspect that's close enough to tell u what comes next.
to .03MM use the 20% off coupon. I suspect that's close enough to tell u what comes next.
Griso Guy
Cruisin' Guzzisti
I did not read the whole thread, but in case it was not mentioned before; you can check the state of the big end by running your nail across the surface. If you feel anything at all, you're in for a re-grind. But since you found the bearing in the sump, chances are high that you have damage.
If you do have the crank re-ground; make sure the workshop is aware of the proper radius since this is where re-ground cranks tend to break. Oh, and clean out the sludge trap in the big end.
Best of luck!
If you do have the crank re-ground; make sure the workshop is aware of the proper radius since this is where re-ground cranks tend to break. Oh, and clean out the sludge trap in the big end.
Best of luck!
Vagrant,
Thank you. i picked one up from Menards that has an accuracy to .01 mm.
Girso Guy,
Thank you for your opinion. It may make me take them apart even if they do pass the liquid test.
JR1967,
Exactly what I thought when I evaluated likelihood of damage. A chunk would most likely come out kicking and screaming.
Readings were very difficult to get as I rotated the crank because it was hard to read the digital meter in the tight space/lighting. 44.00 side, middle, side. I would squeeze the in part of the caliper...which would get it to 43.99... and then release to take off the pressure and it went to 44.00. It took a lot of patience to find a proper angle.
Yeah! Like someone said... getting an accurate reading free hand
At first I could not feel any lines but when I took off my gloves and ran my nail from the undamaged to the damaged side I could feel a little line but it would not catch my nail.
I'm going to do 600 grit and then 800 grit wet sanding with WD-40 as the lubricant: cut the paper to fit, spay WD on journal and paper, wrap around, and use some material to wrap around to get even pressure.
Just want to polish it smooth so it should take a few minutes of being gentle. Fingers crossed in five minutes its as smooth as glass.
Looks like I have learned to not hit my head on the cylinder as I slide out from underneath! Subconscious learning.
Live and learn!
Thank you. i picked one up from Menards that has an accuracy to .01 mm.
Girso Guy,
Thank you for your opinion. It may make me take them apart even if they do pass the liquid test.
JR1967,
Exactly what I thought when I evaluated likelihood of damage. A chunk would most likely come out kicking and screaming.
Readings were very difficult to get as I rotated the crank because it was hard to read the digital meter in the tight space/lighting. 44.00 side, middle, side. I would squeeze the in part of the caliper...which would get it to 43.99... and then release to take off the pressure and it went to 44.00. It took a lot of patience to find a proper angle.
Yeah! Like someone said... getting an accurate reading free hand
At first I could not feel any lines but when I took off my gloves and ran my nail from the undamaged to the damaged side I could feel a little line but it would not catch my nail.
I'm going to do 600 grit and then 800 grit wet sanding with WD-40 as the lubricant: cut the paper to fit, spay WD on journal and paper, wrap around, and use some material to wrap around to get even pressure.
Just want to polish it smooth so it should take a few minutes of being gentle. Fingers crossed in five minutes its as smooth as glass.
Looks like I have learned to not hit my head on the cylinder as I slide out from underneath! Subconscious learning.
Live and learn!
The Liquid test is the quickest way to tell if you have a valve that is not sealing, you will not know why it is not sealing without removing the valve. You can chuck it in a drill to see if the head wobbles, if it does, you need a new valve. Looking at the pictures of your cylinder heads, it appears that one cylinder has been running lean, and one cylinder appears to be either running rich, or burning oil. A cylinder that is too lean is susceptible to detonation under load. Detonation could cause the rod bearings to look the way they do. It would be interesting to know which cylinder had the bad rod bearings. If there has been detonation, there will be evidence on the top of the piston too. Just my experience.
... I'm going to do 600 grit and then 800 grit wet sanding with WD-40 as the lubricant: cut the paper to fit, spay WD on journal and paper, wrap around, and use some material to wrap around to get even pressure.
Just want to polish it smooth so it should take a few minutes of being gentle. Fingers crossed in five minutes its as smooth as glass...
Looks like I have learned to not hit my head on the cylinder as I slide out from underneath! Subconscious learning.
I don’t want to kick you while you are down but what you are describing here, will not work. It is ABSOLUTELY IMPOSSIBLE to resurface the crankshaft journal as you are describing. It will not be absolutely round and it will grenade on you at running speed.
It needs the loving touch of a skilled engine machine shop.
Sorry.
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Vagrant
GT Reference
that mother is butt ugly. give it up and do it right. as grandpa always said "if you don't have time to do it right the first time where will you find the time to do it again". might add money to the sentence to.