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Piston Failure

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UMG0251 Avatar
UMG0251 Platinum Member John H Twist
Grand Rapids, MI, USA   USA
1962 MG MGA MkII De-Luxe "The A"
When the rings fail, piston failure follows quickly. This rod is from a late model 18V MGB.


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greenrman Gold Member Don B
Kelowna, BC, Canada   CAN
1973 MG MGB "Oscar"
2005 BMW 3 Series Cabriolet "Sabrina"
Hey John, All is not lost. Always a use for things....that is now a conversational coffee table beer coaster knick knack. smileys with beer

PS. Love your videos. Post more, keep the hobby going!

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tahoe36c Paul Hruza
Panama City, FL, USA   USA
1969 MG MGC GT "Little Red Rocket..."
1972 MG MGB GT "Tiny Dancer"
2002 Harley-Davidson Dyna
Remember when they used them for ashtrays??? LOL

I'm so glad I don't smoke anymore... Not tobacco anyway!!! LOL...

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Gerald O Avatar
Gerald O Gerald O'Docharty
Wake Forest, North Carolina, USA   USA
1978 MG MGB
That looks familiar.





Edited 1 time(s). Last edit at 2019-03-14 09:40 PM by Gerald O.

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Speedracer Avatar
Speedracer Platinum AdvertiserAdvertiser Hap Waldrop
Greenville, SC, USA   USA
1967 MG MGB Racecar "The Biscuit"
Hey John, yep seen that a time, or two in my life, 1275s are notorious for it. This is one thing I always warn about when "re-freshening" a engine using original pistons, is folks often time will sweat the bore condition, and the piston to bore clearances, but completely ignore ring land wear, and this is what excessive ring wear can do. I have seen his in teardown just before it happen as well, when you take the piston out of the bore, the captured ring/s comes out in many pieces.



Hap Waldrop
Acme Speed Shop
864-370-3000
Website: www.acmespeedshop.com
hapwaldrop@acmespeedshop.com


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MG/ Triumph Performance Street/Race Engines - Cylinder Head Porting - Modified SU HS Carbs - DIY Engine Rebuild Kits With Free Tech Advice - VTO alloy wheels for British Sport Cars, and others
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GTgeezer Avatar
GTgeezer Lynn Kirkpatrick
Columbia City, IN, USA   USA
So what happened to the piston in John's picture? Did the ring break and a piece was stuck in the groove for a while, wallowing it out? How long would that have gone on, and would there have been any sign of it? Noise? Blowing oil or smoke?
Same questions on Jerald's.
Just wondering.



The important thing is not to get ahead, but to get along.

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Norton Tom Avatar
Norton Tom Thomas Renda
Baltimore, Hon, MD, USA   USA
I thought broken pistons (and rings) were most often caused by just slapping new rings into an irregularly worn bore?

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albeegreen1 Avatar
albeegreen1 Gold Member bob tresch
bordentown, NJ, USA   USA
1972 MG MGB MkIII "ALBERT"
They can be mounted and used for trophys for poker runs or for hard luck prizes. Just sayin.



"Only those who have patience to do simple things perfectly ever acquire the skill to do difficult things easily".

- James Corbett.

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Gerald O Avatar
Gerald O Gerald O'Docharty
Wake Forest, North Carolina, USA   USA
1978 MG MGB
Ring breakage can be from:
excess vertical clearance in the ring groove causing excess movement,
ring end-gap too narrow causing ring to seize in the bore when it heats up,
shock loads such as detonation,
bore taper causing excess flex cycling,
installation error, such as hammering the piston down past lack of chamfer at top of bore,

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RAY 67 TOURER Avatar
RAY 67 TOURER Ray Marloff
Fort Bragg, CA, USA   USA
1967 MG MGB "My Girl"
Rod? You should see the pistons and wrist pins out of a logging truck Diesel engine. The pistons are over 8" in diameter and the wrist pins are solid and 2" in diameter. The pistons make for great ottomans. RAY

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Stewart Avatar
Stewart Stewart Langenberg
Santa Barbara, CA, USA   USA
1967 MG MGB GT
1975 MG MGB
been there done that




1975 Mineral Blue MGB Supercharged
1967 Tartanish Red MGB GT Supercharged
Restoration of the 75 MGB Click here
Restoration of the 67 MGB GT Click here


You Can't Prove It Won't Happen

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little G Avatar
little G Charlie T
queensland, QLD, Australia   AUS
1964 MG MGB "Little G"
I just turn them into lights ...a Cat piston and rod...smoking smiley


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Lonwuff Gerald Beach
NAMPA, ID, USA   USA
Back in the day that was an ashtray or business card holder.

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Lonwuff Gerald Beach
NAMPA, ID, USA   USA
I bought a brand new b off the showroom floor in 1974. It had the rubber blocks (don't remember the tech name) on the chrome bumper. The color was mirage and I don't believe they imported many of them. It looked white in the daylight and a very pale purple at night. Anyone have mirage?

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greenrman Gold Member Don B
Kelowna, BC, Canada   CAN
1973 MG MGB "Oscar"
2005 BMW 3 Series Cabriolet "Sabrina"
In reply to # 3908901 by greenrman Hey John, All is not lost. Always a use for things....that is now a conversational coffee table beer coaster knick knack. smileys with beer

PS. Love your videos. Post more, keep the hobby going!

Hmmm. -2 on a genuine #2 post like this ? I suggest Skye has +1/ -1 's representable and accountable to these ying-yangs. Jus sayin.

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