Wristpin Retainer Destroys Engine!!!!
09-10-2008, 06:44 PM
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Wristpin Retainer Destroys Engine!!!!
Question:
How many have had an engine get ruined when the wristpin retainer clip came out when running?
And what are the causes?
Engine #1
Happened to my Picco P15KSM Ron Paris Modified....engine was getting hard to start, and keep a tune. I looked into the exhaust port, and noticed a scratch on the piston.
The engine was disassembled, and apeared that the wrist pin hole in the aluminum piston cracked away, and thus, released the rear wrist pin clip. out the rear exhaust of the engine.
Engine #2
Recently, I put a NEW Associated .12 into a friends car. After break-in, and around the 12th tank, the engine locked up when running.
Again, caused by the wristpin retainer, this time, the front retainer came out.
The wristpin retainer groove in the piston looked fine (aluminum was intact)
Retainer showed no signs of rust or other corrosion.
My only speculation, was a two tanks prior, the car had a head-on with a curb.....could the frontal impact somehow push the wrist pin into the retainer with enough force, causing the retainer to pop out?
How many have had an engine get ruined when the wristpin retainer clip came out when running?
And what are the causes?
Engine #1
Happened to my Picco P15KSM Ron Paris Modified....engine was getting hard to start, and keep a tune. I looked into the exhaust port, and noticed a scratch on the piston.
The engine was disassembled, and apeared that the wrist pin hole in the aluminum piston cracked away, and thus, released the rear wrist pin clip. out the rear exhaust of the engine.
Engine #2
Recently, I put a NEW Associated .12 into a friends car. After break-in, and around the 12th tank, the engine locked up when running.
Again, caused by the wristpin retainer, this time, the front retainer came out.
The wristpin retainer groove in the piston looked fine (aluminum was intact)
Retainer showed no signs of rust or other corrosion.
My only speculation, was a two tanks prior, the car had a head-on with a curb.....could the frontal impact somehow push the wrist pin into the retainer with enough force, causing the retainer to pop out?
09-10-2008, 07:57 PM
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RE: Wristpin Retainer Destroys Engine!!!!
[:@]feel your pain thats a great engine that tuned picco! have an elwardo tuned 15 also.I've also had clip slip out an seize few of my engines over the years, these motors do rev high unseen stresses play part of it
09-10-2008, 09:24 PM
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RE: Wristpin Retainer Destroys Engine!!!!
A few questions... Have you EVER removed the e-clips? I never remove e-clip unless absolutely required.
What RPM were you running the engines at? E-Clip failures are as old as performance engines themselves but usually occur only at higher RPM (or if not properly installed).
Sorry if these questions sound like an accusation.... They just needs to be asked.
Bill
What RPM were you running the engines at? E-Clip failures are as old as performance engines themselves but usually occur only at higher RPM (or if not properly installed).
Sorry if these questions sound like an accusation.... They just needs to be asked.
Bill
09-10-2008, 09:48 PM
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RE: Wristpin Retainer Destroys Engine!!!!
Not an answer to your question but a tip to minimize the risk of them breaking.
Always install the clips with the 'tab' you grip to remove/install pointing straight up or down. Installing them horizontal increases the risk of them breaking due to the up-down movement.
Always install the clips with the 'tab' you grip to remove/install pointing straight up or down. Installing them horizontal increases the risk of them breaking due to the up-down movement.
09-10-2008, 11:23 PM
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RE: Wristpin Retainer Destroys Engine!!!!
To answer the questions:
Until they came apart, both engines have never been disassembled.
The Ron Paris Picco (other than what Ron Paris did) had never been opened up. At first, I was wondering if the clip was not installed correctly, but when I saw the aluminum break around the retaining groove, that was the failure which caused the clip to come out.
The AE engine, either it was a factory defect on assembly, or impact contributed from the hitting the curb, or flaw in the clip or something else????.
At the time of sieze, don't know what RPM....we were racing around the parking lot. (I wasn't driving) Could have been anywhere between 1/2 to WOT?????
This engine did run well, not the 40K's the Racing engines turn, but was impressive for a RTR sport engine. Just would have been nice if the engine lasted longer.
When rebuilding, the alignment of the clip makes good sense.....I wonder if we clip the tab off, would that improve reliability? Or is there a better wire material available?
Until they came apart, both engines have never been disassembled.
The Ron Paris Picco (other than what Ron Paris did) had never been opened up. At first, I was wondering if the clip was not installed correctly, but when I saw the aluminum break around the retaining groove, that was the failure which caused the clip to come out.
The AE engine, either it was a factory defect on assembly, or impact contributed from the hitting the curb, or flaw in the clip or something else????.
At the time of sieze, don't know what RPM....we were racing around the parking lot. (I wasn't driving) Could have been anywhere between 1/2 to WOT?????
This engine did run well, not the 40K's the Racing engines turn, but was impressive for a RTR sport engine. Just would have been nice if the engine lasted longer.
When rebuilding, the alignment of the clip makes good sense.....I wonder if we clip the tab off, would that improve reliability? Or is there a better wire material available?
09-11-2008, 03:27 AM
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RE: Wristpin Retainer Destroys Engine!!!!
Looks nasty
I've taken my gudgeon pin out and never had any failures with it
I don't know how much an accident could cause this. Lets not forget the forces that go on it from 30,000+ rpm would be far far far greater than any accident could ever inflict on it
I've taken my gudgeon pin out and never had any failures with it
I don't know how much an accident could cause this. Lets not forget the forces that go on it from 30,000+ rpm would be far far far greater than any accident could ever inflict on it
09-11-2008, 04:46 PM
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RE: Wristpin Retainer Destroys Engine!!!!
Thats how my bros TRX 2.5R crapped out TWICE in a row with 2 new piston/sleeves within a span of 25 tanks... Traxxas told me at the time that the engine was most likely over revved
09-11-2008, 08:27 PM
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RE: Wristpin Retainer Destroys Engine!!!!
ORIGINAL: Red7fifty
To answer the questions:
Until they came apart, both engines have never been disassembled.
The Ron Paris Picco (other than what Ron Paris did) had never been opened up. At first, I was wondering if the clip was not installed correctly, but when I saw the aluminum break around the retaining groove, that was the failure which caused the clip to come out.
The AE engine, either it was a factory defect on assembly, or impact contributed from the hitting the curb, or flaw in the clip or something else????.
At the time of sieze, don't know what RPM....we were racing around the parking lot. (I wasn't driving) Could have been anywhere between 1/2 to WOT?????
This engine did run well, not the 40K's the Racing engines turn, but was impressive for a RTR sport engine. Just would have been nice if the engine lasted longer.
When rebuilding, the alignment of the clip makes good sense.....I wonder if we clip the tab off, would that improve reliability? Or is there a better wire material available?
To answer the questions:
Until they came apart, both engines have never been disassembled.
The Ron Paris Picco (other than what Ron Paris did) had never been opened up. At first, I was wondering if the clip was not installed correctly, but when I saw the aluminum break around the retaining groove, that was the failure which caused the clip to come out.
The AE engine, either it was a factory defect on assembly, or impact contributed from the hitting the curb, or flaw in the clip or something else????.
At the time of sieze, don't know what RPM....we were racing around the parking lot. (I wasn't driving) Could have been anywhere between 1/2 to WOT?????
This engine did run well, not the 40K's the Racing engines turn, but was impressive for a RTR sport engine. Just would have been nice if the engine lasted longer.
When rebuilding, the alignment of the clip makes good sense.....I wonder if we clip the tab off, would that improve reliability? Or is there a better wire material available?
09-11-2008, 08:37 PM
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RE: Wristpin Retainer Destroys Engine!!!!
I wasn't sure if I stated...but on the AE .12, it wasn't the tab that broke off....the ENTIRE clip popped out.
Maybe......the tab flexed.......caught the port opening, then got yanked out?
SMan...with removing the tab, did you ever have an engine throw the clip afterwards?
Maybe......the tab flexed.......caught the port opening, then got yanked out?
SMan...with removing the tab, did you ever have an engine throw the clip afterwards?
09-12-2008, 04:05 AM
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RE: Wristpin Retainer Destroys Engine!!!!
In my expieriance three factors either independantly or together affect wrist pin failure: 1. High rpm. now, im not too sure what the exact rpm is that causes the failure and im sure its quite diffrent for every engine but over reving an engine is sure to have this problem. 2. excessive heat. excessive heat causes the spring steel to become brittle again the temp at witch this occures depends on what type of engine, how long it was sustained, and how hot it accually got. 3. time. to go along with number two over time the spring steel becomes brittle and adventually breaks down. There are probebly alot more things that cause this type of break down but in my expireance these are the leading causes. if you take a moment and think of what we ask theese engines to do and what they are made out of its accually amazing that they run for as long as they do.
