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+--- Thread: Over tightened end caps (/showthread.php?tid=5167)
Over tightened end caps - 12jslater - 30-10-2020
My torque wrench broke today, so when refitting my end caps just did them "bloody tight" not as tight as I could go but still very tight with my normal socket wrench, are there are any issues than could arise with this?
RE: Over tightened end caps - Nick Turley - 30-10-2020
It is really impossible to say from your information.
My suggestion would be to wait, get another decent torque wrench.
Then refit putting new big end bolts and nylocks and tighten to 19 ft lb.
Then you should be able to rest in your bed.
RE: Over tightened end caps - Steve Jones - 30-10-2020
How do you break a Torque Wrench doing up big end caps? Nick's advice is appropriate.
Steve
RE: Over tightened end caps - 12jslater - 30-10-2020
I did it when tightening the head bolts, the spring in, the pawl suddenly split, thankfully on the last but.
RE: Over tightened end caps - Bob Culver - 30-10-2020
The bolts are comparatively large for the light components, short stroke and modest revs. Much larger and high revving engines survive on 5/16.
Probably the main threat to fatigue failure is stretched bolts and frequent repeat tightening to a high stress, as when scraping bearings.
Torsion wrenches were almost unknown pre war.
For an ordinary 45 ton HT bolt 15 lbs/ft is recommended, adequate for a non racer.
RE: Over tightened end caps - Zetomagneto - 30-10-2020
If you have done them B tight you have no idea how tight. I would certainly get a new torque wrench, and new bolts and nuts. Conrod bolt failure is terminal and expensive
RE: Over tightened end caps - Chris KC - 30-10-2020
Neither big ends nor head nuts want to be much more than 20lbft.
RE: Over tightened end caps - Dave Wortley - 31-10-2020
Oh dear! I am doomed. Been tightening big end bolts with my trusty ring spanner for 50 plus years. I may try my new torque wrench next time.
RE: Over tightened end caps - Zetomagneto - 31-10-2020
Dave, I am quite happy to tighten bolts without a torque wrench, been doing so for over 50yrs
but when giving advice like to err on the side of caution
RE: Over tightened end caps - John Mason - 31-10-2020
I am with you Dave. I see no point in a torque wrench when using nylock nuts as they surely grip to tight on the threads. A similar situation to whether or not you oil the threads.
John Mason